Chemical Formula: MgSiO3 Locality: Common worldwide. Name Origin: From the Greek enstates – “opponent.”
Enstatite is the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, (Mg,Fe)SiO3, has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20).
Physical Properties
Cleavage: {110} Distinct, {010} Distinct Color: White, Yellowish green, Brown, Greenish white, Gray. Density: 3.1 – 3.3, Average = 3.2 Diaphaneity: Translucent to opaque Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Hardness: 5.5 – Knife Blade Luminescence: Non-fluorescent. Luster: Vitreous – Pearly Streak: gray
Photos :
Enstatite Kilosa District, Morogoro Region, Tanzania Thumbnail, 2.8 x 1.5 x 1.2 cm “Courtesy of Rob Lavinsky, The Arkenstone, www.iRocks.com”Enstatite Thumbnail, 8.40 x 5.11 mm ; 1.13 carats “Courtesy of Rob Lavinsky, The Arkenstone, www.iRocks.com”
This scanning electron microscope image of a polished thin section of a meteorite from Mars shows tunnels and curved microtunnels. Credit: NASA
A team of scientists at NASA’s Johnson Space Center in Houston and the Jet Propulsion Laboratory in Pasadena, Calif., has found evidence of past water movement throughout a Martian meteorite, reviving debate in the scientific community over life on Mars.
In 1996, a group of scientists at Johnson led by David McKay, Everett Gibson and Kathie Thomas-Keprta published an article in Science announcing the discovery of biogenic evidence in the Allan Hills 84001(ALH84001) meteorite. In this new study, Gibson and his colleagues focused on structures deep within a 30-pound (13.7-kilogram) Martian meteorite known as Yamato 000593 (Y000593). The team reports that newly discovered different structures and compositional features within the larger Yamato meteorite suggest biological processes might have been at work on Mars hundreds of millions of years ago.
The team’s findings have been published in the February issue of the journal Astrobiology. The lead author, Lauren White, is based at the Jet Propulsion Laboratory. Co-authors are Gibson, Thomas-Keprta, Simon Clemett and McKay, all based at Johnson. McKay, who led the team that studied the ALH84001 meteorite, died a year ago.
“While robotic missions to Mars continue to shed light on the planet’s history, the only samples from Mars available for study on Earth are Martian meteorites,” said White. “On Earth, we can utilize multiple analytical techniques to take a more in-depth look into meteorites and shed light on the history of Mars. These samples offer clues to the past habitability of this planet. As more Martian meteorites are discovered, continued research focusing on these samples collectively will offer deeper insight into attributes which are indigenous to ancient Mars. Furthermore, as these meteorite studies are compared to present day robotic observations on Mars, the mysteries of the planet’s seemingly wetter past will be revealed.”
Analyses found that the rock was formed about 1.3 billion years ago from a lava flow on Mars. Around 12 million years ago, an impact occurred on Mars which ejected the meteorite from the surface of Mars. The meteorite traveled through space until it fell in Antarctica about 50,000 years ago.
The rock was found on the Yamato Glacier in Antarctica by the Japanese Antarctic Research Expedition in 2000. The meteorite was classified as a nakhlite, a subgroup of Martian meteorites. Martian meteoritic material is distinguished from other meteorites and materials from Earth and the moon by the composition of the oxygen atoms within the silicate minerals and trapped Martian atmospheric gases.
The team found two distinctive sets of features associated with Martian-derived clay. They found tunnel and micro-tunnel structures that thread their way throughout Yamato 000593. The observed micro-tunnels display curved, undulating shapes consistent with bio-alteration textures observed in terrestrial basaltic glasses, previously reported by researchers who study interactions of bacteria with basaltic materials on Earth.
The second set of features consists of nanometer- to-micrometer-sized spherules that are sandwiched between layers within the rock and are distinct from carbonate and the underlying silicate layer. Similar spherical features have been previously seen in the Martian meteorite Nakhla that fell in 1911 in Egypt. Composition measurements of the Y000593 spherules show that they are significantly enriched in carbon compared to the nearby surrounding iddingsite layers.
A striking observation is that these two sets of features in Y000593, recovered from Antarctica after about 50,000 years residence time, are similar to features found in Nakhla, an observed fall collected shortly after landing.
The authors note that they cannot exclude the possibility that the carbon-rich regions in both sets of features may be the product of abiotic mechanisms: however, textural and compositional similarities to features in terrestrial samples, which have been interpreted as biogenic, imply the intriguing possibility that the Martian features were formed by biotic activity.
“The unique features displayed within the Martian meteorite Yamato 000593 are evidence of aqueous alterations as seen in the clay minerals and the presence of carbonaceous matter associated with the clay phases which show that Mars has been a very active body in its past,” said Gibson. “The planet is revealing the presence of an active water reservoir that may also have a significant carbon component.
“The nature and distribution of Martian carbon is one of the major goals of the Mars Exploration Program. Since we have found indigenous carbon in several Mars meteorites, we cannot overstate the importance of having Martian samples available to study in earth-based laboratories. Furthermore, the small sizes of the carbonaceous features within the Yamato 000593 meteorite present major challenges to any analyses attempted by remote techniques on Mars,” Gibson added.
“This is no smoking gun,” said JPL’s White. “We can never eliminate the possibility of contamination in any meteorite. But these features are nonetheless interesting and show that further studies of these meteorites should continue.”
Note : The above story is based on materials provided by NASA/Jet Propulsion Laboratory
Chemical Formula: Cu3AsS4 Locality: Butte, Montana, USA. Name Origin: From the Greek enarges – “obvious.”
Enargite is a copper arsenic sulfosalt mineral with formula: Cu3AsS4. It takes its name from the Greek word enarge, “distinct.” Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates. It has a hardness of 3 and a specific gravity of 4.45.
A plankton bloom in the Capricorn Channel off the Queensland coast of Australia – Trichodesmium a photosynthetic cyanobacteria and nitrogen fixer. Credit: Astronaut photograph ISS005-E-21572 taken December 3, 2002, provided by NASA’s Earth Sciences and Image Analysis
University of Bristol researchers study genomic data of cyanobacteria to shed new light on how complex life evolved on Earth
Plankton in the Earth’s oceans received a huge boost when microorganisms capable of creating soluble nitrogen ‘fertilizer’ directly from the atmosphere diversified and spread throughout the open ocean. This event occurred at around 800 million years ago and it changed forever how carbon was cycled in the ocean.
It has long been believed that the appearance of complex multicellular life towards the end of the Precambrian (the geologic interval lasting up until 541 million years ago) was facilitated by an increase in oxygen, as revealed in the geological record. However, it has remained a mystery as to why oxygen increased at this particular time and what its relationship was to ‘Snowball Earth’ – the most extreme climatic changes the Earth has ever experienced – which were also taking place around then.
This new study shows that it could in fact be what was happening to nitrogen at this time that helps solve the mystery.
The researchers, led by Dr Patricia Sanchez-Baracaldo of the University of Bristol, used genomic data to reconstruct the relationships between those cyanobacteria whose photosynthesis in the open ocean provided oxygen in quantities sufficient to be fundamental in the development of complex life on Earth.
Some of these cyanobacteria were also able to transform atmospheric nitrogen into bioavailable nitrogen in sufficient quantities to contribute to the marine nitrogen cycle, delivering ‘nitrogen fertiliser’ to the ecosystem. Using molecular techniques, the team were able to date when these species first appeared in the geological record to around 800 million years ago.
Dr Sanchez-Baracaldo, a Royal Society Dorothy Hodgkin Research Fellow in Bristol’s Schools of Biological and Geographical Sciences said: “We have known that oxygenic photosynthesis – the process by which microbes fix carbon dioxide into carbohydrates, splitting water and releasing oxygen as a by-product – first evolved in freshwater habitats more than 2.3 billion years ago. But it wasn’t until around 800 million years ago that these oxygenating cyanobacteria were able to colonise the vast oceans (two thirds of our planet) and be fertilised by enough bioavailable nitrogen to then produce oxygen – and carbohydrate food – at levels high enough to facilitate the next ‘great leap forward’ towards complex life.
“Our study suggests that it may have been the fixing of this nitrogen ‘fertiliser’ in the oceans at this time that played a pivotal role in this key moment in the evolution of life on Earth.”
Co-author, Professor Andy Ridgwell said: “The timing of the spread in nitrogen fixers in the open ocean occurs just prior to global glaciations and the appearance of animals. Although further work is required, these evolutionary changes may well have been related to, and perhaps provided a trigger for, the occurrence of extreme glaciation around this time as carbon was now being buried in the sediments on a much larger scale.”
Dr Sanchez-Baracaldo added: “It’s very exciting to have been able to use state of the art genetic techniques to help solve an age-old mystery concerning one of the most important and pivotal moments in the evolution of life on Earth. In recent years, genomic data has been helping re-tell the story of the origins of life with increasing clarity and accuracy. It is a privilege to be contributing to our understanding of how microorganisms have contributed to make our planet habitable.”
Note : The above story is based on materials provided by University of Bristol.
Chemical Formula: CuBiS2 Locality: Czechoslovakia at Schlaggenwald, Bohemia. Name Origin: From the Greek emplektos, “interwoven.”
Physical Properties
Cleavage: {001} Perfect Color: Gray, Grayish yellow, Silver white, Tin white. Density: 6.3 – 6.5, Average = 6.4 Diaphaneity: Opaque Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Hardness: 2 – Gypsum Luminescence: Non-fluorescent. Luster: Metallic Magnetism: Nonmagnetic Streak: black
Photo :
EMPLECTITE Tannenbaum-Stollen, Antonsthal, Breitenbrunn, Erzgebirge, Saxony, Germany, Europe Size: 5.4 x 3.6 x 2.5 cm (Small Cabinet) Owner: Crystal Classics
The Furongian is the fourth and final series of the Cambrian. It lasted from ~497 to 485.4 ± 1.9 million years ago. It succeeds the still unnamed 3rd series of the Cambrian and precedes the Lower Ordovician Tremadocian stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.
Naming
The Furongian was also known as the “Series 4” of the Cambrian and replaced the older term “Upper Cambrian” and equivalent to the local term “Hunanian”. The name “Furongian” was ratified by the International Commission on Stratigraphy in 2003. Furong (芙蓉) means “lotus” in Chinese and refers to Hunan which is known as the “lotus state”.
Definition
The lower boundary is defined in the same way as the GSSP of the Paibian stage. Both begin with the first appearance of the trilobite Glyptagnostus reticulatus around ~497 million years ago. The upper boundary is the lower boundary and GSSP of the Tremadocian stage which is the first appearance of the conodont Iapetognathus fluctivagus around 485.4 ± 1.9 million years ago
Subdivisions
The following table shows the subdivisions of the Furongian series/epoch:
The base of two of three stages of the Furongian are defined as the first appearance of a trilobite. The base of the Paibian is the first appearance of Glyptagnostus reticulatus and the base of the Jiangshanian is the first appearance of Agnostotes orientalis. The still unnamed Cambrian Stage 10 might be defined as the first appearance of Lotagnostus americanus or the conodont Eoconodontus notchpeakensis.
The Furongian can be divided into a number of trilobite zones:
Series
Stage
Trilobite zone
Trilobite GSSP
Furongian
Stage 10
Saukia zone (upper part), Eurekia apopsis zone, Tangshanaspis Zone, Parakoldinioidiazone, Symphysurina zone
Lotagnostus americanus (undecided)
Jiangshanian
Ellipsocephaloides zone, Saukia zone (lower part)
Agnostotes orientalis
Paibian
? (?)
Glyptagnostus reticulatus
Cedaria
Note : The above story is based on materials provided by Wikipedia
Cambrian Series 3 is the still unnamed 3rd Series of the Cambrian. It lasted from about ~509 to ~497 million years ago and is divided into 3 stages: the unnamed Stage 5, the Drumian, and the Guzhangian. Cambrian Series 3 is preceded by also unnamed Cambrian Series 2 and succeeded by the Furongian series.
Naming
The International Commission on Stratigraphy still has to decide on the official name of the 2nd series of the Cambrian. The new name will also replace the older term “Middle Cambrian”.
Definition
The lower boundary of Series 3 has the same definition as Cambrian Stage 5. This boundary has not been formally defined yet by the ICS but a number of proposals for fossils and type sections have been made. The most promising fossil markers are the respective first appearances of either trilobite species Ovatoryctocara granulata or Oryctocephalus indicus.[3] Either species should have an age close to ~509. The Series 3-Furongian boundary has the same definition as the Paibian stage. It is defined as the first appearance of Glyptagnostus reticulatus around ~497 million years ago.
Subdivision
Cambrian Series 3 is subdivided into the following stages:
Cambrian Series 2 is the unnamed 2nd series of the Cambrian. It lies above the Terreneuvian series and below the Cambrian Series 3. Series 2 has not been formally defined by the International Commission on Stratigraphy, lacking a precise lower and upper boundary and subdivision into stages. The proposed lower boundary is the first appearance of trilobites which is estimated to be around ~521 million years ago. The upper boundary is proposed as the first appearance of either the trilobite species Oryctocephalus indicus or Ovatoryctocara granulata, currently estimated to be around ~509 million years ago.
Naming
The International Commission on Stratigraphy has not named the 2nd stage of the Cambrian yet. The new name will replace the older terms “Lower Cambrian” and “Early Cambrian”. The nomenclature used in Sibera uses the term “Yakutian” for this series.
Subdivisions
The 2nd series is currently subdivided by the ICS into two stages: Cambrian Stage 3 and Cambrian Stage 4. Both of these stages also lack formal definition. The Siberian nomenclature distinguishes three stages (lowest first): Atdabanian, Botomian and Toyonian. In general most subdivisions of this series rely on biostratigraphy of trilobite zones.
Biostratigraphy
The 2nd series of the Cambrian marks the appearance of trilobites. Correlating this event on different continents has proven difficult and resolving this is essential for the definition of the lower boundary of this series. Currently the oldest trilobite known is Lemdadella which marks the beginning of the Fallotaspis zone.
Note : The above story is based on materials provided by Wikipedia
The skeletons are remarkably complete, having being subjected to very little scavenging at death
It is one of the most astonishing fossil discoveries of recent years – a graveyard of whales found beside the Pan-American Highway in Chile.
And now scientists think they can explain how so many of the animals came to be preserved in one location more than five million years ago.
It was the result of not one but four separate mass strandings, they report in a Royal Society journal.
The evidence strongly suggests the whales all ingested toxic algae.
The dead and dying mammals were then washed into an estuary and on to flat sands where they became buried over time.
The scientists brought in a number of digital techniques to record the discoveries
It was well known that this area in Chile’s Atacama Desert preserved whale fossils.
Their bones could be seen sticking out of rock faces, and the spot acquired the name Cerro Ballena (“whale hill”) as a result.
But it was only when a cutting was made to widen the Pan-American Highway that US and Chilean researchers got an opportunity to fully study the fossil beds.
They were given just two weeks to complete their field work before the heavy plant returned to complete construction of the new road.
The team set about recording as much detail as possible, including making 3D digital models of the skeletal remains in situ and then removing bones for further study in the lab.
Identified in the beds were over 40 individual rorquals – the type of large cetacean that includes the modern blue, fin and minke whales.
Among them were other important marine predators and grazers.
“We found extinct creatures such as walrus whales – dolphins that evolved a walrus-like face. And then there were these bizarre aquatic sloths,” recalls Nicholas Pyenson, a palaeontologist at the Smithsonian’s National Museum of Natural History.
“To me, it’s amazing that in 240m of road-cut, we managed to sample all the superstars of the fossil marine-mammal world in South America in the Late Miocene. Just an incredibly dense accumulation of species,” he told BBC News.
The team immediately noticed that the skeletons were nearly all complete, and that their death poses had clear commonalities. Many had come to rest facing in the same direction and upside down, for example.
This all pointed to the creatures succumbing to the same, sudden catastrophe; only, the different fossils levels indicated it was not one event but four separate episodes spread over a period of several thousand years.
The best explanation is that these animals were all poisoned by the toxins that can be generated in some algal blooms.
Such blooms are one of the prevalent causes for repeated mass strandings seen in today’s marine animals.
The Smithsonian has produced tools to allow the public to tour and investigate Cerro Ballena
If large quantities of contaminated prey are consumed, or the algae are simply inhaled – death can be rapid.
“All the creatures we found – whether whales, seals or billfishes – fed high up in marine food webs and that would have made them very susceptible to harmful algal blooms,” said Dr Pyenson.
The researchers believe the then configuration of the coastline at Cerro Ballena in the late Miocene Epoch worked to funnel carcases into a restricted area where they were lifted on to sand flats just above high tide, perhaps by storm waves.
This would have put the bodies beyond marine scavengers. And, being a desert region, there would have been very few land creatures about to steal bones either.
A lot of the fossils at Cerro Ballena are perfect but for a few nicks inflicted by foraging crabs.
The researchers are not in a position to say for sure that harmful algal blooms were responsible for the mass strandings. There were no distinct algal cell fragments in the sediments; such a presence could have amounted to a “smoking gun”. What the team did find, however, were multiple grains encrusted in iron oxides that could hint at past algal activity.
Hundreds of fossils await unearthing and description at Cerro Ballena
“There are tiny spheres about 20 microns across – that’s exactly the right size to be dinoflagellate cysts,” said Dr Pyenson.
“They’re found in algal-like mats all around the site. We can’t say whether those were the killer algae, but they do not falsify the argument for harmful algal blooms being the cause in the way that the sedimentology falsifies tsunami being a potential cause.”
Cerro Ballena is now regarded as one of the densest fossil sites in the world – certainly for whales and other extinct marine mammals. The scientists calculate there could be hundreds of specimens in the area still waiting to be unearthed and investigated.
The University of Chile in Santiago is currently working to establish a research station to carry this into effect.
To coincide with the publication of a scholarly paper in Proceedings B of the Royal Society, the Smithsonian has put much of its digital data, including 3D scans and maps, online at cerroballena.si.edu.
Note : The above story is based on materials provided by Jonathan Amos Science correspondent, BBC News
LLNL scientist Benjamin Santer and his climbing group ascend Mt. St. Helens via the “Dogshead Route” in April 1980, about a month before its major eruption. The group was the last to reach the summit of Mt. St. Helens before its major eruption that May. New research by Santer and his colleagues shows that volcanic eruptions contribute to a recent warming “hiatus.” Credit: Image courtesy of DOE/Lawrence Livermore National Laboratory
Volcanic eruptions in the early part of the 21st century have cooled the planet, according to a study led by Lawrence Livermore National Laboratory. This cooling partly offset the warming produced by greenhouse gases.
Despite continuing increases in atmospheric levels of greenhouse gases, and in the total heat content of the ocean, global-mean temperatures at the surface of the planet and in the troposphere (the lowest portion of Earth’s atmosphere) have shown relatively little warming since 1998. This so-called ‘slow-down’ or ‘hiatus’ has received considerable scientific, political and popular attention. The volcanic contribution to the ‘slow-down’ is the subject of a new paper appearing in the Feb. 23 edition of the journal Nature Geoscience.
Volcanic eruptions inject sulfur dioxide gas into the atmosphere. If the eruptions are large enough to add sulfur dioxide to the stratosphere (the atmospheric layer above the troposphere), the gas forms tiny droplets of sulfuric acid, also known as “volcanic aerosols.” These droplets reflect some portion of the incoming sunlight back into space, cooling Earth’s surface and the lower atmosphere.
“In the last decade, the amount of volcanic aerosol in the stratosphere has increased, so more sunlight is being reflected back into space,” said Lawrence Livermore climate scientist Benjamin Santer, who serves as lead author of the study. “This has created a natural cooling of the planet and has partly offset the increase in surface and atmospheric temperatures due to human influence.”
From 2000-2012, emissions of greenhouse gases into the atmosphere have increased — as they have done since the Industrial Revolution. This human-induced change typically causes the troposphere to warm and the stratosphere to cool. In contrast, large volcanic eruptions cool the troposphere and warm the stratosphere. The researchers report that early 21st century volcanic eruptions have contributed to this recent “warming hiatus,” and that most climate models have not accurately accounted for this effect.
“The recent slow-down in observed surface and tropospheric warming is a fascinating detective story,” Santer said. “There is not a single culprit, as some scientists have claimed. Multiple factors are implicated. One is the temporary cooling effect of internal climate noise. Other factors are the external cooling influences of 21st century volcanic activity, an unusually low and long minimum in the last solar cycle, and an uptick in Chinese emissions of sulfur dioxide.
“The real scientific challenge is to obtain hard quantitative estimates of the contributions of each of these factors to the slow-down.”
The researchers performed two different statistical tests to determine whether recent volcanic eruptions have cooling effects that can be distinguished from the intrinsic variability of the climate. The team found evidence for significant correlations between volcanic aerosol observations and satellite-based estimates of lower tropospheric temperatures as well as the sunlight reflected back to space by the aerosol particles.
“This is the most comprehensive observational evaluation of the role of volcanic activity on climate in the early part of the 21st century,” said co-author Susan Solomon, the Ellen Swallow Richards professor of atmospheric chemistry and climate science at MIT. “We assess the contributions of volcanoes on temperatures in the troposphere — the lowest layer of the atmosphere — and find they’ve certainly played some role in keeping Earth cooler.”
The research is funded by the Department of Energy’s Office of Biological and Environmental Science in the Office of Science. The research involved a large, interdisciplinary team of researchers with expertise in climate modeling, satellite data, stratospheric dynamics and volcanic effects on climate, model evaluation and computer science.
Note : The above story is based on materials provided by DOE/Lawrence Livermore National Laboratory.
Jean-Bernard Caron extracting fossils from the shale. Credit: Gabriela Mangano
Yoho National Park’s 505-million-year-old Burgess Shale — home to some of the planet’s earliest animals, including a very primitive human relative — is one of the world’s most important fossil sites. Now, more than a century after its discovery, a compelling sequel has been unearthed: 42 kilometres away in Kootenay National Park, a new Burgess Shale fossil bed has been located that appears to equal the importance of the original discovery, and may one day even surpass it.
A paper published today in the scientific journal Nature Communications describes Kootenay National Park’s new ‘Marble Canyon’ fossil beds for the first time. The authors suggest that the area and its extraordinary fossils will greatly further our understanding of the sudden explosion of animal life during the Cambrian Period.
The find was made in the summer of 2012 by a team from the Royal Ontario Museum (ROM, Jean-Bernard Caron), Pomona College (Robert Gaines), the University of Toronto (Jean-Bernard Caron, Cédric Aria), the University of Saskatchewan (Gabriela Mángano) and Uppsala University (Michael Streng).
“This new discovery is an epic sequel to a research story that began at the turn of the previous century. There is no doubt in my mind that this new material will significantly increase our understanding of early animal evolution,” said Dr. Jean-Bernard Caron, Curator of Invertebrate Paleontology at the ROM, Associate Professor at the University of Toronto and the study’s lead author. “The rate at which we are finding animals — many of which are new — is astonishing, and there is a high possibility that we’ll eventually find more species here than at the original Yoho National Park site, and potentially more than from anywhere else in the world.”
In a short 15-day field season, the researchers collected thousands of specimens representing more than 50 species, several of which were new to science. Incredibly, many of the species previously known from Yoho are better preserved in Kootenay, retaining very fine, never-before-seen anatomical details that are important for understanding the shape of the animal ‘family tree.’
The new site parallels Yoho in its spectacular richness of arthropods, a group that today represents more than 80% of all living animals, including insects, spiders and lobsters.
Another curious similarity between Marble Canyon and the original discovery is that both sites would still be buried today if not for the dedicated exploratory work of scientists.
In 1909, world-renowned paleontologist Charles Walcott spent a summer exploring Yoho National Park’s mountainous topography in search of hidden treasures, only to stumble upon what he would later name the Burgess Shale on the final day of his field season on August 29. Similarly, in 2012, a ROM field expedition led by Caron spent part of their summer in search of the next big paleontological discovery.
“We were already aware of the presence of some Burgess Shale fossils in Kootenay National Park,” said Dr. Robert Gaines, a geologist from Pomona College, who along with Caron and colleagues had spent August 2008 at a much smaller fossil deposit in the park located near Stanley Glacier. “We had a hunch that if we followed the formation along the mountain topography into new areas with the right rock types, maybe, just maybe, we would get lucky — though we never in our wildest dreams thought we’d track down a motherload like this.”
Just like Walcott a century before, a hunch led Caron and his team to a talus slope high in the Canadian Rockies. Along this rocky slope they found a startling variety of fossils that immediately caught their attention. The researchers then pinpointed the source of the fossils to higher up on the slopes and began to excavate the fossils layer-by-layer.
“It didn’t take us very long at all to realize that we had dug up something special,” added Gaines. “To me, the Burgess Shale is a grand tale in every way imaginable, and we are incredibly proud to be part of this new chapter and to keep the story alive and thriving in everyone’s imagination.”
“We are very excited to go back to the field this summer,” said Caron. “One of our main goals is to discover more new species.”
The new fossil site is protected by Parks Canada, with the exact location remaining confidential to protect its integrity. Future visitor opportunities have not been ruled out.
Burgess Shale facts:
• This new finding is the latest in a recent string of Burgess Shale discoveries, including confirmation that Pikaia, found only in Yoho National Park, is the most primitive known vertebrate and therefore the ancestor of all descendant vertebrates, including humans.
• In over 100 years of research, approximately 200 animal species have been identified at the original Burgess Shale discovery in Yoho National Park in over 600 field days. In just 15 days of field collecting, 50 animal species have already been unearthed at the new Kootenay National Park site.
• Some species found at the new Kootenay site are also found in China’s famous Chengjiang fossil beds, which are 10 million years older. This contributes to the pool of evidence suggesting that the local and worldwide distribution of Cambrian animals, as well as their longevity, might have been underestimated.
• The original Burgess Shale site in Yoho National Park was recognized in 1980 as one of Canada’s first UNESCO World Heritage Sites. Now protected under the larger Rocky Mountain Parks UNESCO World Heritage Site, the Burgess Shale attracts thousands of visitors to Yoho National Park each year for guided hikes to the restricted fossil beds from July to September. Both Parks Canada and the Burgess Shale Geoscience Foundation lead hikes to the fossils.
• All the Burgess Shale fossil specimens in the Marble Canyon area of were collected under a Parks Canada Research and Collection permit and are held in trust for Parks Canada at the Royal Ontario Museum in Toronto.
Note : The above story is based on materials provided by Uppsala Universitet. The original article was written by Linda Koffmar.
The fossil remains of the Spinosaurid sauropod (carnivorous dinosaur). Credit: Image courtesy of ResearchSEA
A team of palaeontology researchers from the Department of Geology, Faculty of Science, University of Malaya and Japanese universities (Waseda University and Kumamoto University) has found dinosaur fossil teeth in the rural interiors of Pahang — the first known discovery of dinosaur remains in Malaysia.
“We have started our collaboration and carried out field expeditions to search for potential dinosaur deposits in Malaysia since Sep. 2012. Recently, we have successfully confirmed the presence of dinosaur remains (fossilised teeth) in Pahang,” said lead researcher, Dr. Masatoshi Sone.
“Acting as a team leader, and one of the collaborators, Professor Ren Hirayama from Waseda University (Tokyo), a specialist in reptile palaeontology, identified that one of the teeth, Sample UM10575, belongs to a spinosaurid dinosaur (known as a carnivorous “fish-eating” dinosaur),” he added.
UM10575 is about 23mm long and 10mm wide. It develops fairly distinct carinae (front and rear edges) with serrations, typical to a tooth of a theropod (carnivorous dinosaur). Well-marked coarse ridges are developed on the surface of the tooth, and the surface bears micro-ornament (very fine sculptures); these characterise a spinosaurid tooth.
The new fossils were found from sedimentary rock strata of late Mesozoic age, most likely Cretaceous (ca. 145-75 million years ago). In the interior of Peninsular Malaysia, Jurassic¬-Cretaceous sediments are known to be widely distributed, so that the team researchers have targeted a potential dinosaur deposit there since.
It is expected that large deposits of dinosaur fossils still remain in Malaysia. We currently continue further research and hope to conduct more extensive field investigations that may disclose more significant finds.
Alongside making the public announcement of this discovery, it is urgent to take measures for the protection and conservation of the present fossil site (and to make it accessible only to the qualified researchers). Since the site is in the open area, it is concerned that, once the public is aware, some destruction due to lawless excavations by private fossil collectors and/or robbers may happen, as has happened, for example, in Thailand, Laos, and Mongolia.
It is also hoped that the current discovery can lead to development of palaeontology study in the country and to eventually establish a Malaysian dinosaur museum in a near future.
Note :The above story is based on materials provided by ResearchSEA.
With global greenhouse gas emissions continuing to increase proposals to limit the effects of climate change through the large-scale manipulation of Earth system are increasingly being discussed. Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel have now studied with computer simulations the long-term global consequences of several “climate engineering” methods. They show that all the proposed methods would either be unable to significantly reduce global warming if CO2 emissions remain high, or they could not be stopped without causing dangerous climate disruption.
The study is published in the journal Nature Communications.
Despite international agreements on climate protection and political declarations of intent, global greenhouse gas emissions have not decreased. On the contrary, they continue to increase. With a growing world population and significant industrialization in emerging markets such as India and China the emission trend reversal necessary to limit global warming seems to be unlikely. Therefore, large-scale methods to artificially slow down global warming are increasingly being discussed. They include proposals to fertilize the oceans, so that stimulated plankton can remove carbon dioxide (CO2) from the atmosphere, or to reduce the Sun’s incoming radiation with atmospheric aerosols or mirrors in space, so as to reduce climate warming. All of these approaches can be classified as “climate engineering.” “However, the long-term consequences and side effects of these methods have not been adequately studied,” says Dr. David Keller from the GEOMAR Helmholtz Centre for Ocean Research Kiel. Together with colleagues the expert in earth system modelling has compared several Climate Engineering methods using a computer model.
“The problem with previous research was that in most cases the methods were studied with different models using different assumptions and different sets of earth system components, making it difficult to compare the effects and side effects of different methods,” Dr. Keller says. He adds: “We wanted to simulate different climate engineering methods using the same basic assumptions and Earth system model.” For their study, the researchers chose five well-known climate engineering approaches: The reduction of incoming solar radiation, the afforestation of large desert areas in North Africa and Australia, and three different techniques aimed at increasing ocean carbon uptake. In parallel, the scientists also simulated future changes in Earth system without climate engineering, based on the high-CO2 emission scenario used by the UN IPCC.
Even under ideal conditions assumed in the simulations, the potential benefits of the various climate engineering methods were limited. Only a continuous reduction of solar radiation could prevent Earth from warming significantly. The afforestation of the Sahara and the Australian outback, however even caused some additional global warming: “The forests removed carbon dioxide from the atmosphere, but at the same time Earth’s surface became darker and could store more heat,” Dr. Keller explains of this phenomenon. All of the other techniques showed significant side effects, too. For example, the fertilization of the oceans allowed plankton to remove CO2 from the atmosphere, but also changed the size of ocean oxygen minimum zones.
Another important question for the researchers: What happens if climate engineering is stopped after a few decades for technical or political reasons? “For several methods we saw a rapid change in the simulated climate when climate engineering ended,” says Dr. Keller. For example, if after 50 years the sun’s rays were no longer partially blocked, Earth warmed by several degrees within a few decades. “This change would be much faster than the current rate of climate change, with potentially even more catastrophic consequences,” says Keller.
The study is the basis for further research in the priority program “Climate Engineering: Risks, Challenges, Opportunities?” of the German Research Foundation (DFG), coordinated by co-author Prof. Dr. Andreas Oschlies from GEOMAR. “In addition to natural science studies, we also want to learn more about the potential social, political, legal and ethical aspects of proposed climate engineering methods. For one thing, this study clearly shows that there would always be many losers in addition to possible winners. Some side effects would even affect future generations. A decision for or against climate engineering thus would have to be considered carefully and be fully legitimized, and must thus be based on a much better understanding of possible effects, uncertainties and risks than we have today,” says Professor Oschlies.
Note : The above story is based on materials provided by Helmholtz Centre for Ocean Research Kiel (GEOMAR).
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.
Etymology
The word “Emerald” is derived (via Old French: Esmeraude and Middle English: Emeraude), from Vulgar Latin: Esmaralda/Esmaraldus, a variant of Latin Smaragdus, which originated in Greek: σμάραγδος (smaragdos; “green gem”).
Properties determining value
Emeralds, like all colored gemstones, are graded using four basic parameters–the four Cs of Connoisseurship: Color, Cut, Clarity and Carat weight. Before the 20th century, jewelers used the term water, as in “a gem of the finest water”, to express the combination of two qualities: color and clarity. Normally, in the grading of colored gemstones, color is by far the most important criterion. However, in the grading of emeralds, clarity is considered a close second. Both are necessary conditions. A fine emerald must possess not only a pure verdant green hue as described below, but also a high degree of transparency to be considered a top gem.
In the 1960s, the American jewelry industry changed the definition of “emerald” to include the green vanadium-bearing beryl as emerald. As a result, vanadium emeralds purchased as emeralds in the United States are not recognized as such in the UK and Europe. In America, the distinction between traditional emeralds and the new vanadium kind is often reflected in the use of terms such as “Colombian Emerald”.
Emerald localities
Emeralds in antiquity have been mined in Egypt since 1500 BCE, and India, and Austria since at least the 14th century CE.
Colombia is by far the world’s largest producer of emeralds, constituting 50–95% of the world production, with the number depending on the year, source and grade. Emerald production in Colombia has increased drastically in the last decade, increasing by 78% from 2000 to 2010. The three main emerald mining areas in Colombia are Muzo, Coscuez, and Chivor. Rare ‘trapiche’ emeralds are found in Colombia, distinguished by a six-pointed radial pattern made of ray-like spokes of dark carbon impurities.
Zambia is the world’s second biggest producer, with its Kafubu River area deposits (Kagem Mines) about 45 km (28 mi) southwest of Kitwe responsible for 20% of the world’s production of gem quality stones in 2004. In the first half of 2011 the Kagem mines produced 3.74 tons of emeralds.
Emeralds are found all over the world in countries such as Afghanistan, Australia, Austria, Brazil, Bulgaria, Cambodia, Canada, China, Egypt, Ethiopia, France, Germany, India, Italy, Kazakhstan, Madagascar, Mozambique, Namibia, Nigeria, Norway, Pakistan, Russia, Somalia, South Africa, Spain, Switzerland, Tanzania, United States, Zambia, and Zimbabwe. In the US, emeralds have been found in Connecticut, Montana, Nevada, North Carolina, and South Carolina. In 1997 emeralds were discovered in the Yukon.
Water-ice clouds, polar ice and other geographic features can be seen in this full-disk image of Mars from 2011. NASA’s Mars Curiosity Rover touched down on the planet on August 6, 2012.
(CNN) — The presence of water on Mars is often talked about in the past tense — as in, billions of years in the past. But researchers have found clues that water could be flowing in the present, at least during warm seasons.
Researchers at Georgia Institute of Technology are looking at dark features on Martian slopes that are finger-shaped. They appear and disappear seasonally.
These flows represent the best suggestion we know of that Mars has water right now, scientists say. The study is published in the journal Geophysical Research Letters.
In 2011, Lujendra Ojha and his colleagues announced the evidence for possible saltwater flows on Mars. They published a study in the journal Science based on data from the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter.
As an undergraduate at the University of Arizona, Tucson, Ojha was the lucky one to spot irregular features in a Martian crater he was studying. He had no idea what they were. Researchers spent months figuring it out, and determined that the finger-like shapes could be briny water.
How an undergrad spotted possible water on Mars
“In HiRISE images, we see them forming, elongating and then fading over time,” Ojha said Monday. “That’s why they’re called seasonal — they form and flow when the temperature is right.”
Since that study, Ojha has enrolled in graduate school at Georgia Institute of Technology, and continued studying the phenomena. He and Georgia Tech assistant professor James Wray looked more deeply at 13 sites with confirmed recurring slope features.
This time they found chemical evidence supporting their earlier findings that water flows may appear and disappear on Mars with the seasons.
In most cases, the possible water features appear to last for the equivalent of about two Earth months, Ojha said.
The researchers used the orbiter’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument to see if they could find more clues of water. CRISM looks for chemical signatures based on the fact that different substances absorb light at distinct wavelengths.
Wavelengths can reveal a lot about what things are made of, Ojha said.
Mystery rock spotted on Mars
Ojha and colleagues did not find direct evidence of water using the spectrometer method. Instead, they found light absorption features consistent with “something iron in nature” at the flows. The light absorption varied with season, however. The absorption bands are stronger when the features are forming and growing, and weaker when they fade away.
“Something in these areas is actually causing the spectroscopic signature to fluctuate as well,” Ojha said.
Water could explain these variations, Ojha said. Water in the seasonal flow would wash away small-sized grains — dust — and leave bigger grains. When water is not present, the bigger grains would remain, accounting for the changes in light absorption that researchers observed over time.
Grain sizes could vary without water, though. The Martian atmosphere could also be responsible for some variation in the spectrometer data, because one season is dustier than another, but Ojha thinks there is something else going on.
If there is water on Mars, it would be near to the surface and salty. Specifically, the flows may host an iron-containing mineral called ferric sulfate, a substance known to exist on Mars. Ferric sulfate would bring the melting point of ice down to a lower temperature, Ojha said.
More research needs to be done to confirm this idea, obviously, but if there is briny water on Mars, could we drink it?
No life on Earth could survive in water saturated with ferric sulfate, Wray said in an e-mail.
“But if there’s enough water initially to form a dilute solution, maybe it would be OK,” he said. “Personally I wouldn’t want to risk it!”
Note : The above story is based on materials provided by Elizabeth Landau, CNN
Volcanoes spewing Sun-reflecting particles into the atmosphere have partly offset the effects of Man’s carbon emissions over a 15-year period that has become a global-warming battleground, researchers said Sunday.
A so-called hiatus in warming since 1998 has pitched climate sceptics against mainstream scientists.
While temperatures have risen relentlessly—13 of the l4 warmest years on record occurred since the start of the century—they tracked far below the increase in man-made greenhouse gases.
This gap between the expected and actual temperatures has been cited by sceptics as proof that human-induced global warming is either a green scare or bad science.
But a study in the journal Nature Geoscience said volcanic eruptions helped explain the apparent warming slowdown.
Researchers using satellite data found a link between surface temperatures and the impact from nearly 20 volcanic eruptions since 2000.
Sulphuric droplets disgorged by the volcanoes reflected sunlight and slightly cool the lower atmosphere, they said.
The effect of these “aerosols” accounted for as much as 15 percent of the gap between expected and measured temperatures between 1998 and 2012, according to the team’s figures.
“The ‘warming hiatus’ since 1998 has a number of different causes,” study co-author Ben Santer of the Lawrence Livermore National Laboratory in California told AFP by email.
“The cooling caused by early 21st century volcanic eruptions is one of the causes.”
Other explanations for the “hiatus” have been a bigger-than-expected takeup of atmospheric heat by the ocean, or a decline in solar activity.
Blockbuster eruptions, notably that of Mount Pinatubo in the Philippines in 1991, were known to have discernible cooling effects on Earth’s surface.
But volcanoes have not featured in the “hiatus” debate mainly because there had been no major eruptions since the mooted pause began in 1998, only smaller ones whose impact is harder to measure.
– Better models needed –
This is a gap, as it left computer models of climate change incomplete, the new study suggested.
“Better observations of eruption-specific properties of volcanic aerosols are needed, as well as improved representation of these… in climate model simulations,” it said.
Global warming sceptics have pointed to the “hiatus” as proof of flaws in models used to predict warming and thus play a key role in driving policies to tackle climate change.
They contend that these models exaggerate the heat-trapping effect from carbon dioxide (CO2) emitted by fossil fuel burning.
Santer said the new findings “do not support” such an argument.
“We’ve been lucky that a natural cooling influence (an uptick in 21st century volcanic activity) has partly counteracted human-caused warming,” he said.
“We do not know how volcanic activity will evolve over the coming decades, and thus we do not know how long our luck will continue.”
Experts generally agree that Earth is on track for greatly exceeding the maximum two degrees Celsius (3.6 degrees Fahrenheit) of warming targeted in UN climate negotiations.
Last year the level of carbon dioxide (CO2) in the atmosphere crossed a threshold of 400 parts per million (ppm)—a level never experienced by humans.
CO2 concentrations are rising at two or three ppm per year, driven especially by the burning of coal in emerging economies.
Commenting on the study, Piers Forster, a professor of climate change at the University of Leeds, said it confirmed that volcanoes contributed to the slowdown, but could not be the only cause.
“Volcanoes give us only a temporary respite from the relentless warming pressure of continued increases in CO2,” he added.
Chemical Formula: Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH) Locality: Island of Elba, Italy. Name Origin: Named for the locality.
Elbaite, a sodium, lithium, aluminium boro-silicate, is a mineral species belonging to the six member ring cyclosilicate tourmaline group, with the following general composituion: Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
Elbaite forms three series, with dravite, with fluor-liddicoatite, and with schorl. Due to these series, specimens with the ideal end-member formula are not found occurring naturally.
As a gemstone, elbaite is a desirable member of the tourmaline group because of the variety and depth of its colours and quality of the crystals. Originally discovered on the island of Elba, Italy in 1913, it has since been found in many parts of the world. In 1994, a major locality was discovered in Canada, at O’Grady Lakes in the Yukon.
Elbaite forms in igneous and metamorphic rocks and veins in association with lepidolite, microcline, and spodumene in granite pegmatites; with andalusite and biotite in schist; and with molybdenite and cassiterite in massive hydrothermal replacement deposits.
Physical Properties
Cleavage: {1011} Indistinct Color: Blue, Colorless, Green, Yellow, White. Density: 2.9 – 3.2, Average = 3.05 Diaphaneity: Transparent to translucent to opaque Fracture: Sub Conchoidal – Fractures developed in brittle materials characterized by semi-curving surfaces. Hardness: 7.5 – Garnet Luminescence: Fluorescent, Short UV=weak blue white to blue. Luster: Vitreous (Glassy) Streak: white
The Terreneuvian is the lowermost and oldest Series of the Cambrian geological System.Its base is defined by the first appearance datum of the trace fossil Treptichnus pedum around 541.0 ± 1.0 million years ago. Its top is defined as the first appearance of trilobites in the stratigraphic record around ~521 million years ago. This series was formally ratified by the International Commission on Stratigraphy in 2012.
The Fortunian Stage and presently unnamed Cambrian Stage 2 are the Stages within this Series. The Terreneuvian corresponds to the pre-trilobitic Cambrian.
The name Terreneuvian is derived from Terre Nueve, a French name for the island of Newfoundland, Canada, where many rocks of this age are found, including the type section.
Type locality
The type locality (GSSP) of the Terreneuvian is in Fortune Head, at the northern edge of the Burin Peninsula, Newfoundland, Canada (47.0762°N 55.8310°W). The outcrops show a carbonate-siliciclastic succession which is mapped as the Chapel Island Formation. The formation is divided into the following members that are composed of peritidal sandstones and shales (Member 1), muddy deltaic and shelf sandstones and mudstones (Member 2A), laminated siltstones (Member 2B and 3) and mudstones and limestones of the inner shelf (Member 4). The Precambrian-Cambrian boundary lies 2.4 m above the base of the second member, which is the lowest occurrence of Treptichnus pedum. The traces can be seen on the lower surface of the sandstone layers. The first calcareous shelled skeletal fossils (Ladatheca cylindrica) are 400 m above the boundary. The first trilobites appear 1400 m above the boundary, which corresponds to the beginning of the Branchian Series.
Note : The above story is based on materials provided by Wikipedia
Chemical Formula: Na2ZrSi6O15 · 3H2O Locality: Narsarsuk in the Julianehaab district, southern Greenland. Name Origin: From the Greek “ELPIS” = hope, in allusion to the hope of finding another mineral in the layer
Elpidite is in the long list of unusual mineral that come from agpaitic pegmatite rocks. Agpaitic pegmatite intrusions are unusual igneous rocks that are high in alkaline metals (such as sodium) and poor in silica. These intrusions also contain a large number of unusual elements such as zirconium. Elpidite was first discovered at Narsarsuk, Greenland, from where the first specimens were described in 1932.
Physical Properties
Color: Brown, Colorless, Yellow brown, White, Light red. Density: 2.54 Diaphaneity: Transparent to translucent Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Habit: Fibrous – Crystals made up of fibers. Hardness: 7 – Quartz Luminescence: Fluorescent, Short UV=yellow-green, Long UV=yellow-green. Luster: Vitreous (Glassy) Streak: white
This is a timeline of the history of our planet places the formation of the Jack Hills zircon and a “cool early Earth” at 4.4 billion years. Credit: Andree Valley
With the help of a tiny fragment of zircon extracted from a remote rock outcrop in Australia, the picture of how our planet became habitable to life about 4.4 billion years ago is coming into sharper focus.
Writing today (Feb. 23, 2014) in the journal Nature Geoscience, an international team of researchers led by University of Wisconsin-Madison geoscience Professor John Valley reveals data that confirm the Earth’s crust first formed at least 4.4 billion years ago, just 160 million years after the formation of our solar system. The work shows, Valley says, that the time when our planet was a fiery ball covered in a magma ocean came earlier.
“This confirms our view of how the Earth cooled and became habitable,” says Valley, a geochemist whose studies of zircons, the oldest known terrestrial materials, have helped portray how the Earth’s crust formed during the first geologic eon of the planet. “This may also help us understand how other habitable planets would form.”
The new study confirms that zircon crystals from Western Australia’s Jack Hills region crystallized 4.4 billion years ago, building on earlier studies that used lead isotopes to date the Australian zircons and identify them as the oldest bits of the Earth’s crust. The microscopic zircon crystal used by Valley and his group in the current study is now confirmed to be the oldest known material of any kind formed on Earth.
The study, according to Valley, strengthens the theory of a “cool early Earth,” where temperatures were low enough for liquid water, oceans and a hydrosphere not long after the planet’s crust congealed from a sea of molten rock. “The study reinforces our conclusion that Earth had a hydrosphere before 4.3 billion years ago,” and possibly life not long after, says Valley.
The study was conducted using a new technique called atom-probe tomography that, in conjunction with secondary ion mass spectrometry, permitted the scientists to accurately establish the age and thermal history of the zircon by determining the mass of individual atoms of lead in the sample. Instead of being randomly distributed in the sample, as predicted, lead atoms in the zircon were clumped together, like “raisins in a pudding,” notes Valley.
The clusters of lead atoms formed 1 billion years after crystallization of the zircon, by which time the radioactive decay of uranium had formed the lead atoms that then diffused into clusters during reheating. “The zircon formed 4.4 billion years ago, and at 3.4 billion years, all the lead that existed at that time was concentrated in these hotspots,” Valley says. “This allows us to read a new page of the thermal history recorded by these tiny zircon time capsules.”
The formation, isotope ratio and size of the clumps — less than 50 atoms in diameter — become, in effect, a clock, says Valley, and verify that existing geochronology methods provide reliable and accurate estimates of the sample’s age. In addition, Valley and his group measured oxygen isotope ratios, which give evidence of early homogenization and later cooling of the Earth.
“The Earth was assembled from a lot of heterogeneous material from the solar system,” Valley explains, noting that the early Earth experienced intense bombardment by meteors, including a collision with a Mars-sized object about 4.5 billion years ago “that formed our moon, and melted and homogenized the Earth. Our samples formed after the magma oceans cooled and prove that these events were very early.”
Note : The above story is based on materials provided by University of Wisconsin-Madison. The original article was written by Terry Devitt.
