Great ape dietary specialization allowed spread in Eurasia, and also lead to extinction
Newly analyzed tooth samples from the great apes of the Miocene indicate that the same dietary specialization that allowed the apes to move from Africa to Eurasia may have led to their extinction, according to results published May 21, 2014, in the open access journal PLOS ONE by Daniel DeMiguel from the Institut Catalá de Palontologia Miquel Crusafont (Spain) and colleagues.
Apes expanded into Eurasia from Africa during the Miocene (14 to 7 million years ago) and evolved to survive in new habitat. Their diet closely relates to the environment in which they live and each type of diet wears the teeth differently. To better understand the apes’ diet during their evolution and expansion into new habitat, scientists analyzed newly-discovered wearing in the teeth of 15 upper and lower molars belonging to apes from five extinct taxa found in Spain from the mid- to late-Miocene (which overall comprise a time span between 12.3?.2 and 9.7 Ma). They combined these analyses with previously collected data for other Western Eurasian apes, categorizing the wear on the teeth into one of three ape diets: hard-object feeders (e.g., hard fruits, seeds), mixed food feeders (e.g. fruit), and leaf feeders.
Previous data collected elsewhere in Europe and Turkey suggested that the great ape’s diet evolved from hard-shelled fruits and seeds to leaves, but these findings only contained samples from the early-Middle and Late Miocene, while lack data from the epoch of highest diversity of hominoids in Western Europe.
In their research, the scientists found that in contrast with the diet of hard-shelled fruits and seeds at the beginning of the movement of great apes to Eurasia, soft and mixed fruit-eating coexisted with hard-object feeding in the Late Miocene, and a diet specializing in leaves did not evolve. The authors suggest that a progressive dietary diversification may have occurred due to competition and changes in the environment, but that this specialization may have ultimately lead to their extinction when more drastic environmental changes took place.
Citation: DeMiguel D, Alba DM, Moya-Sola S (2014) Dietary Specialization during the Evolution of Western Eurasian Hominoids and the Extinction of European Great Apes. PLoS ONE 9(5): e97442. doi:10.1371/journal.pone.0097442
Note : The above story is based on materials provided by PLOS
Chemical Formula: Pb Locality: Langban, Sweden. Name Origin: Anglo-Saxon, lead; Latin plumbum.
Lead is a chemical element in the carbon group with symbol Pb and atomic number 82. Lead is a soft and malleable heavy and post-transition metal. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed to air. Lead has a shiny chrome-silver luster when it is melted into a liquid. It is also the heaviest non-radioactive element.
Lead is used in building construction, lead-acid batteries, bullets and shot, weights, as part of solders, pewters, fusible alloys, and as a radiation shield. Lead has the highest atomic number of all of the stable elements, although the next higher element, bismuth, has one isotope with a half-life that is so long (over one billion times the estimated age of the universe) that it can be considered stable. Lead’s four stable isotopes have 82 protons, a magic number in the nuclear shell model of atomic nuclei. The isotope lead-208 also has 126 neutrons, another magic number, and is hence double magic, a property that grants it enhanced stability: lead-208 is the heaviest known stable isotope.
If ingested, lead is poisonous to animals and humans, damaging the nervous system and causing brain disorders. Excessive lead also causes blood disorders in mammals. Like the element mercury, another heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China.
Physical Properties
Cleavage: None Color: Lead gray, Gray white. Density: 11.37 Diaphaneity: Opaque Fracture: Malleable – Deforms rather than breaking apart with a hammer. Hardness: 2-2.5 – Gypsum-Finger Nail Luminescence: Non-fluorescent. Luster: Metallic Magnetism: Nonmagnetic Streak: lead gray
Dr. Rebecca Williams and the remarkable volcanic deposit on Pantelleria island are shown. Credit: Credit: Mike Branney/ University of Leicester
University of Leicester team uncover explosive history of a ‘celebrity hotspot’
A tiny Mediterranean island visited by the likes of Madonna, Sting, Julia Roberts and Sharon Stone is now the focus of a ground-breaking study by University of Leicester geologists.
Pantelleria, a little-known island between Sicily and Tunisia, is a volcano with a remarkable past: 45 thousand years ago, the entire island was covered in a searing-hot layer of green glass.
Volcanologists Drs Mike Branney, Rebecca Williams and colleagues at the University of Leicester Department of Geology have been uncovering previously unknown facts about the island’s physical history.
And their study, published in “Geology” earlier this year, also provides insights into the nature of hazardous volcanic activity in other parts of the world.
Describing the volcanic activity on the island, Dr Branney said: “A ground-hugging cloud of intensely hot gases and volcanic dust spread radially out from the erupting volcano in all directions.
“Incandescent rock fragments suspended in the all-enveloping volcanic cloud were so hot, molten and sticky that they simply fused to the landscape forming a layer of glass, over hills and valleys alike. The hot glass then actually started flowing down all the slopes rather like sticky lava. ‘Ground zero’ in this case was the entire island – nothing would have survived – nature had sterilized and completely enamelled the island.
“Today Pantelleria is verdant and has been re-colonised, but even as you approach it by ferry you can see the green layer of glass covering everything – even sea cliffs look like they’ve been draped in candle wax. Exactly how this happened has only recently come to light.”
The Leicester team have reconstructed how the incandescent density current gradually inundated the entire island. They carefully mapped-out how the chemistry of the glass varies from place to place, and use this to show in unparalleled detail how the ground-hugging current at first was restricted to low, central areas, but then gradually advanced radially towards hills, eventually overtopping them all. Even more remarkably, the devastating current then gradually retreated from hill-tops, and the area covered by it gradually decreased so that, by the end of the eruption, only lower ground, close to the volcano continued to be immersed by it. Such advance-retreat behaviour may be typical of catastrophic currents in nature, such as at other volcanoes, and it may help us better understand undersea currents that are triggered by earthquakes.
“We are trying to ascertain whether this volcanic eruption was just a freak, oddball event. Well, it turns out that the delightful island, now used as a quiet getaway by celebrities, has been the site of at least five catastrophic eruptions of similar type.
“The remarkable volcanic activity on the island was not just a one-off. And as the volcano continues to steam away quite safely, it seems reasonable that in thousands of years time, it may once again erupt with devastating effect.
“Our investigations should help us understand what happens during similar and much larger explosive eruptions elsewhere around the world, such as the Yellowstone–Snake River region of USA”.
Note : The above story is based on materials provided by University of Leicester
Allison Speers, MSU graduate student, works on a fuel cell that can eliminate biodiesel producers’ hazardous wastes and dependence on fossil fuels. Photo by Kurt Stepnitz
A new fuel-cell concept, developed by an Michigan State University researcher, will allow biodiesel plants to eliminate the creation of hazardous wastes while removing their dependence on fossil fuel from their production process.
The platform, which uses microbes to glean ethanol from glycerol and has the added benefit of cleaning up the wastewater, will allow producers to reincorporate the ethanol and the water into the fuel-making process, said Gemma Reguera, MSU microbiologist and one of the co-authors.
“With a saturated glycerol market, traditional approaches see producers pay hefty fees to have toxic wastewater hauled off to treatment plants,” she said. “By cleaning the water with microbes on-site, we’ve come up with a way to allow producers to generate bioethanol, which replaces petrochemical methanol. At the same time, they are taking care of their hazardous waste problem.”
The results, which appear in the journal Environmental Science and Technology, show that the key to Reguera’s platform is her patented adaptive-engineered bacteria – Geobacter sulfurreducens.
Geobacter are naturally occurring microbes that have proved promising in cleaning up nuclear waste as well in improving other biofuel processes. Much of Reguera’s research with these bacteria focuses on engineering their conductive pili or nanowires. These hair-like appendages are the managers of electrical activity during a cleanup and biofuel production.
MSU is working to eliminate biodiesel producers’ hazardous wastes and dependence on fossil fuels. Courtesy of Gemma Reguera
First, Reguera, along with lead authors and MSU graduate students Allison Speers and Jenna Young, evolved Geobacter to withstand increasing amounts of toxic glycerol. The next step, the team searched for partner bacteria that could ferment it into ethanol while generating byproducts that ‘fed’ the Geobacter.
“It took some tweaking, but we eventually developed a robust bacterium to pair with Geobacter,” Reguera said. “We matched them up like dance partners, modifying each of them to work seamlessly together and eliminate all of the waste.”
Together, the bacteria’s appetite for the toxic byproducts is inexhaustible.
“They feast like they’re at a Las Vegas buffet,” she added. “One bacterium ferments the glycerol waste to produce bioethanol, which can be reused to make biodiesel from oil feedstocks. Geobacter removes any waste produced during glycerol fermentation to generate electricity. It is a win-win situation.”
The hungry microbes are the featured component of Reguera’s microbial electrolysis cells, or MECs. These fuel cells do not harvest electricity as an output. Rather, they use a small electrical input platform to generate hydrogen and increase the MEC’s efficiency even more.
The promising process already has caught the eye of economic developers, who are helping scale up the effort. Through a Michigan Translational Research and Commercialization grant, Reguera and her team are developing prototypes that can handle larger volumes of waste.
Reguera also is in talks with MBI, the bio-based technology “de-risking” enterprise operated by the MSU Foundation, to develop industrial-sized units that could handle the capacities of a full-scale biodiesel plant. The next step will be field tests with a Michigan-based biodiesel manufacturer.
Note : The above story is based on materials provided by Michigan State University
Chemical Formula: (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)] Locality: District of Badakhshan, Afghanistan. Name Origin: From the Persian lazward – “blue.”
Lazurite is a tectosilicate mineral with sulfate, sulfur and chloride with formula: (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]. It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.
Lazurite is a deep blue to greenish blue. The colour is due to the presence of S−3 anions. It has a Mohs hardness of 5.0 to 5.5 and a specific gravity of 2.4. It is translucent with a refractive index of 1.50. It is fusible at 3.5 and soluble in HCl. It commonly contains or is associated with grains of pyrite.
Lazurite is a product of contact metamorphism of limestone and typically is associated with calcite, pyrite, diopside, humite, forsterite, hauyne and muscovite.
History
Discovery date : 1890 Town of Origin : BADAKHSTAN PROV. Country of Origin: AFGHANISTAN
Optical properties
Optical and misc. Properties : Translucent Refractive Index: from 1,50 to 1,52
Physical Properties
Cleavage: {110} Imperfect Color: Blue, Azure blue, Violet blue, Greenish blue. Density: 2.38 – 2.42, Average = 2.4 Diaphaneity: Translucent Fracture: Conchoidal – Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz). Hardness: 5.5 – Knife Blade Luminescence: Non-Fluorescent. Luster: Vitreous – Dull Streak: light blue
The Lena is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean (the other two being the Ob River and the Yenisei River). It is the 11th longest river in the world and has the 9th largest watershed. It is the largest among the rivers whose watershed is entirely within the Russian territorial boundaries.
Course
Rising at a height of 1,640 metres (5,381 ft) at its source in the Baikal Mountains south of the Central Siberian Plateau, 7 kilometres (4 mi) west of Lake Baikal, the Lena flows northeast, being joined by the Kirenga River, Vitim River and Olyokma River. From Yakutsk it enters the lowlands and flows north until joined by its right-hand tributary the Aldan River. The Verkhoyansk Range deflects it to the north-west; then after receiving its most important left-hand tributary, the Vilyuy River, it makes its way nearly due north to the Laptev Sea, a division of the Arctic Ocean, emptying south-west of the New Siberian Islands by the Lena Delta – 30,000 square kilometres (11,583 sq mi) in area, and traversed by seven principal branches, the most important being the Bykov, farthest east.
Basin
Neighbourhood of the sources of Lena River to Lake Baikal
The total length of the river is estimated at 4,400 km (2,700 mi). The area of the Lena river basin is calculated at 2,490,000 square kilometres (961,394 sq mi). Gold is washed out of the sands of the Vitim and the Olyokma, and mammoth tusks have been dug out of the delta.
Tributaries
The Kirenga River flows north between the upper Lena and Lake Baikal. The Vitim River drains the area northeast of Lake Baikal. The Olyokma River flows north. The Amga River makes a long curve southeast and parallel to the Lena and flows into the Aldan. The Aldan River makes similar curve southeast of the Aldan and flows into the Lena north of Yakutsk. The Maya River, a tributary of the Aldan, drains an area almost to the Sea of Okhotsk. The T-shaped Chona-Vilyuy River system drains most of the area to the west.
History
It is commonly believed that the river Lena derives its name from the original Even-Evenk name Elyu-Ene, which means “the Large River”.
According to folktales related a century after the fact, in the years 1620–23 a party of Russian fur hunters under the leadership of Demid Pyanda sailed up Lower Tunguska, and discovered the proximity of Lena and either carried their boats there or built new ones. In 1623 Pyanda explored some 2,400 kilometers of the river from its upper rocky part to its wide flow in the central Yakutia. In 1628 Vasily Bugor and ten men reached the Lena, collected yasak from the natives and founded Kirinsk in 1632. In 1631 the voyevoda of Yeniseisk sent Pyotr Beketov and twenty men to found an ostrog at Yakutsk (founded in 1632). From Yakutsk other expeditions spread out to the south and east. The Lena delta was reached in 1633.
Baron Eduard Von Toll, accompanied by Alexander von Bunge, carried out an expedition to the Lena delta area and the islands of New Siberia on behalf of the Russian Imperial Academy of Sciences in 1885. They explored the Lena delta with its multitude of arms that flow towards the Arctic Ocean. Then in spring 1886 they investigated the New Siberian Islands and the Yana River and its tributaries. During one year and two days the expedition covered 25,000 km, of which 4,200 km were up rivers, carrying out geodesic surveys en route.
Vladimir Ilyich Ulyanov may have taken his alias, Lenin, from the river Lena, when he was exiled to the Central Siberian Plateau, but the origin of his pen name is uncertain.
Lena delta
Lena river Delta by Landsat 2000
At the end of the Lena River there is a large delta that extends 100 kilometres (62 mi) into the Laptev Sea and is about 400 km (250 mi) wide. The delta is frozen tundra for about 7 months of the year, but in May transforms the region into a lush wetland for the next few months. Part of the area is protected as the Lena Delta Wildlife Reserve.
The Lena delta divides into a multitude of flat islands. The most important are (from west to east): Chychas Aryta, Petrushka, Sagastyr, Samakh Ary Diyete, Turkan Bel’keydere, Sasyllakh Ary, Kolkhoztakh Bel’keydere, Grigoriy Diyelyakh Bel’kee (Grigoriy Islands), Nerpa Uolun Aryta, Misha Bel’keydere, Atakhtay Bel’kedere, Arangastakh, Urdiuk Pastakh Bel’key, Agys Past’ Aryta, Dallalakh Island, Otto Ary, Ullakhan Ary and Orto Ues Aryta.
Turukannakh-Kumaga is a long and narrow island off the Lena delta’s western shore.
One of the Lena delta islands, Ostrov Amerika-Kuba-Aryta or Ostrov Kuba-Aryta, was named after the island of Cuba during Soviet times. It is on the northern edge of the delta.
Note : The above story is based on materials provided by Wikipedia
A young man overlooks his home, the coastal community of Cabo Pulmo. Credit: Octavio Aburto.
Cabo Pulmo is a close-knit community in Baja California Sur, Mexico, and the best preserved coral reef in the Gulf of California. But now the lands adjacent to the reef are under threat from a mega-development project, “Cabo Dorado,” should construction go ahead.
Scientists at the University of California, Riverside have published a report on the terrestrial biodiversity of the Cabo Pulmo region that shows the project is situated in an area of extreme conservation value, the center of which is Punta Arena, an idyllic beach setting proposed to be completely cleared to make way for 20,000+ hotel rooms.
“Until recently, the biological value of the lands adjacent to the coral reef of Cabo Pulmo had remained a mystery,” said UC Riverside’s Benjamin Wilder, who helped produce the report. “We now know that these desert lands mirror the tropical waters in importance. This desert-sea ecosystem is a regional biodiversity hotspot.”
According to Wilder, if the Cabo Dorado project proceeds as planned, the regionally endemic plant species and vegetation of Punta Arena will be made extinct.
“Forty-two plants and animals on the Mexican endangered species list would lose critical habitat, two recently described plant species only known from Punta Arena would be lost entirely, and development of the sand dunes of Punta Arena would imperil the most diverse coral reef in the Gulf of California,” he said.
The report resulted from a survey conducted in November 2013 that in just a week’s time documented 560 plants and animals on the land surrounding Cabo Pulmo. The report highlights the unique and ecologically important habitats of the sand spit, Punta Arena, the core zone of the pending development proposal.
The ‘bioblitz’ and resulting report were organized by UCR alum Sula Vanderplank, a biodiversity explorer with the Botanical Research Institute of Texas, and Wilder, a Ph.D. graduate student in the Department of Botany and Plant Sciences, with their advisor Exequiel Ezcurra, a professor of ecology at UCR. The report represents a binational collaboration of 22 scientists from 11 institutions that participated in the expedition and are the top experts on the plants, birds, mammals, and reptiles of Baja California. The survey was organized using the Next Generation of Sonoran Desert Researchers network to assemble a ‘dream-team’ of field biologists.
Ezcurra, the director of UC MEXUS and an acclaimed conservationist, said, “We need to take a careful look at such large scale development projects. Far too many times along the coasts of Mexico we have seen the destruction of areas of great biological importance and subsequent abandonment. By incorporating the natural wealth of the region into development initiatives we can collectively pursue a vision of a prosperous future for our communities that matches the grandeur of the regional landscape.”
In the early 1990s the local community of Cabo Pulmo saw that overfishing was greatly depleting the coral reef ecosystem. The community shifted its local economy to ecotourism and non-extractive livelihoods, and lobbied the Mexican government to make the reef a national park, which was realized in 1995. Since that time there has been a more than 460 percent increase in the total amount of fish in the reserve — the most robust marine reserve in the world.
Wilder, Ezcurra and Vanderplank stress in the report that it is very important that development in this area take into account the inherent limitations of resources, especially fresh water, in a desert setting; the unique habitats found at Punta Arena and the coral reefs of Cabo Pulmo; and, perhaps most important, the local community of Cabo Pulmo.
“We were surprised to see that these desert lands mirrored the biological diversity of the adjacent coral sea,” Wilder said. “Specifically we were not expecting to find such a concentration of rare and endemic taxa in the single region of Punta Arena. This unique biodiversity results from regional geologic forces that were previously un-investigated.
“The bottom line is that the scale of the proposed development, more than 20,000 hotel rooms, is completely disconnected from the ecology of this desert region,” he added. “Any development in the area must account for and sustain the areas natural wealth as well as the local communities of Cabo Pulmo and the nearby town of La Ribera.”
The research team has proposals pending to better understand the linkage between the desert-sea interface of this coastal area. Their aim is to further establish the value of the biological richness of Cabo Pulmo and Punta Arena.
The final report, which based on the scientific results recommends an extension of the Cabo Pulmo National Park to include Punta Arena, was delivered at a public hearing to SEMARNAT, the Mexican federal environmental department. SEMARNAT is expected to make a decision on the future of the Cabo Dorado project by June 15, 2014.
Chemical Formula: (Mg,Fe2+)Al2(PO4)2(OH)2 Locality: Werfen, Salzburg, Austria Name Origin: From the Arabic azul – “sky” and the Greek lithos – “stone.”
Lazulite ((Mg,Fe2+)Al2(PO4)2(OH)2) is a blue, phosphate mineral containing magnesium, iron, and aluminium phosphate. Lazulite forms one endmember of a solid solution series with the darker iron rich scorzalite.
Lazulite crystallizes in the monoclinic system. Crystal habits include steep bipyramidal or wedge-shaped crystals. Lazulite has a Mohs hardness of 5.5 to 6 and a specific gravity of 3.0 to 3.1. It is infusible and insoluble.
History
Discovery date : 1795
Optical properties
Optical and misc. Properties : Subtranslucent to opaque Refractive Index : from 1,61 to 1,64 Axial angle 2V: 69°
Physical Properties
Color: Blue, Blue green, Light blue, Black blue. Density: 3 – 3.1, Average = 3.05 Diaphaneity: Subtranslucent to opaque Fracture: Uneven – Flat surfaces (not cleavage) fractured in an uneven pattern. Hardness: 5-6 – Between Apatite and Orthoclase Luminescence: Non-fluorescent. Luster: Vitreous (Glassy) Streak: white
The late Dr Linda Moore sampling microbialites. Credit: Bob Burne
Scientists have discovered that the earliest living organisms on Earth were capable of making a mineral that may be found on Mars.
The clay-mineral stevensite has been used since ancient times and was used by Nubian women as a beauty treatment, but scientists had believed deposits could only be formed in harsh conditions like volcanic lava and hot alkali lakes.
Researchers led by Dr Bob Burne from the ANU Research School of Earth Sciences have found living microbes create an environment that allows stevensite to form, raising new questions about the stevensite found on Mars.
“It’s much more likely that the stevensite on Mars is made geologically, from volcanic activity,” Dr Burne said.
“But our finding — that stevensite can form around biological organisms — will encourage re-interpretation of these Martian deposits and their possible links to life on that planet.”
Dr Burne and his colleagues from ANU, University of Western Australia and rock imaging company Lithicon, have found microbes can become encrusted by stevensite, which protects their delicate insides and provides the rigidity to allow them to build reef-like structures called “microbialites.”
“Microbialites are the earliest large-scale evidence of life on Earth,” Dr Burne said. “They demonstrate how microscopic organisms are able to join together to build enormous structures that sometimes rivalled the size of today’s coral reefs.”
He said the process still happens today in some isolated places like Shark Bay and Lake Clifton in Western Australia.
“Stevensite is usually assumed to require highly alkaline conditions to form, such as volcanic soda lakes. But our stevensite microbialites grow in a lake less salty than seawater and with near-neutral pH.”
One of the paper’s authors, Dr Penny King from ANU, is a science co-investigator on NASA’s Mars Curiosity rover, which uncovered the presence of possible Martian stevensite.
The findings also have implications for how some of the world’s largest oil reservoirs were formed.
The discovery was made using ANU-developed imaging technology licensed to Lithicon. The data was run on Raijin, the most powerful supercomputer in the Southern Hemisphere, based at the National Computational Infrastructure in Canberra.
Journal Reference:
R. V. Burne, L. S. Moore, A. G. Christy, U. Troitzsch, P. L. King, A. M. Carnerup, P. J. Hamilton. Stevensite in the modern thrombolites of Lake Clifton, Western Australia: A missing link in microbialite mineralization? Geology, 2014; DOI: 10.1130/G35484.1
Note : The above story is based on materials provided by Australian National University.
Professor Francisco J. Rodríguez-Tovar, of the University of Granada, pointing to the bio-event in the late Cretaceous/early Tertiary (when the dinosaurs became extinct) in Agost (Alicante). Credit: Image courtesy of University of Granada
Analysing palaeontological data helps characterize irregular paleoenvironmental cycles, lasting between less than 1 day and more than millions of years.
Francisco J. Rodríguez-Tovar, Professor of Stratigraphy and Paleontology at the University of Granada has shown that the cyclical phenomena that affect the environment, like climate change, in the atmosphere-ocean dynamic and, even, disturbances to planetary orbits, have existed since hundreds of millions of year ago and can be studied by analysing fossils.
This is borne out by the palaeontological data analysed, which have facilitated the characterization of irregular cyclical paleoenvironmental changes, lasting between less than 1 day and up to millions of years.
Francisco J. Rodríguez-Tovar, Professor de Stratigraphy and Paleontology at the University of Granada, has analysed how fossil records can be used as a key tool to characterize these cyclical phenomena that have varying time scales.
The results of this research have been published in the prestigious journal Annual Reviews of Earth and Planetary Sciences, the second-ranked journal in the category of Geosciences, Multidisciplinary in the Journal Citation Reports ranking, after Nature Geosciences, with an impact factor close to 9. Never before has a Spanish scientist succeeded in having an article published in this journal.
As Dr Rodríguez-Tovar indicates, these are cyclical phenomena of a variable scale, from less than a day to more than millions of years, and which have appeared in different ways in the fossil record.
In the case of those lasting between less than 1 day and 1 year, “these are phenomena on an ecological scale essentially associated with variations in tidal and solar cycles that were recorded in the models of growth of organisms like bivalve shells or corals. Hence, we find evidence of them in fossils dating from the Paleozoic (more than 500 million years ago)”, says Prof. Rodríguez-Tovar of the University of Granada.
Moreover, in his article he has studied cyclical phenomena that have lasted between 1 year and 10,000 years, like those associated with the El Niño phenomenon (a cyclical climactic phenomenon causing the warming of South American seas), the so-called Dansgaard-Oeschger Cycles or the Heinrich Events. The latter took place during the last Ice Age, and determined variations in the abundance, distribution and diversity of populations and marine and terrestrial species.
Also, he has analysed cyclical phenomena of between 10 000 and 1 million years ago, essentially associated with climactic changes due to orbital variations (Milankovitch cycles), that are recorded in the evolutionary patterns of specific species, even bringing about their extinction.
Finally, Professor Rodríguez-Tovar has studied cyclical changes lasting over 1 million years, occurring throughout the Phanerozoic period, which are interpretation as being associated with extraterrestrial phenomena (meteorite impacts, such as those occurring in the late Cretaceous/early Tertiary, some 65 million years ago) or terrestrial phenomena (such as large-scale volcanism).
“These changes are related with major periodic extinctions, which affect a high percentage of the biota, since in most cases more than 65% of living organisms became extinct”, Prof. Rodríguez-Tovar points out.
Journal Reference:
Francisco J. Rodríguez-Tovar. Orbital Climate Cycles in the Fossil Record: From Semidiurnal to Million-Year Biotic Responses. Annual Review of Earth and Planetary Sciences, 2013; 42 (1): 140205180347002 DOI: 10.1146/annurev-earth-120412-145922
Note : The above story is based on materials provided by University of Granada.
Chemical Formula: CaAl2(Si2O7)(OH)2·H2O Locality: Reed Station, Tiburon peninsula, Marin County, California, USA. Name Origin: Named for Andrew Cowper Lawson (1861-1952), Scottish-American geologist.
Lawsonite is a hydrous calcium aluminium sorosilicate mineral with formula CaAl2(Si2O7)(OH)2·H2O. Lawsonite crystallizes in the orthorhombic system in prismatic, often tabular crystals. Crystal twinning is common. It forms transparent to translucent colorless, white, and bluish to pinkish grey glassy to greasy crystals. Refractive indices are nα=1.665, nβ=1.672 – 1.676, and nγ=1.684 – 1.686. It is typically almost colorless in thin section, but some lawsonite is pleochroic from colorless to pale yellow to pale blue, depending on orientation. The mineral has a Mohs hardness of 8 and a specific gravity of 3.09. It has perfect cleavage in two directions and a brittle fracture.
Lawsonite is a metamorphic mineral typical of the blueschist facies. It also occurs as a secondary mineral in altered gabbro and diorite. Associate minerals include epidote, titanite, glaucophane, garnet and quartz. It is an uncommon constituent of eclogite.
It was first described in 1895 for occurrences in the Tiburon peninsula, Marin County, California. It was named for geologist Andrew Lawson (1861–1952) of the University of California by two of Lawson’s graduate students, Charles Palache and Frederick Leslie Ransome.
History
Discovery date : 1895 Town of Origin: PENINSULE DE TIBURON, MARIN CO., CALIFORNIE Country of Origin : USA
Optical properties
Optical and misc. Properties: Translucent to transparent Refractive Index: from 1,66 to 1,68 Axial angle 2V : 76-87°
Kaitlin Keegan, the study’s lead author and a Dartmouth doctoral student, investigates the newly deposited snow layering, known as firn, in the Greenland ice sheet. Credit: Laura Levy
A Dartmouth-led study finds that rising temperatures and ash from Northern Hemisphere forest fires combined to cause large-scale surface melting of the Greenland ice sheet in 1889 and 2012. This contradicts conventional thinking that the melting was driven by warming alone.
The findings suggest that continued climate change will result in nearly annual widespread melting of the ice sheet’s surface by the year 2100. Melting in the dry snow region does not contribute to sea level rise. Instead, the meltwater percolates into the snowpack and refreezes, leaving a less reflective surface. This reformed surface becomes even more susceptible to future melting due to the surface’s reduced reflectance. The ability to reflect sunlight is known as “albedo.”
The study, conducted by Thayer School of Engineering and the Desert Research Institute, is reported in the Proceedings of the National Academy of Sciences. The research was supported by the National Science Foundation and NASA.
“The widespread melting of the Greenland ice sheet required the combination of both of these effects — a lowered snow albedo from ash and unusually warm temperatures — to push the ice sheet over the threshold,” says Kaitlin Keegan, the study’s lead author and a Dartmouth doctoral student. “With both the frequency of forest fires and warmer temperatures predicted to increase with climate change, widespread melt events are likely to happen much more frequently in the future.”
The massive Greenland ice sheet experiences annual melting at low elevations near the coastline, but surface melt is rare in the dry snow region in its center. In July 2012, however, more than 97 percent of the ice sheet experienced surface melt, the first widespread melt during the era of satellite observation. Keegan, who added critical information to NASA’s announcement of the 2012 melt, studies the newly deposited layers of snow that top the 2-mile-thick ice sheet.
In the new study, an analysis of six Greenland shallow ice cores from the dry snow region confirmed that the most recent prior widespread melt occurred in 1889. An ice core from the center of the ice sheet demonstrated that exceptionally warm temperatures combined with black carbon sediments from Northern Hemisphere forest fires reduced albedo below a critical threshold in the dry snow region and caused the large-scale melting events in both 1889 and 2012.
The study did not focus on analyzing the ash to determine the source of the fires, but the presence of a high concentration of ammonium concurrent with the black carbon indicates the ash’s source was large boreal forest fires during the summer in Siberia and North America in June and July 2012. Air masses from these two areas arrived at the Greenland ice sheet’s summit just before the widespread melt event. As for 1889, there are historical records of testimony to Congress of large-scale forest fires in the Pacific Northwest of the United States that summer, but it would be difficult to pinpoint which forest fires deposited ash onto the ice sheet that summer.
The researchers also used Intergovernmental Panel on Climate Change data to project the frequency of widespread surface melting into the year 2100. Since Arctic temperatures and the frequency of forest fires are both expected to rise with climate change, the researchers’ results suggest that large-scale melt events on the Greenland ice sheet may begin to occur almost annually by the end of century. These events are likely to alter the surface mass balance of the ice sheet, leaving the surface susceptible to further melting. The Greenland ice sheet is the second largest ice body in the world after the Antarctic ice sheet.
“Our Earth is a system of systems,” says Thayer Professor Mary Albert, co-author of the study and the director of the U.S. Ice Drilling Program Office. “Improved understanding of the complexity of the linkages and feedbacks, as in this paper, is one challenge facing the next generation of engineers and scientists — people like Kaitlin.”
Note : The above story is based on materials provided by Dartmouth College.
Chemical Formula: PbCl(OH) Locality: Ancient lead slags at Laurium, Greece. Name Origin: Named after its locality.
Laurionite (PbCl(OH)) is a lead halide mineral. It forms colorless to white crystals in the orthorhombic crystal system and is dimorphous with paralaurionite, both members of the matlockite group.
It was first described in 1887 for an occurrence in the Laurium District, Attica, Greece and named after the town Laurium. It occurs as an oxidation product in lead ore deposits, and is also produced on lead-bearing slag by reaction with saline solutions. It occurs associated with paralaurionite, penfieldite, fiedlerite, phosgenite, cerussite and anglesite.
History
Discovery date : 1887 Town of Origin : LAURION, ATTIQUE Country of Origin : GRECE
Optical properties
Optical and misc. Properties : Transparent. Refractive Index: from 2,07 to 2,15 Axial angle 2V: LARGE
Aerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles. Credit: Wikipedia.
A cluster of closely timed earthquakes over 100 years in the 17th and 18th centuries released as much accumulated stress on San Francisco Bay Area’s major faults as the Great 1906 San Francisco earthquake, suggesting two possible scenarios for the next “Big One” for the region, according to new research published by the Bulletin of the Seismological Society of America (BSSA).
“The plates are moving,” said David Schwartz, a geologist with the U.S. Geological Survey and co-author of the study. “The stress is re-accumulating, and all of these faults have to catch up. How are they going to catch up?”
The San Francisco Bay Region (SFBR) is considered within the boundary between the Pacific and North American plates. Energy released during its earthquake cycle occurs along the region’s principal faults: the San Andreas, San Gregorio, Calaveras, Hayward-Rodgers Creek, Greenville, and Concord-Green Valley faults.
“The 1906 quake happened when there were fewer people, and the area was much less developed,” said Schwartz. “The earthquake had the beneficial effect of releasing the plate boundary stress and relaxing the crust, ushering in a period of low level earthquake activity.”
The earthquake cycle reflects the accumulation of stress, its release as slip on a fault or a set of faults, and its re-accumulation and re-release. The San Francisco Bay Area has not experienced a full earthquake cycle since its been occupied by people who have reported earthquake activity, either through written records or instrumentation. Founded in 1776, the Mission Dolores and the Presidio in San Francisco kept records of felt earthquakes and earthquake damage, marking the starting point for the historic earthquake record for the region.
“We are looking back at the past to get a more reasonable view of what’s going to happen decades down the road,” said Schwartz. “The only way to get a long history is to do these paleoseismic studies, which can help construct the rupture histories of the faults and the region. We are trying to see what went on and understand the uncertainties for the Bay Area.”
Schwartz and colleagues excavated trenches across faults, observing past surface ruptures from the most recent earthquakes on the major faults in the area. Radiocarbon dating of detrital charcoal and the presence of non-native pollen established the dates of paleoearthquakes, expanding the span of information of large events back to 1600.
The trenching studies suggest that between 1690 and the founding of the Mission Dolores and Presidio in 1776, a cluster of earthquakes ranging from magnitude 6.6 to 7.8 occurred on the Hayward fault (north and south segments), San Andreas fault (North Coast and San Juan Bautista segments), northern Calaveras fault, Rodgers Creek fault, and San Gregorio fault. There are no paleoearthquake data for the Greenville fault or northern extension of the Concord-Green Valley fault during this time interval.
“What the cluster of earthquakes did in our calculations was to release an amount of energy somewhat comparable to the amount released in the crust by the 1906 quake,” said Schwartz.
As stress on the region accumulates, the authors see at least two modes of energy release – one is a great earthquake and other is a cluster of large earthquakes. The probability for how the system will rupture is spread out over all faults in the region, making a cluster of large earthquakes more likely than a single great earthquake.
“Everybody is still thinking about a repeat of the 1906 quake,” said Schwartz. “It’s one thing to have a 1906-like earthquake where seismic activity is shut off, and we slide through the next 110 years in relative quiet. But what happens if every five years we get a magnitude 6.8 or 7.2? That’s not outside the realm of possibility.”
More information: The paper, “The Earthquake Cycle in the San Francisco Bay Region: AD 1600-2012,” will be published online May 20, 2014 by BSSA and will appear in the June print issue: DOI: 10.1785/0120120322
Note : The above story is based on materials provided by Seismological Society of America
Scientists have used a computer model of ocean circulation to predict the movement of the rafts of floating pumice given off by an erupting underwater volcano.
These rafts can cause problems for ships, so the researchers hope their work will lead to the development of early-warning systems to let mariners avoid risky areas in the wake of an eruption.
The researchers used NEMO, the UK’s high-resolution model of ocean circulation, to represent the ocean currents around Havre, a volcano deep under the southwest Pacific that erupted in July 2012. They then used its output to calculate the movements of thousands of particles representing areas of drifting pumice.
Finally, they compared the results with what satellite images and sailors’ sightings tell us actually happened. The match was encouragingly close, showing that although it needs more development the technique is capable of accurately predicting the movement of these floating islands.
‘The eruption was far from coastal interference, so it produced a single raft spanning over 400km2 in one day, initiating a gigantic, high-precision natural experiment in surface dispersion,’ says Dr Bob Marsh of the University of Southampton.
He was part of a team led by Dr Martin Jutzeler of the National Oceanography Centre, which recently published their findings in Nature Communications. ‘It’s only recently that we’ve had oceanographic models that represent how things spread out in the ocean accurately enough to do this kind of thing, so it’s a big opportunity for new research,’ Marsh adds.
His methods can be used to predict the movement of any floating objects that are carried about the ocean by currents – he’s already applied them to everything from debris associated with accidents to icebergs and baby turtles. Although NEMO itself needs to run on national supercomputers, the additional calculations he performs based on its output can be done in mere hours on normal computing hardware, allowing scientists to respond quickly to natural disasters.
‘If we see a big undersea volcanic eruption, we can react within 24-48 hours to produce maps of where pumice will drift to over time,’ he says. ‘All we need to know is where the volcano is.’
Pumice rafts are mostly made up of tiny pieces of floating rock, less than a centimetre across, so in most cases they aren’t likely to breach a ship’s hull. They can endanger its ability to keep moving, though, for example by clogging up water intakes so that engines have no cooling and overheat. ‘It’s not like an iceberg that can sink the ship, but it could effectively cordon off a large area of ocean for several weeks, which could cost the maritime industry a lot of money,’ Marsh says.
He now hopes to work with the shipping and marine insurance industries, as well as with colleagues in the Met Office, to investigate whether these techniques can be turned into a useful information service for sailors – perhaps an add-on to the Met Office’s existing services. He is already working on developing an early-warning system for icebergs, and says it would be relatively easy to incorporate pumice raft forecasting.
More information: “On the fate of pumice rafts formed during the 2012 Havre submarine eruption.” Martin Jutzeler, Robert Marsh, Rebecca J. Carey, James D. L. White, Peter J. Talling & Leif Karlstrom. Nature Communications 5, Article number: 3660. DOI: 10.1038/ncomms4660
Note : The above story is based on materials provided by PlanetEarth Online
Laumontite Himalaya Mine, Mesa Grande, San Diego Co., California, USA Miniature, 4 x 3.2 x 2.5 cm “Courtesy of Rob Lavinsky, The Arkenstone, www.iRocks.com”
Chemical Formula: CaAl2Si4O12·4H2O Locality: Nagy-Ag, Transylvania of Romania. Name Origin: Named after the Frenchman, F. P. N. de Laumont (1747-1834).
Laumontite is a mineral, one of the zeolite group. Its molecular formula is CaAl2Si4O12·4H2O, a hydrated calcium-aluminium silicate. Potassium or sodium may substitute for the calcium but only in very small amounts.
The identification of laumontite goes back to the early days of mineralogy. It was first named lomonite by R. Jameson (System of Mineralogy) in 1805, and laumonite by René Just Haüy in 1809. The current name was given by K.C. von Leonhard (Handbuch der Oryktognosie) in 1821. It is named after Gillet de Laumont who collected samples from lead mines in Huelgoat, Brittany, making them the type locality.
Laumontite easily dehydrates when stored in a low humidity environment. When freshly collected, if it has not already been exposed to the environment, it can be translucent or transparent. Over a period of hours to days the loss of water turns it opaque white. In the past, this variety has been called leonhardite, though this is not a valid mineral species. The dehydrated laumontite is very friable, often falling into a powder at the slightest touch.
History
Discovery date : 1805 Town of Origin : MINES HUELGOET, BRETAGNE Country of Origin : FRANCE
Optical properties
Optical and misc. Properties : Transparent to translucent to opaque Refractive Index: from 1,50 to 1,52 Axial angle 2V : 26-47°
Physical Properties
Cleavage: {010} Perfect, {110} Perfect Color: Brownish, Gray, Yellowish, Pearl white, Pink. Density: 2.25 – 2.35, Average = 2.29 Diaphaneity: Transparent to translucent to opaque Fracture: Brittle – Conchoidal – Very brittle fracture producing small, conchoidal fragments. Hardness: 3.5-4 – Copper Penny-Fluorite Luminescence: Fluorescent, Short UV=Weak white, Long UV=weak white. Luster: Vitreous (Glassy) Streak: white
Ergune or Argun is the river which is a part of the Russia–China border. Its upper reaches are known as Hailar River (Chinese: 海拉尔河; pinyin: Hăilā’ěr Hé) in China. Its length is 1,007 mi (1,620 km). The Ergune marks the border (established by the Treaty of Nerchinsk in 1689) between Russia and China for about 944 km, until it meets the Amur River. The name derives from Buryat Urgengol ‘wide river’ (urgen ‘wide’ + gol ‘river’).
The river flows from the Western slope of the Greater Khingan Range in Inner Mongolia. Its confluence with Shilka River at Ust-Strelka forms the Amur River.
Kherlen–Ergune–Amur
In years with high precipitation, the normally exitless Hulun Lake may overflow at its northern shore, and the water will meet the Ergune after about 30 km. The Kherlen–Ergune–Amur system has a total length of 5,052 km.
Ergune in The Secret History of the Mongols
In The Secret History of the Mongols speaks legend related to the Ergüne hun Mongol ancestry. In this legend, the Mongols prevailed over other tribes and carried such slaughter among them, that in living remained no more than two men and two women. These two families, in fear of the enemy, fled to the inhospitable terrain, which included only mountains and forests and to which there was no road. Among those mountains was the abundant grass and healthy climate of the steppe. Then, legend tells that in Ergune-Khun, Mongols multiplied and become masters of iron smelting and blacksmithing. According to legend, it is the art of melting iron that has helped them escape from the mountain gorges on scope of the current Mongolian steppes, to the Kherlen River and Onon River.
Note : The above story is based on materials provided by Wikipedia
Australia’s coastline has been struck by up to 145 possible tsunamis since prehistoric times, causing deaths previously unreported in the scientific literature, a UNSW study has revealed.
The largest recorded inundation event in Australia was caused by an earthquake off Java in Indonesia on 17 July 2006, which led to a tsunami that reached up to 7.9 metres above sea level on land at Steep Point in Western Australia.
The continent was also the site of the oldest known tsunami in the world — an asteroid impact that occurred 3.47 billion years ago in what is now the Pilbara district of Western Australia.
Details of the 145 modern day and prehistoric events are outlined in a revised Australian tsunami database, which has been extensively updated by UNSW researchers, Professor James Goff and Dr Catherine Chagué-Goff.
“Our research has led to an almost three-fold increase in the number of events identified — up from 55 in 2007. NSW has the highest number of tsunamis in the database, with 57, followed by Tasmania with 40, Queensland with 26 and Western Australia with 23,” says Professor Goff, of the UNSW School of Biological, Earth and Environmental Sciences.
“Historical documents indicate that up to 11 possible tsunami-related deaths have occurred in Australia since 1883. This is remarkable, because our tsunami-prone neighbour, New Zealand, has only one recorded death.”
Professor Goff and Dr Chagué-Goff, who also works at the Australian Nuclear Science and Technology Organisation, scoured scientific papers, newspaper reports, historical records and other tsunami databases to update the 2007 Australian database.
“And it is still incomplete. Much more work needs to be done, especially to identify prehistoric events and those on the east coast. Our goal is to better understand the tsunami hazard to Australia and the region. The geographical spread of events and deaths suggests the east coast faces the most significant risk,” says Professor Goff.
The results are published in the journal Progress in Physical Geography.
The country’s largest tsunami had been listed in 2007 as one that hit Western Australia following an earthquake off Sumba Island in Indonesia on 19 August 1977, but this rating was based on wrong information about its wave height.
Giant wave heights of about 13 metres — bigger than those of the current record-holding event in 2006 — have also been attributed to a possible tsunami on 8 April 1911 in Warrnambool in Victoria, but no hard evidence is available as yet to back this up.
The study identified three prehistoric events that had an impact across the whole of the South West Pacific Ocean: an asteroid impact 2.5 million years ago and large earthquakes about 2900 years ago and in the mid-15th Century.
Note : The above story is based on materials provided by University of New South Wales.
Chemical Formula: (Mn2+,Ca)4(Mn3+,Fe3+)9Sb5+(SiO4)2O16 Locality: At Langbanshyttan, Vermland, Sweden and the Sjo mines near Orebro in Orebro. Name Origin: After its locality.
History
Discovery date : 1877 Town of Origin : MINE LANGBAN, FILIPSTAD, VARMLAND Country of Origin : SUEDE
Optical properties
Optical and misc. Properties : Opaque Refractive Index: from 2,31 to 2,36
Physical Properties
Cleavage: {0001} Good Color: Iron black. Density: 4.91 Diaphaneity: Opaque Hardness: 6.5 – Pyrite Luster: Metallic Streak: grayish black
