Chemical Formula: (Au,Ag)Te2 Locality: Sacarâmb (Nagyág, Szekerembe), Transylvania, Romania. Name Origin: Named for Joseph A. Krenner (1839-1920), Hungarian mineralogist.
Krennerite is an orthorhombic gold telluride mineral which can contain a relatively small amount of silver in the structure. The formula is AuTe2 varying to (Au0.8,Ag0.2)Te2. Both of the chemically similar gold-silver tellurides, calaverite and sylvanite, are in the monoclinic crystal system, whereas krennerite is orthorhombic.
The color varies from silver-white to brass-yellow. It has a specific gravity of 8.53 and a hardness of 2.5. It occurs in high temperature, hydrothermal environments.
Krennerite was discovered in 1878 in Sacaramb, Romania, and first described by the Hungarian mineralogist Joseph Krenner (1839–1920).
Using satellite imagery to monitor which volcanoes are deforming provides statistical evidence of their eruption potential, according to a new study in Nature Communications.
The European Space Agency’s Sentinel satellite, launched April 3, should allow scientists to test this link in greater detail and eventually develop a forecast system for all volcanoes, including those that are remote and inaccessible.
Volcano deformation and, in particular, uplift are often considered to be caused by magma moving or pressurizing underground. Magma rising towards the surface could be a sign of an imminent eruption. On the other hand, many other factors influence volcano deformation and, even if magma is rising, it may stop short, rather than erupting.
Satellite interferometric synthetic aperture radar, called InSAR for short, is a spaceborne imaging technology that will help scientists understand how volcanoes work, according to study co-author and geophysicist Zhong Lu, Southern Methodist University in Dallas.
“InSAR will aid in the prediction of future eruptions,” said Lu, a professor and Shuler-Foscue Chair of geophysics in SMU’s Roy M. Huffington Department of Earth Sciences. “At SMU, we are developing and applying this technique to track motions of volcanic activities, landslide movements, land subsidence and building stability, among other events.”
Juliet Biggs, the University of Bristol in England, led the study. Biggs looked at the archive of satellite data covering more than 500 volcanoes worldwide, many of which have been systematically observed for more than 18 years.
Satellite radar can provide high-resolution maps of deformation, allowing the detection of unrest at many volcanoes that might otherwise go unrecognized. Such satellite data is often the only source of information for remote or inaccessible volcanoes.
The researchers, who included scientists from Cornell University and Oxford University also, applied statistical methods more traditionally used for medical diagnostic testing and found that many deforming volcanoes also erupted (46 percent). Together with the very high proportion of non-deforming volcanoes that did not erupt (94 percent), these jointly represent a strong indicator of a volcano’s long-term eruptive potential.
“The findings suggest that satellite radar is the perfect tool to identify volcanic unrest on a regional or global scale and target ground-based monitoring,” Biggs said.
New technology may improve forecasting of volcanic eruptions
The work was co-funded by the U.K. Centre for Observation and Modelling of Earthquakes, Volcanoes and Tectonics and STREVA, a research consortium aimed at finding ways to reduce the negative consequences of volcanic activity on people and their assets.
“Improving how we anticipate activity using new technology such as this is an important first step in doing better at forecasting and preparing for volcanic eruptions,” said STREVA Principal Investigator Jenni Barclay.
Global studies of volcano deformation using satellite data will increasingly play a part in assessing eruption potential at more and more volcanoes, said researcher Willy Aspinall, University of Bristol, especially in regions with short historical records or limited conventional monitoring.
However, many factors and processes, some observable, but others not, influence deformation to a greater or lesser extent. These include the type of rock that forms the volcano, its tectonic characteristics and the supply rate and storage depth of magma beneath it. Thus deformation can have different implications for different types of volcanoes.
For volcanoes with short eruption cycles the satellite record typically spans episodes that include both deformation and eruption, resulting in a high correlation between the two. For volcanoes with long eruption cycles the satellite record tends to capture either deformation or eruption but rarely both.
Seismological data indicate unrest before eruption may only be a few days
In the past, radar images of the majority of the world’s volcanoes were only acquired a few times a year, but seismological data indicate that the duration of unrest before an eruption might be as short as only a few days.
“This study demonstrates what can be achieved with global satellite coverage even with limited acquisitions,” Biggs said, “so we are looking forward to the step-change in data quantity planned for the next generation of satellites.”
The European Space Agency launched its latest radar mission, Sentinel-1, in early April. The mission is designed for global monitoring and will collect images every six to twelve days. Using this, scientists should be able to test the causal and temporal relationship with deformation on much shorter timescales.
“This study is particularly exciting because Sentinel-1 will soon give us systematic observations of the ups and downs of every volcano on the planet,” said Tim Wright, director of the U.K. Centre for Observation and Modelling of Earthquakes. “For many places, particularly in developing countries, these data could provide the only warning of an impending eruption.”
Note : The above story is based on materials provided by Southern Methodist University
The map shows the fractional amount of surface water that is likely to enter the hyporheic zone, where it can undergo filtration. Orange and red represent areas experiencing a lower fraction of water entering the hyporheic zone. Dark blue areas approach 100 percent likelihood water will enter the zone. Credit: Kiel and Cardenas, Jackson School of Geosciences, The University of Texas at Austin.
A new method of measuring the interaction of surface water and groundwater along the length of the Mississippi River network adds fresh evidence that the network’s natural ability to chemically filter out nitrates is being overwhelmed.
The research by hydrogeologists at The University of Texas at Austin, which appears in the May 11 edition of the journal Nature Geoscience, shows for the first time that virtually every drop of water coursing through 311,000 miles (500,000 kilometers) of waterways in the Mississippi River network goes through a natural filtering process as it flows to the Gulf of Mexico.
The analysis found that 99.6 percent of the water in the network passes through filtering sediment along the banks of creeks, streams and rivers.
Such a high level of chemical filtration might sound positive, but the unfortunate implication is that the river’s natural filtration systems for nitrates appear to be operating at or very close to full capacity. While further research is needed, this would make it unlikely that natural systems can accommodate the high levels of nitrates that have made their way from farmland and other sources into the river network’s waterways.
As a result of its filtration systems being overwhelmed, the river system operates less as a buffer and more as a conveyor belt, transporting nitrates to the Gulf of Mexico. The amount of nitrates flowing into the gulf from the Mississippi has already created the world’s second biggest dead zone, an oxygen-depleted area where fish and other aquatic life can’t survive.
The research, conducted by Bayani Cardenas, associate professor of hydrogeology, and Brian Kiel, a Ph.D. candidate in geology at the university’s Jackson School of Geosciences, provides valuable information to those who manage water quality efforts, including the tracking of nitrogen fertilizers used to grow crops in the Midwest, in the Mississippi River network.
“There’s been a lot of work to understand surface-groundwater exchange,” said Aaron Packman, a professor in the Department of Civil and Environmental Engineering at Northwestern University. “This is the first work putting together a physics-based estimate on the scale of one of these big rivers, looking at the net effect of nitrate removal in big river systems.”
The Mississippi River network includes the Ohio River watershed on the east and the Missouri River watershed in the west as well as the Mississippi watershed in the middle.
Using detailed, ground-level data from the United States Geological Survey (USGS) and Environmental Protection Agency, Cardenas and Kiel analyzed the waterways for sinuosity (how much they bend and curve); the texture of the materials along the waterways; the time spent in the sediment (known as the hyporheic zone); and the rate at which the water flows through the sediment.
The sediment operates as a chemical filter in that microbes in the sand, gravel and mud gobble up compounds such as oxygen and nitrates from the water before the water discharges back into the stream. The more time the water spends in sediment, the more some of these compounds are transformed to potentially more environmentally benign forms.
One compound, nitrate, is a major component of inorganic fertilizers that has helped make the area encompassed by the Mississippi River network the biggest producer of corn, soybeans, wheat, cattle and hogs, in the United States.
But too much nitrogen robs water of oxygen, resulting in algal blooms and dead zones.
While the biggest source of nitrates in the Mississippi River network are industrial fertilizers, nitrates also come from animal manure, urban areas, wastewater treatment and other sources, according to USGS.
Cardenas and Kiel found that despite an image of water flowing freely downstream, nearly each drop gets caught up within the bank at one time or another. But not much of the water—only 24 percent—lingers long enough for nitrate to be chemically extracted.
The “residence times” when water entered the hyporheic zones ranged from less than an hour in the river system’s headwaters to more than a month in larger, meandering channels. A previous, unrelated study of hyporheic zones found that a residence time of about seven hours is required to extract nitrogen from the water.
Cardenas said the research provides a large-scale, holistic view of the river network’s natural buffering mechanism and how it is failing to operate effectively.
“Clearly for all this nitrate to make it downstream tells us that this system is very overwhelmed,” Cardenas said.
The new model, he added, can be a first step to enable a wider analysis of the river system.
When a river system gets totally overwhelmed, “You lose the chemical functions, the chemical buffering,” said Cardenas. “I don’t know whether we’re there already, but we are one big step closer to the answer now.”
Note : The above story is based on materials provided by University of Texas at Austin
Chemical Formula: Zn3(AsO4)2·8H2O Locality: Daniel mine, Scheeberg, Saxony, Germany. Name Origin: Named for Otto Köttig (1824-1892), chemist of Schneeberg, Saxony, Germany.
Köttigite is a rare hydrated zinc arsenate which was discovered in 1849 and named by James Dwight Dana in 1850 in honour of Otto Friedrich Köttig (1824 – 1892), a German chemist from Schneeberg, Saxony, who made the first chemical analysis of the mineral. It has the formula Zn3(AsO4)2·8H2O and it is a dimorph of metaköttigite, which means that the two minerals have the same formula, but a different structure: köttigite is monoclinic and metaköttigite is triclinic. There are several minerals with similar formulae but with other cations in place of the zinc. Iron forms parasymplesite Fe2+3(AsO4)2.8H2O; cobalt forms the distinctively coloured pinkish purple mineral erythrite Co3(AsO4)2.8H2O and nickel forms annabergite Ni3(AsO4)2.8H2O. Köttigite forms series with all three of these minerals and they are all members of the vivianite group.
An international research team led by Newcastle University, UK, reveal Earth’s mantle under Antarctica is at a lower viscosity and moving at such a rapid rate it is changing the shape of the land at a rate that can be recorded by GPS.
At the surface, Antarctica is a motionless and frozen landscape. Yet hundreds of miles down the Earth is moving at a rapid rate, new research has shown.
The study, led by Newcastle University, UK, and published this week in Earth and Planetary Science Letters, explains for the first time why the upward motion of Earth’s crust in the Northern Antarctic Peninsula is currently taking place so quickly.
Previous studies have shown Earth is ‘rebounding’ due to the overlying ice sheet shrinking in response to climate change. This movement of the land was understood to be due to an instantaneous, elastic response followed by a very slow uplift over thousands of years.
But GPS data collected by the international research team, involving experts from Newcastle University, UK; Durham University; DTU, Denmark; University of Tasmania, Australia; Hamilton College, New York; the University of Colorado and the University of Toulouse, France, has revealed that the land in this region is actually rising at a phenomenal rate of 15mm a year — much greater than can be accounted for by the present-day elastic response alone.
And they have shown for the first time how the mantle below Earth’s crust in the Antarctic Peninsula is flowing much faster than expected, probably due to subtle changes in temperature or chemical composition.
This means it can flow more easily and so responds much more quickly to the lightening load hundreds of miles above it, changing the shape of the land.
Lead researcher, PhD student Grace Nield, based in the School of Civil Engineering and Geosciences at Newcastle University, explains: “You would expect this rebound to happen over thousands of years and instead we have been able to measure it in just over a decade. You can almost see it happening which is just incredible.
“Because the mantle is ‘runnier’ below the Northern Antarctic Peninsula it responds much more quickly to what’s happening on the surface. So as the glaciers thin and the load in that localised area reduces, the mantle pushes up the crust.
“At the moment we have only studied the vertical deformation so the next step is to look at horizontal motion caused by the ice unloading to get more of a 3-D picture of how Earth is deforming, and to use other geophysical data to understand the mechanism of the flow.”
Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, causing the solid Earth to ‘bounce back’.
“Think of it a bit like a stretched piece of elastic,” says Nield, whose project is funded by the Natural Environment Research Council (NERC).
“The ice is pressing down on the Earth and as this weight reduces the crust bounces back. But what we found when we compared the ice loss to the uplift was that they didn’t tally — something else had to be happening to be pushing the solid Earth up at such a phenomenal rate.
“Collating data from seven GPS stations situated across the Northern Peninsula, the team found the rebound was so fast that the upper mantle viscosity — or resistance to flow — had to be at least ten times lower than previously thought for the region and much lower than the rest of Antarctica.
Professor Peter Clarke, Professor of Geophysical Geodesy at Newcastle University and one of the authors of the paper, adds: “Seeing this sort of deformation of the Earth at such a rate is unprecedented in Antarctica. What is particularly interesting here is that we can actually see the impact that glacier thinning is having on the rocks 250 miles down.”
Note : The above story is based on materials provided by Newcastle University.
Image shows surface oil, emulsions and tar mats. Credit: Samantha Joye
The 2010 Deepwater Horizon blowout discharged roughly five million gallons of oil and up to 500,000 tons of natural gas into Gulf of Mexico offshore waters over a period of 84 days. In the face of a seemingly insurmountable cleanup effort, many were relieved by reports following the disaster that naturally-occurring microbes had consumed much of the gas and oil.
Now, a team of researchers led by University of Georgia marine scientists have published a paper in the journal Nature Geoscience that questions this conclusion and provides evidence that microbes may not be capable of removing contaminants as quickly and easily as once thought.
“Most of the gas injected into the Gulf was methane, a potent greenhouse gas that contributes to global climate change, so we were naturally concerned that this potent greenhouse gas could escape into the atmosphere,” said Samantha Joye, senior author of the paper, director of the study and professor of marine science in UGA’s Franklin College of Arts and Sciences. “Many assumed that methane-oxidizing microbes would simply consume the methane efficiently, but our data suggests that this isn’t what happened.”
Joye and colleagues from other universities and government organizations measured methane concentrations and the activity of methane-consuming bacteria for ten months, starting before the blowout with collection of an invaluable set of pre-discharge samples taken in March 2010.
The abundance of methane in the water allowed the bacteria that feed on the gas to flourish in the first two months immediately following the blowout, but their activity levels dropped abruptly despite the fact that methane was still being released from the wellhead.
This new data suggests the sudden drop in bacterial activity was not due to an absence of methane, but a host of environmental, physiological, and physical constraints that made it difficult or impossible for bacteria to consume methane effectively.
“For these bacteria to work efficiently, they need unlimited access to nutrients like inorganic nitrogen and trace metals, but they also need elevated methane levels to persist long enough to support high rates of consumption,” Joye said. “The bacteria in the Gulf were probably able to consume about half of the methane released, but we hypothesize that an absence of essential nutrients and the dispersal of gas throughout the water column prevented complete consumption of the discharged methane.”
Joye insists that while her group’s conclusions differ from those presented in previous studies, there is no serious conflict between their analyses.
“The issue here was short-term sampling versus long-term time series sampling,” she said. “I hope our paper clearly relays the message that long-term sampling is the only way to capture the evolution of a natural system as it responds to large perturbations like oil well blowouts or any other abrupt methane release.”
Ultimately, scientists need to better understand the behavior of these microbes so that they may better gauge the environmental impacts of future accidents and methane releases due to climate change, she said.
“It’s only a matter of time before we face another serious incident like Deepwater Horizon,” Joye said. “The key is understanding the things that regulate how fast bacteria can consume methane, and that will give us insight into the ultimate fate of this potent greenhouse gas in our oceans.”
Note : The above story is based on materials provided by University of Georgia
Chemical Formula: (Mg,Fe2+)4(Al,Fe3+)6(SiO4,BO4)5(O,OH)2 Locality: Fiskernaes, SW Greenland. Name Origin: Named after the Danish geologist, Andreas Nikolaus Kornerup (1857-1881).
Kornerupine is a rare boro-silicate mineral with the formula (Mg,Fe2+)4(Al,Fe3+)6(SiO4,BO4)5(O,OH)2. It crystallizes in the orthorhombic – dipyramidal crystal system as brown, green, yellow to colorless slender tourmaline like prisms or in massive fibrous forms. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.34. Its indices of refraction are nα=1.660 – 1.671, nβ=1.673 – 1.683 and nγ=1.674 – 1.684.
It occurs in boron-rich volcanic and sedimentary rocks which have undergone high grade metamorphism. It is also found in metamorphosed anorthosite complexes.
Kornerupine is valued as a gemstone when it is found in translucent green to yellow shades. The emerald green varieties are especially sought after.
It was first described in 1884 for an occurrence in Fiskernaes in SW Greenland. It was named in honor of the Danish geologist, Andreas Nikolaus Kornerup (1857–1883)
Plexus ricei was a broadly curving tube that resided on the Ediacaran seafloor. Individuals range in size from 5 to 80 cm long and 5 to 20 mm wide, and are comprised of two main components: a rigid median tubular structure and a fragile outer tubular wall. Letters and arrows point to the fossil. Credit: Droser Lab, UC Riverside.
Scientists at the University of California, Riverside have discovered a fossil of a newly discovered organism from the “Ediacara Biota” — a group of organisms that occurred in the Ediacaran period of geologic time.
Named Plexus ricei and resembling a curving tube, the organism resided on the Ediacaran seafloor. Plexus ricei individuals ranged in size from 5 to 80 centimeters long and 5 to 20 millimeters wide. Along with the rest of the Ediacara Biota, it evolved around 575 million years ago and disappeared from the fossil record around 540 million years ago, just around the time the Cambrian Explosion of evolutionary history was getting under way.
“Plexus was unlike any other fossil that we know from the Precambrian,” said Mary L. Droser, a professor of paleontology, whose lab led the research. “It was bilaterally symmetrical at a time when bilaterians — all animals other than corals and sponges — were just appearing on this planet. It appears to have been very long and flat, much like a tapeworm or modern flatworm.”
Study results appeared online last month in the Journal of Paleontology.
“Ediacaran fossils are extremely perplexing: they don’t look like any animal that is alive today, and their interrelationships are very poorly understood,” said Lucas V. Joel, a former graduate student at UC Riverside and the first author of the research paper. Joel worked in Droser’s lab until June 2013.
He explained that during the Ediacaran there was no life on land. All life that we know about for the period was still in the oceans.
“Further, there was a complete lack of any bioturbation in the oceans at that time, meaning there were few marine organisms churning up marine sediments while looking for food,” he said. “Then, starting in the Cambrian period, organisms began churning up and mixing the sediment.”
According to the researchers, the lack of bioturbators during the Ediacaran allowed thick films of (probably) photosynthetic algal mats to accumulate on ocean floors — a very rare environment in the oceans today. Such an environment paved the way for many mat-related lifestyles to evolve, which become virtually absent in the post-Ediacaran world.
“The lack of bioturbation also created a very unique fossil preservational regime,” Joel said. “When an organism died and was buried, it formed a mold of its body in the overlying sediment. As the organism decayed, sediment from beneath moved in to form a cast of the mold the organism had made in the sediment above. What this means is that the fossils we see in the field are not the exact fossils of the original organism, but instead molds and casts of its body.”
Paleontologists have reported that much of the Ediacara Biota was composed of tubular organisms. The question that Droser and Joel addressed was: Is Plexus ricei a tubular organism or is it an organism that wormed its way through the sand, leaving a trail behind it?
“In the Ediacaran we really need to know the difference between the fossils of actual tubular organisms and trace fossils because if the fossil we are looking at is a trace fossil, then that has huge implications for the earliest origins of bilaterian animals — organisms with bilateral symmetry up and down their midlines and that can move independently of environment forces,” Joel said. “Being able to tell the difference between a tubular organism and a trace fossil has implications for the earliest origins of bilaterian organism, which are the only kinds of creatures that could have constructed a tubular trace fossil. Plexus is not a trace fossil. What our research shows is that the structure we see looks very much like a trace fossil, but is in fact a new Ediacaran tubular organism, Plexus ricei.”
Plexus ricei was so named for plexus, meaning braided in Latin, a reference to the organism’s morphology, and ricei for Rice, the last name of the South Australian Museum’s Dennis Rice, one of the field assistants who helped excavate numerous specimens of the fossil.
“At this time, we don’t know for sure that Plexus ricei was a bilateral but it is likely that it was related to our ancestors,” Droser said.
Note : The above story is based on materials provided by University of California – Riverside.
This false-colored infrared image from NASA’s AIRS instrument shows the high, cold cloud tops (purple) associated with the thunderstorms in System 91B as it moves over southern Mexico on May 8 at 20:11 UTC/4:11 p.m. EDT. Credit: NASA JPL, Ed Olsen
As the dissipating tropical low pressure system known as System 90E continued rain on Guerrero State in southern Mexico, the U.S. Geological Survey reported a 6.4 magnitude earthquake occurred there on Thursday, May 8 around noon local time (1 p.m. EDT). NASA’s Aqua satellite captured an infrared image of the low pressure area just three hours after the earthquake.
As showers fell on Guerrero State, USGS noted that the quake’s center was 9.3 miles (5 km) north of Tecpan de Galeana, Mexico. That’s about 60 miles (96.5 km) northwest of Acapulco and 172 miles (276.8 km) southwest of Mexico City. According to USGS, back on April 18, an 7.2 earthquake occurred just 40 miles from yesterday’s epicenter.
A false-colored infrared image from NASA’s Atmospheric Infrared Sounder (AIRS) instrument showed high, cold cloud tops associated with the thunderstorms in System 90E moving over southern Mexico on May 8 at 20:11 UTC/4:11 p.m. EDT. Some of the cloud tops were near -63 F (-52C) indicating some potential for heavy rainfall.
On May 9, the National Hurricane Center (NHC) noted that showers and thunderstorms associated with System 90E continued to become less organized during the early morning hours. The low pressure area is large and centered about 150 miles (241.4 km) southwest of Zihuatenejo, Guerrero State, Mexico.
The NHC discussion on May 9 noted that the upper-level winds have become unfavorable for development and this system, so System 90E now has a very low chance, near 0 percent of becoming a tropical cyclone during the next 48 hours or over the next five days for that matter- which is good news for southwestern Mexico.
Despite not having the potential to develop, however, System 90E is expected to continue to produce locally heavy rainfall and gusty winds over portions of southwestern Mexico during the next day or so, according to NHC. The Mexican Weather Service noted that System 90E has the potential to bring torrential rainfall to Michoacán and Guerrero states totaling between 5.9 to 9.8 inches (150 to 250 mm). These rains could produce life-threatening flash floods and mud slides.
Video :
Note :The above story is based on materials provided by NASA’s Goddard Space Flight Center
Chemical Formula: (Hg2N)(Cl,SO4)·nH2O Locality: Terlingua, Brewster Co., Taxas, USA. Name Origin: Named for Carl Klein (1832-1907), German mineralogist, University of Berlin.
History
Discovery date: 1905 Town of Origin : TERLINGUA, BREWSTER CO., TEXAS Country of Origin : USA
Optical properties
Optical and misc. Properties : Translucent to subtranslucent Refractive Index : from 2,19 to 2,21
Physical Properties
Cleavage: {0001} Good Color: Yellow, Orange. Density: 8 Diaphaneity: Translucent to subtranslucent Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Hardness: 3.5 – Copper Penny Luminescence: Non-fluorescent. Luster: Adamantine Magnetism: Nonmagnetic Streak: yellow
This is a view of the palate of the new, small sparassodont from Bolivia. The front end is to the right. The scale bar is 1 cm. Credit: Rick Wherley of the Cleveland Museum of Natural History
A Case Western Reserve University student and his mentor have discovered an ancient kitten-sized predator that lived in Bolivia about 13 million years ago — one of the smallest species reported in the extinct order Sparassodonta.
Third-year undergraduate student Russell Engelman and Case Western Reserve anatomy professor Darin Croft made the finding by analyzing a partial skull that had been in a University of Florida collection more than three decades.
The researchers report their finding in the Journal of Vertebrate Paleontology.
“The animal would have been about the size of a marten, a catlike weasel found in the Northeastern United States and Canada, and probably filled the same ecological niche,” said Engelman, an evolutionary biology major from Russell Township, Ohio.
The researchers refrained from naming the new species mainly because the specimen lacks well-preserved teeth, which are the only parts preserved in many of its close relatives.
The skull, which would have been a little less than 3 inches long if complete, shows the animal had a very short snout. A socket, or alveolus, in the upper jaw shows it had large, canines, that were round in cross-section much like those of a meat-eating marsupial, called the spotted-tailed quoll, found in Australia today, the researchers said.
Although sparassodonts are more closely related to modern opossums than cats and dogs, the group included saber-toothed species that fed on large prey. This small Bolivian species probably fed on the ancient relatives of today’s guinea pigs and spiny rats, the researchers said.
“Most predators don’t go after animals of equal size, but these features indicate this small predator was a formidable hunter,” Croft said.
The specimen had not been studied in detail after being collected. It was provisionally identified as belonging to a particular group of extinct meat-eating opossums, due in part to its small size. Further adding to the identity challenge, almost all small sparassodonts have been identified by their teeth and lower jaws, which this skull lacks.
Croft wanted to study the skull because its age is nearly twice that of the oldest known species of meat-eating opossum. The specimen was found in a mountainous site known as Quebrada Honda, Bolivia, in 1978, in rock layers dated 12 million to 13 million years ago.
Structurally, extinct meat-eating opossums and sparassodont skulls share a number of similarities due to their similar meat-eating diet, Engelman said.
“No single feature found in the skull was so distinctive that we could say one way or the other what it was,” Croft said, “but the combination of features is unique and says this is a sparassodont.”
One key was that a particular bone of the orbit, the boney socket of the eye, does not touch the nasal bone in an opossum but does in a sparassodont.
The short snout was a kind of red herring. While jaguar-sized sparassodonts had them, the smaller members of the order had fox-like faces. And this species was smaller than most of those.
These smaller sparassodonts also have gaps between their teeth that are absent in most larger species. The skull shows no gaps.
Overall, the animal’s features are a mixture of those found in different species of sparassodonts, but are not characteristic of in any one subgroup within the order. That puts this species near the bottom of the family tree, the researchers said.
Croft, who regularly collects from the same site where the skull was found, will return there this summer to gather evidence he hopes will show whether this species lived in an open grassland, forest or mixed habitat.
He also hopes to find the lower jaw, which may enable direct comparisons with known species and provide enough foundation to name the animal.
Note : The above story is based on materials provided by Case Western Reserve University.
Mountains in Yunnan Province, China. Credit: Copyright Adrien Favre
A team of Austrian, Swiss and German researchers of the Biodiversity and Climate Research Centre (BiK-F), the Senckenberg Gesellschaft für Naturforschung and the German Centre for Integrative Biodiversity Research (iDiv), from the University of Leipzig and the Leibniz-Institute of Freshwater Ecology has summarized the current state of knowledge on the diversification of Tibetan plants and animals. The study focuses in particular on how the geological processes that led to the rise of the Qinghai-Tibetan Plateau and Himalayas affected diversification and speciation directly, and indirectly, e.g. by changing climatic conditions. The paper was recently published in Biological Reviews.
“We believe this paper may become a benchmark for geo-biological studies worldwide. It links the geological, climatic and evolutionary history of one of the most fascinating and biodiverse regions of the world, and builds up a promising framework for more hypothesis-driven and synthetic research,” says Prof. Alexandra Muellner-Riehl, from the Department of Molecular Evolution and Systematics of Plants in Leipzig. She heads the DFG Research Cluster and is also member of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig.
Muellner-Riehl and her collaborators found that the link between diversity, speciation and the geological processes was still poorly understood. They identified two main reasons for this: different authors tend to use a different geological framework in their studies, and they apply different analytical approaches and data that are poorly comparable.
The authors show three ways how our understanding of the link between uplift processes of the Qinghai-Tibetan Plateau and the Himalayas and species diversity can be improved: 1) They provide a state-of-the-art scenario how the uplift occurred and how this influenced regional climates over the last 40 million years; this will allow future researchers to formulate clear and comparable hypotheses. 2) They summarize recent analytical developments that allow scientists to make the link between geology and diversification more quantitative and less ad hoc. 3) They propose using meta-analyses of many comparable data sets to help researchers gain a broader understanding of species diversity in the region.
“It is very likely that the uplift of the Qinghai-Tibetan Plateau had different impacts on the evolution of different taxa,” lead author Dr. Adrien Favre, Department of Molecular Evolution and Systematics of Plants, University of Leipzig, Germany, points out. “We wanted to provide details on the criteria that individual data sets should meet to guide future research,” adds co-author Dr. Steffen Pauls, Biodiversity and Climate Research Centre (BiK-F).
Note : The above story is based on materials provided by Forschungsverbund Berlin e.V. (FVB).
Chemical Formula:Na
2B
4O
6(OH)
2·3(H
2O) Locality: Boron, Kern County, California, the county that contains the fabulous borate deposits at Kramer. Name Origin: Named after it’s locality.
Kernite, also known as rasorite is a hydrated sodium borate hydroxide mineral with formula Na
2B
4O
6(OH)
2·3(H
2O) , It is a colorless to white mineral crystallizing in the monoclinic crystal system typically occurring as prismatic to acicular crystals or granular masses. It is relatively soft with Mohs hardness of 2.5 to 3 and light with a specific gravity of 1.91. It exhibits perfect cleavage and a brittle fracture.
Kernite is soluble in cold water and alters to tincalconite when it dehydrates. It undergoes a non-reversible alteration to metakernite (Na
2B
4O
7·5(H
2O)) when heated to above 100°C.
Occurrence and history
The mineral occurs in sedimentary evaporite deposits in arid regions.
Kernite was discovered in 1926 in eastern Kern County, in Southern California, and later renamed after the county. The location was the US Borax Mine at Boron in the western Mojave Desert. This type material is stored at Harvard University, Cambridge, Massachusetts, and the National Museum of Natural History, Washington, D.C.
The Kern County mine was the only known source of the mineral for a period of time. More recently, kernite is mined in Argentina and Turkey.
The largest documented, single crystal of kernite measured 2.44 x 0.9 x 0.9 m3 and weighed ~3.8 tons.
Physical Properties
Cleavage: {100} Perfect, {001} Perfect, {201} Good Color: Colorless, White. Density: 1.9 – 1.92, Average = 1.91 Diaphaneity: Transparent to translucent Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Hardness: 2.5-3 – Finger Nail-Calcite Luminescence: Non-fluorescent. Luster: Vitreous – Pearly Streak: white
Dinosaur phylogeny showing nodes with exceptional rates of body size evolution. Credit: Benson RBJ, Campione NE, Carrano MT, Mannion PD, Sullivan C, et al. (2014) Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage. PLoS Biol 12(5): e1001853. doi:10.1371/journal.pbio.1001853
Although most dinosaurs went extinct 65 million years ago, one dinosaur lineage survived and lives on today as a major evolutionary success story — the birds.
A study that has ‘weighed’ hundreds of dinosaurs suggests that shrinking their bodies may have helped the group that became birds to continue exploiting new ecological niches throughout their evolution, and become hugely successful today.
An international team, led by scientists at Oxford University and the Royal Ontario Museum, estimated the body mass of 426 dinosaur species based on the thickness of their leg bones. The team found that dinosaurs showed rapid rates of body size evolution shortly after their origins, around 220 million years ago. However, these soon slowed: only the evolutionary line leading to birds continued to change size at this rate, and continued to do so for 170 million years, producing new ecological diversity not seen in other dinosaurs.
A report of the research is published in PLOS Biology.
‘Dinosaurs aren’t extinct; there are about 10,000 species alive today in the form of birds. We wanted to understand the evolutionary links between this exceptional living group, and their Mesozoic relatives, including well-known extinct species like T. rex, Triceratops, and Stegosaurus,’ said Dr Roger Benson of Oxford University’s Department of Earth Sciences, who led the study. ‘We found exceptional body mass variation in the dinosaur line leading to birds, especially in the feathered dinosaurs called maniraptorans. These include Jurassic Park’s Velociraptor, birds, and a huge range of other forms, weighing anything from 15 grams to 3 tonnes, and eating meat, plants, and more omnivorous diets.’
The team believes that small body size might have been key to maintaining evolutionary potential in birds, which broke the lower body size limit of around 1 kilogram seen in other dinosaurs.
‘How do you weigh a dinosaur? You can do it by measuring the thickness of its leg bones, like the femur. This is quite reliable,’ said Dr Nicolás Campione, of the Uppsala University, a member of the team. ‘This shows that the biggest dinosaur Argentinosaurus, at 90 tonnes, was 6 million times the weight of the smallest Mesozoic dinosaur, a sparrow-sized bird called Qiliania, weighing 15 grams. Clearly, the dinosaur body plan was extremely versatile.’
The team examined rates of body size evolution on the entire family tree of dinosaurs, sampled throughout their first 160 million years on Earth. If close relatives are fairly similar in size, then evolution was probably quite slow. But if they are very different in size, then evolution must have been fast.
‘What we found was striking. Dinosaur body size evolved very rapidly in early forms, likely associated with the invasion of new ecological niches. In general, rates slowed down as these lineages continued to diversify,’ said Dr David Evans at the Royal Ontario Museum, who co-devised the project. ‘But it’s the sustained high rates of evolution in the feathered maniraptoran dinosaur lineage that led to birds — the second great evolutionary radiation of dinosaurs.’
The evolutionary line leading to birds kept experimenting with different, often radically smaller, body sizes — enabling new body ‘designs’ and adaptations to arise more rapidly than among larger dinosaurs. Other dinosaur groups failed to do this, got locked in to narrow ecological niches, and ultimately went extinct. This suggest that important living groups such as birds might result from sustained, rapid evolutionary rates over timescales of hundreds of millions of years, which could not be observed without fossils.
‘The fact that dinosaurs evolved to huge sizes is iconic,’ said team member Dr Matthew Carrano of the Smithsonian Institution’s National Museum of Natural History. ‘And yet we’ve understood very little about how size was related to their overall evolutionary history. This makes it clear that evolving different sizes was important to the success of dinosaurs.’
Note : The above story is based on materials provided by University of Oxford.
Scientists have used state-of-the-art imaging techniques to examine the cracks, fractures and breaks in the bones of a 150 million-year-old predatory dinosaur. Credit: Phil Manning
Scientists have used state-of-the-art imaging techniques to examine the cracks, fractures and breaks in the bones of a 150 million-year-old predatory dinosaur.
The University of Manchester researchers say their groundbreaking work – using synchrotron-imaging techniques – sheds new light, literally, on the healing process that took place when these magnificent animals were still alive.
The research, published in the Royal Society journal Interface, took advantage of the fact that dinosaur bones occasionally preserve evidence of trauma, sickness and the subsequent signs of healing.
Diagnosis of such fossils used to rely on the grizzly inspection of gnarled bones and healed fractures, often entailing slicing through a fossil to reveal its cloying secrets. But the synchrotron-based imaging, which uses light brighter than 10 billion Suns, meant the team could tease out the chemical ghosts lurking within the preserved dinosaur bones.
The impact of massive trauma, they discovered, seemed to be shrugged off by many predatory dinosaurs – fossil bones often showed a multitude of grizzly healed injuries, most of which would prove fatal to humans if not medically treated.
Dr Phil Manning, one of the paper’s authors based in Manchester’s School of Earth, Atmospheric and Environmental Sciences, said: “Using synchrotron imaging, we were able to detect astoundingly dilute traces of chemical signatures that reveal not only the difference between normal and healed bone, but also how the damaged bone healed.
“It seems dinosaurs evolved a splendid suite of defence mechanisms to help regulate the healing and repair of injuries. The ability to diagnose such processes some 150 million years later might well shed new light on how we can use Jurassic chemistry in the 21st Century.”
He continued: “The chemistry of life leaves clues throughout our bodies in the course of our lives that can help us diagnose, treat and heal a multitude of modern-day ailments. It’s remarkable that the very same chemistry that initiates the healing of bone in humans also seems to have followed a similar pathway in dinosaurs.”
Co-author Jennifer Anné said: “Bone does not form scar tissue, like a scratch to your skin, so the body has to completely reform new bone following the same stages that occurred as the skeleton grew in the first place. This means we are able to tease out the chemistry of bone development through such pathological studies.
“It’s exciting to realise how little we know about bone, even after hundreds of years of research. The fact that information on how our own skeleton works can be explored using a 150-million-year-old dinosaur just shows how interlaced science can be.”
Professor Roy Wogelius, another co-author from The University of Manchester, added: “It is a fine line when diagnosing which part of the fossil was emplaced after burial and what was original chemistry to the organism. It is only through the precise measurements that we undertake at the Diamond Synchrotron Lightsource in the UK and the Stanford Synchrotron Lightsource in the US that we were able to make such judgments.”
Note : The above story is based on materials provided by Manchester University.
Chemical Formula: Sb2S2O Locality: Braunsdorf, near Freiberg, Saxony, Germany. Name Origin: Name from kermes, a name given from the Persian qurmizq, “crimson” in the older chemistry to red amorphous antimony trisulphide, often mixed with antimony trioxide.Kermesite or antimony oxysulfide is also known as red antimony (Sb2S2O) . The mineral’s color ranges from cherry red to a dark red to a black. Kermesite is the result of partial oxidation between stibnite (Sb2S3)) and other antimony oxides such as valentinite (Sb2O3) or stibiconite (Sb3O6(OH)). Under certain conditions with oxygenated fluids the transformation of all sulfur to oxygen would occur but kermesite occurs when that transformation is halted.
Physical Properties
Cleavage: {100} Perfect Color: Violet red, Cherry red, Red. Density: 4.5 – 4.6, Average = 4.55 Diaphaneity: Translucent to Opaque Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals. Hardness: 1.5-2 – Talc-Gypsum Luminescence: Non-fluorescent. Luster: Adamantine Magnetism: Nonmagnetic Streak: brownish red
Ice core in the drill head. Past variations of local surface temperatures in polar regions are reconstructed by analysing ice cores drilled in Greenland and Antarctica. Credit: Laurent Augustin
Analysis of data collected from ice cores and marine sediment cores in both polar regions has given scientists a clearer picture of how the Earth’s climate changed during the last Interglacial period. This comparatively warm time period occurred between 130,000 and 115,000 years ago.
By lining up the records, and establishing a common chronology, Dr Emilie Capron, from British Antarctic Survey, concluded that Antarctica was a few degrees warmer than it is today and that the Southern Hemisphere warmed earlier than the Northern Hemisphere.
Results from her findings have been presented to the European Geosciences Union General Assembly in Vienna, Austria this week (27th April – 2nd May 2014).
Dr. Capron said: “To understand our changing climate we need to go back in time. Past warm periods, called interglacials, are particularly interesting because they provide insights as to how current natural changes may interact with those originating from human influences.”
The results, which have been submitted to a science journal for publication, will help climate modellers predict future climate change. Questions remain about the contribution Antarctic and Greenland glaciers may make towards sea level rise.
Dr Capron’s results not only confirm the last interglacial period was warmer than today but also that surface temperature peaks weren’t uniform across the globe.
Data from more than forty cores were examined as part of the research project.
The work is part of a broad ranging interdisciplinary programme, the iGlass consortium, which integrates new field data, data synthesis and numerical modelling, in order to study the response of ice volume and sea level to different climatic states during the last five interglacial periods.
Over the last 1 million years, the Earth’s climate has alternated between warm interglacial periods and cold glacial periods characterised by the growth of ice sheets in the northern hemisphere. Interglacials re-occur roughly every 100,000 years between ice ages. The present interglacial began around 10,000 years ago and has been relatively stable since then.
Note : The above story is based on materials provided by British Antarctic Survey
File photo taken in March 2014 shows scientists work at the Comandante Ferraz base in Antarctica
Polar scientists said Thursday they had successfully drilled a 2,000-year-old ice core in the heart of Antarctica in a bid to retrieve a frozen record of how the planet’s climate has evolved.
The Aurora Basin North project involves scientists from Australia, China, France, Denmark, Germany and the United States who hope it will also advance the search for the scientific “holy grail” of the million-year-old ice core.
The five-week expedition, in a hostile area that harbours some of the deepest ice in the frozen continent, over three kilometres (1.9-miles) thick, will give experts access to some of the most detailed records yet of past climate in the vast region.
About two tonnes of ice core sections drilled at Aurora Basin, 500 kilometres (310 miles) inland of Australia’s Casey station, is now being distributed to Australian and international ice core laboratories.
They will conduct an analysis of atmospheric gases, particles and other chemical elements that were trapped in snow as it fell and compacted to form ice.
Australian Antarctic Division glaciologist and project leader Mark Curran said it will help fill a gap in the science community’s knowledge of climate records.
“Using a variety of scientific tests on each core, we’ll be able to obtain information about the temperature under which the ice formed, storm events, solar and volcanic activity, sea ice extent, and the concentration of different atmospheric gases over time,” he said.
The team, working in temperatures of minus 30 Celsius, used a Danish Hans Tausen drill to extract the main 303-metre-long ice core, which will provide annual climate records for the past 2,000 years.
“There are only a handful of records with comparable resolution that extend to 2,000 years from the whole of Antarctica, and this is only the second one from this sector of East Antarctica,” added Curran.
Additionally two smaller drills were used to take out 116 and 103-metre cores spanning the past 800 to 1,000 years.
Data collected during the drill should help scientists locate a suitable site for a more ambitious expedition to collect a one million year-old ice core in the future.
“Such an ice core would help us understand what caused a dramatic shift in the frequency of ice ages about 800,000 years ago, and further understand the role of carbon dioxide in climate change,” said Curran.
This is a map showing the location of Daisy and Old Faithful geysers in Yellowstone’s Upper Geyser Basin. Inset map of Yellowstone National Park shows the weather station at Yellowstone Lake, seismic stations LKWY and H17A, and strainmeter B944. Credit: Journal of Geophysical Research: Solid Earth, DOI:10.1002/2013JB010803
The intervals between geyser eruptions depend on a delicate balance of underground factors, such as heat and water supply, and interactions with surrounding geysers. Some geysers are highly predictable, with intervals between eruptions (IBEs) varying only slightly. The predictability of these geysers offer earth scientists a unique opportunity to investigate what may influence their eruptive activity, and to apply that information to rare and unpredictable types of eruptions, such as those from volcanoes.
Dr. Shaul Hurwitz took advantage of a decade of eruption data—spanning from 2001 to 2011—for two of Yellowstone’s most predictable geysers, the cone geyser Old Faithful and the pool geyser, Daisy.
Dr. Hurwitz’s team focused their statistical analysis on possible correlations between the geysers’ IBEs and external forces such as weather, earth tides and earthquakes. The authors found no link between weather and Old Faithful’s IBEs, but they did find that Daisy’s IBEs correlated with cold temperatures and high winds. In addition, Daisy’s IBEs were significantly shortened following the 7.9 magnitude earthquake that hit Alaska in 2002.
The authors note that atmospheric processes exert a relatively small but statistically significant influence on pool geysers’ IBEs by modulating heat transfer rates from the pool to the atmosphere. Overall, internal processes and interactions with surrounding geysers dominate IBEs’ variability, especially in cone geysers.
More information: Shaul Hurwitz, Robert A. Sohn, Karen Luttrell, Michael Manga, “Triggering and modulation of geyser eruptions in Yellowstone National Park by earthquakes, earth tides, and weather”, Journal of Geophysical Research: Solid Earth, DOI: 10.1002/2013JB010803
Note :The above story is based on materials provided by Wiley
Chemical Formula: Sb2S2O
