A 455-million-year-old fossil fish provides a new perspective on how vertebrates evolved to protect their brains, a study has found.
In a paper published in Nature today (Wednesday 20th September), researchers from the University of Birmingham, Naturalis Biodiversity Centre in Leiden, Netherlands; and the Natural History Museum have pieced together the skull of Eriptychius americanus.
The research, funded by the Leverhulme Trust, suggests that the ancient jawless fish found in ancient deposits in Colorado, USA has a skull unlike that of any previously seen, and fills a gap currently spanning 100 million years in the evolutionary history of the vertebrate skull.
Using computed tomography, a form of x-ray technique, scientists recreated a detailed 3D representation of the skull of Eriptychius and is the first time that such a comprehensive recreation has been done on the specimen which was collected in the 1940s, originally described in the 1960s and is housed in the Field Museum of Natural History, Chicago.
This ancient fish had separated, independent cartilages encasing the brain, rather than the solid bone or cartilage structure of jawless and jawed fish that followed it.
While later specieshave a fully bound cage of cartilage that holds the brain, these results suggest that the early evolution of structures to separate the brain from other parts of the head may have begun with Eriptychius.
Dr Ivan Sansom, Senior Lecturer in Palaeobiology at the University of Birmingham and senior author of the paper said:
“These are tremendously exciting results that may reveal the early evolutionary history of how primitive vertebrates protected their brains. Eriptychius americanus appears to be the first evidence for a series of cartilages separating the brain from the rest of the head. This study emphasises the importance of museum collections and the application of new techniques in studying them.”
Dr Richard Dearden, Postdoctoral Research Fellow in Palaeobiology at Naturalis Biodiversity Center and lead author of the paper said:
“On the face of it Eriptychius is not the most beautiful of fossils. However, by using modern imaging techniques we were able to show that it preserves something unique: the oldest three-dimensionally preserved vertebrate head in the fossil record. This fills a major gap in our understanding of the evolution of the skull of all vertebrates, ultimately including humans.”
Reference:
Dearden, R.P., Lanzetti, A., Giles, S. et al. The oldest three-dimensionally preserved vertebrate neurocranium. Nature, 2023 DOI: 10.1038/s41586-023-06538-y
A gigantic, ancient crocodylomorph species that was recently discovered grew slower than other large reptiles of its day, such as dinosaurs.
Today’s crocodilians (including crocodiles and alligators) all grow slowly, taking years to reach maximum size. In contrast, birds are crocodilian’s closest living relatives, and they can reach adult size in less than a year (~150 days for a chicken!). When, how, and why crocodilians evolved to grow so slowly has eluded researchers for years. A new study titled “Origins of slow growth on the crocodilian stem lineage” in Current Biology, is beginning to shed light on this question.
By investigating the internal structure of fossil bones of 200 million-year-old fossil crocodile ancestors (known as crocodylomorphs) from South Africa, a team of researchers has shown that they grew slowly, similar to their living descendants. “After studying the internal structure of the bones of the animal we were surprised to find that the bone tissues consisted of a type of bone tissue called parallel-fibred bone. This shows that this crocodylomorph grew at a rate between that of its fast-growing ancestors and slower-growing living crocodiles,” says co-author Professor Jennifer Botha, from the University of the Witwatersrand.
Unlike today’s sprawling ambush predators, these early crocodylomorphs were active, fully terrestrial animals with upright limb postures. This research finding casts doubt on prevailing wisdom that slow growth in living crocodiles is linked to the evolution of their sedentary, semiaquatic lifestyles.
The researchers also studied fossils of a gigantic new crocodilian ancestor that lived 210 million years ago, discovered in the village of Qhemegha, Eastern Cape, South Africa. Professor Jonah Choiniere of the University of the Witwatersrand, and co-author of the paper says “This fantastic specimen is one of dozens of new fossils we’ve recovered from our excavations in Late Triassic rocks at Qhemegha Village. The fossil area was initially discovered by local people and has developed into a superb example of integrating local knowledge with scientific enquiry.”
The researchers combined this with data from specimens previously collected and held in South African museums. By cutting the bones and examining their features under a high-powered microscope, they could assess the age at death, the amount of annual growth, and the bone tissue characteristics of these extinct crocodilian forebears. “When comparing this new specimen to other known species we found that it was a very early crocodile ancestor, possibly the earliest of the group that contains modern crocodiles,” says Bailey Weiss, another co-author of the study from the University of the Witwatersrand.
They found that the gigantic new species grew more slowly than other large reptiles of its day (such as dinosaurs) and that other crocodylomorph species that evolved more recently retained this slow growth strategy, decelerating it even further. The strategy of slow growth became a characteristic of all known crocodylomorphs descending from their ancient ancestor. Soon after slow growth first appeared in the crocodilian stem lineage, the world faced a mass extinction event at the end of the Triassic Period, and only the slower-growing members of the group managed to survive through it.
In contrast, dinosaurs are hypothesised to have survived the extinction event by growing fast. After the extinction, the world was left with fast-growing dinosaurs and slow-growing crocodylomorphs, building a foundation for the stark growth differences in their descendants — the birds and crocodilians alive today.
“Our new results show that the major difference we see between living, fast-growing birds and their slow-growing croc relatives was established really early in the evolutionary history of the group, despite the fact that their common ancestor would have been a fast-growing animal,” says Paul Barrett, Merit Professor of Palaeontology at the Natural History Museum, London.
Reference:
Jennifer Botha, Bailey M. Weiss, Kathleen Dollman, Paul M. Barrett, Roger B.J. Benson, Jonah N. Choiniere. Origins of slow growth on the crocodilian stem lineage. Current Biology, 2023; DOI: 10.1016/j.cub.2023.08.057
Gemstones have captivated humanity for centuries with their mesmerizing beauty, vibrant colors, and innate rarity. These precious treasures of the Earth are not only symbols of luxury and wealth but also hold cultural, spiritual, and historical significance. While many gemstones are widely known and cherished, there exists a hidden realm of rare gemstones that are equally, if not more, enchanting. In this exploration, we will unveil 20 of the most stunning rare gemstones, each with its own unique story, characteristics, and allure.
1. Painite: The World’s Rarest Gemstone
Natural 236.40 Ct Huge Red Painite Rough Burmese Facet Raw Loose Gemstone Credit: supremgem/etsy
Discovered in Myanmar during the mid-20th century, Painite has earned its reputation as one of the rarest and most coveted gemstones on Earth. Its captivating reddish-brown hue and extraordinary brilliance have captured the hearts of collectors and gem enthusiasts worldwide.
The story of Painite‘s discovery is one of serendipity and astonishment. In 1951, British mineralogist Arthur C.D. Payne stumbled upon a unique mineral that bore a remarkable resemblance to brownish-red topaz. However, upon closer examination, it was revealed to be an entirely new gemstone with dazzling optical properties. Named after gemologist Richard T. Liddicoat, Painite’s journey from obscurity to fame began.
What sets Painite apart is not only its exceptional beauty but also its extreme rarity. For decades after its initial discovery, only two known Painite specimens existed – one in the British Museum and the other in the Gemological Institute of America (GIA) collection. This scarcity, coupled with the gem’s mesmerizing appearance, sent shockwaves through the world of gemology, leading to Painite’s title as the “world’s rarest gemstone.”
Painite’s visual appeal is a symphony of colors that dance within its reddish-brown depths. Its hexagonal crystal structure and remarkable pleochroism, which causes the gem to display different colors when viewed from different angles, contribute to its enchanting beauty. Under the glow of light, Painite exhibits an exceptional play of color and brilliance that evokes a sense of wonder.
While the gem’s unique allure has propelled it into the spotlight, the challenges associated with its rarity and sourcing have also brought ethical considerations to the forefront. Painite is primarily found in Myanmar, a region known for its complex political landscape and gem trade-related issues. Responsible sourcing and sustainable practices are essential to ensure that the beauty of Painite does not come at the cost of ethical concerns.
In recent years, additional deposits of Painite have been discovered, easing its scarcity to some extent. However, the gem’s aura of exclusivity and its ongoing appeal to collectors and connoisseurs remain steadfast. Painite’s value has escalated in accordance with its rarity, often reaching astronomical figures in the market.
2. Musgravite: Born from Meteorite Impact
This 0.86 ct gray musgravite displays an unusual iridescent phenomenon that is clearly visible in the table facet. Photo by Kevin Schumacher.
In the realm of gemstones, where each treasure holds a story etched in time, Musgravite emerges as a gem of cosmic wonder. Born from the aftermath of a meteorite impact, this remarkable gemstone showcases a vivid bluish-green hue and an otherworldly charm that has captivated gem enthusiasts and collectors alike.
The story of Musgravite begins in the Musgrave Range of South Australia, where a meteorite collision with Earth’s surface created the conditions necessary for its formation. Discovered in 1967, Musgravite quickly earned its place as one of the rarest gemstones on the planet, owing its name to the region of its origin.
What makes Musgravite truly exceptional is its celestial heritage. Created through the intense heat and pressure generated by a meteorite impact, this gem embodies a connection to the cosmos that few other gemstones can claim. Its mesmerizing bluish-green color, reminiscent of the depths of outer space, adds to its allure, making it a prized possession for those who seek gems with a story as captivating as their appearance.
Musgravite’s remarkable hardness further elevates its status as a sought-after gemstone. With a rating of 8.5 on the Mohs scale, it boasts exceptional durability that enables it to withstand the rigors of daily wear. This combination of rarity, color, and durability makes Musgravite a gem of exceptional value for both collectors and jewelry enthusiasts.
However, Musgravite’s scarcity remains one of its defining features. With only a handful of known specimens in existence, its allure is further heightened. Each Musgravite gemstone becomes a piece of Earth’s history, a fragment of the cosmic event that birthed its existence.
For those who seek gems that transcend the ordinary, Musgravite offers a journey into the cosmos itself. Its celestial origins, stunning bluish-green hue, and rarity create a captivating trifecta that sets it apart in the world of gemstones. As we continue to unearth the secrets of our universe, Musgravite stands as a tangible connection to the mysteries of the cosmos, a gem that sparkles with the brilliance of celestial creation.
3. Grandidierite: A Kaleidoscope of Hues
Grandidierite
Grandidierite emerges as a true masterpiece of nature’s artistry. Named after French explorer Alfred Grandidier, this gemstone is renowned for its remarkable trichroism, showcasing an enchanting play of colors that dance within its depths.
Discovered in Madagascar in the early 20th century, Grandidierite’s striking appearance and scarcity have earned it a place among the most coveted gemstones in the world. What sets Grandidierite apart is its unique ability to display three distinct colors when viewed from different angles. The gem transitions from blue-green to bluish-violet and, on occasion, even colorless, creating a visual symphony that captures the imagination.
This captivating trichroism is a result of the gem’s crystal lattice structure, which interacts with light in a way that produces a kaleidoscope of hues. As light enters the gem, it is split into different wavelengths, revealing the spectrum of colors that lie within. The interplay of colors within Grandidierite gives each gemstone an almost magical quality, as if it holds a secret world of colors waiting to be discovered.
Grandidierite’s rarity further enhances its allure. Found in only a handful of locations across the globe, including Madagascar, Sri Lanka, and parts of Africa, the gem’s scarcity has contributed to its status as a collector’s dream. With limited availability, each Grandidierite gem becomes a unique and cherished piece of nature’s artistry.
Beyond its visual appeal, Grandidierite also holds significance as a gem that encourages self-discovery and introspection. Believed by some to promote harmony and inner peace, the gem’s tranquil colors and mesmerizing trichroism add a spiritual dimension to its already enchanting character.
4. Red Beryl: The Scarlet Jewel of Utah
Red Beryl Crystals from Utah. Credit: Treasure Mountain Mining
Red Beryl. Often referred to as “red emerald” due to its stunning color, this gemstone is a true marvel of nature, with a fiery hue that ignites the imagination and a scarcity that has collectors and enthusiasts in pursuit.
The story of Red Beryl begins in the Wah Wah Mountains of Utah, USA, where it was first discovered in 1904. Its vibrant red tones, ranging from rich raspberry to deep scarlet, immediately set it apart from other gemstones. The gem’s vivid coloration is attributed to the presence of manganese, which infuses it with an irresistible intensity.
What makes Red Beryl even more captivating is its rarity. This gemstone is one of the rarest in the world, with only a handful of known deposits scattered across the globe. The Wah Wah Mountains remain its primary source, but even there, finding high-quality Red Beryl is a daunting challenge. As a result, Red Beryl is often considered rarer than diamonds, making it a highly sought-after prize among collectors.
The scarcity of Red Beryl has led to its astronomical value. Its vivid color, combined with its rarity, has catapulted it into the upper echelons of the gem market. The gem’s breathtaking beauty and limited availability have caused its prices to rival those of other renowned gemstones.
In addition to its exquisite appearance, Red Beryl also holds cultural and spiritual significance for some Native American communities in the region. It is believed to carry energy that aligns with the root chakra, enhancing vitality and grounding.
To uncover the world of Red Beryl is to embark on a journey of both beauty and rarity. Its fiery red hues, intertwined with the rich history of the earth, create a gem that is truly a wonder to behold. As collectors and enthusiasts continue to seek the hidden treasures of the natural world, Red Beryl remains a beacon of beauty, rarity, and the untamed forces of nature’s artistry.
5. Jadeite: Imperial Jade of Burma
Jadeite
Known for its rich green hues and unparalleled beauty, Jadeite is not just a gemstone; it is a symbol of prestige, spirituality, and a connection to ancient civilizations.
Jadeite is one of the two recognized types of jade, the other being nephrite. However, it is Jadeite that holds a special place in the hearts of gem enthusiasts and collectors, especially the coveted “imperial jade.” The most exquisite Jadeite hails from Myanmar (formerly Burma), a region where it has been revered for centuries and associated with both cultural and spiritual beliefs.
What distinguishes Jadeite from other gemstones is its remarkable translucence and vivid green colors. Ranging from delicate mint greens to deep emerald tones, the gem’s hues are often likened to the lush foliage of a pristine forest. The intensity and saturation of these greens are influenced by the presence of chromium and iron within the gem.
In Chinese culture, Jadeite is a symbol of virtue, purity, and longevity. It is often carved into intricate shapes and symbols, such as the “pi” disc and the mythical “bi” ring, which carry deep spiritual meanings. Additionally, Jadeite has a special connection to imperial history, with emperors of ancient China considering it the “royal gem.”
The scarcity of high-quality Jadeite has further elevated its value and desirability. While there are several sources of Jadeite worldwide, including Myanmar, Guatemala, and Japan, Myanmar remains the primary supplier of the finest imperial green Jadeite. Due to its limited availability and the demand for this prestigious gemstone, prices can reach astounding levels in the market.
In recent years, Jadeite has gained international recognition and appreciation beyond its cultural origins. As modern designers incorporate Jadeite into contemporary jewelry designs, its allure continues to captivate a global audience. Whether cherished for its historical significance, spiritual connotations, or breathtaking beauty, Jadeite remains an eternal gem that bridges the gap between the past and the present.
6. Benitoite: A Californian Treasure
Benitoite crystals under UV light. Dallas Gem Mine (Benitoite Mine ; Benitoite Gem Mine ; Gem Mine), Dallas Gem Mine area, San Benito River headwaters area, New Idria District, Diablo Range, San Benito Co., California, USA. Photo Credit: Parent Géry
Benitoite emerges as a rare and captivating treasure that is uniquely tied to the state of California. This gem, often referred to as California’s state gemstone, boasts a mesmerizing sapphire-blue hue that has intrigued collectors and enthusiasts for generations.
Benitoite was first discovered in 1907 in the San Benito County of California, USA, from which it derives its name. What sets this gem apart is its remarkable fluorescence under ultraviolet (UV) light, which transforms its appearance from a stunning blue to a dazzling shade of white. This characteristic property has earned it the moniker “blue diamond under UV light.”
The vivid blue color of Benitoite is due to the presence of barium, titanium, and silica in its composition. The combination of these elements produces a hue that is reminiscent of the deep blue skies and oceans. Benitoite’s color is further accentuated by its transparency and brilliance, making it a true gemological wonder.
One of the most intriguing aspects of Benitoite is its limited geographic occurrence. Although other deposits have been found, the gem is most famously associated with the Benitoite Gem Mine in California. Its scarcity and unique fluorescence have fueled its demand among collectors and enthusiasts, making it a sought-after and prized gemstone.
In addition to its rarity and beauty, Benitoite carries a piece of California’s history and geological heritage. In 1985, Benitoite was designated as the official state gemstone of California, highlighting its significance to the region’s natural treasures. The Benitoite Gem Mine, once a source of gem-quality material, is now a protected area, preserving its delicate ecosystem and ensuring the gem’s sustainable future.
Alexandrite stands as a true marvel of nature’s ingenuity. Renowned for its remarkable color-changing properties, this gemstone transforms under different lighting conditions, revealing hues that range from lush green to deep purplish-red. This chameleon-like characteristic has earned Alexandrite the affectionate nickname, “emerald by day, ruby by night.”
Discovered in the Ural Mountains of Russia in the 1830s, Alexandrite’s mesmerizing color shift captured the imagination of gem enthusiasts and collectors around the world. Its unique ability to change color is a result of the interplay between chromium and iron within its crystal structure. In daylight or fluorescent light, Alexandrite appears green or bluish-green, reflecting the gem’s chromium content. However, under incandescent light, which has a higher proportion of red wavelengths, the gem takes on a deep red hue.
This color-changing phenomenon is best appreciated when Alexandrite is viewed in various lighting settings. The gem’s ability to adapt its appearance adds a layer of intrigue and fascination, making it a highly sought-after gemstone for those who appreciate the interplay of light and color.
Beyond its captivating optical properties, Alexandrite carries a legacy of rarity. While deposits of this gemstone have been found in various locations, including Russia, Brazil, Sri Lanka, and East Africa, high-quality specimens are scarce and command significant value in the market. Natural Alexandrite with strong color change and good clarity is particularly prized among collectors and connoisseurs.
Alexandrite’s uniqueness has inspired jewelry designers and enthusiasts alike to create pieces that highlight its exceptional color shift. From solitaire rings to intricate necklaces, Alexandrite’s beauty continues to captivate the hearts of those who seek gemstones that transcend the ordinary.
In essence, Alexandrite is a gem that reveals nature’s artistic brilliance. Its color-changing abilities, combined with its rarity, make it a gemstone that embodies the magic of light and color. As collectors and admirers continue to uncover the hidden gems of the Earth, Alexandrite stands as a testament to the wonders that nature has to offer, inviting us to marvel at its ever-changing beauty.
8. Poudretteite: Delicate and Rare
Poudretteite
Named after the Poudrette family who owned the quarry where it was first discovered, this gemstone captivates with its charming pink hues and limited availability.
Poudretteite’s journey into the gemological spotlight began in 1965 when it was unearthed in Quebec, Canada. Its soft, rosy shades range from delicate pastels to more vibrant pinks, making it a favorite among those who appreciate gems with a touch of femininity and grace.
What sets Poudretteite apart is not only its color but also its scarcity. This gemstone is exceptionally rare, with only a handful of known deposits worldwide. Its limited availability has elevated its desirability among collectors and enthusiasts, who often seek it out for its uniqueness and captivating color.
Poudretteite’s charming appearance has earned it a place in the jewelry world, where it is sometimes featured in elegant pieces that showcase its gentle pink hues. Its relatively recent discovery, combined with its limited mining sources, makes Poudretteite a gemstone that is both a collector’s dream and a testament to the hidden treasures of the Earth.
Beyond its visual appeal, Poudretteite also carries a sense of wonder and discovery. As we continue to explore the depths of our planet, gems like Poudretteite remind us that there are still mysteries waiting to be uncovered, waiting to reveal their beauty and secrets to those who appreciate their rarity and allure.
9. Taaffeite: A Fortuitous Discovery
Taaffeite
Taaffeite stands as a symbol of the unexpected and the extraordinary. Named after its discoverer, gemologist Richard Taaffe, this alluring gem has captivated collectors and enthusiasts with its enigmatic charm and captivating hues.
Taaffeite’s story began with a case of mistaken identity. In 1945, a spinel gemstone from Sri Lanka was initially misclassified as spinel, but upon closer examination, it was revealed to be an entirely new gemstone species. This serendipitous discovery unveiled a gem of stunning lavender to mauve shades, often embraced by collectors for its rarity and captivating color.
The scarcity of Taaffeite has made it a true gemological rarity. This gem is found in only a few select locations around the world, primarily in Sri Lanka, Myanmar, and a few other regions. Its limited availability, coupled with its exquisite appearance, has given rise to its status as a highly sought-after collector’s gem.
One of the most intriguing aspects of Taaffeite is its chameleon-like nature. The gem can exhibit different colors depending on the lighting conditions and the angle from which it is viewed. This color-shifting quality adds a touch of mystique to its allure, making it a gem that continues to surprise and delight those who admire it.
Taaffeite’s journey from obscurity to gemological fame serves as a reminder of the ongoing exploration of our planet’s hidden treasures. Its delicate lavender hues, paired with its captivating play of colors, create a gemstone that sparks curiosity and admiration. As collectors and enthusiasts continue to seek out the rare and the exceptional, Taaffeite stands as a gemstone that embodies the magic of discovery and the allure of the unknown.
10. Serendibite: Named after Serendib
Serendibite
Named after the old Arabic name for Sri Lanka, “Serendib,” this gemstone is celebrated for its deep blue to bluish-green hues that evoke a sense of mystery and enchantment.
Serendibite’s story began on the island of Sri Lanka, where it was first discovered in the early 20th century. Its stunning blue color, often reminiscent of the depths of the ocean, immediately set it apart as a gemstone of exceptional beauty. With hues that range from rich navy blues to vibrant teals, Serendibite has captured the attention of collectors and gem enthusiasts worldwide.
What makes Serendibite particularly captivating is its rarity. The gem is found in only a few select locations, including Sri Lanka, Myanmar, and a handful of other regions. Its limited geographic occurrence has elevated its status as a sought-after collector’s gem, adding an element of exclusivity to its allure.
Serendibite’s mesmerizing appearance is a result of its unique mineral composition. Comprising aluminum, magnesium, silicon, and oxygen, this gemstone captures and reflects light in a way that produces its signature deep blue colors. Its pleochroism, which causes the gem to display different colors when viewed from different angles, adds to its complexity and charm.
In addition to its visual allure, Serendibite carries a sense of history and connection to the island from which it takes its name. The gem’s deep blue hues have led to associations with the sea, symbolizing tranquility, depth, and the mysteries that lie beneath the surface.
As collectors and gem enthusiasts continue to seek out the rarest and most remarkable gems, Serendibite shines as a testament to the hidden treasures of the Earth. Its deep blue and bluish-green colors, combined with its scarcity, create an aura of intrigue and fascination. Serendibite stands as a gemstone that invites us to explore the mysteries of the natural world and the captivating beauty that lies within it.
11. Black Opal: Play-of-Color in Darkness
Black Opal
Black Opal’s story begins in Australia, where it is primarily mined. The opal-rich fields of Lightning Ridge, New South Wales, have been the source of many exquisite Black Opal specimens. What distinguishes Black Opal from other opal varieties is its deep, dark base color, which sets the stage for its vibrant play of colors.
Opals are known for their unique optical properties, specifically their ability to diffract light into an array of spectral colors. Black Opal, with its dark body tone, allows these colors to shine even more brilliantly, creating a mesmerizing dance of hues that change with the angle of observation and lighting conditions.
The play of colors within Black Opal is a result of the arrangement of silica spheres within the gemstone. When light enters the opal, it interacts with these spheres, producing the spectral colors that make opals so captivating. From fiery reds and oranges to cool blues and greens, the spectrum of colors that Black Opal exhibits is a testament to nature’s ability to create breathtaking beauty.
Black Opal’s allure extends beyond its captivating play of colors. It has earned a special place in jewelry design, where its unique appearance is often the centerpiece of exquisite pieces. From opulent rings to intricate pendants, Black Opal’s striking beauty adds a touch of magic to any jewelry creation.
12. Jeremejevite: Elusive and Enchanting
Jeremejevite
Jeremejevite’s story began in 1883 when it was discovered in Siberia and named after the Russian mineralogist Pavel Vladimirovich Eremeev. However, it was initially mistaken for aquamarine due to its similar blue color. It wasn’t until later that Jeremejevite was recognized as a distinct mineral species with its own unique properties.
What sets Jeremejevite apart is its scarcity. The gemstone is found in only a few locations worldwide, including Namibia, Madagascar, and Afghanistan. This limited geographic occurrence, combined with its captivating color, has elevated Jeremejevite to the status of a collector’s gem, highly sought after for its rarity and aesthetic appeal.
One of the gem’s most enchanting features is its pleochroism, which causes it to display different shades of blue when viewed from different angles. This optical phenomenon adds depth and dimension to the gem’s color, enhancing its allure and capturing the ever-changing shades of the sky.
Jeremejevite’s delicate beauty has also made it a favorite among jewelry designers. From simple settings that showcase its natural elegance to more intricate designs that highlight its unique color play, Jeremejevite’s versatility in jewelry creation is a testament to its timeless charm.
13. Red Diamond: A Rarity Among Rarities
Very rare Argyle Cardinal Fancy Red diamond
Red Diamonds get their captivating hue from the presence of nitrogen within their crystal lattice, which interacts with light in a way that produces their fiery red color. While most diamonds owe their color to impurities or structural defects, the specific conditions required to create a red diamond are exceptionally rare, making them some of the rarest gemstones on Earth.
The most famous red diamond is the “Moussaieff Red Diamond,” a stunning gem weighing 5.11 carats. Its extraordinary color and rarity have earned it a place among the world’s most valuable diamonds. Other notable red diamonds include the “Rob Red” and the “Supreme Purple Star,” both of which boast unique color combinations that set them apart.
The scarcity of red diamonds has propelled them into the realm of high-profile auctions and elite collections. Their limited availability and unparalleled beauty have led to some red diamonds achieving astronomical prices in the market, often breaking records for the most expensive per-carat prices ever paid for gemstones.
In addition to their rarity, red diamonds carry an aura of mystique and desire. The color red is often associated with passion, love, and power, making red diamonds even more alluring to those who seek a gem that embodies these qualities.
14. Padparadscha Sapphire: The Lotus Blossom Gem
Padparadscha Sapphire
Named after the Sinhalese word for the lotus blossom’s delicate color, this gemstone is celebrated for its enchanting blend of pink and orange hues, reminiscent of a breathtaking sunset over a serene landscape.
Padparadscha Sapphires are predominantly found in Sri Lanka, where the gem’s name is derived from its association with the lotus flower, a revered symbol in Eastern cultures. The gem’s color ranges from delicate shades of peachy-pink to vivid orange-pink, creating a captivating palette that evokes a sense of warmth and tranquility.
What sets Padparadscha Sapphire apart is its rarity and the unique interplay of colors within each gem. The delicate balance between pink and orange tones is a result of the presence of trace elements, such as chromium and iron, within the crystal structure of the sapphire. This exquisite combination of colors makes Padparadscha Sapphire highly sought after by collectors and connoisseurs.
The gem’s color not only reflects the hues of nature but also carries symbolism. The pink-orange blend is often associated with qualities such as love, harmony, and creativity, making Padparadscha Sapphire a gemstone that holds deep emotional meaning for those who wear it.
In the realm of jewelry, Padparadscha Sapphires are prized for their versatility. They can be featured in a variety of settings, from classic solitaire rings to more elaborate designs that showcase the gem’s unique color play. Their scarcity and distinctive appearance add an element of exclusivity to any piece of jewelry they grace.
As gem enthusiasts and collectors explore the world of colored gemstones, Padparadscha Sapphire remains a treasure that captures the splendor of nature’s palette. Its harmonious blend of colors, combined with its rarity, creates a gemstone that is as elegant as it is enchanting, embodying the serene beauty of a sunset within a precious jewel.
15. Sugilite: A Gem of Royal Purple
Sugilite
Sugilite was first discovered in Japan in the 1940s and later in South Africa. Its vivid purple color is attributed to its manganese content, which infuses the gemstone with shades ranging from delicate lavender to rich deep violet. The gem’s color, coupled with its rarity, has made it a favorite among individuals who appreciate gems with a touch of mystique.
What sets Sugilite apart is not only its physical beauty but also its spiritual significance. In metaphysical circles, Sugilite is often regarded as a stone of spiritual enlightenment, inner peace, and emotional healing. It is believed to enhance intuition, promote self-discovery, and facilitate a deeper understanding of one’s life path.
Sugilite’s role in holistic and alternative healing practices has brought it into the spotlight, with proponents attributing various metaphysical benefits to the gem. Its energy is thought to resonate with the crown and third eye chakras, helping individuals connect with their higher selves and access higher states of consciousness.
Beyond its metaphysical properties, Sugilite has also made its mark in the world of jewelry design. Its distinctive color and rarity make it an intriguing choice for those who seek gemstones that stand out from the ordinary. From statement rings to elegant pendants, Sugilite’s allure continues to captivate the hearts of those who value the beauty and symbolism that gemstones can offer.
16. Tanzanite: Trichroism in Blue
The Mawenzi : The Largest Tanzanite rough in the World
Tanzanite is celebrated for its mesmerizing blue hues that range from ultramarine to violet.
Tanzanite’s story began in 1967 in the foothills of Mount Kilimanjaro in Tanzania. Originally mistaken for sapphire due to its rich blue color, Tanzanite was later identified as a unique mineral species. Its vivid blue-violet tones, ranging from deep indigo to lighter lilac shades, have since captured the imagination of collectors and gem enthusiasts worldwide.
What sets Tanzanite apart is its exceptional pleochroism, an optical phenomenon that causes the gem to display different colors when viewed from different angles. This unique property adds depth and intrigue to Tanzanite’s appearance, creating a gemstone that seems to shimmer and shift in hue as it catches the light.
Tanzanite’s coloration is attributed to its mineral composition and the presence of vanadium. The gem’s rich blue-violet tones make it a favorite for those who appreciate gems with a touch of both cool and warm colors, resembling the union of sapphire’s blue and amethyst’s purple.
Tanzanite’s allure extends beyond its captivating appearance. Its discovery in a single location, the Merelani Hills of Tanzania, has led to its classification as a “one-source gem.” With mining activity focused primarily on this area, Tanzanite’s availability remains limited, adding an element of exclusivity to its charm.
In the realm of jewelry, Tanzanite’s versatility shines. It can be found in a variety of settings, from classic solitaire rings to contemporary designs that highlight its unique color and play of light. Its rarity and mesmerizing color make it an exquisite choice for those who seek a gemstone that is as exceptional as it is beautiful.
17. Paraiba Tourmaline: Neon Brilliance
Paraiba Tourmaline
Paraiba Tourmaline’s captivating story began in the 1980s when it was discovered in the Brazilian state of Paraíba, which gives the gem its name. What sets Paraiba Tourmaline apart is its remarkable neon-like coloration, ranging from vivid turquoise blue to mesmerizing green. This unparalleled color comes from the presence of copper and manganese trace elements within the crystal structure.
The rarity of true Paraiba Tourmaline cannot be overstated. While other types of tourmaline are found in various locations, genuine Paraiba Tourmaline is sourced primarily from Brazil, as well as from Mozambique and Nigeria. Its limited geographic occurrence, combined with its unique and vibrant color, has made Paraiba Tourmaline one of the most sought-after and valuable gemstones in the world.
The gem’s exceptional color and rarity have earned it a place in both high-end jewelry and the hearts of collectors. Designers are drawn to Paraiba Tourmaline’s electric hues, which can add a vibrant pop of color to any jewelry piece. Whether set as a solitaire stone or surrounded by complementary diamonds, Paraiba Tourmaline’s beauty shines with an almost otherworldly brilliance.
Beyond its aesthetic allure, Paraiba Tourmaline has also captured the attention of those who appreciate ethical and sustainable gem sourcing. The gemstone’s discovery led to a surge in interest in responsible mining practices, as well as the protection of local environments where these treasures are found.
18. Kashmir Sapphire: Velvety Blue Elegance
A selection of both rough and cut Kashmir sapphires. The cut stones range from 6–14 ct. (Photo: Henry Hänni/SSEF)
The story of the Kashmir Sapphire begins in the late 19th century when a remarkable discovery was made high in the remote mountains of Kashmir, India. Nestled amid the breathtaking landscapes, these sapphires showcased an unparalleled velvety blue color, often described as “cornflower blue.” The gem’s unique color was attributed to the presence of a combination of iron and titanium within its crystal lattice.
What sets Kashmir Sapphires apart is their mesmerizing color and incredible rarity. The velvety blue hue, coupled with exceptional clarity, creates a gemstone that is a true testament to nature’s artistry. However, what truly elevates the Kashmir Sapphire to iconic status is the fact that these sapphires were only mined for a short period of time in the late 19th to early 20th century. Due to the limited duration of mining, the Kashmir Sapphire is now an elusive treasure that is exceedingly rare and highly coveted.
The allure of Kashmir Sapphires extends beyond their appearance and rarity. These gems have a storied history and have graced the jewelry of royalty and the elite. Their deep blue color evokes feelings of serenity and elegance, making them a favorite for those who seek both beauty and meaning in their gemstone choices.
As the world of gemstones continues to evolve, Kashmir Sapphires remain a symbol of enduring beauty and timeless allure. Their velvety blue hues, coupled with their legendary history, create a gemstone that transcends trends and speaks to the heart of gem enthusiasts and collectors alike. Kashmir Sapphires stand as a reminder that the Earth holds treasures that are not only visually stunning but also hold stories of the past and dreams of the future.
Chameleon Diamonds are a subset of naturally occurring diamonds with a unique and fascinating characteristic: they have the ability to temporarily change color when exposed to certain environmental conditions. Typically, a Chameleon Diamond will shift from its original color, which is often a light olive or grayish green, to a deeper, more intense greenish-yellow or brownish hue. The color change occurs when the diamond is subjected to heat or light and then gradually reverts to its original color when left in the dark.
The exact cause of this phenomenon is still the subject of ongoing scientific research, but it is believed to be related to the diamond’s atomic structure and the presence of hydrogen within the crystal lattice. The temporary nature of the color change adds an element of intrigue to the gem, as it undergoes a metamorphosis before returning to its original state.
Chameleon Diamonds are exceedingly rare, making them highly sought after by collectors. Their unique color-changing property adds an element of surprise and delight to these already precious gems. Jewelry designers and connoisseurs are drawn to their captivating nature, creating pieces that showcase the gem’s dynamic transformation.
The mystique of Chameleon Diamonds lies not only in their rarity and color-changing ability but also in the ongoing research that seeks to unravel the secrets behind this phenomenon. As scientists continue to explore the mysteries of these gems, Chameleon Diamonds remain a gemological wonder that reminds us of the complex and enchanting nature of the Earth’s treasures.
20. Blue Garnet: A Color-Changing Wonder
Blue Garnet
The Blue Garnet’s captivating journey began in the late 1990s when it was discovered in the Bekily region of Madagascar. Its name hints at its remarkable characteristic: a mesmerizing shift from blue-green under daylight to purplish-red under incandescent light. This exceptional color change is a result of the interplay between the garnet’s trace elements and its crystal lattice structure.
The precise combination of vanadium, chromium, and other elements within the Blue Garnet’s composition is responsible for its extraordinary color-changing phenomenon. The gem’s ability to showcase two distinct hues depending on the lighting conditions sets it apart as a gemological rarity that continues to intrigue gemologists and collectors alike.
The rarity of the Blue Garnet is further elevated by the fact that it is found in only a few select locations around the world. Its limited geographic occurrence, coupled with its color-changing beauty, has made it highly sought after by collectors and enthusiasts who appreciate gems that offer a captivating visual experience.
In the world of jewelry design, Blue Garnets have been embraced for their unique color-shifting nature. Jewelry pieces featuring Blue Garnets can showcase the gem’s dual personality, transitioning seamlessly from one enchanting color to another. From solitaire rings to intricate pendant designs, the gem’s color-changing ability adds an element of surprise and fascination.
Conclusion
The world of gemstones is a treasure trove of diversity, beauty, and rarity. While some gemstones are widely recognized, there exists a realm of rare gems that are even more captivating due to their scarcity and exceptional characteristics. From painite to
What is the risk of a volcano erupting? To answer this question, scientists need information about its underlying internal structure. However, gathering this data can take several years of fieldwork, analyses and monitoring, which explains why only 30% of active volcanoes are currently well documented. A team from the University of Geneva (UNIGE) has developed a method for rapidly obtaining valuable information. It is based on three parameters: the height of the volcano, the thickness of the layer of rock separating the volcano’s reservoir from the surface, and the average chemical composition of the magma. These results open new prospects for identifying volcanoes that present the greatest risk and are published in the journal Geology.
The Earth is home to some 1,500 active volcanoes, yet we only have accurate data for 30% of them. This is due to the difficulty of observing their “fuel,” the famous magma, which is rich in information. This molten rock is first generated at a depth of between 60 km and 150 km in the Earth’s mantle, whereas the deepest human boreholes generally only reach a depth of around ten kilometres, preventing direct observation. The production rate of magma in the Earth’s deep crust beneath a volcano determines the size and frequency of future eruptions.
This lack of data is a danger as more than 800 million people live close to active volcanoes. Therefore, in many regions, there is no basis on which to assess the risk a given volcano poses and the extent of the protective measures to be taken — the evacuation perimeter, for example — in the event of a suspected eruption.
Three key parameters
Geochemical and geophysical analysis methods are regularly used by scientists to monitor volcanoes, but it can take decades to gain an in-depth understanding of how a specific volcano works. Thanks to recent work by the team of Luca Caricchi, full professor at the Department of Earth Sciences of the UNIGE Faculty of Science, it is now possible to obtain valuable information more rapidly.
This method uses three easy-to-measure parameters: the height of the volcano, the thickness of the rocks separating the volcano’s “reservoir” from the surface, and the chemical composition of the magma released over its eruptive history. The first can be determined by satellite, the second by geophysics and/or chemical analysis of minerals (crystals) in the volcanic rocks, and the third by direct sampling in the field.
A “snapshot”
By analysing existing data on the volcanic arc of the Lesser Antilles, a well-studied archipelago of volcanic islands, the UNIGE team has highlighted a correlation between the height of volcanoes and the rate at which magma is produced. “The highest volcanoes produce the biggest eruptions on average during their life. In other words, they can erupt a greater quantity of magma in a single event,” explains Oliver Higgins, a former doctoral student in Luca Caricchi’s group and first author of the study.
Scientists have also found that the thinner the Earth’s crust beneath the volcano, the closer its magma reservoir is to the surface, and the more thermally mature the volcano is. “When the magma rises from depth, it tends to cool and solidify, which halts its ascent. But when the supply of magma is large, magma retains its temperature, accumulates in the reservoir that will fuel a future eruption, and ‘eats away’ at the Earth’s crust,” explains Luca Caricchi, the second and last author of the study.
Identifying the volcanoes most at risk
Finally, the researchers observed that the average chemical composition of magma that has already erupted is an indicator of its explosiveness. “High levels of silica, for example, indicate that the volcano is fed by a large quantities of magma. In this case, there is a greater risk of a large, explosive eruption from that volcano,” explains the researcher.
Together, the three parameters identified by the UNIGE team produce a “snapshot” of a volcano’s internal structure. They enable an initial assessment of the hazard associated with poorly studied volcanoes, without the need for major technical and financial resources. This method can be used to identify the active volcanoes that are most likely to produce a large-scale eruption, and that require increased surveillance.
Reference:
Oliver Higgins, Luca Caricchi. Eruptive dynamics reflect crustal structure and mantle productivity beneath volcanoes. Geology, 2023; DOI: 10.1130/G51355.1
Tiny mineral inclusions picture for the first time oxygen accumulated in the atmosphere and changed the composition of the mantle. Credit: Hugo Moreira / Nature Geoscience
Using synchrotron techniques, scientists have unveiled important information on The Great Oxidation Event by studying apatite inclusions in zircon crystals from old magmas with the ESRF — Extremely Brilliant Source. The results are published in Nature Geoscience.
Around 2.4 billion years ago, a pivotal moment in Earth’s history took place: The Great Oxidation Event. During this period, a significant amount of oxygen accumulated in the atmosphere. This surge in oxygen production led to a dramatic shift in the composition of the atmosphere, altering the chemistry of the planet. The event marked a turning point as oxygen levels rose, enabling the development of more complex multicellular life forms and fundamentally reshaping Earth’s ecosystems.
Plate tectonics are an effective mechanism for the cycling and interchange of elements among Earth’s surface, atmosphere, and mantle. As mountains undergo weathering and erosion through interactions with water and the atmosphere, they break down into sediments. These sediments are then partially returned to the mantle through subduction processes (one tectonic plate sinking beneath another). The formation of magmas in the mantle above subduction zones provides a unique opportunity to explore how the atmosphere could have impacted the mantle by assimilating materials from subducted sediments, offering insights into this intriguing geological relationship.
Scientists have long tried to study the interaction between atmosphere and the Earth’s mantle. The mission is already complicated to be accomplished in the modern Earth, and even more so in the early Earth, when the atmosphere and plate tectonics were changing at rapid rates. A team led by the University of Montpellier and University of Portsmouth teamed up with the ESRF — The European Synchrotron- and found a way to overcome obstacles by studying apatite inclusions in zircon from subduction zones.
“In 2017, a paper on the mineral apatite unveiled that when it grows at reduced conditions, meaning there is little or no free oxygen for chemical reactions, its sulphur would show a very specific signature. However, if it crystalised in oxidised conditions, the sulphur inside the apatite would look very different. This means that apatite is a proxy for redox conditions,” explains Hugo Moreira, a CNRS postdoctoral researcher at the University of Montpellier and first author of the paper.
Moreira and colleagues decided to explore inclusions of phosphate-mineral apatite in zircon grains that are crystallized in magmas formed in an ancient subduction zone, and measured their sulphur valence speciation using X-ray absorption near edge structure (XANES) at the ESRF, the brightest synchrotron light source.
Sulphur incorporation and speciation in apatite is intrinsically dependent on the oxygen fugacity of the magma and therefore ideal for assessing the oxidation state during the evolution of magmatic systems. “Using apatite inclusions in zircons rather than apatite from the rock matrix was paramount, as the inclusions have been shielded by the extremely robust zircon crystals, preserving their original composition,” explains Moreira.
The experiment results show that apatite inclusions in zircons from magmas that crystallised prior to the Great Oxidation Event have a relatively reduced sulphur redox state, whereas after the Great Oxidation Event they are more oxidised. The analysis on zircon shows that these magmas shared a similar source and that the younger samples had incorporated a sediment component. Overall, the clear implication is that sediments affected by an increasingly oxidised atmosphere modified the mantle and shifted the fugacity of magmas towards more oxidised conditions.
“Our study shows that investigating apatite inclusions in zircon using synchrotron X-rays is a powerful tool to constraint a critical magma parameter,” concludes Moreira.
The next step for the team is to study other magmas that crystallised in key periods of Earth’s history, such as the Neoproterozoic Oxidation Event (beginning 850 million years ago) and when the first signs of oxygen emerged in the Archaean period.
Reference:
Hugo Moreira, Craig Storey, Emilie Bruand, James Darling, Mike Fowler, Marine Cotte, Edgar E. Villalobos-Portillo, Fleurice Parat, Luís Seixas, Pascal Philippot, Bruno Dhuime. Sub-arc mantle fugacity shifted by sediment recycling across the Great Oxidation Event. Nature Geoscience, 2023; DOI: 10.1038/s41561-023-01258-4
The Earth is getting hotter and consequences have been made manifest this summer around the world. Looking back in geological history, global warming events are not uncommon: Around 56 million years ago, during the period known as the Paleocene-Eocene Thermal Maximum (PETM), the temperatures rose by an average of 5 to 8 degrees Celsius. This development was most likely linked to increased volcanism and the associated release of masses of carbon dioxide into the atmosphere. The higher temperatures persisted for about 200,000 years. Back in 2021, Professor Philip Pogge von Strandmann of Johannes Gutenberg University Mainz (JGU) had already investigated the effect that eventually led to global cooling and climatic recovery after the PETM warming.
In short: Rainwater combined with the atmospheric carbon dioxide, resulting in carbonic acid that caused enhanced weathering of rock, thus releasing calcium and magnesium. Rivers then transported the calcium, magnesium, and carbonic acid into the oceans where the calcium, magnesium — and also the carbon dioxide — came together to form insoluble limestone. “In other words, there is a feedback effect that helps control the climate. High temperatures accelerate the chemical rock weathering process, reducing the levels of carbon dioxide in the atmosphere, allowing the climate to recover,” said Pogge von Strandmann.
Climate required twice as long to regenerate 40 million years ago
Climate warming occurred again 16 million years after the PETM during the Middle Eocene Climatic Optimum or MECO. Although volcanic activity resulted in the discharge of roughly the same amounts of carbon dioxide into the atmosphere as during the PETM, it took far longer for the climate to restabilize. The warming effect lasted for an immense 400,000 years, twice as long as in the PETM. Why was recovery so slow during that period?
In searching for an answer, Pogge von Strandmann and co-authors, including first author Alex Krause, began analyzing 40-million-year-old oceanic carbonates and clay minerals to compare the results with those for similar 56-million-year-old examples. “Just as during the PETM, there was also intensified weathering and erosion in the MECO. However, there was far less exposed rock on the Earth’s surface 40 million years ago. Instead, the Earth was extensively covered by a global rainforest the soil of which largely consisted of clay minerals,” explained the researcher. In contrast with rock, clay does not weather; in fact, it is actually the product of weathering. “So despite the high temperatures, the widespread clay soil prevented rocks from being effectively weathered, a process known as soil shielding,” the geoscientist pointed out.
Enhanced weathering for climate protection
How can we use this knowledge in today’s world? “We study paleoclimates to determine whether and how we can positively influence our present climate. One option might be to boost the chemical weathering of rock. To help achieve this, we could plough finely crushed rock into our fields,” said Pogge von Strandmann. The fine-grained particles of rock would erode rapidly, resulting in the binding of atmospheric carbon dioxide, thus enabling the climate to recuperate. Negative emissions technologies (NETs) such as this involving the absorption of carbon dioxide are the subjects of intense research across the globe. At the same time, however, if the weathering results in the formation of clay, the effects of the process would be significantly less efficient, as Pogge von Strandmann has discovered. Clay retains the calcium and magnesium that would otherwise be delivered to the ocean. The carbon dioxide would continue to flow into the oceans, but it would not be bound there and would be able to escape back into the atmosphere. In this case, the weathering effect would have next to no influence on the climate.
If the rock particles fully dissolve as a result of weathering, the enhanced weathering concept would turn out to be 100 percent efficient. However, if all the weathered materials were turned into clay, this would in its turn completely nullify the effect. In reality, the actual outcome would probably be somewhere between the two extremes: While there was enhanced erosion of rock in the PETM so that the climate normalized more rapidly, clay formation was predominant during the MECO. The extent to which the crushed rock dissolves and how much of it is preserved as clay depends on a range of local factors, such as the globally pre-existing levels of clay and rock. So in order to establish whether the process of enhanced weathering is a viable approach, it would first be necessary to find out how much clay is formed during the weathering process at each potential location.
The corresponding research paper has recently been published in Nature Geoscience. Also involved in the project were researchers at University College London and the University of Essex in the UK as well as Utrecht University in the Netherlands.
Reference:
Alexander J. Krause, Appy Sluijs, Robin van der Ploeg, Timothy M. Lenton, Philip A. E. Pogge von Strandmann. Enhanced clay formation key in sustaining the Middle Eocene Climatic Optimum. Nature Geoscience, 2023; 16 (8): 730 DOI: 10.1038/s41561-023-01234-y
Sea salt hides a secret: tiny droplets of the seawater from which it came, preserving geologic history.
Using specializing equipment obtained from National Science Foundation grant funds, Mebrahtu Weldeghebriel, PhD ’22, a postdoctoral fellow at Princeton University, and Binghamton University Distinguished Professor of Earth Sciences Tim Lowenstein were able to reconstruct changes in seawater chemistry over the last 150 million years, also gaining insight into related geological processes and climate changes. Their article, “Seafloor Hydrothermal Systems Control Long-Term Changes in Seawater [Li+]: Evidence from Fluid Inclusions,” was recently published in the journal Science Advances.
The ocean “is like a giant soup of different elements,” Lowenstein explained. “Sodium and chloride are the most common ones, but there are dozens of others dissolved in seawater in trace amounts such as lithium.”
They looked at sea salt (halite) formed at various times over the past 150 million years in geographically diverse sedimentary basins in the United States, Europe, Asia and Africa. Within the salt samples were tiny pockets containing a bit of ancient seawater.
To access the tiny droplets, the researchers used a laser to drill holes into the salt crystals and then a mass spectrometer to analyze the different trace elements present. In this research, they focused specifically on the concentration of lithium, a trace element that sustained a seven-fold decrease over the past 150 million years, paralleled by a rise in magnesium to calcium ratios.
But why?
The cause for the long-term variations in seawater composition has been debated for the past two decades. The researchers proposed that the decline in lithium concentration in seawater is mainly associated with reduced production of oceanic crust and decreased seafloor hydrothermal activity, both of which are influenced by the movements of tectonic plates. The slowdown in plate activity over the past 150 million years led to less lithium being added to the ocean and reduced amounts of carbon dioxide released into the atmosphere, which ultimately led to global cooling and the present ice age. Turning back the clock 150 million years, the earth was a warmer place with more carbon dioxide in the atmosphere and more lithium in the sea.
“There is a close link between ocean chemistry and atmospheric chemistry,” Weldeghebriel said. “Whatever changes happen in the ocean also reflect what’s happening in the atmosphere.”
Overall, Weldeghebriel and Lowenstein’s research has made a significant advance in understanding the chemistry of Earth’s ancient oceans and how the movement of tectonic plates has influenced the composition of our Earth’s hydrosphere and atmosphere. Such chemical changes impact biology, as well, such as the marine creatures that build their shells out of calcium carbonate.
“The oceans and atmosphere are connected to one another, and how they change is related,” Lowenstein explained. “Everything is connected.”
Reference:
Mebrahtu F. Weldeghebriel, Tim K. Lowenstein. Seafloor hydrothermal systems control long-term changes in seawater [Li + ]: Evidence from fluid inclusions. Science Advances, 2023; 9 (30) DOI: 10.1126/sciadv.adf1605
Note: The above post is reprinted from materials provided by Binghamton University. Original written by Jennifer Micale.
Oxidised apatite inclusions. Credit: Dr Hugo Moreira
An international team of scientists have uncovered an important link between Earth’s early atmosphere and the chemistry of its deep mantle.
The study, which was led by researchers at the University of Portsmouth and University of Montpellier, sheds new light on the evolution of life on our planet and the rise of atmospheric oxygen.
The team investigated magmas formed in ancient subduction zones, where portions of Earth’s crust sink back into the mantle, from a pivotal moment in Earth’s history—the Great Oxidation Event (GOE). This event, which is estimated to have happened between 2.1 and 2.4 billion years ago, was a period of time when oxygen levels in Earth’s atmosphere increased rapidly and transformed life and environments on Earth.
However, there has been little research into how atmospheric changes have left their mark on the Earth’s mantle.
The new study, published in the journal Nature Geoscience, examined the role of plate tectonics—the process by which our planet’s outer shell moves and reshapes its surface—in cycling and exchanging elements between the atmosphere, Earth’s surface, and the deep mantle. Until now, reliable methods to understand these interactions were elusive.
By studying magmas from before and after the GOE, the team found a shift from reduced to more oxidized magmas. This was a result of the deep subduction of oxidized sediments from mountains transformed into sediments during weathering and erosion that were then recycled into the mantle via subduction processes—revealing how sediment recycling provided atmospheric access to the mantle.
This discovery implies that these “whiffs” of oxygen may have changed the mantle by contributing to increased oxidation of calc-alkaline magma, altering the composition of the continental crust, and leading to the formation of ore deposits on Earth.
Lead author, Dr. Hugo Moreira from the University of Montpellier and visiting researcher at the University of Portsmouth, said, “With these findings, our understanding of Earth’s ancient ‘breath’ has taken a significant leap forward. Not only does it provide crucial insights into Earth’s geological evolution, but it also sheds light on how the deep Earth and its mantle are intimately connected to atmospheric changes. It provides us a better understanding of the relationship between Earth’s external and internal reservoirs.
“Moreover, it raises fascinating questions about the role that oxygen played in shaping our planet’s history and the conditions that paved the way for life as we know it.”
The research team used the ID21 beamline at the European Synchrotron Radiation Facility in France to analyze sulfur state in minerals found in two-billion-year-old zircon crystals from the Mineiro Belt in Brazil, which acted as time capsules, preserving their original composition. They discovered that minerals from magmas that crystallized before the GOE had a reduced sulfur state. However, after the GOE, these became more oxidized.
Dr. Moreira said, “Mantle oxygen fugacity, in simple terms, is a measure of oxygen’s ability to drive chemical reactions in magmas and is critical for understanding volcanic activity and ore formation. However, in the past, we lacked a reliable way to track changes in this parameter for ancient parts of Earth’s history—until now.
“It provides a powerful tool for understanding the relationship between Earth’s external and internal reservoirs. Sulfur speciation and magma fugacity are dynamic parameters that can change throughout a magma’s journey from formation to crystallization. While our study considered factors like pressure and temperature, further analyses are needed to trace the complete ‘fugacity path’ from magma generation to final crystallization.”
Co-author Professor Craig Storey, Professor of Geology at the University of Portsmouth, said, “Our study opens exciting new avenues of research, offering a deeper understanding of the Earth’s ancient past and its profound connection to the development of our atmosphere. It challenges us to ponder questions about the evolution of magma types over time and the intricate interplay between plate tectonics and atmospheric cycles.”
Dr. Moreira added, “As we continue to probe the mysteries of Earth’s geological history, one thing is certain—there is much more to discover beneath the surface.”
The study involved researchers from the University of Portsmouth, the Universities of Brest, Montpellier and University of Sorbonne, (France), the Federal University of Ouro Preto and University of São Paulo (Brazil) and the European Synchrotron Radiation Facility.
Reference:
Sub-arc mantle fugacity shifted by sediment recycling across the Great Oxidation Event’, Nature Geoscience (2023). DOI: 10.1038/s41561-023-01258-4
Obsidian, a naturally occurring volcanic glass, has captivated humanity for centuries with its mesmerizing beauty and unique properties. Formed from rapidly cooled lava, obsidian’s intriguing appearance and versatility have made it a sought-after material for both practical and aesthetic purposes. While obsidian comes in various forms and colors, some types stand out for their rarity and exorbitant price tags. In this article, we’ll delve into the world’s rarest and most expensive types of obsidian, exploring their origins, characteristics, and the reasons behind their high value.
1. Rainbow Obsidian: Nature’s Display of Color
Polished Rainbow Obsidian
Rainbow obsidian, often referred to as “Sheen Obsidian,” is a captivating variation of this volcanic glass that showcases a stunning array of iridescent colors. The play of colors is a result of microscopic mineral inclusions, such as magnetite nanoparticles, diffusing light in intricate patterns. This phenomenon creates a visual treat for those who admire this exquisite gem.
The rarity of rainbow obsidian stems from the specific conditions required for its formation. As the lava cools rapidly, the mineral inclusions need to align perfectly to create the rainbow effect. This intricate process occurs only in limited geological environments, making rainbow obsidian a rare find indeed.
Collectors and jewelry enthusiasts are particularly drawn to rainbow obsidian due to its striking appearance. Crafted into pendants, beads, and other jewelry pieces, this obsidian variety allows individuals to carry a piece of nature’s artistry wherever they go. The rarity of rainbow obsidian contributes significantly to its high market value, making it a coveted gemstone among collectors.
2. Fire Obsidian: A Blaze of Magnificence
Fire obsidian
Fire obsidian, also known as “Fire Sheen Obsidian,” is an exceptional type of obsidian that embodies the fierce beauty of blazing flames. This variety is renowned for its vibrant play of colors, which range from deep reds to fiery oranges and mesmerizing golds. The name “fire” is an apt descriptor for its intense and captivating hues.
The formation of fire obsidian is a delicate process that requires the presence of certain mineral elements within the volcanic environment. As the lava cools rapidly, these minerals create the distinctive iridescence that defines fire obsidian. The rarity of the necessary geological conditions contributes to the scarcity of this captivating gem.
Due to its vivid and fiery appearance, fire obsidian is highly sought after by collectors and gem enthusiasts alike. Jewelry designers often incorporate fire obsidian into their creations, adding a touch of fiery elegance to rings, necklaces, and earrings. The rarity and visual impact of fire obsidian contribute to its premium price in the market.
Spiderweb obsidian, as its name suggests, exhibits a delicate web-like pattern that traverses its surface. This captivating variety of obsidian features intersecting lines that resemble a spider’s intricate silk threads, lending it an air of mystery and elegance. The web patterns are usually formed by mineral inclusions that settle in fractures as the lava cools.
The intricate formation process of spiderweb obsidian, involving the precise alignment of mineral inclusions, contributes to its rarity. Each piece of spiderweb obsidian is a unique work of natural art, with its distinct web-like pattern telling a geological story millions of years in the making.
Collectors and jewelry aficionados are drawn to the enigmatic charm of spiderweb obsidian. Crafted into polished cabochons or carved into ornamental pieces, this variety of obsidian adds an element of fascination to any collection. The rarity and aesthetic appeal of spiderweb obsidian make it one of the most valuable and sought-after forms of obsidian on the market.
4. Midnight Lace Obsidian: Elegance in Black and White
Midnight Lace Obsidian
Midnight Lace Obsidian, also known as “Lace Agate Obsidian,” is a mesmerizing variety characterized by its intricate lacy patterns in contrasting black and white. This variety is formed when mineral-rich solutions infiltrate the volcanic glass and create the delicate filigree-like patterns that adorn its surface.
The interplay of light and dark in midnight lace obsidian creates a striking visual effect, making it a favorite among jewelry designers and collectors seeking unique and elegant pieces. This obsidian variety is often transformed into pendants, earrings, and other ornamental jewelry items, showcasing the delicate beauty of its lace-like patterns.
The rarity of midnight lace obsidian arises from the specific geological conditions required for its formation. The intricate process of mineral infiltration and the subsequent cooling of lava with precise timing contribute to its scarcity in the natural world. As a result, midnight lace obsidian commands a high price in the market, appealing to those who appreciate its intricate beauty.
5. Mahogany Obsidian: Earthy Elegance
Mahogany Obsidian
Mahogany Obsidian derives its name from its rich brown hue that resembles the warm tones of mahogany wood. This variety of obsidian often features intricate patterns caused by the inclusion of iron oxide or other mineral impurities during formation. The resulting designs can resemble tree branches or intricate landscapes, adding a sense of artistic flair to each piece. Mahogany Obsidian is known for its grounding properties and is often used in spiritual practices. The combination of its aesthetic appeal and metaphysical significance contributes to its rarity and elevated price tag.
6. Black Amethyst Obsidian: A Sublime Fusion
Black Amethyst Obsidian
Black Amethyst Obsidian, also known as “Black Amethyst Sage” or “Black Amethyst Flower,” is a captivating fusion of deep black and luxurious purple hues. This unique combination is achieved through the interplay of amethyst and obsidian during its formation. The result is a stone that exudes both the protective energy of obsidian and the spiritual properties of amethyst. The scarcity of Black Amethyst Obsidian is attributed to the specific conditions required for the amalgamation of these two minerals, making it a rare and prized addition to any collection.
In Conclusion
Obsidian, with its captivating beauty and intriguing origins, continues to be a source of fascination for enthusiasts, collectors, and artisans. The rarest and most expensive types of obsidian, such as rainbow obsidian, fire obsidian, spiderweb obsidian, and midnight lace obsidian, stand as testament to the marvels of nature’s artistic expression. These unique gems, born from volcanic fires and shaped by millennia of geological processes, offer a glimpse into the Earth’s remarkable creative potential. Whether admired as part of a collection or worn as exquisite jewelry, these precious obsidian varieties are a testament to the allure of the natural world’s rarest treasures.
Fossils have been found of several types of abelisaur showing the diversity of dinosaurs in Morocco at the end of the Cretaceous period. (Credit: Andrey Atuchin)
Fossils of primitive cousins of T. rex that had short, bulldog snouts and even shorter arms have been discovered by scientists in Morocco. The two new dinosaur species belong to the Abelisauridae, a family of carnivorous dinosaurs that were counterparts to the tyrannosaurs of the Northern Hemisphere. They lived at the end of the Cretaceous period and show that dinosaurs were diverse in Africa just before their mass extinction by an asteroid 66 million years ago.
Two new species of dinosaur have been found from the end of the Cretaceous in Morocco, just outside of Casablanca. One species, found near the town of Sidi Daoui, is represented by a foot bone from a predator about two and a half metres (eight feet) long. The other, from nearby Sidi Chennane, is the shin bone of a carnivore that grew to around five metres (15 feet) in length.
Both were part of a family of primitive carnivorous dinosaurs known as abelisaurs, and lived alongside the much larger abelisaur Chenanisaurus barbaricus, showing that Morocco was home to diverse dinosaur species just before a giant asteroid struck at the end of the Cretaceous, ending the age of dinosaurs.
Dr Nick Longrich, from the Milner Centre for Evolution at the University of Bath, led the study. He said: “What’s surprising here is that these are marine beds.
“It’s a shallow, tropical sea full of plesiosaurs, mosasaurs, and sharks. It’s not exactly a place you’d expect to find a lot of dinosaurs. But we’re finding them.”
Even though dinosaurs account for a small proportion of the fossils, the region is so rich in fossils, it has produced the best picture of African dinosaurs from the end of the age of dinosaurs.
Rather than finding the same few species, palaeontologists often recover fossils from new species, suggesting the beds host an extremely diverse dinosaur fauna.
So far, the small number of dinosaur fossils that have been recovered represent five different species — a small duckbill dinosaur named Ajnabia, a long-necked titanosaur, the giant abelisaur Chenanisaurus, and now the two new abelisaurs.
Dr Longrich said: “We have other fossils as well, but they’re currently under study. So we can’t say much about them at the moment, except that this was an amazingly diverse dinosaur fauna.”
The last dinosaurs vanished around 66 million years ago, along with as much as 90% of all species on earth, including mosasaurs, plesiosaurs, pterosaurs and ammonites. The pattern of the end-Cretaceous extinction and its causes have been debated for over two hundred years.
A giant asteroid impact in the Yucatan peninsula has been linked to their demise, although it’s been argued that dinosaurs were already in decline. The Moroccan dinosaurs suggest that they thrived in North Africa up to the very end.
“The end of the Cretaceous in western North America definitely seems to become less diverse at the end,” said Longrich. “But that’s just one small part of the world. It’s not clear that you can generalise from the dinosaurs of Wyoming and Montana to the whole world.
“It also grew colder near the end, so it might not be surprising if dinosaurs at higher latitudes became less diverse. But we don’t know much about dinosaurs from lower latitudes.”
In Morocco at least, they seem to have remained diverse and successful up until the end.
“When T. rex reigned as a megapredator in North America, abelisaurs sat at the top of the food chains in North Africa,” said Nour-Eddine Jalil, a professor at the Natural History Museum and a researcher at Universite Cadi Ayyad in Morocco, who was a co-author on the paper.
“The dinosaur remains, despite their rarity, give the same messages as the more abundant marine reptile remains.
“They tell us that, just before the Cretaceous-Paleogene crisis, biodiversity was not declining but on the contrary, was diverse.”
The new study is published in Cretaceous Research by Dr Nick Longrich from the University of Bath, Prof. Xabier Pereda-Suberbiola and Erik Isasmendi of the Basque Country in Bilbao, and Nour-Eddine Jalil of the Museum of Natural History of Paris and Universite Cadi Ayyad in Marrakech.
Reference:
Nicholas R. Longrich, Erik Isasmendi, Xabier Pereda-Suberbiola, Nour-Eddine Jalil. New fossils of Abelisauridae (Dinosauria: Theropoda) from the upper Maastrichtian of Morocco, North Africa. Cretaceous Research, 2023; 105677 DOI: 10.1016/j.cretres.2023.105677
Plots of mineral modal abundance and the weight percentage of mineral-bound water (blue lines) for (a) metabasaltic and (b) metasedimentary rocks from the modern Cocos plate at 1.3 GPa and over the range of temperatures along the flat slab top beneath Guerrero.
The Mexican state of Guerrero, located on the country’s Pacific coast, is known for its rich cultural history and for iconic beach destinations like Acapulco. It is also home to a geologically curious subduction zone.
The subduction zone beneath Guerrero is formed by the Cocos plate sliding beneath the North American plate and is shaped in part by a fault-slip phenomenon known as episodic tremor and slow slip (ETS). In contrast to more common slip behaviors such as earthquakes, scientists understand relatively little about how ETS deforms tectonic plates.
P. C. Lindquist and colleagues developed petrologic models to study the variables that drive ETS, focusing on Guerrero as a natural laboratory for plate deformation research. Specifically, the authors investigate how the chemical alteration, or metasomatism, of serpentinized peridotite rock produces talc in the subduction zone. Talc is a weak, hydrous mineral that can preferentially host deformation in subduction zones and, the authors suggest, may facilitate ETS at subduction zone interfaces.
With their petrologic models, the researchers predicted mineral occurrences at the plate interface beneath Guerrero using realistic pressure, temperature, and composition conditions. They found that where ETS occurs in the subduction zone, serpentinites must react with enough of the fluids being released by the subducting Cocos plate to reach 43% silica by weight for talc to form. However, even small silica additions beyond that amount result in significant volumes of talc at the plate interface that should then host deformation in the subduction zone.
The team’s models also predicted that talc grows in serpentinite mainly where subducting basalts undergo enough dehydration to produce sufficient volumes of silica-rich fluid.
Although the models did not replicate the large, geophysically inferred talc volume in the subduction zone beneath Guerrero, they did predict the formation of thin zones of talc-rich rocks near where ETS occurs along the plate interface. The research, according to the authors, shows the importance of including metasomatism in fault slip models, and it provides direction for future research studying seismicity along Mexico’s Pacific coast.
Reference:
P. C. Lindquist et al, Metasomatism and Slow Slip: Talc Production Along the Flat Subduction Plate Interface Beneath Mexico (Guerrero), Geochemistry, Geophysics, Geosystems (2023). DOI: 10.1029/2023GC010981
Dalian Coherent Light Source revealing vacuum ultraviolet photodissociation of sulfur dioxide as an important prebiotic-O2 source. Credit: Yuan Kaijun
The provenance of oxygen (O2) has been linked to the early Earth’s atmospheric and biological evolution. A permanent rise to appreciable concentrations of O2 in the atmosphere, known as the “Great Oxidation Event (GOE),” was estimated to have occurred at around 2.4 billion years ago. However, the cause of the GOE still remains unclear.
Besides the biogenic processes leading to O2 production, the widely accepted abiotic O2 production is through photolysis of carbon dioxide (CO2) and water molecules (H2O).
Now, a research group led by Prof. Yuan Kaijun and Prof. Yang Xueming from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences has reported oxygen production from vacuum ultraviolet photodissociation of sulfur dioxide (SO2) using the Dalian Coherent Light Source. Their findings were published in Chemical Science on Aug. 1.
“Our experimental results revealed a direct dissociation channel yielding S(1D) + O2 products from vacuum ultraviolet (VUV) photodissociation of SO2 in the wavelength range between 120 and 160 nm,” said Prof. Yuan.
Geological evidences have identified the strong activity of SO2 photochemistry during the Earth’s late Archaean eon, which linked to the origin of the sulfur mass independent fractionation in ancient rocks. But its role in the formation of molecular oxygen is ignored.
The quantitative determination demonstrated that O2 production was an important channel from SO2 VUV photodissociation, with a branching ratio of around 30% at the H Lyman-a wavelength (121.6 nm).
The relatively large amounts of SO2 emitted from volcanic eruptions in the Earth’s late Archaean eon imply that VUV photodissociation of SO2 could have provided a crucial additional source term in the O2 budget in Earth’s primitive atmosphere. Therefore, this event may have led to transient O2 accumulation and could be one possible cause of the GOE.
Reference:
Yao Chang et al, Vacuum ultraviolet photodissociation of sulfur dioxide and its implications for oxygen production in the early Earth’s atmosphere, Chemical Science (2023). DOI: 10.1039/D3SC03328G
A team of researchers have confirmed that 107-million-year-old pterosaur bones discovered more than 30 years ago are the oldest of their kind ever found in Australia, providing a rare glimpse into the life of these powerful, flying reptiles that lived among the dinosaurs.
Published in the journal Historical Biology and completed in collaboration with Museums Victoria, the research analysed a partial pelvis bone and a small wing bone discovered by a team led by Museums Victoria Research Institute’s Senior Curator of Vertebrate Palaeontology Dr Tom Rich and Professor Pat Vickers-Rich at Dinosaur Cove in Victoria, Australia in the late 1980s.
The team found the bones belonged to two different pterosaur individuals. The partial pelvis bone belonged to a pterosaur with a wingspan exceeding two metres, and the small wing bone belonged to a juvenile pterosaur — the first ever reported in Australia.
Lead researcher and PhD student Adele Pentland, from Curtin’s School of Earth and Planetary Sciences, said pterosaurs — which were close cousins of the dinosaurs — were winged reptiles that soared through the skies during the Mesozoic Era.
“During the Cretaceous Period (145-66 million years ago), Australia was further south than it is today, and the state of Victoria was within the polar circle — covered in darkness for weeks on end during the winter. Despite these seasonally harsh conditions, it is clear that pterosaurs found a way to survive and thrive,” Ms Pentland said.
“Pterosaurs are rare worldwide, and only a few remains have been discovered at what were high palaeolatitude locations, such as Victoria, so these bones give us a better idea as to where pterosaurs lived and how big they were.
“By analysing these bones, we have also been able to confirm the existence of the first ever Australian juvenile pterosaur, which resided in the Victorian forests around 107 million years ago.”
Ms Pentland said that although the bones provide important insights about pterosaurs, little is known about whether they bred in these harsh polar conditions.
“It will only be a matter of time until we are able to determine whether pterosaurs migrated north during the harsh winters to breed, or whether they adapted to polar conditions. Finding the answer to this question will help researchers better understand these mysterious flying reptiles,” Ms Pentland said.
Dr Tom Rich, from Museums Victoria Research Institute, said it was wonderful to see the fruits of research coming out of the hard work of Dinosaur Cove which was completed decades ago.
“These two fossils were the outcome of a labour-intensive effort by more than 100 volunteers over a decade,” Dr Rich said.
“That effort involved excavating more than 60 metres of tunnel where the two fossils were found in a seaside cliff at Dinosaur Cove.”
The research was co-authored by researchers from Curtin’s School of Earth and Planetary Sciences, the Australian Age of Dinosaurs Museum of Natural History, Monash University, and Museums Victoria Research Institute.
Reference:
Adele H. Pentland, Patricia Vickers-Rich, Thomas H. Rich, Samantha L. Rigby, Stephen F. Poropat. Oldest pterosaur remains from Australia: evidence from the Lower Cretaceous (lower Albian) Eumeralla Formation of Victoria. Historical Biology, 2023; 1 DOI: 10.1080/08912963.2023.2201827
Note: The above post is reprinted from materials provided by Curtin University. Original written by Lauren Sydoruk.
Image: Jorge Gonzalez This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
A newly discovered plant-eating dinosaur may have been a species’ “last gasp” during a period when Earth’s warming climate forced massive changes to global dinosaur populations.
The specimen, named Iani smithi after Janus, the two-faced Roman god of change, was an early ornithopod, a group of dinosaurs that ultimately gave rise to the more commonly known duckbill dinosaurs such as Parasaurolophus and Edmontosaurus. Researchers recovered most of the juvenile dinosaur’s skeleton — including skull, vertebrae and limbs — from Utah’s Cedar Mountain Formation.
Iani smithi lived in what is now Utah during the mid-Cretaceous, approximately 99 million years ago. The dinosaur’s most striking feature is its powerful jaw, with teeth designed for chewing through tough plant material.
The mid-Cretaceous was a time of big changes, which had big effects on dinosaur populations. Increased atmospheric carbon dioxide during this time caused the Earth to warm and sea levels to rise, corralling dinosaurs on smaller and smaller landmasses. It was so warm that rainforests thrived at the poles. Flowering plant life took over coastal areas and supplanted normal food sources for herbivores.
In North America, giant plant-eating sauropods — once titans of the landscape — were disappearing, along with their allosaurian predators. At the same time, smaller plant eaters, like early duckbills and horned dinosaurs, and feathered theropods like tyrannosaurs and enormous oviraptorosaurs, were arriving from Asia.
Enter Iani smithi, unique not only because it’s newly discovered, but also because of its rarity in the North American fossil record and its position in dinosaur history.
“Finding Iani was a streak of luck. We knew something like it lived in this ecosystem because isolated teeth had been collected here and there, but we weren’t expecting to stumble upon such a beautiful skeleton, especially from this time in Earth’s history. Having a nearly complete skull was invaluable for piecing the story together,” says Lindsay Zanno, associate research professor at North Carolina State University, head of paleontology at the North Carolina Museum of Natural Sciences, and corresponding author of the work.
Zanno and her team used the well-preserved skeleton to analyze the evolutionary relationships of Iani and were surprised — and a bit skeptical — of the results.
“We recovered Iani as an early rhabdodontomorph, a lineage of ornithopods known almost exclusively from Europe,” Zanno says. “Recently, paleontologists proposed that another North American dinosaur, Tenontosaurus — which was as common as cattle in the Early Cretaceous — belongs to this group, as well as some Australian critters. If Iani holds up as a rhabdodontomorph, it raises a lot of cool questions.”
Key among these is, could Iani be a last gasp, a witness to the end of a once successful lineage? Zanno thinks that studying this fossil in the context of environmental and biodiversity changes during the mid-Cretaceous will give us more insight into the history of our planet.
Iani smithi is named for Janus, the two-faced god who symbolized transitions — an apt name, given its position in history.
“Iani may be the last surviving member of a lineage of dinosaurs that once thrived here in North America but were eventually supplanted by duckbill dinosaurs,” Zanno says. “Iani was alive during this transition — so this dinosaur really does symbolize a changing planet.
“This dinosaur stood on the precipice,” she says, “able to look back at the way North American ecosystems were in the past, but close enough to see the future coming like a bullet train. I think we can all relate to that.”
The work appears in PLOS ONE and was supported by the National Science Foundation. Zanno is lead author as well as corresponding. Terry Gates and Haviv Avrahami, both of NC State and the North Carolina Museum of Natural Sciences, along with Ryan Tucker of Stellenbosch University and Peter Makovicky of the University of Minnesota, also contributed to the work.
Reference:
Lindsay E. Zanno, Terry A. Gates, Haviv M. Avrahami, Ryan T. Tucker, Peter J. Makovicky. An early-diverging iguanodontian (Dinosauria: Rhabdodontomorpha) from the Late Cretaceous of North America. PLOS ONE, 2023; 18 (6): e0286042 DOI: 10.1371/journal.pone.0286042
Spinosaur tooth from the Wealden seen from two different angles.
Palaeontologists at the University of Southampton (UK) studying a British dinosaur tooth have concluded that several distinct groups of spinosaurs — dinosaurs with fearsome crocodile-like skulls — inhabited southern England over 100 million years ago.
The team, from the University’s EvoPalaeoLab, carried out a series of tests on the 140 million year old tooth, discovered in the early 20th century, in a thick, complicated rock structure named the Wealden Supergroup. The Wealden lies across south-eastern England and was formed around 140-125 million years ago.
The scientists conducted statistical analysis on the tooth, which is stored at the Hastings Museum and Art Gallery in East Sussex. They meticulously compared its characteristics with other species in the spinosaur ‘family’ of dinosaurs to which it belongs. Their findings, published in the journal PeerJ, confirm the tooth doesn’t match that of any identified spinosaur species.
Project supervisor, Dr Neil Gostling explains: “While we can’t formally identify a new species from one tooth, we can say this spinosaur tooth doesn’t match any of the existing species we know about. Given how many individual teeth exist in collections, this could be just the tip of the iceberg and it’s quite possible that Britain may have once teemed with a diverse range of these semi-aquatic, fish-eating dinosaurs.”
The Wealden is famous for its spinosaur fossils. Baryonyx — discovered in Surrey in 1983 — is one of the world’s most significant spinosaur specimens, since it was the first to reveal the true appearance of this crocodile-headed group. Less impressive spinosaur remains — isolated teeth — are common throughout the Wealden, and have often been identified as belonging to Baryonyx. However, some experts have long suspected that this is incorrect.
“We used a variety of techniques to identify this specimen, in order to test whether isolated spinosaur teeth could be referred to Baryonyx,” said lead author Chris Barker, whose PhD focuses on the spinosaurs of southern Britain. “The tooth did not group with Baryonyx in any of our data runs. It must belong to a different type of spinosaur.”
The results show that distinct and distantly related spinosaur types lived in the region during Early Cretaceous times. This backs up research by the EvoPalaeoLab team, who argued in previous studies that the spinosaurs of southern England are more diverse than previously thought.
In 2021, they named the ‘Hell Heron’ Ceratosuchops from the Isle of Wight, and in 2022 announced the discovery of what might be Europe’s largest ever land predator, a giant known only as the ‘White Rock’ spinosaur. These several spinosaurs did not all live at the same time, but inhabited the region over the course of more than 15 million years.
“Museums themselves are places to make exciting discoveries as our understanding of specimens changes from the time they were deposited,” said Dr Neil Gostling. “What this work highlights is the importance of keeping collections alive, and developing our understanding of them. Curators are essential to help us navigate the cupboards and displays, helping us to unpick the often-incomplete records — either never fully recorded, or lost to time. The diversity of palaeoenvironments is not always hidden in rocks, it is often waiting in a museum, its importance waiting to be rediscovered!”
Co-author Darren Naish said “Dinosaur teeth preserve numerous anatomical details, and we can use various analytical techniques to see how similar, or different, they are to other teeth. Our new study shows that previously unrecognised spinosaur species exist in poorly known sections of the Wealden’s history, and we hope that better remains will be discovered that improves our knowledge. Here’s another reminder that even well-studied places like southern England have the potential to yield new dinosaur species.”
Reference:
Chris T. Barker, Darren Naish, Neil J. Gostling. Isolated tooth reveals hidden spinosaurid dinosaur diversity in the British Wealden Supergroup (Lower Cretaceous). PeerJ, 2023; 11: e15453 DOI: 10.7717/peerj.15453
Aotearoa New Zealand’s largest fault, the Hikurangi Subduction Zone (HSZ), is where the Pacific tectonic plate dives west beneath the Australian plate and underneath the east coast of the North Island.
In some parts of the subduction zone, GPS instruments are showing the plates slowly move by a few millimeters a year. This behavior is called a “slow slip” and occurs over periods of weeks or months. However, in other parts the plates are stuck, locked together, and building up pressure.
By understanding the structural factors that create the smoother slipping and stuck zones, scientists are seeking to better diagnose what areas could generate potential future earthquakes and tsunami. As Aotearoa’s largest source of potential earthquakes and tsunami, its critical to be able understand the HSZ in high-resolution detail.
New 3D images reveal hidden structures in the HSZ
In 2018 a collaboration of researchers from U.S., Japan, UK, and GNS Science used the RV Marcus Langseth to record numerous overlapping race-track “seismic reflection data” lines. The data were gathered together alongside deployments of ocean bottom seismographs and onshore seismometer in a effort called the “NZ3D” survey.
In an international collaborative effort spanning three recent high-profile publications, the first ever spectacular 3D seismic images of the northern part of Hikurangi margin have now documented new insights for understanding the structural, stratigraphic and hydrogeologic characteristics of the HSZ.
Understanding these qualities, specifically how they transport fluids, are key to knowing the conditions that lead to generation of subduction earthquakes.
How the 3D images were created
Seismic reflection data are typically how geophysicists visualize the crust. To capture this data a specialist vessel, in this case the R/V Marcus Langseth, tows an array of individual sound sources that are tuned and combined to radiate a sound wave downward to the seafloor. The echoes that bounce back from layers in the earth are recorded on a streamer towed behind the vessel and on sensitive seismographs located onshore and on the seabed.
While a grid of 2D profiles is good enough to identify major plate boundary structures, this high-resolution 3D data are needed to visualize details within subduction zones to improve understanding of fault geometry and slip behavior. The 3D data are combined in a CAT scan image of the subduction zone that shows the architecture and properties of the boundary between tectonic plates can contribute to variability in the location of strong and seismogenic versus weak slipping segments.
The 3D data provides new constraints on the physical conditions and rock properties to inform computer simulations and forecasts of earthquake ground shaking and tsunami inundation that greatly help improved hazard preparedness and response.
How fluids and underwater volcanoes influence how New Zealand’s largest fault moves
In June 2023 a Nature Geoscience paper reports how the NZ3D data capture a seamount (underwater volcano) caught in the act of subducting beneath the shallow part of the Hikurangi margin and forms sediment lenses in its wake that appear to enhance slow slip.
Further, in a Geology paper the NZ3D data reveal a detailed map of the deeper parts plate interface that shows that it has kilometer-high hill and valleys.
The new NZ3D data show that the plate interface may strongly govern the nature of how the margin deforms, including the localization of both slow slip and hazardous fast-slip earthquakes.
Most recently, a Science Advances paper revealed a previously hidden water reservoir within the layers of the Pacific plate being swallowed up in the subduction process.
The new finding suggests that subducting plate of volcanic rocks act as amplified source of water that influences the slip behavior of the margin. The trapped water is under pressure and results in the plate boundary being weak and prone to unlocking and sliding in slow slip. The study highlights the presence of significant water delivery to slow slip source from the incoming Pacific, that were previously unknown.
“Importantly, we are able to pinpoint the location of water rich layers, that allow smooth slipping, versus other water-poor segments that are stuck and will likely rupture in fast earthquakes,” says Dr. Stuart Henrys, project lead and principal scientist, GNS Science.
Revealing the mysteries of the subduction process in ways never possible before
The hope is that these new generation 3D images will be able to identify areas of the plate boundary where water rich layers enable smooth slip and other areas that are locked and stuck.
By understanding how the slip behavior varies along the subduction zone, it allows scientists to better diagnose and pinpoint areas that are more prone to generate large earthquakes.
Our 3D data also provides new constraints on the physical conditions and rock properties to inform simulations of earthquake ground shaking and tsunami inundation that greatly help improved hazard preparedness and response.
Henrys says, “Our unique 3D seismic data, acquired offshore Gisborne along the northern Hikurangi subduction zone, is providing breakthroughs in understanding of the physical processes that control earthquakes. Globally subduction zones are where one plate dives beneath another and can rupture in devastating earthquakes and tsunami like those in Sumatra (2004) and Japan (2011).”
“These zones are also subjected to benign slow slip behavior that lasts weeks or months. Diagnosing whether slip is fast or slow along the Hikurangi subduction zone, our largest fault, will provide more reliable forecasts and assessments of the risks to vulnerable people and buildings.
“The 3D data we acquired is combined in a medical CAT scan like image providing super cool visualization of a small part of the subduction zone. For the first time we are able to map in detail the architecture and determine properties of the boundary between tectonic plates. Importantly we are able to pinpoint the location of water rich layers, that allow smooth slipping, versus other segments that are water poor, stuck and will likely rupture in fast earthquakes.
“The results represent another piece in the subduction puzzle that we can start using in large-scale earthquake cycle simulations that greatly help improved hazard preparedness and response.”
Reference:
Andrew C. Gase et al, Subducting volcaniclastic-rich upper crust supplies fluids for shallow megathrust and slow slip, Science Advances (2023). DOI: 10.1126/sciadv.adh0150
New Mexico is renowned for its rich geological heritage and is home to a variety of rare gems and minerals. The state’s diverse landscape, including its deserts, mountains, and volcanic regions, has given rise to unique geological formations that have produced some spectacular and sought-after gemstones and minerals. In this article, we will explore a few of the rare gems and minerals found in New Mexico.
Rare gems and minerals
1- Turquoise
New Mexico is famous for its turquoise, which has been revered by Native American cultures for centuries. The state is known to have some of the finest turquoise deposits in the world. The most significant turquoise mines in New Mexico include the Cerrillos, Tyrone, and Burro Mountains mines. New Mexico turquoise is highly valued for its vibrant blue and green colors and is often used in Native American jewelry and artwork.
2- Rhodochrosite
Rhodochrosite is a beautiful pink to red mineral that is relatively rare and highly prized by collectors. In New Mexico, the Sweet Home Mine near the town of Alma in the southern part of the state has produced some exceptional rhodochrosite specimens. These crystals are renowned for their deep pink color and distinct crystal formations. The Sweet Home Mine is considered one of the premier rhodochrosite localities in the world.
3- Apache Tears
Apache Tears are a unique type of obsidian, a volcanic glass formed from rapidly cooled lava. Found in various locations across New Mexico, including the Black Rock and Zuni Mountains, Apache Tears are small, dark, and translucent stones. They are highly valued for their smooth, black appearance and are often used in jewelry and lapidary work.
4- Amethyst
Amethyst, a purple variety of quartz, can be found in several areas of New Mexico. The most notable amethyst locality is the Arturo Mine in the Organ Mountains near Las Cruces. The amethyst crystals from this mine exhibit a rich purple color and can range in size from small druzy clusters to larger individual crystals.
5- Flourite
Fluorite is a colorful mineral that forms in a variety of hues, including purple, green, blue, and yellow. Notable fluorite deposits in New Mexico can be found in the Hansonburg Mining District near the town of Bingham. The fluorite crystals from this area are highly coveted for their vibrant colors and exceptional clarity.
6- Geodes
New Mexico is known for its abundant geode deposits. Geodes are spherical or oblong rocks that contain hollow cavities lined with crystals. The Rio Grande Rift Valley, in particular, is a prominent geode-producing area. The geodes found in this region often contain quartz, amethyst, calcite, and other minerals. The famous Black Hills Geode Beds near Deming and the Otero Mesa are popular collecting sites for geode enthusiasts.
7- Fire Agate
Fire agate is a unique and mesmerizing gemstone known for its iridescent play of colors. It is formed from chalcedony with a thin layer of iridescent limonite or goethite on its surface. Fire agate can be found in various locations across New Mexico, including the Deer Creek and Round Mountain mines. The gemstone exhibits a range of colors, including fiery reds, oranges, and greens, and is highly prized by collectors and jewelry designers.
8- Smithsonite
Smithsonite, also known as zinc spar, is a zinc carbonate mineral that occurs in a variety of colors, including blue, green, pink, and yellow. It is a secondary mineral that forms in the oxidized zones of zinc ore deposits. Notable smithsonite localities in New Mexico include the Kelly Mine near Magdalena and the San Pedro Mine near San Pedro.
9- Petrified Wood
New Mexico is famous for its petrified wood, which is the result of ancient trees being preserved and transformed into stone over millions of years. Petrified wood specimens found in the state exhibit a wide range of colors, including red, yellow, and brown. The Petrified Forest National Park in northeastern Arizona, near the New Mexico border, is a popular destination for observing and collecting petrified wood.
10- Agate
Agate is a banded form of chalcedony, a microcrystalline variety of quartz. It is known for its beautiful patterns and vibrant colors. New Mexico has several locations where agate can be found, including the Datil-Mogollon area and the Rio Puerco Valley. The agates from these regions display a variety of banding patterns and colors, making them highly prized by lapidaries and collectors.
11- Variscite
Variscite is a rare phosphate mineral that is typically green in color. It is valued for its attractive hue and can be used as a gemstone or in ornamental carvings. The Little Green Monster Variscite Mine in Utah, near the New Mexico border, has produced some exceptional variscite specimens. The mine’s name originates from the vibrant green color of the variscite nodules found there.
12- Wulfenite
Wulfenite is a lead molybdate mineral known for its striking orange to red color. It typically forms as thin tabular crystals and is highly sought after by mineral collectors. New Mexico is home to several wulfenite localities, including the Glove Mine near Lordsburg and the Kelly Mine near Magdalena. The wulfenite crystals from these mines are renowned for their exceptional transparency and vibrant color.
13- Barite
Barite, also known as baryte, is a mineral composed of barium sulfate. It commonly occurs in a variety of colors, including white, yellow, and blue. Notable barite deposits in New Mexico include those found in the Harding Mine near Dixon and the Elk Creek locality in the Magdalena Mountains. The barite crystals from these localities can exhibit exceptional transparency and form intricate formations.
14- Apache Gold
Apache Gold, also known as Chalcopyrite, is a striking mineral that displays a brassy yellow color. It is a copper iron sulfide mineral that forms in hydrothermal veins. Apache Gold is often found in association with copper mineralization in various parts of New Mexico, including the southwestern region. The mineral’s metallic luster and unique color make it a sought-after collector’s item.
15- Topaz
New Mexico is known for its topaz deposits, particularly in the region around the Capitan Mountains and the Organ Mountains. Topaz can occur in various colors, but the most prized variety is the golden to sherry-colored Imperial Topaz. While topaz crystals from New Mexico are often small, they are highly valued for their exceptional clarity and rich colors.
16- Jasper
New Mexico is rich in jasper, a variety of chalcedony often characterized by its vibrant colors and unique patterns. Jasper can be found in various locations across the state, including the Jemez Mountains and the Rio Puerco Valley. The jasper varieties in New Mexico can display hues of red, yellow, brown, and green, and their beautiful patterns make them highly valued by lapidaries and jewelry designers.
17- Uvarovite Garnet
Uvarovite is a rare green variety of garnet known for its vibrant emerald-green color. It typically occurs as small, bright-green crystals that are rich in chromium. The northern part of New Mexico, particularly the area around the Grants District, is known for its uvarovite garnet deposits. While uvarovite crystals from this region are generally small, they are highly prized by collectors for their intense green color.
18- Apatite
Apatite is a phosphate mineral that can occur in a variety of colors, including green, blue, yellow, and purple. In New Mexico, the Harding Mine near Dixon is renowned for its exceptional blue and green apatite crystals. The crystals from this locality are highly transparent and can display vibrant colors, making them highly sought after by mineral collectors.
19- Chalcedony Roses
Chalcedony roses, also known as “desert roses,” are unique mineral formations that resemble rose blossoms. They are composed of chalcedony, a variety of quartz, and are typically formed in arid environments with abundant silica-rich sediments. New Mexico’s White Sands National Park is a notable location to find chalcedony roses. These delicate formations are a popular collectible due to their intricate beauty and resemblance to actual flowers.
20- Copper Minerals
New Mexico has significant copper deposits, and various copper minerals can be found throughout the state. These include chalcopyrite, bornite, and malachite, among others. Copper minerals often occur in association with other minerals, such as quartz, calcite, and azurite. Copper specimens from New Mexico can exhibit vibrant colors and intricate crystal formations, making them prized by collectors and mineral enthusiasts.
21- Eudialyte
Eudialyte is a rare and visually striking mineral that is highly sought after by collectors. It typically occurs in shades of pink, red, and brown and often exhibits intricate patterns and zoning. New Mexico’s Harding Pegmatite Mine near Dixon is known for producing exceptional eudialyte specimens. These specimens are prized for their intense colors and unique crystal formations.
22- Chalcedony Nodules
Chalcedony nodules are rounded formations composed of microcrystalline quartz. They often display a variety of colors, including shades of white, gray, brown, and red. New Mexico is known for its extensive deposits of chalcedony nodules, particularly in the southwestern part of the state. The nodules can be found in various sizes and shapes and are popular among lapidaries and rock collectors.
23- Selenite
Selenite is a translucent variety of gypsum that forms in delicate, elongated crystals. In New Mexico, the White Sands National Park is a notable location for finding selenite crystals. The gypsum dunes of White Sands create a unique environment for the formation of these crystals. Selenite crystals from this region can range in size from small, needle-like formations to larger, intricate specimens.
24- Vanadinite
Vanadinite is a vibrant red to orange mineral that consists of lead vanadate. It often forms hexagonal crystals and is prized for its rich color and high luster. New Mexico’s famous San Carlos Mine near the town of San Carlos is renowned for its exceptional vanadinite specimens. Crystals from this mine can exhibit intense color saturation and are highly sought after by collectors.
25- Hematite Roses
Hematite roses, also known as “iron roses” or “iron flowers,” are unique formations of hematite mineral that resemble roses. They are composed of radiating bladed crystals of hematite and can exhibit a metallic luster. Hematite roses can be found in various locations across New Mexico, including the Jemez Mountains and the Rio Grande Valley. These formations are popular among collectors and are prized for their aesthetic appeal.
26- Staurolite
Staurolite is a brown to black mineral that forms characteristic cross-shaped twins, known as “fairy crosses.” It is often found in metamorphic rocks and is associated with regions of high-grade metamorphism. Staurolite can be found in parts of northern New Mexico, particularly in the Taos area. The fairy crosses are treasured by collectors for their unique twinned crystal structure and folklore associations.
27- Zircon
Zircon is a gemstone known for its brilliance and wide range of colors, including colorless, yellow, brown, and red. It is a common accessory mineral in many granitic rocks. In New Mexico, zircon can be found in various locations, including the Harding Pegmatite Mine near Dixon and the Pala District. Zircon crystals from these localities can exhibit excellent transparency and are highly valued by gem enthusiasts.
28- Covellite
Covellite is a rare copper sulfide mineral that is known for its vibrant indigo-blue to black color. It often forms as thin coatings or crystal aggregates. Covellite can be found in limited quantities in certain copper mining districts of New Mexico, including the Tyrone and Burro Mountains. Its striking color and rarity make covellite specimens a prized find for mineral collectors.
29- Amazonite
Amazonite is a variety of microcline feldspar known for its vibrant blue-green color. It often occurs in granitic rocks and is valued for its beauty and ornamental use in jewelry and carvings. New Mexico’s Custer County is known for its amazonite deposits, particularly in the Mount Mica and Stoneham areas. Amazonite crystals from these localities can display intense blue-green hues and are highly sought after by collectors.
30- Azurite
Azurite is a striking blue copper mineral that often forms in granular or prismatic crystals. It is known for its intense color and is often associated with malachite, another copper mineral. New Mexico’s famous Copper Flat Mine near Hillsboro is known for its azurite-rich deposits. Azurite specimens from this mine can exhibit deep blue hues and are highly prized by mineral collectors.
31- Marcasite
Marcasite is a pale yellow to metallic gray mineral that belongs to the pyrite group. It often forms in crystal clusters or as stalactitic masses. Marcasite can be found in various locations across New Mexico, including the Magdalena District. Marcasite specimens from this region can display intricate crystal formations and a metallic luster, making them popular among collectors.
32- Turquoise
Turquoise is a prized gemstone known for its vibrant blue to green-blue color. It is a hydrated phosphate mineral that often forms in veins and nodules. New Mexico has a rich history of turquoise mining, with notable deposits in the Cerrillos Mining District and the Tyrone Mine. New Mexico turquoise is highly regarded for its intense color and is widely used in Native American jewelry and art.
33- Pyrolusite
Pyrolusite is a manganese oxide mineral known for its metallic luster and black color. It often occurs as botryoidal, stalactitic, or earthy masses. New Mexico’s famous Manganese District, located near the town of Lake Valley, is known for its pyrolusite deposits. Pyrolusite specimens from this area can exhibit a velvety black appearance and are sought after by collectors.
34- Rhodochrosite
Rhodochrosite is a beautiful manganese carbonate mineral that is highly valued for its pink to red color. It often forms as botryoidal or banded masses and can exhibit translucent to semi-transparent properties. New Mexico’s famous Sweet Home Mine near Alma is renowned for producing exceptional rhodochrosite specimens. The crystals from this mine are prized for their vibrant color and gem-quality transparency.
Conclusion
In conclusion, New Mexico is a treasure trove for rare gems and minerals, offering a diverse range of geological wonders. The state’s rich mining history and unique geological formations have contributed to the discovery of numerous rare and sought-after specimens. From the vibrant blue-green amazonite of Custer County to the intense red rhodochrosite of the Sweet Home Mine, New Mexico showcases a remarkable variety of gemstones and minerals.
Collectors and enthusiasts can find an array of fascinating specimens, including the golden Imperial Topaz, the intricate chalcedony roses, and the striking covellite. The state is also known for its deposits of smithsonite, fluorite, azurite, and turquoise, which have captivated the attention of gem and mineral enthusiasts worldwide.
New Mexico’s mining districts, such as the Harding Pegmatite Mine and the Copper Flat Mine, have yielded exceptional specimens that showcase the state’s geological diversity. Additionally, natural areas like White Sands National Park provide unique formations like selenite crystals and chalcedony roses.
Exploring New Mexico’s landscapes and mineral-rich regions offers a captivating journey into the Earth’s geological history. Whether it’s uncovering rare minerals in the mountains or searching for gemstones in the desert, New Mexico continues to be a haven for those fascinated by the beauty and rarity of these geological treasures.
Venetia Diamond Mine, South Africa. Photo by Dr Tom Gernon, University of Southampton
An international team of scientists led by the University of Southampton has discovered that the breakup of tectonic plates is the main driving force behind the generation and eruption of diamond-rich magmas from deep inside the Earth.
Their findings could shape the future of the diamond exploration industry, informing where diamonds are most likely to be found.
Diamonds, which form under great pressures at depth, are hundreds of millions, or even billions, of years old. They are typically found in a type of volcanic rock known as kimberlite. Kimberlites are found in the oldest, thickest, strongest parts of continents — most notably in South Africa, home to the diamond rush of the late 19th century. But how and why they got to Earth’s surface has, until now, remained a mystery.
The new research examined the effects of global tectonic forces on these volcanic eruptions spanning the last billion years. The findings have been published in the journal Nature.
Southampton researchers collaborated with colleagues from the University of Birmingham, the University of Potsdam, the GFZ German Research Centre for Geosciences, Portland State University, Macquarie University, the University of Leeds, the University of Florence, and Queen’s University, Ontario.
Tom Gernon, Professor of Earth Science and Principal Research Fellow at the University of Southampton, and lead author of the study, said: “The pattern of diamond eruptions is cyclical, mimicking the rhythm of the supercontinents, which assemble and break up in a repeated pattern over time. But previously we didn’t know what process causes diamonds to suddenly erupt, having spent millions — or billions — of years stashed away 150 kilometres beneath the Earth’s surface.”
To address this question, the team used statistical analysis, including machine learning, to forensically examine the link between continental breakup and kimberlite volcanism. The results showed the eruptions of most kimberlite volcanoes occurred 20 to 30 million years after the tectonic breakup of Earth’s continents.
Dr Thea Hincks, Senior Research Fellow at the University of Southampton, said: “Using geospatial analysis, we found that kimberlite eruptions tend to gradually migrate from the continental edges to the interiors over time at rates that are consistent across the continents.”
Geological processes
This discovery prompted the scientists to explore what geological process could drive this pattern. They found that the Earth’s mantle — the convecting layer between the crust and core — is disrupted by rifting (or stretching) of the crust, even thousands of kilometres away.
Dr Stephen Jones, Associate Professor in Earth Systems at the University of Birmingham, and study co-author said: “We found that a domino effect can explain how continental breakup leads to formation of kimberlite magma. During rifting, a small patch of the continental root is disrupted and sinks into the mantle below, triggering a chain of similar flow patterns beneath the nearby continent.”
Dr Sascha Brune, Head of the Geodynamic Modelling Section at GFZ Potsdam, and a co-author on the study, ran simulations to investigate how this process unfolds. He said: “While sweeping along the continental root, these disruptive flows remove a substantial amount of rock, tens of kilometres thick, from the base of the continental plate.”
The typical migration rates estimated in models matched what the scientists observed from kimberlite records.
“Remarkably, this process brings together the necessary ingredients in the right amounts to trigger just enough melting to generate kimberlites,” added Dr Gernon.
The team’s research could be used to identify the possible locations and timings of past volcanic eruptions tied to this process, offering valuable insights that could enable the discovery of diamond deposits in the future.
Professor Gernon, who was recently awarded a major philanthropic grant from the WoodNext Foundation to study the factors contributing to global cooling over time, said the study also sheds light on how processes deep within the Earth control those at the surface: “Breakup not only reorganises the mantle, but may also profoundly impact Earth’s surface environment and climate, so diamonds might be just a part of the story.”
Reference:
Thomas M. Gernon, Stephen M. Jones, Sascha Brune, Thea K. Hincks, Martin R. Palmer, John C. Schumacher, Rebecca M. Primiceri, Matthew Field, William L. Griffin, Suzanne Y. O’Reilly, Derek Keir, Christopher J. Spencer, Andrew S. Merdith, Anne Glerum. Rift-induced disruption of cratonic keels drives kimberlite volcanism. Nature, 2023; DOI: 10.1038/s41586-023-06193-3
Explosive lava spews from the latest eruption of the Fogo volcano located on the Cape Verde islands in November 2014. Science now knows that carbon dioxide – instead of water – triggered it. Credit: Ricardo Ramalho/Cardiff University
Geoscientists have long thought that water — along with shallow magma stored in Earth’s crust — drives volcanoes to erupt. Now, thanks to newly developed research tools at Cornell, scientists have learned that gaseous carbon dioxide can trigger explosive eruptions.
A new model suggests that basaltic volcanoes, typically located on the interior of tectonic plates, are fed by a deep magma within the mantle, stored about 20 to 30 kilometers below Earth’s surface.
The research, which offers a clearer picture of our planet’s deep internal dynamics and composition, with implications for improving volcanic-hazards planning, will publish August 7, 2023 at 3:00pm ET in the Proceedings of the National Academy of Sciences.
“We used to think all the action happened in the crust,” said senior author Esteban Gazel, the Charles N. Mellowes Professor in Engineering in the Department of Earth and Atmospheric Sciences, in Cornell Engineering. “Our data implies the magma comes directly from the mantle — passing fast through the crust – driven by the exsolution (the process phase of separating gas from liquid) of carbon dioxide.
“This completely changes the paradigm of how these eruptions happen,” Gazel said. “All volcanic models had been dominated by water as the main eruption driver, but water has little to do with these volcanoes. It’s carbon dioxide that brings this magma from the deep Earth.”
About four years ago, Gazel and Charlotte DeVitre, Ph.D. ’22, now a postdoctoral researcher at University of California, Berkeley, developed a high-precision carbon dioxide densimeter (which measures density in a tiny vessel) for Raman spectroscopy (a device that examines scattered photons through a microscope).
The natural samples — microscopic-sized carbon dioxide rich bubbles trapped in crystals emanating from the volcanic eruption — are then measured via Raman and quantified applying the newly developed densimeter. Essentially, the scientists are examining a microscopic time capsule to provide a history of the magma. This new technique is critical for near real-time precise estimations of magma storage, tested during the 2021 eruption in Las Palmas, in the Canary Islands by Gazel’s group.
Further, the scientists developed methods to assess the effect of laser heating on carbon-dioxide rich inclusions (found swathed in the crystals), and to accurately assess melt inclusion and bubble volumes. They also developed an experimental reheating method to increase accuracy and properly account for carbon dioxide trapped as carbonate crystals inside the bubbles.
“The method of development and instrument design were challenging, especially during the height of the pandemic,” Gazel said.
Using these new tools, the scientists scrutinized volcanic deposits from the Fogo volcano in Cabo Verde, west of Senegal in the Atlantic Ocean. They found a high concentration of volatiles in the micro-sized melt inclusions encased within the magnesium-iron silicate crystals. The higher amount of carbon dioxide enclosed in the crystals suggested that the magma was stored tens of kilometers below the surface — within the Earth’s mantle.
The group also discovered that this process is connected to the deep mantle source that supply these volcanoes.
This implies that eruptions such as Fogo’s volcanic flareups start and are fed from the mantle, effectively bypassing storage in the Earth’s crust and driven by deep carbon dioxide, according to the paper.
“These magmas have extremely low viscosities and come directly from the mantle,” DeVitre said. “So here, viscosity and water cannot play the common roles that they do in shallower and/or more silicic (rich in silica) volcanic systems. Rather at Fogo volcano the magma must be driven up fast by the carbon dioxide and this likely plays a significant role in its explosive behavior. This is a major step in our understanding of the controls on basaltic explosivity.”
Comprehending magma storage helps best prepare society for future eruptions, said Gazel, who is also a faculty fellow at the Cornell Atkinson Center for Sustainability.
“As deep magma storage will not be detected by ground deformation until the melt is close to surface,” he said, “this has important repercussions to our understanding of volcanic hazards. We need to understand the drivers of these eruptions. The only way to see these processes now is by observing earthquakes, but earthquakes don’t tell you exactly what’s happening.”
Said Gazel: “With precise measurements that tell us where eruptions start, where magmas melt and where they are stored — and what triggers the eruption — we can develop a much better plan for future eruptions.”
In addition to Gazel and DeVitre, the other authors of “Oceanic Intraplate Explosive Eruptions Fed Directly from the Mantle” are Ricardo S. Ramalho, Cardiff University, Wales, U.K.; Swetha Venugopal, Lunar and Planetary Institute, Universities Space Research Association, Houston; Matthew Steele-MacInnis, University of Alberta, Edmonton, Alberta; Junlin Hua, University of Texas, Austin; Chelsea M. Allison, Baylor University, Waco, Texas; Lowell R. Moore, Virginia Tech, Blacksburg, Virginia; Juan Carlos Carracedo, Universidad de Las Palmas de Gran Canaria, Spain; and Brian Monteleone, Woods Hole Oceanographic Institution, Massachusetts.
Reference:
Charlotte L. DeVitre, Esteban Gazel, Ricardo S. Ramalho, Swetha Venugopal, Matthew Steele-MacInnis, Junlin Hua, Chelsea M. Allison, Lowell R. Moore, Juan Carlos Carracedo, Brian Monteleone. Oceanic intraplate explosive eruptions fed directly from the mantle. Proceedings of the National Academy of Sciences, 2023; 120 (33) DOI: 10.1073/pnas.2302093120
Note: The above post is reprinted from materials provided by Cornell University. Original written by Blaine Friedlander, courtesy of the Cornell Chronicle.
Close up image on one wall showing numerous depressions of hadrosaur footprints. The ice ax in the lower left of the frame is approximately 3 feet long, for scale. Photo by Patrick Druckenmiller
University of Alaska Fairbanks scientists have discovered and documented the largest known single dinosaur track site in Alaska. The site, located in Denali National Park and Preserve, has been dubbed “The Coliseum” by researchers.
The Coliseum is the size of one-and-a-half football fields and contains layer upon layer of prints preserved in rock. The site is a record of multiple species of dinosaurs over many generations that thrived in what is now Interior Alaska nearly 70 million years ago. The scientists describe the site in a paper recently published in the journal Historical Biology.
“It’s not just one level of rock with tracks on it,” said Dustin Stewart, the paper’s lead author and a former UAF graduate student who published the paper as part of his master’s thesis. “It is a sequence through time. Up until now, Denali had other track sites that are known, but nothing of this magnitude.”
At first glance, the site is unremarkable in the context of the park’s vast landscape: just a layered, rocky outcrop rising 20-some stories from its base.
“When our colleagues first visited the site, they saw a dinosaur trackway at the base of this massive cliff,” said Pat Druckenmiller, senior author of the paper and director of the University of Alaska Museum of the North. “When we first went out there, we didn’t see much either.”
Stewart recalled being initially underwhelmed when he approached the site at the end of a seven-hour hike. Then dusk approached, and the team took another look.
“When the sun angles itself perfectly with those beds, they just blow up,” he said. “Immediately all of us were just flabbergasted, and then Pat said, ‘Get your camera.’ We were freaking out.”
In the Late Cretaceous Period, the cliffs that make up The Coliseum were sediment on flat ground near what was likely a watering hole on a large flood plain. As Earth’s tectonic plates collided and buckled to form the Alaska Range, the formerly flat ground folded and tilted vertically, exposing the cliffs covered with tracks.
The tracks are a mix of hardened impressions in the ancient mud and casts of tracks created when sediment filled the tracks and then hardened.
“They are beautiful,” Druckenmiller said. “You can see the shape of the toes and the texture of the skin.”
In addition to the dinosaur tracks, the research team found fossilized plants, pollen grains, and evidence of freshwater shellfish and invertebrates.
“All these little clues put together what the environment looked like as a whole,” Stewart said.
The area was part of a large river system, he said, with ponds and lakes nearby. The climate in the area was warmer than today, more like the Pacific Northwest. There were coniferous and deciduous trees and an understory of ferns and horsetails.
Based on the tracks, a variety of juvenile to adult dinosaurs frequented the area over thousands of years. Most common were large plant-eating duck-billed and horned dinosaurs. The team also documented rarer carnivores, including raptors and tyrannosaurs, as well as small wading birds.
Every year, thousands of people visit Denali National Park and Preserve to experience the stunning natural landscape and environment, Druckenmiller said. “It’s amazing to know that around 70 million years ago, Denali was equally impressive for its flora and fauna.
“It was forested and it was teeming with dinosaurs,” he said. “There was a tyrannosaur running around Denali that was many times the size of the biggest brown bear there today. There were raptors. There were flying reptiles. There were birds. It was an amazing ecosystem.”
Preserving fossil sites like The Coliseum is an important part of the National Park Service’s mission, said Denny Capps, the park’s geologist.
“On one hand, we must protect world-class fossil sites like The Coliseum from disturbance and theft,” he said. “On the other hand, we encourage visitors to explore for fossils in their geologic context to better grasp the evolution of landscapes and ecosystems through time, while leaving them undisturbed for others to appreciate.”
Druckenmiller plans to continue collaborating with the National Park Service to study The Coliseum and other track sites.
“Our track research in the park complements our work on dinosaur bones we collect in northern Alaska, along the Colville River,” Druckenmiller said. “Denali National Park and Preserve is a world-class area for dinosaur tracks. There is a lifetime of exploring left to do, and I can only wonder what other surprises await.”
Reference:
Dustin G. Stewart, Patrick S. Druckenmiller, Gregory M. Erickson, Jeff A. Benowitz, Denny M. Capps, Cassandra L. Knight, Kevin C. May, Paul J. McCarthy. Vertebrate ichnology and palaeoenvironmental associations of Alaska’s largest known dinosaur tracksite in the Cretaceous Cantwell Formation (Maastrichtian) of Denali National Park and Preserve. Historical Biology, 2023; 1 DOI: 10.1080/08912963.2023.2221267
