The warm beauty of amber was captivating and mysterious enough to inspire myths in ancient times, and even today, some of its secrets remain locked inside the fossilized tree resin. But for the first time, scientists have now solved at least one of its puzzles that had perplexed them for decades. Their report on a key aspect of the gemstone’s architecture appears in the ACS journal Analytical Chemistry.
Jennifer Poulin and Kate Helwig of the Canadian Conservation Institute point out that much of the amber we see today had its origins millions of years ago, when it exuded from trees and then fossilized over time. Some of the oldest recovered samples even predate the rise of dinosaurs — and could outlast even the most advanced materials that science can make today. But it’s exactly that extreme durability that has made amber’s internal structure so difficult to understand. Scientists have used one particular technique to probe the inner molecular architecture of the ancient resin, but the process seemed to destroy evidence of certain relationships between compounds. Poulin and Helwig decided to try a new approach.
Building on past attempts using something called pyrolysis-gas chromatography-mass spectrometry, they slowed down the pyrolysis phase, which essentially uses heat to break down a substance. By doing so, the researchers were able to show that specific groups of atoms within their samples were bound to succinic acid, known historically as “spirit of amber.” “There can be no doubt that much of the stability and durability of certain kinds of amber comes from the succinic acid cross-linking within the matrix,” the researchers said.
Note : The above story is based on materials provided by American Chemical Society.
Chemical Formula: Mn(OH)2 Locality: Vermland at Pajsberg near Persberg, Sweden. Name Origin: Named from the Greek, puro, “fire” and khroma, “color”, because of the change in color upon ignition.
Both graceful and docile, this modern sandtiger shark swims through a school of round scad fish in the coastal waters off North Carolina. Modern sand tigers prefer waters of high salinity, though they tolerate brackish waters for short periods as well. Credit: Erik Rebeck
A new study shows that some shark species may be able to cope with the rising salinity of Arctic waters that may come with rising temperatures.
The Arctic today is best known for its tundra and polar bear population, but it wasn’t always like that. Roughly 53 to 38 million years ago during what is known as the Eocene epoch, the Arctic was more similar to a huge temperate forest with brackish water, home to a variety of animal life, including ancestors of tapirs, hippo-like creatures, crocodiles and giant tortoises. Much of what is known about the region during this period comes from well-documented terrestrial deposits. Marine records have been harder to come by.
A new study of shark teeth taken from a coastal Arctic Ocean site has expanded the understanding of Eocene marine life. Leading the study was Sora Kim, the T.C. Chamberlin Postdoctoral Fellow in Geophysical Sciences at the University of Chicago, in coordination with Jaelyn Eberle at the University of Colorado, Boulder, and their three co-authors. Their findings were published online June 30 by the journal Geology.
The Arctic is of special interest today because it is increasing in temperature at twice the global rate. According to Kim, past climate change in the Arctic can serve as a proxy to better understand our current climate change and aid future predictions. The Eocene epoch, she said, is like a “deep-time analogue for what’s going to happen if we don’t curb CO2 emissions today, and potentially what a runaway greenhouse effect looks like.”
Before this study, marine records primarily came from deep-sea cores pulled from a central Arctic Ocean site, the Lomonosov Ridge. Kim and Eberle studied shark teeth from a new coastal site on Banks Island. This allowed them to better understand the changes in ocean water salinity across a broader geographic area during a time of elevated global temperatures. Shark teeth are one of the few available vertebrate marine fossils for this time period. They preserve well and are incredibly abundant.
To arrive at their results, Kim isolated and measured the mass ratio of oxygen isotopes 18 to 16 found in the prepared enameloid (somewhat different from human tooth enamel) of the shark teeth. Sharks constantly exchange water with their environment, so the isotopic oxygen ratio found in the teeth is directly regulated by water temperature and salinity. With assumptions made about temperatures, the group was able to focus on extrapolating salinity levels of the water.
The results were surprising. “The numbers I got back were really weird,” Kim said. “They looked like fresh water.” The sand tiger sharks she was studying are part of a group called lamniform sharks, which prefer to stay in areas of high salinity.
“As more freshwater flows into the Arctic Ocean due to global warming, I think we are going to see it become more brackish,” said Eberle, associate professor of geological sciences at CU-Boulder. “Maybe the fossil record can shed some light on how the groups of sharks that are with us today may fare in a warming world.”
Because the teeth are 40 to 50 million years old, many tests were run to eliminate any possible contaminates, but the results were still the same. These findings suggest that sharks may be able to cope with rises in temperature and the subsequent decrease of water salinity. It has long been known that sharks are hardy creatures. They have fossil records dating back some 400 million years, surviving multiple mass extinctions, and have shown great ecological plasticity thus far.
Additionally, these results provide supporting evidence for the idea that the Arctic Ocean was most likely isolated from global waters.
“Through an analysis of fossil sand tiger shark teeth from the western Arctic Ocean, this study offers new evidence for a less salty Arctic Ocean during an ancient ‘greenhouse period,'” said Yusheng (Chris) Liu, program director in the National Science Foundation (NSF)’s Division of Earth Sciences, which co-funded the research with NSF’s Division of Polar Programs. “The results also confirm that the Arctic Ocean was isolated during that long-ago time.”
While Kim has hopes to expand her research both geographically and in geologic time in an effort to better understand the ecology and evolution of sharks, she remarked that “working with fossils is tricky because you have to work within the localities that are preserved. “You can’t always design the perfect experiment.”
Note : The above story is based on materials provided by University of Chicago.
Map of the Amazon Basin with the Purus River highlighted
The Purus is a tributary of the Amazon River in South America. Its drainage basin is 63,166 km2 (24,389 sq mi), and the mean discharge is 8,400 m³/s.
It enters the Amazon River west of the Madeira River, which it parallels as far south as the falls of the latter stream. It runs through a continuous forest at the bottom of the great depression lying between the Madeira River, which skirts the edge of the Brazilian sandstone plateau, and the Ucayali which hugs the base of the Andes. The river forms a small part of the international boundary between Brazil and Peru.
One of its marked features is the five parallel furos which from the north-west at almost regular intervals the Amazon sends to the Purus; the most south-westerly one being about 150 miles (240 km) above the mouth of the latter river. They cut a great area of very low-lying country into five islands. Farther down the Purus to the right three smaller furos also connect it with the Amazon.
William Chandless found its elevation above sea-level to be only 107 feet (33 m) 590 miles (950 km) from its mouth. It is one of the most crooked streams in the world, and its length in a straight line is less than half that by its curves. It is practically only a drainage ditch for the half-submerged, lake-flooded district it traverses.
Its width is very uniform for 1000 miles (1600 km) up, and for 800 miles (1300 km) its depth is never less than 45 feet (15 m).
It is navigable by steamers for 1648 miles (2650 km) as far as the little stream, the Curumaha, but only by light-draft craft. Chandless ascended it 1866 miles (3,000 km). At 1792 miles (2,880 km) it forks into two small streams. Occasionally a cliff touches the river, but in general the lands are subject to yearly inundations throughout its course, the river rising at times above 50 feet (15 m), the numerous lakes to the right and left serving as reservoirs.[citation needed]
In 2008, a previously unknown precolumbian civilization was discovered in the upper region of the river close to the Bolivian border. After much of the forest in the region was cleared for agricultural use, satellite pictures revealed the remains of large geometric earthworks.
Note : The above story is based on materials provided by Wikipedia
Locality: Scotch Lake quarry, Scotch Lake, Cape Breton County, Nova Scotia, Canada Source: Donald Doell
Chemical Formula: Mg6Fe3+2(OH)16[CO3]·4H2O Locality: Langbanshyttan, Sweden. Name Origin: From the Greek, pyro and the Latin aurium, “fire” and “golden” because of the gold-like submetallic scales present in its type locality.
This image shows the teeth (above and middle) and a side view of the lower jaw (below) of Heptodon, an ancient cousin to tapirs, found in early Eocene (52-million-year-old) rocks of northern British Columbia. This extinct mammal was about half the size of today’s tapirs. Credit: Jaelyn J. Eberle, Natalia Rybczynski, and David R. Greenwood
The Earth has experienced many dramatic changes in climate since the dinosaurs went extinct 66 million years ago. One of the warmest periods was the early Eocene Epoch, 50 to 53 million years ago. During this interval, North American mammal communities were quite distinct from those of today. This is illustrated by a study published in the latest issue of the Journal of Vertebrate Paleontology that describes an ancient hedgehog and tapir that lived in what is now Driftwood Canyon Provincial Park, British Columbia, some 52 million years ago.
“Within Canada, the only other fossil localities yielding mammals of similar age are from the Arctic, so these fossils from British Columbia help fill a significant geographic gap,” said Dr. Natalia Rybczynski of the Canadian Museum of Nature, a co-author of the study. Other fossils of this age come from Wyoming and Colorado, some 2,700 miles to the south of the Arctic site of Ellesmere Island.
The ancient hedgehog is a species hitherto unknown to science. It is named Silvacola acares, which means “tiny forest dweller,” since this minute hedgehog likely had a body length of only 2 to 2.5 inches. The delicate fossil jaw of Silvacola was not freed from the surrounding rock as is typical for fossils. Rather, it was scanned with an industrial, high resolution CT (computed tomography) scanner at Penn State University so it could be studied without risking damage to its tiny teeth. Modern hedgehogs and their relatives are restricted to Europe, Asia, and Africa.
The other mammal discovered at the site, Heptodon, is an ancient relative of modern tapirs, which resemble small rhinos with no horns and a short, mobile, trunk or proboscis.
“Heptodon was about half the size of today’s tapirs, and it lacked the short trunk that occurs on later species and their living cousins. Based upon its teeth, it was probably a leaf-eater, which fits nicely with the rainforest environment indicated by the fossil plants at Driftwood Canyon,” said Dr. Jaelyn Eberle of the University of Colorado, lead author of the study.
Most of the fossil-bearing rocks at Driftwood Canyon formed on the bottom of an ancient lake and are well-known for their exceptionally well-preserved leaves, insects, and fishes. But no fossils of mammals had ever before been identified at the site. The fieldwork that resulted in these discovered was supported by Natural Sciences and Engineering Research Council of Canada.
“The discovery in northern British Columbia of an early cousin to tapirs is intriguing because today’s tapirs live in the tropics. Its occurrence, alongside a diversity of fossil plants that indicates a rainforest, supports an idea put forward by others that tapirs and their extinct kin are good indicators of dense forests and high precipitation,” said Eberle.
Fossil plants from the site indicate the area seldom experienced freezing temperatures and probably had a climate similar to that of Portland, Oregon, located roughly 700 miles to the south.
“Driftwood Canyon is a window into a lost world — an evolutionary experiment where palms grew beneath spruce trees and the insects included a mixture of Canadian and Australian species. Discovering mammals allows us to paint a more complete picture of this lost world,” said Dr. David Greenwood of Brandon University, a co-author of the study. “The early Eocene is a time in the geological past that helps us understand how present day Canada came to have the temperate plants and animals it has today. However, it can also help us understand how the world may change as the global climate continues to warm.”
Note: The above story is based on materials provided by Society of Vertebrate Paleontology.
Imaging seismic susceptibility makes it possible to detect regions affected by high-pressure volcanic fluids. The image in the background is catalogued as ‘Red Fuji’ (Katsushika Hokusai, 1830). Credit: Copyright Florent Brenguier
Researchers at the Institut des Sciences de la Terre (CNRS/Université Joseph Fourier/Université de Savoie/IRD/IFSTTAR) and the Institut de Physique du Globe de Paris (CNRS/Université Paris Diderot/IPGP), working in collaboration with Japanese researchers, have for the first time observed the response of Japanese volcanoes to seismic waves produced by the giant Tohoku-oki earthquake of 2011. Their conclusions, published in Science on July 4, 2014, reveal how earthquakes can impact volcanoes and should help to assess the risk of massive volcanic eruptions worldwide.
Until the early 2000s, seismic noise* was systematically removed from seismological analyses. This background noise is in fact associated with seismic waves caused by ocean swell. These waves, which can be compared to permanent, continuous microseisms, can be used by seismologists instead of earthquakes (which are highly localized over a limited time period) to image Earth’s interior and its evolution over time, rather like an ultrasound scan on a global scale.
Now, seismic noise has been used for the continuous measurement of perturbations of the mechanical properties of Earth’s crust. Researchers at the Institut des Sciences de la Terre (CNRS/Université Joseph Fourier/Université de Savoie/IRD/IFSTTAR) and the Institut de Physique du Globe de Paris (CNRS/Université Paris Diderot/IPGP) have applied this novel method while working in collaboration with Japanese colleagues using the Hi-net network, which is the world’s densest seismic network (comprising more than 800 seismic detectors throughout Japan).
After the giant Tohoku-oki earthquake of 2011, the researchers analyzed over 70 terabytes of seismic data from the network. For the first time, they showed that the regions where the perturbations of Earth’s crust were the greatest were not those where the shocks were the strongest. They were in fact localized under volcanic regions, especially under Mount Fuji. The new method thus enabled the scientists to observe the anomalies caused by the perturbations from the earthquake in volcanic regions under pressure. Mount Fuji, which exhibits the greatest anomaly, is probably under great pressure, although no eruption has yet followed the Tohoku-oki earthquake. The 6.4-magnitude seism that occurred four days after the 2011 quake confirms the critical state of the volcano in terms of pressure. These findings lend support to theories that the last eruption of Mount Fuji in 1707 was probably triggered by the giant 8.7-magnitude Hoei earthquake, which took place 49 days before the eruption.
More generally, the results show how regions affected by high-pressure volcanic fluids can be characterized using seismic data from dense seismic detector networks. This should help to anticipate the risk of major volcanic eruptions worldwide.
*Seismic noise includes all the unwanted components affecting an analysis, such as the noise produced by the measuring device itself or external perturbations inadvertently picked up by the measuring devices.
Note : The above story is based on materials provided by CNRS.
Chemical Formula: FeS2 Locality: Common world wide. Name Origin: From the Greek, pyrites lithos, “stone which strikes fire,” in allusion to the sparking produced when iron is struck by a lump of pyrite.
The mineral pyrite, or iron pyrite, also known as fool’s gold, is an iron sulfide with the formula FeS2. This mineral’s metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool’s gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal.
Pyrite is the most common of the sulfide minerals. The name pyrite is derived from the Greek πυρίτης (pyritēs), “of fire” or “in fire”, in turn from πύρ (pyr), “fire”. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what we now call pyrite. By Georgius Agricola’s time, the term had become a generic term for all of the sulfide minerals.
Pyrite is usually found associated with other sulfides or oxides in quartz veins, sedimentary rock, and metamorphic rock, as well as in coal beds and as a replacement mineral in fossils. Despite being nicknamed fool’s gold, pyrite is sometimes found in association with small quantities of gold. Gold and arsenic occur as a coupled substitution in the pyrite structure. In the Carlin–type gold deposits, arsenian pyrite contains up to 0.37 wt% gold.
Scientists collect water samples from a hot spring near Dixie Valley, Nevada. Berkeley Lab scientists are developing a computer program that calculates the temperature of subsurface geothermal reservoirs that feed such springs.
CA lot can happen to water as it rises to the surface from deep underground. It can mix with groundwater, for example. This makes it difficult for scientists to estimate the temperature of a geothermal reservoir, which is an important step as they decide whether a site merits further exploration as a source of clean, renewable energy.
Now, Berkeley Lab researchers have developed a new way to take a geothermal reservoir’s temperature.
The method isn’t new really, but rather a high-tech makeover of a 20-year-old technique. It’s a computer program, called GeoT, which calculates a deep reservoir’s temperature by starting with the concentrations of dissolved salts in a fluid sample obtained at the surface, such as from a hot spring. It then reconstructs the data to reflect what the water composition would be in a deep geothermal reservoir, which can be one kilometer underground.
Because the solubility of a mineral is a function of temperature, this reconstruction can indicate the temperature of the subsurface reservoir.
Initial tests show that the technique has the potential to be more reliable than current methods for thermal waters that have mixed with groundwater, lost gases, or both. As such, it could become a valuable tool to help scientists evaluate geothermal sites.
“Our method is not intended to replace older techniques, but to complement them and advance a way of investigating deep reservoirs in a more integrated manner,” says Nicolas Spycher, a scientist in Berkeley Lab’s Earth Sciences Division who leads the project.
“It’s another way of increasing our confidence over whether a geothermal resource is worth further study,” Spycher adds.
The technique is based on a time-tested method called solute geothermometry, in which the temperature of a deep reservoir is estimated by measuring the concentrations of dissolved minerals in a water sample. Simple tests are based on the concentration of silica, while others use elements such as sodium and potassium.
But these chemical signatures can change as fluid rises. Minerals can reach a new equilibrium, water can boil away as pressure changes, or the fluid can mix with saline water. When this happens, a fluid sample obtained at the surface may not be a good indicator of a subsurface reservoir’s temperature.
Back in the mid 1980s, Spycher, then a graduate student at the University of Oregon, helped Prof. Mark Reed develop a method that estimates a reservoir’s temperature by measuring the full water composition, not just one or two elements. This “whole-water analysis” irons out some of the influences that perturb traditional solute geothermometry measurements.
Working with several scientists, Spycher has now modernized this approach by developing GeoT. The program automatically reconstructs the deep-reservoir composition of a fluid sample, and then estimates the reservoir temperature by numerically lining up the myriad saturation points of the minerals in the sample. Unknown or poorly understood variables are estimated by numerical optimization.
The software has been tested on a well-characterized geothermal system at Dixie Valley, Nevada.
“In the past, processing whole-water analyses was time-consuming, and lining-up mineral saturation points required eyeballing and trial and error,” says Spycher. “Our new software makes the process much easier, and allows processing multiple waters at the same time.”
CRocha is a Portuguese family name. It literally means “rock” or “boulder” in Portuguese; for instance, “rochas sedimentares, metamórficas e magmáticas” means “sedimentary, metamorphic and magmatic rocks”. It is also a topographical surname that is found in Portugal as “da Rocha” or simply Rocha, literally, “one who is from/of the rock”.
The first documented usage of the surname in Portugal was from a Monsignor de la Roche who arrived in Portugal on his way to the Holy Land from possibly Flanders during the reign of Afonso III of Portugal and assisted in the taking of Silves from the Moors. Afonso III of Portugal granted this gentlemen lands in Torres Novas and other locales for his services. His descendants used the Portuguese version of the word, ‘da Rocha’.
Another wave of the Roche family arrived from the Diocese of Fermoy, Ireland where they were viscounts during the reign of Joao I. This family helped with the Portuguese war against Castile and this gentlemen had three sons, Gomes, Louis, and Raymond. It is from D. Gomes da Rocha where the Portuguese version of the name continued onto later generations.
According to the “Dicionário das Famílias Portuguesas” (Dictionary of Portuguese Families) by D. Luiz de Lancastre e Távora, Gomes da Rocha was commandante of Pombeiro, Portugal and other monasteries in 1482 before becoming bishop of Tripoli in the middle of the 15th century. Another Portuguese author, Felgueiras Gayo, states Gomes was married to a lady by the name of D. Ines de Meneses and after becoming a widow, he became commandante of Pombeiro. It is from this family that the current coat-of-arms bearing ‘da Rocha’ families of Portugal are said to be descended.
Note : The above story is based on materials provided by Wikipedia
Chemical Formula: Ag3SbS3 Locality: Fresnillo, Zacatecas, and Guanajuato, Mexico and other silver districts in the world. Name Origin: From the Greek, pyr and argyros, “fire-silver” in allusion to color and silver content.
Pyrargyrite is a sulfosalt mineral consisting of silver sulfantimonide, Ag3SbS3. Known also as dark red silver ore or ruby silver, it is an important source of the metal.
It is closely allied to, and isomorphous with, the corresponding sulfarsenide known as proustite or light red silver ore. Ruby silver or red silver ore (German Rotgiiltigerz) was mentioned by Georg Agricola in 1546, but the two species so closely resemble one another that they were not completely distinguished until chemical analyses of both were made.
Both crystallize in the ditrigonal pyramidal (hemimorphic-hemihedral) class of the rhombohedral system, possessing the same degree of symmetry as tourmaline. Crystals are perfectly developed and are usually prismatic in habit; they are frequently attached at one end, the hemimorphic character being then evident by the fact that the oblique striations on the prism faces are directed towards one end only of the crystal. Twinning according to several laws is not uncommon. The hexagonal prisms of pyrargyrite are usually terminated by a low hexagonal pyramid or by a drusy basal plane.
Authors (inventeurs) : GLOCKER Discovery date : 1831
Optical properties
Optical and misc. Properties : Translucide – Fragile, cassant – Macles possibles – Opaque – Reflective Power: 26,4-31,7% (580) Refractive Index: from 2,88 to 3,08
Physical properties
Hardness : 2,50 Density : 5,82 Color : dark red; dark grey; black brown; violet red; red; grey black Luster : adamantine; submetallic Streak/Trace : dark red; red brown; purplish red Break : conchoidal; irregular Cleavage: yes
This is a reconstruction of the world’s largest-ever flying bird, Pelagornis sandersi, identified by Daniel Ksepka, Curator of Science at the Bruce Museum in Greenwich, Conn. Reconstruction art is by Liz Bradford. Credit: Liz Bradford
Scientists have identified the fossilized remains of an extinct giant bird that could be the biggest flying bird ever found. With an estimated 20-24-foot wingspan, the creature surpassed size estimates based on wing bones from the previous record holder — a long-extinct bird named Argentavis magnificens — and was twice as big as the Royal Albatross, the largest flying bird today. Scheduled to appear online the week of July 7, 2014, in the journal Proceedings of the National Academy of Sciences, the findings show that the creature was an extremely efficient glider, with long slender wings that helped it stay aloft despite its enormous size.
The new fossil was first unearthed in 1983 near Charleston, South Carolina, when construction workers began excavations for a new terminal at the Charleston International Airport. The specimen was so big they had to dig it out with a backhoe. “The upper wing bone alone was longer than my arm,” said author Dan Ksepka of the National Evolutionary Synthesis Center in Durham, North Carolina.
Now in the collections at the Charleston Museum, the strikingly well-preserved specimen consisted of multiple wing and leg bones and a complete skull. Its sheer size and telltale beak allowed Ksepka to identify the find as a previously unknown species of pelagornithid, an extinct group of giant seabirds known for bony tooth-like spikes that lined their upper and lower jaws. Named ‘Pelagornis sandersi’ in honor of retired Charleston Museum curator Albert Sanders, who led the fossil’s excavation, the bird lived 25 to 28 million years ago — after the dinosaurs died out but long before the first humans arrived in the area.
Researchers have no doubt that P. sandersi flew. It’s paper-thin hollow bones, stumpy legs and giant wings would have made it at home in the air but awkward on land. But because it exceeded what some mathematical models say is the maximum body size possible for flying birds, what was less clear was how it managed to take off and stay aloft despite its massive size.
To find out, Ksepka fed the fossil data into a computer program designed to predict flight performance given various estimates of mass, wingspan and wing shape. P. sandersi was probably too big to take off simply by flapping its wings and launching itself into the air from a standstill, analyses show. Like Argentavis, whose flight was described by a computer simulation study in 2007, P. sandersi may have gotten off the ground by running downhill into a headwind or taking advantage of air gusts to get aloft, much like a hang glider.
Once it was airborne, Ksepka’s simulations suggest that the bird’s long, slender wings made it an incredibly efficient glider. By riding on air currents that rise up from the ocean’s surface, P. sandersi was able to soar for miles over the open ocean without flapping its wings, occasionally swooping down to the water to feed on soft-bodied prey like squid and eels.
“That’s important in the ocean, where food is patchy,” said Ksepka, who is now Curator of Science at the Bruce Museum in Greenwich Connecticut.
Researchers hope the find will help shed light on why the family of birds that P. sandersi belonged to eventually died out, and add to our understanding of how the giants of the skies managed to fly.
Note : The above story is based on materials provided by National Evolutionary Synthesis Center (NESCent).
A–C: Size ranges of tracks found at Denali National Park, Alaska, tracksite. D: Adult hadrosaurid track with skin impressions. Scale bar for C1 is 5 cm. Credit: Fiorillo et al.
A trio of paleontologists has discovered a remarkable new tracksite in Alaska’s Denali National Park filled with duck-billed dinosaur footprints — technically referred to as hadrosaurs — that demonstrates they not only lived in multi-generational herds but thrived in the ancient high-latitude, polar ecosystem.
The paper provides new insight into the herd structure and paleobiology of northern polar dinosaurs in an arctic greenhouse world.
The article, “Herd structure in Late Cretaceous polar dinosaurs: A remarkable new dinosaur tracksite, Denali National Park, Alaska, USA,” was written for Geology by lead author Anthony R. Fiorillo, curator of earth sciences at the Perot Museum of Nature and Science, and co-authors Stephen Hasiotis of the University of Kansas and Yoshitsugu Kobayashi of the Hokkaido University Museum.
“Denali is one of the best dinosaur footprint localities in the world. What we found that last day was incredible — so many tracks, so big and well preserved,” said Fiorillo. “Many had skin impressions, so we could see what the bottom of their feet looked like. There were many invertebrate traces — imprints of bugs, worms, larvae and more — which were important because they showed an ecosystem existed during the warm parts of the years.”
Note : The above story is based on materials provided by Geological Society of America.
Dark-green tabular crystals associated with chalcosiderite Locality: Cerro Negro mine, Carrizalillo, Chile Source: William W. Pinch
Chemical Formula: Cu5(PO4)2(OH)4 Locality: Virneberg Mine, Rheinbreitbach, Westerwald, Rhineland-Palatinate, Germany. Name Origin: From the Greek, pseudo – “false” and malachite.
Pseudomalachite is a phosphate of copper with hydroxyl, named from the Greek for “false” and “malachite”, because of its similarity in appearance to the carbonate mineral malachite, Cu2(CO3)(OH)2. Both are green coloured secondary minerals found in oxidised zones of copper deposits, often associated with each other. Pseudomalachite is polymorphous with reichenbachite and ludjibaite. It was discovered in 1813. Prior to 1950 it was thought that dihydrite, lunnite, ehlite, tagilite and prasin were separate mineral species, but Berry analysed specimens labelled with these names from several museums, and found that they were in fact pseudomalachite. The old names are no longer recognised by the IMA.
Discovery date: 1813 Etymology:” PSEUDO” = faux” et MALACHITE
Optical properties
Refractive Index: from 1,79 to 1,86 Axial angle 2V : 48°
Physical properties
Hardness: from 4,50 to 5,00 Density : 4,35 Color : green; blackish green; bluish green; pale blue green; black green; blue green Luster: vitreous; greasy Streak : green blue; green Break : splintery; conchoidal Cleavage : yes
These images show typical soot superagregattes observed with an electron microscope in wildfire smoke samples collected from three fires in Northern California, New Mexico and Mexico City. Credit: Desert Research Institute
Every year, wildfires clear millions of hectares of land and emit around 34-percent of global soot mass into the atmosphere. In certain regions, such as Southeast Asia and Russia, these fires can contribute as much as 63-percent of regional soot mass.
In a paper published in Nature’s Scientific Reports, a team of scientists led by Rajan Chakrabarty from Nevada’s Desert Research Institute report the observation of a previously unrecognized form of soot particle, identified by the authors as “superaggregates,” from wildfire emissions. These newly identified particles were detected in smoke plumes from wildfires in Northern California, New Mexico, Mexico City, and India.
For several decades, scientists have been trying to quantitatively assess the impacts of wildfire soot particles on climate change and human health. However, due to the unpredictability of wildfire occurrences and the extreme difficulty in sampling smoke plumes in real-time, accurate knowledge of wildfire-emitted soot physical and optical properties has eluded the scientific community.
Unlike conventional sub-micrometer size soot particles emitted from vehicles and cook stoves, superaggregates are on average ten times longer and have a more compact shape. However, these particles have low effective densities which, according to the authors, gives them similar atmospheric long-range transportation and human lung-deposition characteristics to conventional soot particles.
“Our observations suggest that we cannot simply assume a universal form of soot to be emitted from all combustion sources. Large-scale combustion sources, such as wildfires, emit a different form of soot than say, a small-scale, controlled combustion source, such as vehicles.” says Chakrabarty, who also holds a faculty appointment at Washington University in St. Louis.
The study points to the need for revisiting the soot formation mechanism in wildfires, he adds.
The multi-institutional research team first detected the ubiquitous presence of soot superaggregates in smoke plumes from the 2012 Nagarhole National Forest fire in western India.
To verify the presence of superaggregate particles in other fires around the world, the team next analyzed smoke samples collected from the 2010 Millerton Lake fire in Northern California, and the 2011 Las Conchas fire in New Mexico, as well as wildfires near Mexico City. The authors found that a large portion of soot emitted during the flaming phase of these fires were superaggregates.
To assess the potential impact of superaggregates on global climate, scientists also calculated the radiative properties of soot superaggregates using numerically-exact electromagnetic theory.
“We found that superaggregates contribute up to 90-percent more warming than spherical sub-micrometer soot particles, which current climate models use,” said Chakrabarty. “These preliminary findings warrant further research to quantify the significant impact these particles may have on climate, human health, and air pollution around the world.”
New UAlberta assistant professor Alberto Reyes above a glacier at the edge of the Greenland ice sheet. New research by Reyes and colleagues indicates that ice disappeared from most of south Greenland during a long period of warm climate about 400,000 years ago. Credit: Robert Hatfield, Oregon State University
A former University of Alberta PhD student has come back to campus as an assistant professor, to explore and teach about the mysteries of natural climate warming and ice age history, on the heels of a newly published paper in Nature.
Alberto Reyes, an assistant professor in the Faculty of Science who received his PhD from the U of A in 2010, led a study which provides the first scientific evidence that the southern portion of Greenland’s ice sheet nearly disappeared in the geologically recent past, during a long period of warm climate about 400,000 years ago. The findings also indicate that the collapse of the ice sheet, which would have contributed 4.5 to six metres of global sea level rise, likely occurred under conditions that may have been only a few degrees warmer than the present day.
“The study highlights the sensitivity of the ice sheet to small levels of climate warming,” Reyes said.
Reyes, who led the study while at Queen’s University Belfast in collaboration with researchers from the University of Wisconsin-Madison and Oregon State University, spent several years collecting sediment samples from rivers in south Greenland to develop a chemical “fingerprint” of eroded rocks beneath the ice sheet. The group then used that fingerprint to determine when different parts of south Greenland stopped contributing sediment into the ocean.
“This only happens when there is no ice sheet or glacier to erode the rocks at the surface, so the chemistry allows us to broadly track retreat of the ice sheet,” he said.
Their findings indicated a near-complete absence of ice in the region just under a half-million years ago, which indicates the impact of just a small level of climate warming, Reyes noted.
Pointing to recent evidence that the west Antarctic ice sheet has begun collapsing, “This really highlights the sensitivity to the kind of magnitude of climate warming projected over the next several hundred years, so there are long-term consequences,” he added.
Reyes, who researched how permafrost and peatlands responded to past climate warming during his PhD studies at the U of A, will share his knowledge and sense of wonder with students as he teaches second- and third-year courses in global change and ice age history through the environmental earth sciences program.
“During my PhD I had the opportunity to do a lot of fieldwork, which the U of A is really strong in, and I spent a lot of time in the Yukon and Alaska learning about long-term environmental change and interactions between elements of Earth’s systems.
“It’s like history, but with science thrown in, so it’s very interesting.”
Reyes will also continue his research into long-term landscape and environmental change, through his appointment with the Department of Earth and Atmospheric Sciences.
Focused on the Arctic and subarctic regions, Yukon in particular, Reyes’ work will help address “what we might expect from a future warming climate in terms of how things like ice sheets and permafrost will respond.
“I want to understand how interactions between climate, environment and geological processes all work together to shape the landscape we see. The U of A has a strong history as a leader in northern research, so it’s really satisfying to return to the university as an educator and scientist.”
Formula: Fe2TiO5 Environment: Magmatic, post-volcanic or young volcanic rocks. Locality: Vesuvius and Etna, Italy. Name Origin: From the Greek pseudo – “I mislead” and the mineral brookite.
Authors (inventeurs) : KOCH Discovery date: 1878 Town of Origin : DEALUL UROIU (ARANYI-HEGY), COMTE DE HUNEDOARA, TRANSYLVANIE Country of Origin : ROUMANIE
Optical properties
Optical and misc. Properties : Translucide – Opaque Refractive Index: from 2,38 to 2,42 Axial angle 2V : 50°
Locations of Antarctic ice core sites used for volcanic sulfate aerosol deposition reconstruction (right); a DRI scientist examines a freshly drilled ice core in the field before ice cores are analyzed in DRI’s ultra-trace ice core analytical laboratory. Credit: M. Sigl
A team of scientists led by Michael Sigl and Joe McConnell of Nevada’s Desert Research Institute (DRI) has completed the most accurate and precise reconstruction to date of historic volcanic sulfate emissions in the Southern Hemisphere.
The new record, described in a manuscript published today in the online edition of Nature Climate Change, is derived from a large number of individual ice cores collected at various locations across Antarctica and is the first annually resolved record extending through the Common Era (the last 2,000 years of human history).
“This record provides the basis for a dramatic improvement in existing reconstructions of volcanic emissions during recent centuries and millennia,” said the report’s lead author Michael Sigl, a postdoctoral fellow and specialist in DRI’s unique ultra-trace ice core analytical laboratory, located on the Institute’s campus in Reno, Nevada.
These reconstructions are critical to accurate model simulations used to assess past natural and anthropogenic climate forcing. Such model simulations underpin environmental policy decisions including those aimed at regulating greenhouse gas and aerosol emissions to mitigate projected global warming.
Powerful volcanic eruptions are one of the most significant causes of climate variability in the past because of the large amounts of sulfur dioxide they emit, leading to formation of microscopic particles known as volcanic sulfate aerosols. These aerosols reflect more of the sun’s radiation back to space, cooling Earth. Past volcanic events are measured through sulfate deposition records found in ice cores and have been linked to short-term global and regional cooling.
This effort brought together the most extensive array of ice core sulfate data in the world, including the West Antarctic Ice Sheet (WAIS) Divide ice core — arguably the most detailed record of volcanic sulfate in the Southern Hemisphere. In total, the study incorporated 26 precisely synchronized ice core records collected in an array of 19 sites from across Antarctica.
“This work is the culmination of more than a decade of collaborative ice core collection and analysis in our lab here at DRI,” said Joe McConnell, a DRI research professor who developed the continuous-flow analysis system used to analyze the ice cores.
McConnell, a member of several research teams that collected the cores (including the 2007-2009 Norwegian-American Scientific Traverse of East Antarctica and the WAIS Divide project that reached a depth of 3,405 meters in 2011), added, “The new record identifies 116 individual volcanic events during the last 2000 years.”
“Our new record completes the period from years 1 to 500 AD, for which there were no reconstructions previously, and significantly improves the record for years 500 to 1500 AD,” Sigl added. This new record also builds on DRI’s previous work as part of the international Past Global Changes (PAGES) effort to help reconstruct an accurate 2,000-year-long global temperature for individual continents.
This study involved collaborating researchers from the United States, Japan, Germany, Norway, Australia, and Italy. International collaborators contributed ice core samples for analysis at DRI as well as ice core measurements and climate modeling.
According to Yuko Motizuki from RIKEN (Japan’s largest comprehensive research institution), “The collaboration between DRI, National Institute of Polar Research (NIPR), and RIKEN just started in the last year, and we were very happy to be able to use the two newly obtained ice core records taken from Dome Fuji, where the volcanic signals are clearly visible. This is because precipitation on the site mainly contains stratospheric components.” Dr. Motizuki analyzed the samples collected by the Japanese Antarctic Research Expedition.
Simulations of volcanic sulfate transport performed with a coupled aerosol-climate model were compared to the ice core observations and used to investigate spatial patterns of sulfate deposition to Antarctica.
“Both observations and model results show that not all eruptions lead to the same spatial pattern of sulfate deposition,” said Matthew Toohey from the German institute GEOMAR Helmholtz Centre for Ocean Research Kiel. He added, “Spatial variability in sulfate deposition means that the accuracy of volcanic sulfate reconstructions depends strongly on having a sufficient number of ice core records from as many different regions of Antarctica as possible.”
With such an accurately synchronized and robust array, Sigl and his colleagues were able to revise reconstructions of past volcanic aerosol loading that are widely used today in climate model simulations. Most notably, the research found that the two largest volcanic eruptions in recent Earth history (Samalas in 1257 and Kuwae in 1458) deposited 30 to 35 percent less sulfate in Antarctica, suggesting that these events had a weaker cooling effect on global climate than previously thought.
Note : The above story is based on materials provided by Desert Research Institute.
Map of the Amazon Basin showing Río Grande (highlighted)
The Río Grande (or Río Guapay) in Bolivia rises on the southern slope of the Cochabamba mountains, east of the city Cochabamba, at 17°26′11″S 65°52′22″W. At its source it is known as the Rocha River. It crosses the Cochabamba valley basin in a westerly direction. After 65 km the river turns south east and after another 50 km joins the Arque River at 17°42′10″S 66°14′45″W and an elevation of 2.350 m.
From this junction the river receives the name Caine River for 162 km and continues to flow in a south easterly direction, before it is called Río Grande. After a total of 500 km the river turns north east and in a wide curve flows round the lowland city of Santa Cruz.
After 1.438 km, the Río Grande joins the Ichilo River at 15°48′09″S 64°43′47″W which is a tributary to the Mamoré.
Note : The above story is based on materials provided by Wikipedia
Chemical Formula: Ag3AsS3 Locality: Himmelsfurst mine, Erbisdor, near Freiberg, Germany Name Origin: After the French chemist, J. L. Proust (1755-1826).
Proustite is a sulfosalt mineral consisting of; silver sulfarsenide, Ag3AsS3, known also as light red silver or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding sulfantimonide, pyrargyrite, from which it was distinguished by the chemical analyses of Joseph L. Proust (1754-1826) in 1804, after whom the mineral received its name.
The prismatic crystals are often terminated by the scalenohedron and the obtuse rhombohedron, thus resembling calcite (dog-tooth-spar) in habit. The color is scarlet-vermilion and the lustre adamantine; crystals are transparent and very brilliant, but on exposure to light they soon become dull black and opaque. The streak is scarlet, the hardness 2.5, and the specific gravity 5.57.
Proustite occurs in hydrothermal deposits as a phase in the oxidized and supergene zone. I is associated with other silver minerals and sulfides such as native silver, native arsenic, xanthoconite, stephanite, acanthite, tetrahedrite and chlorargyrite.
Magnificent groups of large crystals have been found at Chañarcillo in Chile; other localities which have yielded fine specimens are Freiberg and Marienberg in Saxony, Joachimsthal in Bohemia and Markirch in Alsace.
