Breaking the strongest link triggered big Baja earthquake

February 16, 2016

Breaking the strongest-GeologyPage — This 3-D LiDAR imaging of the Borrego Fault, ruptured during the 2010 El Mayor-Cucapah earthquake in Baja California, Mexico shows numerous small faults. The various colors represent elevation changes during the earthquake. Credit: UC Davis

A spate of major earthquakes on small faults could overturn traditional views about how earthquakes start, according to a study from researchers at the Centro de Investigación Científica y de Educación Superior in Ensenada, Mexico, and the University of California, Davis.

The study, published Feb. 15 in the journal Nature Geoscience, highlights the role of smaller faults in forecasting California’s risk of large earthquakes.

In the past 25 years, many of California’s biggest earthquakes struck on small faults, away from the San Andreas Fault plate boundary. These events include the Landers, Hector Mine and Napa earthquakes. Several of the quakes were unexpected, rattling areas thought seismically quiet.

A closer look at one of the surprise events, the magnitude-7.2 El Mayor-Cucapah earthquake, showed that small faults may often link together along a “keystone” fault. A keystone is the central stone that holds a masonry structure together. During the El Mayor-Cucapah earthquake, the keystone fault broke first, unlocking seven smaller faults, the study found.

However, the research team discovered that of all the faults unzipped during the El Mayor-Cucapah earthquake, the keystone fault was not the one closest to breaking.

“One of the important outcomes of this study is you can have a whole network of faults activated together by one underpinning fault, and that’s an important concern,” said study co-author Michael Oskin, a UC Davis professor of geology. “An earthquake involving a system of small faults can be more damaging than a single event because it increases the amount of seismic energy released.”

House of cards

The April 4, 2010, El Mayor-Cucapah earthquake leapfrogged across seven faults and jumped a 5-mile wide gap. The researchers used a wealth of recorded seismic data and detailed mapping of surface changes to reconstruct the complex earthquake sequence.

The study reveals the underlying reason for this unusual pattern: a hidden fault buried at a shallow angle to the surface. Each of the seven faults steeply dips toward this hidden fault, linking up deep underground.

Lead author John Fletcher, a professor at CICESE, likened the system to a house of cards—remove one key piece and the entire structure tumbles.

“The trick here is the cards can bend, but it isn’t until one particular fault goes that the whole set ruptures,” Fletcher said.

Earthquake risk

The El Mayor-Cucapah earthquake occurred in a transition zone, between faults spreading open to form the Gulf of California and faults where the Pacific and North America tectonic plates slip sideways past one another. The earthquake was centered about 30 miles south-southeast of Mexicali in northern Baja California, Mexico.

The results suggest similar processes are at work in other areas where the Earth’s crust accommodates major changes in shape.

“This gives us insight into how those messy things between the main faults work,” Oskin said. “This might be pretty common.”

In past events, the signal of a low-angle fault could have been masked because it activated a lot of high-angle faults in the same earthquake, the researchers said.

The idea could also explain a longstanding mystery: why the central San Andreas fault is almost perpendicular to its stress field. Oskin said the central San Andreas fault may also behave like a keystone fault.

Background

The El Mayor-Cucapah earthquake caused extensive damage to the city of Mexicali, displacing more than 35,000 people and causing two deaths. The shaking demolished roads and irrigation channels in surrounding agricultural areas. Reports documented widespread liquefaction, road ruptures, cracked infrastructure, tilting power line towers and partial or total collapse of many buildings. Damage topped $440 million in the Mexicali Valley and $90 million in California’s Imperial Valley.

Reference:
John M. Fletcher et al. The role of a keystone fault in triggering the complex El Mayor–Cucapah earthquake rupture, Nature Geoscience (2016). DOI: 10.1038/ngeo2660

Note: The above post is reprinted from materials provided by UC Davis.

Ancient flowering plant was beautiful, but probably poisonous

February 16, 2016

Ancient flowering plant was-GeologyPage — This asterid flower is one of the only fossils of this family ever discovered. Credit: Photo by George Poinar, Jr., courtesy of Oregon State University

Researchers today announced in the journal Nature Plants the discovery of the first-ever fossil specimens of an “asterid” — a family of flowering plants that gave us everything from the potato to tomatoes, tobacco, petunias and our morning cup of coffee.

But these two 20-30 million-year-old fossil flowers, found perfectly preserved in a piece of amber, came from the dark side of the asterid family — they belong to the genus Strychnos, which ultimately gave rise to some of the world’s most famous poisons, including strychnine and curare.

Poisons that would later find their way into blow-gun weapons, rat control, Sherlock Holmes stories and the movie “Psycho” appear to have had some of their ancestral and biological roots in the prehistoric jungles of what’s now the Dominican Republic, researchers say.

“The specimens are beautiful, perfectly preserved fossil flowers, which at one point in time were borne by plants that lived in a steamy tropical forest with both large and small trees, climbing vines, palms, grasses and other vegetation,” said George Poinar, Jr., a courtesy professor in the College of Science at Oregon State University, and one of the world’s experts on plant and animal life forms preserved in amber.

“Specimens such as this are what give us insights into the ecology of ecosystems in the distant past,” Poinar said. “It shows that the asterids, which later gave humans all types of foods and other products, were already evolving many millions of years ago.”

Asterids, the researchers noted in this study, are among Earth’s most important and diverse plants, with 10 orders, 98 families, and about 80,000 species. They represent about one-third of all the Earth’s diversity of angiosperms, or flowering plants.

And one ancient genus, which has now been shown to be inherently toxic, existed for millions of years before humans appeared on the planet.

“Species of the genus Strychnos are almost all toxic in some way,” Poinar said. “Each plant has its own alkaloids with varying effects. Some are more toxic than others, and it may be that they were successful because their poisons offered some defense against herbivores.

“Today some of these toxins have been shown to possess useful and even medicinal properties.”

As natural poisons that humans came to understand and use, two extracts from plants in the Strychnos genus ultimately became famous — strychnine and curare.

Strychnine had practical uses for decades as a pesticide, and was often the deadly component of rat poison. But it also captured the imagination of writers, and was used by Norman Bates in the movie “Psycho” to kill his mother and her male companion. In small doses, it can increase mental and muscular activity.

Curare has an even stranger history. Sir Walter Raleigh may have first encountered it in 1596 when he observed poison arrows in South America, where natives also developed the poison in blow-gun darts to paralyze hunted prey. Curare was featured as the murder weapon in one Sherlock Holmes novel, and in lower doses it has been used as a muscle relaxant in surgery.

There are now about 200 species of Strychnos plants around the world, in forms ranging from shrubs to trees and woody climbing vines, mostly in the tropics. They are still being studied for medicinal properties, such as for the treatment of parasitic worm infections and even as drugs to treat malaria.

The discovery of these two fossil flowers, researchers said, suggests that many other related plant families could have evolved in the Late Cretaceous in tropical forests. Their fossil remains, however, still await discovery.

The co-author of this study, Lena Struwe, is an expert on plants in the strychnine family, Loganaceae, and is a plant biologist at Rutgers University.

Reference:
George O. Poinar, Lena Struwe. An asterid flower from neotropical mid-Tertiary amber. Nature Plants, 2016; 16005 DOI: 10.1038/NPLANTS.2016.5

Note: The above post is reprinted from materials provided by Oregon State University.

Jawless fish brains more similar to ours than previously thought

February 16, 2016

Jawless fish brains more-GeologyPage — (top) The embryonic gnathostome brain based on a mouse embryo (day 12.5). Inset shows a transverse section at the level of the hindbrain showing the position of the rhombic lip. (middle and bottom) Embryonic hagfish and lamprey brains (stages 53 and 26, respectively) as revealed by the present study. rl, rhombic lip; MGE, medial ganglionic eminence. Credit: RIKEN

Researchers at the RIKEN Evolutionary Morphology laboratory and other institutions in Japan have shown that complex divisions in the vertebrate brain first appeared before the evolution of jaws, more than 500 million years ago. Published in Nature, the study shows that two elements of brain genoarchitecture thought to be unique to jawed vertebrates are actually present in two jawless fish–the hagfish and lamprey.

Most living vertebrate species have jaws, a development thought to have occurred sometime in the Paleozoic era. Jawed vertebrates–including humans–share many developmental characteristics that have remained unchanged for millennia. The brain’s basic developmental plan was thought by many scientists to have reached completion in jawed vertebrates because the brains of lampreys and hagfish–the only jawless fish that remain alive today–seem to lack two key domains.

Recent evidence brought this into question, and as the only lab in the world able to study hagfish embryos, the RIKEN team led by Shigeru Kuratani was in a unique position to use techniques derived from developmental biology to tackle this critical issue.

The vertebrate brain develops from a neural tube that is divided into sections. The development of each section is very specific, and is controlled by the expression of particular genes at very precise times and locations. These gene-expression patterns–or the genoarchitecture–are highly conserved in jawed vertebrates. Lampreys–a type of jawless fish–appear to lack two brain regions common to jawed vertebrates–the cerebellum and a region called the medial ganglionic eminence, or MGE, from which the pallidum and cortical interneurons originate.

In jawed vertebrates, the MGE develops from a forward section of the neural tube that expresses Nkx2.1 and Hedgehog genes, and the cerebellum develops from a region called the rhombic lip that expresses Pax6. In hagfish, the team found a region in the correct location that expresses both Nkx2.1 and a Hedgehog gene that was identified for the first time in this study. This indicated that the hagfish brain does indeed have an MGE region. Similarly, although hagfish do not have a true cerebellum, the team was able to identify a clear rhombic lip region that expresses Pax6.

At this point, the team was confident that the brains of both hagfish and jawed vertebrates contain similar developmental patterning.

“The problem was that lampreys had not yet been shown to have a similar patterning,” explains Kuratani. “The shared pattern of brain development between hagfish and jawed vertebrates raised the possibility that the apparently primitive brain of the lamprey is simply a lamprey-unique characteristic.”

Additionally, without an answer to the lamprey question, these shared patterns could be interpreted as changes that independently occurred in each lineage–jawed and jawless–after they split from each other.

To address the issue, the team reinvestigated the lamprey, and discovered several new Nkx2.1 genes expressed in the correct location, but did not find any Hedgehog expression, indicating that the lamprey MGE is slightly different from that found in jawed vertebrates. Then the team looked at lamprey larvae and found a rhombic-lip like region that expresses Pax6B, albeit slightly differently than in hagfish or jawed vertebrates.

“We found that jawed-vertebrate patterning was more similar to the hagfish than to lampreys,” says Kuratani, “and the evidence indicates that this is likely due to secondary evolutionary changes in lamprey evolution, rather than changes unique to jawed vertebrates.”

“With these new findings from hagfish and lampreys, we have shown that both of the extant jawless-fish species have a rhombic lip and an MGE –the sources of the cerebellum, pallidum, and GABAergic interneurons in jawed vertebrates. This firmly places the development of these genoarchitectural patterns back to a common ancestor shared by jawless and jawed vertebrates.”

Reference:
Fumiaki Sugahara, Juan Pascual-Anaya, Yasuhiro Oisi, Shigehiro Kuraku, Shin-ichi Aota, Noritaka Adachi, Wataru Takagi, Tamami Hirai, Noboru Sato, Yasunori Murakami, Shigeru Kuratani. Evidence from cyclostomes for complex regionalization of the ancestral vertebrate brain. Nature, 2016; DOI: 10.1038/nature16518

Note: The above post is reprinted from materials provided by RIKEN.

Trapped in Amber: Rutgers Botanist Names New Flower Species

February 16, 2016

Trapped in Amber Rutgers-GeologyPage — Strychnos electri, encased in amber, was found by George Poinar during a trip to a Dominican amber mine in 1986, named by Lena Struwe in 2015. Credit: George Poinar

A Rutgers scientist has identified a flower trapped in ancient amber as belonging to a species completely new to science.

Lena Struwe, professor of botany in the School of Environmental and Biological Sciences, has discovered that two flowers found encased amber for at least 15 million years belong to none of the known 200 species of the genus Strychnos. Therefore, they represent a newly discovered species, Strychnos electri. Struwe coined the species name in honor of its amber origin, since elektron is the Greek word for amber.

Struwe and the entomologist George Poinar, renowned for his studies of insect fossils trapped in amber, are publishing their findings in the journal Nature Plants. Poinar is professor emeritus of integrative biology at Oregon State University.

Amber is fossilized tree resin. Although scientists often find plant fossils in amber, they’re usually just fragments – a petal here, a stamen there. Intact specimens are rare. These flowers were among 500 fossils, mostly insects, Poinar brought back to his lab from a field trip to an amber mine in the Dominican Republic in 1986. The insects kept Poinar busy for years. But this specimen eventually caught Poinar’s eye. “These flowers looked like they had just fallen from a tree,” Poinar says. “I thought they might be Strychnos, and I sent them to Lena because I knew she was an expert in that genus.”

Struwe received several high-resolution photos of the specimens from Poinar in April. Within a few months, she was able to confirm that Poinar’s fossil belonged to the genus Strychnos, which consists of tropical trees, shrubs and lianas. The genus is famous as the source for the toxin strychnine. Struwe then embarked on a taxonomic comparison with living species of Strychnos.

Technological advances notwithstanding, the search involved physically examining dried specimens of the known species collected by explorers and botanists over the last 200 years and comparing their flowers in detail with the new amber specimens. For Struwe, this meant visits to the William and Linda Steere Herbarium at The New York Botanical Garden, and the Lewis and Clark Herbarium at Drexel University’s Academy of Natural Sciences in Philadelphia, both of which have extensive collections of tropical plants, especially of Strychnos.”The characters mostly used to identify species of Strychnos are flower morphology, and that’s what we luckily have for this fossil,” Struwe says. “I looked at each specimen of New World species, photographed and measured it, and compared it to the photo George sent me. I asked myself, ‘How do the hairs on the petals look ?’ ‘Where are the hairs situated?’ and so on.”

For Struwe, this was a road traveled many times. In more than 20 years of work, she has named one new plant family, discovered three new genera and about 50 new species. “This fossil turned out to have particular significance for our understanding of the evolution of plants in the Caribbean and the New World tropics,” Struwe says. “The discovery of this new species in a 30-year-old amber collection highlights that we still have many undiscovered species hidden away in natural history collections worldwide and not enough taxonomic experts to work through them. Strychnos electri has likely been extinct for a long time, but many new species living and, unfortunately, soon-to-be-extinct species are discovered by scientists every year.”

Reference:
An asterid flower from neotropical mid-Tertiary amber, Nature Plants, DOI: 10.1038/nplants.2016.5

Note: The above post is reprinted from materials provided by Rutgers University.

An afternoon walk and a mammoth find

February 16, 2016

An afternoon walk and-GeologyPage — Mammoth bones in situ. Credit: Bruce Huckell

It began with a man walking along a shallow wash near Abiquiu, New Mexico one afternoon and noticing some flakes of what looked like bone. He happened to be walking near the property line, maybe on his neighbor’s property. So he went to visit his neighbor, to tell him about the find.

His neighbor, Tim Rowe, happened to be a vertebrate paleontologist at the University of Texas in Austin and knew something about old bones. Together they walked to the shallow wash to take a closer look. They found some very big ribs near the edge of the wash and teeth that clearly came from some elephant-like creature. But the only time elephant-like creatures ever roamed New Mexico was about 13,000 years ago when mammoths grazed the plains of eastern New Mexico. No one has ever found a mammoth in the high country.

Abiquiu is a place of sweeping vistas, dramatic mountains and the colors that dazzled artist Georgia O’Keefe. At 6,200 feet above sea level, it’s a wild place, with very little urban development – the kind of place where a very large creature could die and leave bones that were virtually undisturbed for thousands of years.

This is just the kind of thing that interests UNM Professor of Anthropology Bruce Huckell. “Tim contacted me and said I’ve got this mammoth eroding out on my property and I would be interested to know if you would like to take a look. I said sure, and he said by the way my neighbor found an arrowhead near the bones, so I’ll send you a picture of that.”

Huckell hurriedly opened the email before he ran out the door to a faculty meeting and saw a little broken, reworked Clovis point, which is exactly what you might expect to see associated with a mammoth.

“The bones are just chunks and fragments, but it was clear they were from some sort of an elephant-like creature,” said Huckell “And in scratching around along the edges of this little wash, they found a group of three rib fragments that were all just kind of laid together. A little further to the north, they found an erosionally truncated piece of a tusk, which they followed and that connected to the anterior part of the skull.”

The unexpected thrill of finding an ancient mammoth that humans might have hunted and killed has now turned into the exacting work of documenting the find. A National Science Foundation grant has helped pay for the work of excavating the site and documenting the find. Pieces of bone have been sent to a specialist for radiocarbon dating.

Anthropologists think the Clovis people were the earliest humans in North America. They lived about 13,000 years ago. They hunted big game, such as the Columbian mammoth, a southern cousin of the more famous wooly mammoths and they traveled extensively, especially in the Southwest. Their distinctive fluted spear points have been found throughout New Mexico.

Much of what is known about the Clovis people comes from an archeological site near the town of Clovis in eastern New Mexico. At the Blackwater Draw, the Clovis people killed and butchered several mammoths, leaving evidence of their existence, their hunting skills and their beautiful spear tips in one place.

This would be the second time Clovis artifacts have been found in conjunction with a mammoth.

This is the kind of find that intrigues funding entities and Huckell, along with two UNM professors from the Earth and Planetary Sciences Department, Leslie McFadden and Grant Meyer received a National Science Foundation High Risk Research Proposal to excavate the mammoth.

It’s a wonder the mammoth, which they think is a juvenile, was preserved at all because it fell in a place that was vulnerable to the elements, on a little shelf of land between two deep arroyos.

“The bones were buried in a very small stream channel, not much bigger than a person could jump across,” Meyer said. “Even more unusual is the channel location: it is perched on the side of a steep canyon. Landslides occurred here sometime during the last episode of Pleistocene ice ages, when mountain glaciers grew in the high Sangre de Cristo Mountains and the climate was colder and wetter in New Mexico.”

Clovis people arrived in the final stage of this period. The landslide formed benches along the canyon side, and downslope drainage was diverted along the bench where the mammoth was found. A muddy flood down this drainage buried the mammoth bones, but thereafter, flow was diverted off the bench, leaving the bones protected from later erosion – despite their very shallow interment.

“The bones aren’t really articulated. They are there in a jumble, but it looks like pretty soon after the animal was de-fleshed that this little flood came along and put the bones into this channel,” said Huckell.

The researchers are seizing an unexpected opportunity to learn more about the Clovis people. Huckell says they are looking seriously at the question of how much of the mammoth meat the Clovis people actually used once they made a kill. A ton or so of mammoth is a huge amount for hunters to handle. He and his graduate students are comparing information they have from this site, with information from other mammoth kills to try to determine an answer.

He is also seeking a better answer to a question that has long been debated among anthropologists. Flakes of bone were found at the site, but it’s not clear whether that is part of a natural weathering process, whether another animal came along and gnawed or broke the bones or whether the flaking was something done by the hunters as they butchered the animal.

In all, this research is thanks to a chain of serendipitous events.

Huckell said, “The odds of it getting buried and staying buried are real slim. The odds of the property being drawn as it was and being purchased by a vertebrate paleontologist are vanishingly small and then the possibility that that animal met its end and/or was utilized by Clovis people sort of completes the chain of improbable events.”

Most of the excavation was completed last summer, but the research group will be back in Abiquiu in June to complete the excavation portion of the project. Four graduate students have already worked on the project with the professional researchers. This kind of opportunity is usual in the UNM Department of Anthropology, Huckell said graduate anthropology students at UNM have an excellent chance of working directly on research that offers them a chance to explore first-hand the very ancient history of New Mexico.

Note: The above post is reprinted from materials provided by University of New Mexico.

Pakistan scientists ‘find 1.1 million year-old stegodon tusk’

February 16, 2016

Pakistan scientists-GeologyPage — A 1.1 million-year-old stegodon tusk was discovered at Padri village in Jhelum district, Pakistan’s central province of Punjab, potentially shedding new light on the mammal’s evolutionary journey

A team of Pakistani researchers claims to have unearthed a 1.1 million-year-old stegodon tusk in the central province of Punjab, potentially shedding new light on the mammal’s evolutionary journey.

Stegodonts, distant cousins of modern elephants, are thought to have been present on earth from around 11 million years ago until the late Pleistocene period, which lasted until the end of the last Ice Age around 11,700 years ago.

The tusk measures some eight feet (2.44 metres) in length and is around eight inches (20.3 cm) in diameter, making it the the largest ever discovered in the country, according to the team.

It was found by researchers from the zoology department of the University of Punjab during an expedition in the Padri village of Jhelum district, said Khurram Shahzad, a spokesman for the university.

Professor Muhammad Akhtar, who led the research trip, told AFP: “This discovery adds to our knowledge about the evolution of the stegodon, particularly in this region.

“It also sheds light on what the environment was like at the time of the animal’s life.”

Dr Gerrit Van Den Bergh, a paleontologist at the University of Wollongong in Australia who has done extensive research on the ancient mammals including in Pakistan, said: “If you have a complete tusk, that’s quite special—they are quite rare.”

He cautioned however that further verification, including of the dating, would be required.

Akhtar said the fossil belonged to the late Pleistocene period and its age was determined using a uranium-lead radioactive dating technique.

Stegodonts were known for their long, nearly straight tusks and low-crowned teeth with peaked ridges.

This indicated they were browsers or mixed feeders in a forested environment, in contrast to the high-crowned plated molars of mammoths and elephants which allowed them to graze.

They were strong swimmers and are thought to have originated in Africa but to have quickly spread to Asia, where most remains have been found.

“Around 1.2 million years ago they were still thriving,” said Van Den Bergh. “They are mostly an Asian species but remains have been found further afield. Recently a molar fragment was discovered in Greece.”

He added that the species’ extinction coincided with the emergence of modern humans, though it was difficult to say with certainty that men hunted stegodonts.

Note: The above post is reprinted from materials provided by AFP.

Zhangye Danxia National Geological Park “China’s Rainbow Mountains”

February 15, 2016

cover

The Zhangye Danxia National Geological Park, also known as Zhangye Danxia (Landform) Geopark, is located near the city of Zhangye in China’s northwestern Gansu province. It covers an area of 510 square kilometres (200 sq mi). Formerly a provincial park and scenic area, it became a national geopark in November 2011. Known for its colorful rock formations, it has been voted by Chinese media outlets as one of the most beautiful landforms in China.

China Danxia is the name given in China to landscapes developed on continental red terrigenous sedimentary beds influenced by endogenous forces (including uplift) and exogenous forces (including weathering and erosion). The inscribed site comprises six areas found in the sub-tropical zone of south-west China. They are characterized by spectacular red cliffs and a range of erosional landforms, including dramatic natural pillars, towers, ravines, valleys and waterfalls. These rugged landscapes have helped to conserve sub-tropical broad-leaved evergreen forests, and host many species of flora and fauna, about 400 of which are considered rare or threatened.

Location

The park is located in the northern foothills of the Qilian Mountains, in the counties of Linze and Sunan, which are under the administration of the prefecture-level city of Zhangye, Gansu province. The main areas of Danxia landform are in Kangle and Baiyin townships.

The core area of the park, Linze Danxia Scenic Area, is located 30 kilometres (19 mi) west of downtown Zhangye and 20 kilometres (12 mi) south of the seat of Linze County. It is the most developed and most visited part of the park. A second scenic area, Binggou (冰沟), located on the north bank of Liyuan River (梨园河), was officially inaugurated on 3 August 2014. Binggou covers an area of 300 square kilometres (120 sq mi), and its elevation ranges from 1,500 to 2,500 meters above sea level. A third area, Sunan Danxia Scenic Area, is located in Ganjun, south of Linze.

Landscape

Zhangye Danxia is known for the unusual colours of the rocks, which are smooth, sharp and several hundred meters tall. They are the result of deposits of sandstone and other minerals that occurred over 24 million years. The result, similar to a layer cake, is connected to the action of the same tectonic plates responsible for creating parts of the Himalayan mountains. Wind, rain, and time then sculpted extraordinary shapes, including towers, pillars, and ravines, with varying colours, patterns, and sizes.

How Was It Formed?

Zhangye ‘s Danxia was formed by the erosion of red sandstone, forming isolated peaks and steep stratified outcrops. Its special geological structure, combined with long-term desert conditions , freeze-thaw peeling, and wind and water erosion gave rise to its present appearance.

Geologists believe that Danxia topography is formed by folding of layered oceanic crust. Exposed slanting rock layers have different colors, textures, shapes, sizes, and patterns. The combination of differences in density and erosion create towering peaks, cave holes, and stone halls.

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Zhangye Danxia National Geological Park

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X-raying of fossil beetles

February 15, 2016

The layman considers fossil beetles just stones. Even experts were able to describe the rough, outer shape of the millimeter-sized fossils only. Using the ANKA synchrotron radiation source of KIT, 30 million year’ old beetles have now been examined in more detail. The inner anatomy was imaged in such detail that the family tree of the beetles could be analyzed. The results are published in the journal eLIFE. Hence, latest imaging methods can provide access to the enormous store of knowledge of unused natural history collections.

The beetles of a few millimeters in length come from a far more than hundred year’ old collection of fossil arthropods in Quercy, France, that was last studied in 1944. As the specimens are badly preserved on the outside, they have led a rather shadowy existence in the Natural History Museum of Basel since then.

Using modern imaging methods, scientists have now succeeded in obtaining detailed information about the inner structures of these beetles. The researchers subjected the fossils to X-ray microtomography at the ANKA synchrotron radiation source of Karlsruhe Institute of Technology (KIT). In this way, the innermost structures of the untransparent fossils were represented in a three-dimensional manner for the first time. “Measurement proper takes a few seconds only,” co-leader of the project, Thomas van de Kamp of the KIT Laboratory for Applications of Synchrotron Radiation (LAS) explains. During measurement, the object is rotated in the X-ray and examined from various directions. In the future, increasing automation of measurement is expected to allow for a quick examination and study of the anatomy of a number of specimens of natural history collections. After measurement, the three-dimensional object is reconstructed digitally, which is associated with a considerable expenditure. “Data processing and manual reconstruction require know-how of tomography as a tool and of the biology of the object examined.”

Thanks to the extremely good resolution of the tomography measurement station of the ANKA synchrotron radiation source, details of a few micrometers in dimension (millionths of a meter) in the beetle can be imaged. For the first time, this enables scientists to taxonomically describe the fossil beetle and evaluate its inner organs according to modern standards as if it was a specimen of a currently existing species. X-ray tomography of the fossil beetles thus revealed the mouth parts, throat, gastrointestinal tract, genitals, and the complex tracheal network. Then, a family tree analysis was made and relationships of the fossil species in the group of Clown beetles (also called hister beetles, histeridae), a beetle family still existing today, could be corrected and reevaluated.

The level of detail of the fossil beetle images by far exceeds the knowledge normally obtained about fossil arthropods. “The excellent preservation of the soft tissue shows that the beetles were preserved within a very short period of time, presumably within hours or days,” paleontologist Achim Schwermann of the Steinmann Institute of Bonn University and co-leader of the project says. One fossil beetle that is still embedded partly in the rock shows the structures of the exoskeleton. The adhering rock now reveals what the outside of the beetle looked like. Surprisingly, it is the externally worst preserved beetle that is best preserved inside. The adhering rock protected the inner structures and fragile limbs from being destroyed by external environmental impacts. “Never before have I seen the interior of a Clown beetle in such a detail,” Clown beetle expert Michael Caterino of Clemson University, South Carolina, USA, emphasizes.

After the fossil arthropods from Quercy, France, had been found to be badly preserved by a first analysis in the 1940s, this old collection has now turned out to be a true treasure trove. “This makes us scientists look at the old collections of museums and universities with different eyes,” Schwermann and van de Kamp say. Their team now plans to examine also other, similarly preserved fossils. The fact that the Quercy beetles have been left unnoticed for more than 70 years shows the high potential of old collections.

“Optimum adjustment of all components ensures an excellent imaging quality compared to medical computer tomographs,” Tomy dos Santos Rolo of the Institute for Beam Physics and Technology (IBPT) of KIT says. Synchrotrons are among the most intensive sources of X-rays and infrared radiation and of highest use for research in both science and industry. Their pulsed, polarized light enables unique insights into the world of biology, medicine, chemistry, and physics and can be used for the non-destructive analysis of materials and components planned to be applied in future facilities and machines. In facilities, such as ANKA (Angström Source Karlsruhe), synchrotron radiation is generated by the acceleration of fast electrons in magnetic fields.

Reference:
Achim H Schwermann, Tomy dos Santos Rolo, Michael S Caterino, Günter Bechly, Heiko Schmied, Tilo Baumbach, Thomas van de Kamp. Preservation of three-dimensional anatomy in phosphatized fossil arthropods enriches evolutionary inference. eLife, 2016; 5 DOI: 10.7554/eLife.12129

Note: The above post is reprinted from materials provided by Karlsruhe Institute of Technology.

A New Species of Cretaceous Acanthomorph from Canada

February 15, 2016

A New Species of Cretaceous-GeologyPage

For being one of the largest groups of vertebrates, and having one of the richer fossil records among organisms, the relationships of fishes are still hotly debated. Humongous datasets are being compiled that involve molecular (both nuclear and mitochondrial) data, compared and contrasted with thorough morphological analyses. (I’m not going to get into all of it here, simply because of its sheer complexity.)

What I am going to get into, however, is the fossil record of one subset of fishes, the acanthomorphs. Acanthomorphs are teleost fishes that possess true fin spines: a set of prominent, sharp, unsegmented spines in the front portion of their dorsal and/or anal fins, followed by a portion of pliable, segmented, “softer” looking rays. This is not a small subset of living fishes, as almost half of all living fishes (so, around 14,000 living species) is an acanthomorph. These spines can be retracted to sit flush along the body, helping the fish swim faster by reducing drag, or they can be extended completely out to act as a defense mechanism, in case you are a predator looking for a quick bite.

Near the base of the Acanthomorpha phylogenetic tree is a small group of fishes, Polymixiiformes, comprised of a single living genus, Polymixia, more commonly known as the beardfish. This innocuous fish seems harmless, but according to many ichthyologists, Polymixia is just one key to understanding acanthomorph relationships. Unraveling the evolutionary relationships is difficult with a single living genus, but thankfully, polymixiiforms have a fossil record dating back to the Cretaceous, containing an increasing number of taxa as new discoveries are being made, particularly in deposits in North America, where fewer acanthomorph fossils are known compared to the more-studied Eastern Tethys Ocean deposits in Europe.

One such new species was recently described by Alison M. Murray in the Open Access journal Vertebrate Anatomy Morphology Paleontology (VAMP). The paper, which was published this past week, describes in great morphological detail, a new mid-Cretaceous acanthomorph, named Cumbaaichthys oxyrhyncus, from Lac de Bois, Northwest Territories, Canada.

As Murray describes in the paper, getting to the localities is no easy task. The site is in a remote area of the NWT, and only two fossil-collecting trips have been made since the discovery of the site in 1968: 1969 and 2010.

“There were only four of us in the 2010 field party, Steve Cumbaa and Rick Day from the Canadian Museum of Nature, and Rob Holmes and me from University of Alberta,” Murray told me via email. “We were dropped off by float plane on the lake close to shore, and spent the next three weeks collecting. Our only link with civilization was the satellite phone…and an airplane that passed far overhead several times a week, maybe on its way to Alaska or Asia. We also had a visit from a pilot with his helicopter who took us around the area to search for other fossil sites.”

“Most of the best fossils, including Cumbaaichthys, came from the little quarry on the lake shore. While Rick and Steve measured the section and prospected, Rob and I sat at the waters’ edge and lifted the slate up in chunks, looking for fossils.

Cumbaaicthys is beautifully preserved and illustrated in Murray (2015), instantly noticeable by its large head in relation to its body. It’s actually a rather small fish, only around 55 mm in length from the tip of the snout to the base of the tail fin.

With one single living genus, Polymixiiformes and thus Polymixiidae, are monotypic. However, when taking the fossils into account, Polymixiiformes actually contains several families in addition to Polymixiidae, including the families Dalmatichthyidae, Dinopterygidae, Pycnosteroididae, and Boreiohydriidae. Each of these families themselves is monotypic, with the exception of Polymixiidae, which includes the extant genus and several extinct genera. Where does Cumbaaichthys fit into all of these different groups? It’s a bit perplexing for Murray, as several characters could place Cumbaaichthys in separate families, with the greatest similarity to Polymixiidae. Murray concludes that a more comprehensive analysis of the many Cretaceous polymixiiforms, and other acanthomorphs, is needed before she is confident in placing the new taxon, and thus leaves it incertae sedis.

“Polymixiiforms have so many fossil members and very few living members, as well as a very long history, which makes it difficult to resolve their evolutionary history,” Murray said. “There are currently a number of people working (in different teams and from different angles) on the problem, so what needs to be done [to help resolve acanthomorph evolutionary relationships] is exactly what is being done!

“We need to get more data, describe more fossils, find better fossils, and get DNA data and add it all together. I think this is a problem that may well be resolved by these researchers in the next few years.”

This study is a clear example of why paleontological work is relevant to other biological sciences. Polymixiiformes is just a single example of a group that, with just living forms taken into consideration, is throwing a wrench into many a molecular or morphological analysis, and leaves many ichthyologists shrugging their shoulders. This is a group where the history is almost purely in the past, with clearly a greater abundance and diversity leading all the way back into the Cretaceous Period.

Fossils like this are also key in understanding the age of modern taxa, and thus crucial as fossil calibration points. Likewise, they help us fill in the blanks in terms of biogeographic history.

“Cumbaaichthys, and the other polymixiiform from the same site, Boreiohydrias dayi, are very far north and show that acanthomorph fishes were spread throughout the Western Interior Seaway, as well as being in the Tethys, pretty much from the time they are first showing up in the fossil record,” Murray told me. “I think we have many more fossils to find!”

Reference:
Mid-Cretaceous acanthomorph fishes with the description of a new species from the Turonian of Lac des Bois, Northwest Territories, Canada. https://ejournals.library.ualberta.ca/index.php/VAMP/article/view/25439/20021

Note: The above post is reprinted from materials provided by Public Library of Science. The original article was written by Sarah Gibson.

Paleontologists discover evidence of new types of dinosaurs in Idaho including Tyrannosaur ancestors

February 13, 2016

Paleontologists discover-GeologyPage — L.J. Krumenacker is a doctoral candidate and paleontologist in the Department of Earth Sciences at Montana State University. Krumenacker is part of a team of MSU paleontologists who have identified several new types of dinosaurs from fossil evidence discovered in eastern Idaho, demonstrating the presence of a much more diverse group of theropods in the area than was previously known. MSU photo by Sepp Jannotta. Credit: Sepp Jannotta

A team of Montana State University paleontologists have identified several new types of dinosaurs from fossil evidence discovered in eastern Idaho, demonstrating the presence of a much more diverse group of theropods in the area than was previously known.

The findings were published earlier this month in Historical Biology: An International Journal of Paleobiology. MSU doctoral student L.J. Krumenacker in the MSU College of Letters and Science’s Department of Earth Sciences was the lead author of the study. Others who contributed to the work were Krumenacker’s adviser, MSU paleontology professor David J. Varricchio, MSU graduate student Garrett Scofield and current Boise State University adjunct professor and former MSU graduate student Jade Simon.

The fossils, found in the Wayan Formation, which occurs on lands administered by Caribou-Targhee National Forest, represent at least three newly discovered types of theropod — the family of dominantly carnivorous dinosaurs which include animals such as Tyrannosaurus rex. In fact, these formerly unrecognized dinosaurs, which date back to about 95 million years ago, include small- to mid-sized tyrannosauroids, Krumenacker said. Based mostly on fossilized teeth, he estimates the possible larger tyrannosauroid was about the size of a horse, with the small tyrannosauroid being similar in size to a retriever-sized dog.

Also among their findings were a pair of fossilized eggs of a large oviraptorosaur -the largest dinosaurs known to have existed in Idaho. The eggs are the first evidence that oviraptorosaurs lived in the area at that time.

The discoveries are significant, Varricchio said. Dinosaur fossils are rare to find in Idaho and these are some of the few that date back to the middle Cretaceous period.

“We don’t really have many dinosaurs from this time period,” he said. “This new evidence is really filling in the time, temporal and spacial gap.”

Krumenacker, who hails from Idaho, has been searching his home state for dinosaur remains for more than a decade — since he was an undergraduate at Idaho State University.

“He’s made himself the expert on Idaho dinosaurs,” Varricchio said. “He’s largely been the person to describe the Idaho dinosaurs.”

But aside from fossilized evidence of Oryctodromeus cubicularis — a burrowing dinosaur that lived around the same time as these newly discovered tyrannosauroids — the Idaho finds have been limited at best.

“It’s just disappointing,” Krumenacker said. “You’d like to find more. But it just drives me to look more. Persistence pays off — now we’ve found these other fossil localities giving a lot of more data on the animals present at the time.

“The challenge is identifying the animals based on the fragmentary specimens we find,” he added. “I put my best effort into it. It’s possible I could discover some identifications are wrong if we find more complete remains later. But I’d be thrilled because then we’d have an even better understanding. I’d really like to find more.”

The specimens will be curated at the Idaho Museum of Natural History in Pocatello, which holds the permit that allowed the collection of these fossils. A permit is required for all vertebrate fossils collected from federal lands.

Reference:
L.J. Krumenacker, D. Jade Simon, Garrett Scofield, David J. Varricchio. Theropod dinosaurs from the Albian–Cenomanian Wayan Formation of eastern Idaho. Historical Biology, 2016; 1 DOI: 10.1080/08912963.2015.1137913

Note: The above post is reprinted from materials provided by Montana State University.

100-mllion-year-old amber preserves oldest animal societies

February 12, 2016

100-mllion-year-old amber-GeologyPage — This photo shows two different ant species fighting, caught in 100-million-year old Burmese amber. Credit: AMNH/D. Grimaldi and P. Barden

Fighting ants, giant solider termites, and foraging worker ants recently discovered in 100-million-year-old amber provide direct evidence for advanced social behavior in ancient ants and termites–two groups that are immensely successful because of their ability to organize in hierarchies. The new work, led by scientists at the American Museum of Natural History and the University of Kansas, and published today in two papers in the journal Current Biology, proves that advanced sociality in ants and termites was present tens of millions of years earlier than indicated by the previous fossil record.

“Ecologically, advanced sociality is one of the most important adaptive features for animals,” said co-author Dave Grimaldi, a curator in the Museum’s Division of Invertebrate Zoology. “All ants and termites are social, and they are ubiquitous across terrestrial landscapes, with thousands of described species and probably even more that we haven’t yet found.”

Advanced sociality, or eusociality, a hallmark of which is reproductive specialization into worker and queen castes, is essentially a phenomenon of the group of invertebrates known as arthropods. Queens and reproductive males take the roles as the sole reproducers while the soldiers and workers defend and care for the colony. Eusociality occurs in a range of arthropods, from some shrimp, beetles, and aphids, to various wasps, though the phenomenon is nowhere more pronounced than in honey bees, ants, and termites. (Among vertebrates, eusociality is found in just two species of African mole rats.)

Eusociality is thought to have appeared first in termites in the Late Jurassic, about 150-160 million years ago. However, before the new work, the earliest termites ever found that could definitively be tied to a caste system were from the Miocene, a mere 20 to 17 million years ago. A similar story held true for ants, whose evolutionary history with eusociality was also thought to be long, but only weakly supported by the fossil record.

“In the Cretaceous amber we examine, the ants and termites represent the earliest branches of each evolutionary tree, and the species are wildly different from what their modern relatives look like today,” said co-author Phillip Barden, a recent graduate of the comparative biology doctoral program at the Museum’s Richard Gilder Graduate School and a National Science Foundation Postdoctoral Fellow at Rutgers University. “We wanted to know how social these creatures were, if they were social at all.”

A number of spectacular pieces of amber recently recovered from Myanmar gave Barden, Grimaldi, and their colleagues a clear answer: Eusociality was going strong in both groups during the Cretaceous.

In termites, the researchers made this determination based on the diverse anatomy of the animals, indicating the presence of castes. They found six different termite species preserved in the amber, two of which are new to science: Krishnatermes yoddha, comprising workers, reproductives, and soldiers; and Gigantotermes rex, based on one of the largest soldier termites ever found–about an inch in length, half of it being its head, with scissor-like jaws.

The amber ant fossils froze a number of eusocial behaviors in time. Those include: the presence of different castes, including queen ants and workers; groups of worker ants in single pieces of amber, probably nestmates foraging together; and two workers of different ant species engaging in combat.

“We know that wingless solitary relatives of ants don’t fight or defend territories against other species,” Barden said. “But modern ants war all of the time. The behavior of these fossil ants, frozen for 100 million years, resolves any ambiguity regarding sociality and diversity in the earliest ants.”

Reference:
Funding for this work was provided by the U.S. National Science Foundation (NSF) grant #s DEB-0542909, DEB-1144162, and DDIG-1313547, an NSF Predoctoral Fellowship, a 2014 College of Liberal Arts & Sciences (University of Kansas) Travel Award, and the American Museum of Natural History’s Richard Gilder Graduate School.

Current Biology papers:
http://www.cell.com/current-biology/abstract/S0960-9822(16)00041-5
http://www.cell.com/current-biology/abstract/S0960-9822(16)00042-7

Note: The above post is reprinted from materials provided by American Museum of Natural History.

Study confirms giant flightless bird wandered the Arctic 50 million years ago

February 12, 2016

study confirms giant flightless-GeologyPage — A new study involving CU-Boulder and the Chinese Academy of Sciences has confirmed that a flightless bird weighing several hundred pounds roamed Ellesmere Island in the high Arctic about 50 million years ago. Credit: Illustration by Marlin Peterson

It’s official: There really was a giant, flightless bird with a head the size of a horse’s wandering about in the winter twilight of the high Arctic some 53 million years ago.

The confirmation comes from a new study by researchers from the Chinese Academy of Sciences in Beijing and the University of Colorado Boulder that describes the first and only fossil evidence from the Arctic of a massive bird known as Gastornis. The evidence is a single fossil toe bone of the 6-foot tall, several-hundred-pound bird from Ellesmere Island above the Arctic Circle. The bone is nearly a dead ringer to fossil toe bones from the huge bird discovered in Wyoming and which date to roughly the same time.

The Gastornis (formerly Diatryma) fossil from Ellesmere Island has been discussed by paleontologists since it was collected in the 1970s and appears on a few lists of the prehistoric fauna there, said Professor Thomas Stidham of the Chinese Academy of Sciences in Beijing. But this is the first time the bone has been closely examined and described, he said. Gastornis fossils also have been found in Europe and Asia.

“We knew there were a few bird fossils from up there, but we also knew they were extremely rare,” said Eberle, an associate professor in geological sciences who conducts research on fossil mammals, reptiles and fishes. In addition to the Gastornis bone from Ellesmere, another scientist reported seeing a fossil footprint there, probably from a large flightless bird, although its specific location remains unknown, Eberle said.

A paper by Stidham and Eberle appears in the most recent issue of Scientific Reports, an open access, weekly journal from the publishers of Nature.

About 53 three million years ago during the early Eocene Epoch, the environment of Ellesmere Island was probably similar to cypress swamps in the southeast U.S. today, Eberle said. Fossil evidence indicates the island, which is adjacent to Greenland, hosted turtles, alligators, primates, tapirs and even large hippo-like and rhino-like mammals.

Today Ellesmere Island is one of the coldest, driest environments on Earth, where temperatures can drop to minus 40 degrees Fahrenheit in winter, said Eberle, also the curator of paleontology at the University of Colorado Museum of Natural History.

Originally thought to be a fearsome carnivore, recent research indicates Gastornis probably was a vegan, using its huge beak to tear at foliage, nuts, seeds and hard fruit.

A second Ellesmere Island bird from the early Eocene also is described by Stidham and Eberle in the new paper. Named Presbyornis, it was similar to birds in today’s duck, goose and swan family but with long, flamingo-like legs. The evidence was a single humerus, or upper wing bone, collected by the same paleontology team that found the Gastornis bone.

Like Gastornis, Presbyornis was mentioned in several lists of Ellesmere Island fauna over the years but the bone had never been described, said Stidham.

Stidham compared casts of Presbyornis bones excavated in ancient Wyoming to the single bone from Ellesmere Island, including all of the marks for muscle attachments. “I couldn’t tell the Wyoming specimens from the Ellesmere specimen, even though it was found roughly 4,000 kilometers (2,500 miles) to the north,” he said.

While the diversity of plants and animals on Ellesmere was surprisingly high in the early Eocene, one of the biggest challenges to life on the island may have been the Arctic winters, said Eberle. “Since Ellesmere Island is high above the Arctic Circle, the lights still went out there for several months of the year, just as they do today.”

It is not known whether Presbyornis migrated north to Ellesmere Island every year or lived there year-round, said Stidham. “Given the fossils we have, both hypotheses are possible,” he said. “There are some sea ducks today that spend the winter in the cold, freezing Arctic, and we see many more species of waterfowl that are only in the Arctic during the relatively warmer spring and summer months.”

The paleontology team working on Ellesmere Island in the 1970s and who found the Gastornis and Presbyornis bones in the 1970s included Mary Dawson, Robert “Mac” West, Howard Hutchinson and Malcolm McKenna.

The new study has implications for the rapidly warming Arctic climate, primarily a result of greenhouse gases being pumped into Earth’s atmosphere by humans.

“Permanent Arctic ice, which has been around for millennia, is on track to disappear,” Eberle said. “I’m not suggesting there will be a return of alligators and giant tortoises to Ellesmere Island any time soon. But what we know about past warm intervals in the Arctic can give us a much better idea about what to expect in terms of changing plant and animal populations there in the future.”

Reference:
Thomas A. Stidham & Jaelyn J. Eberle, The palaeobiology of high latitude birds from the early Eocene greenhouse of Ellesmere Island, Arctic Canada. DOI:10.1038/srep20912

Note: The above post is reprinted from materials provided by University of Colorado at Boulder.

Discovery of new iron oxides points to large oxygen source inside the Earth

February 12, 2016

Discovery of new iron oxides-GeologyPage — Iron oxides can be carried deep into the Earth’s mantle via subduction zones, where one tectonic plate slides under another. At sufficient pressure and heat, hematite and magnetite decompose to form new iron oxides, thereby releasing large quantities of oxygen. The fate of this oxygen has yet to be explored. Credit: Elena Bykova, University of Bayreuth

Using a special high-pressure chamber, scientists have discovered two new iron oxides in experiments at DESY’s X-ray light source PETRA III and other facilities. The discovery points to a huge, hitherto unknown oxygen source in the lower mantle of the Earth. The team led by Dr. Elena Bykova from the University of Bayreuth reports its results in the scientific journal Nature Communications.

Iron oxides in nature take on different forms. „The most common iron oxide is hematite, Fe2O3, which is the end product of many geological processes and the main source of iron for our civilization,” explains Bykova. During the past five years, however, scientists have discovered other iron oxides like Fe4O5, Fe5O6, and Fe13O19 that form at high pressures and temperatures. Investigating the behaviour of hematite and magnetite (Fe3O4) further, Bykova and her colleagues used a special pressure chamber at DESY’s measuring station for extreme conditions P02.2.

„In this so-called diamond anvil cell, a minute sample can be compressed between two diamonds to several hundred thousand times the atmospheric pressure while a meticulously aligned laser can also heat the sample through the transparent diamond anvils to several thousand degrees Celsius,” explains DESY scientist Dr. Hanns-Peter Liermann, head of the measuring station and a co-author of the paper. At the same time, the exceptionally bright and small X-ray beam of PETRA III can track structural changes in the sample. Similar measurements were also made at the European Synchrotron Radiation Source ESRF in France and at the Advanced Photon Source APS in the US.

When the scientists applied a pressure of more than 67 gigapascals (about 670,000 times the standard atmospheric pressure) to their hematite samples and heated it to more than 2400 degrees Celsius, Fe2O3 decomposed and formed Fe5O7, an iron oxide that has not been seen before. These conditions correspond to roughly 1500 kilometres below the surface of the Earth. At an even higher pressure of 70 gigapascals, corresponding to about 1670 kilometres below the surface, magnetite decomposed and another new iron oxide formed, Fe25O32. The formation of both so far unknown compounds leads to the release of oxygen.

Although iron oxides do not normally exist in the bulk of the Earth’ lower mantle, they can be transported there via subduction zones, where one tectonic plate dives under another. Hematite and magnetite are major components of so-called Banded Iron Formations (BIFs) and ironstones, huge sedimentary rock formations occurring on all continents. These formations may reach up to several hundred meters in thickness and hundreds of kilometres in length.Deposited in the world’s oceans about two billions years ago, Banded Iron Formations form part of the ocean floor and are recycled into the Earth’s interior by subduction to great depths, possibly extending to the core-mantle boundary region.

As the team now observed, at conditions corresponding to the middle of the Earth’s lower mantle hematite and magnetite decompose releasing huge amounts of oxygen-rich fluid (as oxygen is usually liquid under these conditions). „We estimate that this source so far provided an amount of oxygen equivalent to eight to ten times the mass of oxygen in the atmosphere,” says Bykova. “That’s a surprise, and it is not quite clear what happens with the oxygen down there.”

The oxygen-rich fluid could either locally oxidize surrounding materials or pass to the transition zone, or even to the upper mantle. “This remains to be explored”, says co-author Dr. Maxim Bykov of the University of Bayreuth. “For now, we can only say that there is a huge source of oxygen in the mantle that can significantly affect geochemical processes by changing oxidation states and mobilizing trace elements. This will open a large new field of modelling.”

The discovery of the new iron oxides thus not only adds to the knowledge about fundamental characteristics of these substances, underlines Bykov. “Our work shows that we maybe miss significant parts of the processes in the Earth. Subducted slabs can apparently produce unexpected things. The effects on Earth’s global dynamics, including climate variations, have to be investigated.”

Deutsches Elektronen-Synchrotron DESY is the leading German accelerator centre and one of the leading in the world. DESY is a member of the Helmholtz Association and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent). At its locations in Hamburg and Zeuthen near Berlin, DESY develops, builds and operates large particle accelerators, and uses them to investigate the structure of matter. DESY’s combination of photon science and particle physics is unique in Europe.

Reference:
Structural complexity of simple Fe2O3 oxide at high pressures and temperatures; Elena Bykova et al.; Nature Communications, 2016; DOI: 10.1038/NCOMMS10661

Note: The above post is reprinted from materials provided by Deutsches Elektronen-Synchrotron DESY.

Ground water storage helped offset sea level rise, study says

February 12, 2016

Ground water storage helped-GeologyPage — An artist’s depiction of the NASA GRACE satellites and the Earth’s gravity field. This material relates to a paper that appeared in the Feb. 12, 2016 issue of Science, published by AAAS. The paper, by J.T. Reager at Jet Propulsion Laboratory in Pasadena, CA, and colleagues was titled, “A decade of sea level rise slowed by climate-driven hydrology.” Credit: NASA/JPL

Recent increases in the storage of excess groundwater may be helping to offset sea level rise by as much as 22%, a new study finds. While the capacity of land to store water is known to be an important factor affecting sea level rise, the magnitude of its storage contributions are not fully understood.

Land masses store water in numerous ways, though some human-induced changes — including to groundwater extraction, irrigation, impoundment in reservoirs, wetland drainage, and deforestation – are affecting this process, as are climate-driven changes in rainfall, evaporation, and runoff. To gain more insights into how the land storage capacity may have changed over recent years, John Reager and colleagues analyzed satellite data from 2002 to 2014 that measure changes in gravity, and thus underlying changes in water storage.

They combined this satellite data with estimates of mass loss of glaciers to determine what impact land water storage might have had on sea level change. Their analysis suggests that during this timeframe, climate variability resulted in an increase of approximately 3,200 gigatons of water being stored in land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 ± 0.20 millimeters per year, the authors say.

While a small portion of the increase in land water storage can be directly attributed to human activities – primarily, the filling of reservoirs – the authors note that climate is the key driver. The greatest changes in land water storage were associated with regional climate-driven variations in precipitation.

Reference:
J. T. Reager, A. S. Gardner, J. S. Famiglietti, D. N. Wiese, A. Eicker, M.-H. Lo, A decade of sea level rise slowed by climate-driven hydrology. DOI: 10.1126/science.aad8386

Note: The above post is reprinted from materials provided by American Association for the Advancement of Science.

Oldest footprints in Catalonia

February 12, 2016

The ichnites or fossilised footprints of the Manyanet Valley (within the municipality of Sarroca de Bellera) are in two areas that differ in their environments: meandering fluvial systems in one and unconfined waters in the other. These two palaeoenvironments would have been inhabited by groups of different tetrapods during the Permian Period. The early tetrapods (from the Ancient Greek word meaning “four-footed”) were the first vertebrates to tread terra firma, developing lungs to capture atmospheric oxygen and turning fins into legs, but with a life cycle that was still closely tied to aquatic environments.

In what used to be a fluvial zone the researchers have identified ichnites (footprints) of temnospondyls (the predecessors of today’s amphibians) of different sizes. “They are a group with a life pattern similar to that of present-day salamanders. Some species sucked up their food while others hunted actively, in a similar way to today’s crocodiles”, explains Eudald Mujal, a researcher in the UAB Department of Geology who is in charge of the study. In this area there is greater biodiversity than in the area of unconfined waters and it includes ichnites from other groups, like seymouriamorphs, a peculiar group of animals that were almost a metre long, mid-way between the amphibians and the diadectomorphs: reptile-like animals that already laid hard-shelled eggs and could grow to up to two metres in length, approximately.

In the area where the open water used to be, the researchers have identified traces of captorhinids, a group of medium-sized (up to half a metre long) primitive reptiles with several rows of teeth, which became extinct at the end of the Permian. They have also found synapsids, the precursors of present-day mammals. “We have identified footprints of pelycosaurs, a group of synapsids that could reach four metres in length and which, in some cases, featured a sail along the spine whose function we do not know”, explains Dr Mujal. The pelycosaur group died out at the end of the Permian, but another group of synapsids, the cynodonts, went on to give rise to the mammals eventually.

During the Permian all land masses were joined together in a single super-continent known as Pangea, located approximately on today’s Equator and reaching as far as the Poles. In this study the researchers compare the ichnites of the Manyanet Valley with those found in what was the centre of this super-continent and they conclude that the faunistic differences observed could be due to differences in climate. “We have realised that, in similar palaeoenvironments, the associations of ichnites, and therefore of tetrapods, change. These changes coincide with the different palaeoclimate zones proposed in the models, so the faunal distribution was probably climate-related”, comments Josep Fortuny, an ICP researcher who took part in the study.

The Permian began around 300 million years (Ma) ago and ended around 250 Ma ago, leading into the Triassic, which lasted till about 200 Ma ago, and in which the dinosaurs first appeared. These two periods were of crucial importance for the history of life, as their boundary is marked by the greatest extinction the Earth has ever witnessed, when over 90% of its species disappeared: an extinction event far superior to the one that ended the reign of the dinosaurs at the end of the Cretaceous.

The findings were published in the journal Geological Magazine, of Cambridge University Press.

Reference:
EUDALD MUJAL et al. Palaeoenvironmental reconstruction and early Permian ichnoassemblage from the NE Iberian Peninsula (Pyrenean Basin), Geological Magazine (2015). DOI: 10.1017/S0016756815000576

Note: The above post is reprinted from materials provided by Universitat Autonoma de Barcelona.

Researcher studies volcanic gases in remote areas of world

February 12, 2016

Researcher studies volcanic-GeologyPage — Professor Tobias Fischer sits inside a volcanic crater on the Aleutian Islands.

Researchers will often go to the ends of the Earth in search of answers to the mysteries of science. Forming the Aleutian Arc in the Northern Pacific Ocean, approximately 3,400 miles from Albuquerque and the University of New Mexico, the Aleutian Islands are a perfect destination to conduct research that could one day, impact Earth and its inhabitants.

The Aleutian Islands, a chain of 14 large volcanic islands and 55 smaller ones that belong to both the United States and Russia, are just such a location. The Islands occupy an area of more than 6,800 square miles and extend approximately 1,200 miles westward from the Alaska Peninsula toward the Kamchatka Peninsula in Russia. The Aleutian Islands mark the dividing line between the Bering Sea to the north and the Pacific Ocean to the south.

Last fall, an expedition spearheaded by GeoPRISMS (Geodynamic Processes at Rifting and Subducting Margins), a community effort that studies the origin and evolution of continental margins funded by the National Science Foundation (NSF), organized a group of scientists to deploy several multi-disciplinary projects including seismic instruments, sample tephras and volcanic gases, and repair and restore monitoring stations for the Alaska Volcano Observatory (AVO) on seven active volcanoes in 19 days on the Aleutian Islands.

The expedition was conceived originally by a team of geologists and funded by NSF several years ago. Overall, the group included 10 scientists, four crew members, a helicopter pilot and mechanic. Once the scientists got to Adak Island located on Kuluk Bay, where the weather is harsh and the winds burn, they set out on the Maritime Maid, a vessel equipped with Bell 407 helicopter on a boat/helicopter expedition (a helicopter from the boat is the only way to get to the Islands), to explore seven different active volcanoes including: Buldir, Kiska, Segula, Semisopochnoi, Gareloi, Tanaga and Kanaga.

The combined expedition, which included University of New Mexico Department of Earth and Planetary Sciences Professor Tobias Fischer, and lead Research Geologist Elizabeth Cottrell, curator and director of the Global Volcanism Program, National Museum of Natural History, Smithsonian Institution, the scientists spent four weeks on the remote westernmost Aleutian Islands. They were part of a second group of scientists to work on the western Aleutians following a team that conducted research on the eastern Aleutian Islands.

The collaboration also included the U.S. Geological Service and Alaska Volcano Center, the Fish and Wildlife Service, the Deep Carbon Observatory Deep Carbon Degassing initiative (DCO-DECADE ), and NSF’s Polar Programs, which handled all the logistics and essentially enabled Fischer to accompany the group due to his research work with DCO. Polar Field Services and the crew of the Maritime Maid were essential to the success of these projects.

“The expense for expeditions to remote areas of the world is enormous when you include the boat, helicopter, maintenance, sample collection and supplies,” Fischer said.

Fischer’s part in the collaboration was to collect toxic gas samples pouring out of the summits at each of the volcanoes.

“We were guests on an expedition to one of the most remote parts of the world,” Fischer said. “We flew into Adak, a town with about 200 permanent residents. This is as far west as you can fly to commercially in the Aleutians. Beyond Adak there is no infrastructure or inhabitants. The goal was to study Aleutian volcanoes in detail geologically and geochemically and to push the envelope of what we knew about their magmatic degassing.”

Fischer and the gas chemists conducted some of the most dangerous work during the expedition having to obtain samples of toxic gases from the volcano summits.

“We were able to obtain real-time information on where the gases were coming from,” Fischer said. “At Kiska, the westernmost location, we were able to collect the first-ever volcanic gas samples from the summit of the volcano. Gareloi had never been sampled before and we were able to get samples of 300°C gases there. We also obtained samples from Kanaga, which is very steep-sided and exposed. The helicopter had to land right on top of the volcano because there was no other place to land near the volcano’s summit. We also developed a new sampling technique and collected samples from the plume by flying the helicopter directly into the volcanic gas plume. Every group that was part of the expedition achieved its goals.”

Fischer is now looking for answers to the data collected including: the source of the volatiles and how do they vary between the different volcanoes; how do tectonics affect what’s degassing from the magmas; and to characterize each volcano for its state of activity and potential future hazards.

“One of the objectives for the DCO is to determine how much carbon emissions come from natural sources,” Fischer said. “Some regions have been well-studied and other not so much. We’re trying to fill in the gaps as part of this 10-year project. We’re in year seven and making quite a bit of progress, but we still have a ways to go.”

Note: The above post is reprinted from materials provided by University of New Mexico.

South Africa’s Sterkfontein Caves produce two new hominin fossils

February 12, 2016

South Africa's Sterkfontein-GeologyPage — New homonin molar was found in Sterkfontein Caves. Credit: Jason Heaton

Two new hominin fossils have been found in a previously uninvestigated chamber in the Sterkfontein Caves, just North West of Johannesburg in South Africa.

The two new specimens, a finger bone and a molar, are part of a set of four specimens, which seem to be from early hominins that can be associated with early stone tool-bearing sediments that entered the cave more than two million years ago.

“The specimens are exciting not only because they are associated with early stone tools, but also because they possess a mixture of intriguing features that raise many more questions than they give answers,” says lead researcher Dr Dominic Stratford, a lecturer at the Wits School of Geography, Archaeology and Environmental studies, and research coordinator at the Sterkfontein Caves.

The first fossil specimen, which is a very large proximal finger bone, is significantly larger and more robust than any other hand bone of any hominin yet found in South African plio-pleistocene sites.

“It is almost complete and shows a really interesting mix of modern and archaic features. For example, the specimen is markedly curved — more curved than Homo naledi and is similarly curved to the much older species Australopithecus afarensis,” says Stratford.

The level of curvature is often linked to arborealism, but it lacks the strong muscle attachments that are expected to be present.

“The finger is similar in shape to the partial specimen from Olduvai Gorge that has been called Homo habilis, but is much larger. Overall, this specimen is unique in the South African plio-pleistocene fossil hominin record and deserves more studies,” says Stratford.

The other fossil is a relatively small, nearly complete adult 1st molar tooth that also has striking similarities to species Homo habilis.

“In size and shape it also bears a resemblance to two of the 10 1st molars of the H. naledi specimens, although further and more detailed comparisons are needed to verify this.”

The shape of the tooth and particularly the shape and relative sizes of the cones on the surface of the tooth suggest this specimen belonged to an early member of the Homo genus and can be associated with early stone tools dated recently to 2.18 million years ago.

“The two other hominin fossils found are still being studied and further excavations are planned to hopefully find more pieces and expand our understanding of who these intriguing bones belonged to and how they lived and died on the Sterkfontein hill more than two million years ago,” says Stratford.

The Sterkfontein Caves have been one of the most prolific palaeoanthropological sites in the world, since the discovery of the first ever adult Australopithecus by Robert Broom, 80 years ago this year. Since this incredible discovery, some of palaeoanthropology’s most famous finds have come from the Sterkfontein Caves, including Ms. Ples and Little Foot.

Sterkfontein remains the richest Australopithecus-bearing locality in the world and continues to yield remarkable specimens. The underground network of caves at the site extends over 5kms and the caves are filled with fossiliferous sediments that have been deposited underground over a period of more than 3.67 million years.

However, very few of these deep deposits have been systematically excavated and so remain largely unknown. The Milner Hall, where the four new hominin fossils were found, is one such chamber where several large deposits have been identified but never excavated.

The excavations that yielded these new hominin fossils were being conducted as part of a new phase of exploratory excavations away from the known hominin-bearing areas. Excavations in the Jacovec Cavern, Name Chamber and Milner Hall have been started under Dr Stratford’s direction. Each has yielded exciting new fossils that shed further light on the story of our evolution and life on the Sterkfontein hill more than two million years ago.

During the second phase of excavation in the Milner Hall, which were started early in 2015 with student Kelita Shadrach, four hominin fossils were excavated from the upper layers of a long sequence of deposits that document the long history of fossil deposition in the cave, starting over 3.67 million years ago.

Reference:
Dominic Stratford, Jason L. Heaton, Travis Rayne Pickering, Matthew V. Caruana, Kelita Shadrach. First hominin fossils from Milner Hall, Sterkfontein, South Africa. Journal of Human Evolution, 2016; 91: 167 DOI: 10.1016/j.jhevol.2015.12.005

Note: The above post is reprinted from materials provided by University of the Witwatersrand.

Study challenges widely accepted theory of Yellowstone formation

February 11, 2016

Study challenges widely-GeologyPage — Geology professor Lijun Liu used computer simulations to study the origins of the Yellowstone supervolcano. Credit: Photo by L. Brian Stauffer

Understanding the complex geological processes that form supervolcanoes could ultimately help geologists determine what triggers their eruptions. A new study using an advanced computer model casts doubt on previously held theories about the Yellowstone supervolcano’s origins, adding to the mystery of Yellowstone’s formation.

“Our model covered the entire history of Yellowstone volcanic activities,” said Lijun Liu, a geology professor at the University of Illinois. Liu’s computer model accounted for the last 40 million years, prior to even the earliest signs of Yellowstone’s volcanism.

Yellowstone is one of the largest remaining active supervolcanoes. True to its name, a supervolcano is capable of erupting on a much larger scale than an ordinary volcano. The origins of Yellowstone are still under much debate. One of the most prevalent views is that Yellowstone’s supervolcano was formed by a vertical column of hot rocks rising from the top of the earth’s core, known as a mantle plume.

“The majority of previous studies have relied on conceptual, idealized models, which are not physically and geologically accurate,” Liu said. Some recent studies reproduced key geophysical factors in a laboratory setting, including a rising plume and a sinking oceanic plate. However, these studies failed to account for the comprehensive set of geological variables that change over time, influencing the volcanic history.

“Our physical model is more sophisticated and realistic than previous studies, because we simultaneously consider many more relevant dynamic processes,” Liu said.

Using the Blue Waters supercomputer at the National Center for Supercomputing Applications at the U. of I., one of the fastest supercomputers in the world, Liu’s team created a computer model that replicated both the plate tectonic history of the surface and the geophysical image of the Earth’s interior. This study is the first to use a high-performance supercomputer to interpret the layers of complicated geophysical data underlying Yellowstone, Liu said.

The main goal of the study was to examine whether the initiation and subsequent development of the Yellowstone volcanic system was driven by a mantle plume. The simulated data showed that the plume was blocked from traveling upward toward the surface by ancient tectonic plates, meaning that the plume could not have played a significant role in forming Yellowstone, Liu said.

The researchers published their findings in the journal Geophysical Research Letters.

The researchers also examined many other factors that could have played a role in forming Yellowstone. These simulations discounted most of the other theories of Yellowstone’s origins, Liu said. As a result, formation of the Yellowstone volcanic system remains mysterious.

Supervolcanoes are hazardous natural phenomena that evoke public concern, partly because their formation is not well understood. While this area of research is still far from predicting eruptions, Liu said, improving the fundamental understanding of the underlying dynamics of supervolcano formation is key to many future applications of relevant geophysical knowledge.

“This research indicates that we need a multidisciplinary approach to understand complicated natural processes like Yellowstone,” Liu said. “I know people like simple models, but the Earth is not simple.”

Reference:
Tiffany Leonard, Lijun Liu. The Role of a Mantle Plume on the Formation of Yellowstone Volcanism. Geophysical Research Letters, 2016; DOI: 10.1002/2015GL067131

Note: The above post is reprinted from materials provided by University of Illinois at Urbana-Champaign. The original item was written by Sarah Banducci.

Water plus magma equals increased explosivity

February 11, 2016

Water plus magma equals-GeologyPage — This is Figure 1 from Unema et al., including the location of Okmok volcano on Umnak Island in central Aleutian Islands. Credit: J.A. Unema and GSA Bulletin

When water interacts with magma, it can dramatically increase the explosivity of the eruption. However, water in the eruption cloud can also increase the rate at which the particles aggregate into larger clumps, allowing them to settle out faster. The five-week-long 2008 Okmok eruption in the Aleutian Islands of Alaska was explosive due to the interaction of the magma with the abundant water inside the caldera, producing billowing clouds that deposited most of the tephra as fine-grained ash within 10 km of the vent area.

The first four hours of the eruption produced coarse tephra that extended well offshore of Umnak Island, but the remainder deposited ash as ash pellets and as muddy rain and mist. This plume scrubbing likely reduced any aviation hazards.

This paper by Joel A. Unema and colleagues describes the stratigraphy, distribution, and grain size, shape, and composition characteristics of the medial to distal deposits of the 2008 Okmok eruption. These are used to interpret water-magma interactions in the conduit and eruption column, eruption parameters (e.g., volume, column height, mass flux), and fragmentation style. Unema and colleagues then compare the Okmok eruption with the Eyjafjallajökull eruption of 2010.

Reference:
Joel A. Unema, Michael H. Ort, Jessica F. Larsen, Christina A. Neal, Janet R. Schaefer. Water-magma interaction and plume processes in the 2008 Okmok eruption, Alaska. Geological Society of America Bulletin, 2016; B31360.1 DOI: 10.1130/B31360.1

Note: The above post is reprinted from materials provided by Geological Society of America.

Some 5,000 years ago, silver mining on the shores of the Aegean Sea

February 11, 2016

Some 5,000 years ago, silver-GeologyPage — A mining archaeologist is at work in a 5,000 year old silver mine in Thorikos, Greece. Credit: Ghent University

The team of mining archaeologists was supervised by Prof. Dr Denis Morin of the University of Lorraine, connected with the UMR CNRS 5608 (UMR National Center for Scientific Research 5608) of Toulouse. The scientists employed a drone to locate above-ground installations connected to the mining. It is the first time that such complex mining infrastructure is studied.

These subterranean investigations are part of a larger archaeological research program on the site of Thorikos directed by Prof. Roald Docter of Ghent University under the auspices of the Belgian School at Athens, the University of Utrecht and the Ephorate of Eastern Attica.

Denis Morin on this discovery: “today, it is difficult to imagine the extreme conditions in which the miners had to work in this maze of galleries. A smothering heat reigns in this mineral environment. The progress of the underground survey requires a constant vigilance in this stuffy space where the rate of oxygen must be permanently watched. Tool marks on the walls, graffiti, oil lamps, and crushing areas give evidence of the omnipresent activity of these underground workers. The hardness of the bedrock and the mineralizations show the extreme working conditions of these workers, for the greater part slaves, sentenced to the darkness and the extraction of the lead-silver ore … Mapping these cramped, complex and braided underground networks, the ramifications of which are sometimes located at several levels, represent a real challenge in scientific terms”. Underground, the morphology and the organization of the mining infrastructure allow to distinguish several phases of activity.

The archaeological data gathered and observed during the latest phase of the 2015 campaign: pottery, stone hammers made of a volcano-sedimentary rock quarry, point towards a high dating for the earliest phase of mining activities in the area (Late Neolithic / Early Helladic: around 3200 BC). If future research confirms this hypothesis, the chronological framework of mining in the region of Attica and the Aegean world would be profoundly modified. The Classical phase is by far the most perceptible; omnipresent, it is remarkable by the regularity of the sections of divided galleries that cover the whole space. Fragments of pottery and oil lamps, and even a Greek inscription engraved on a wall, testify to the activities in this period. Conduits cut with pointed tools, of quadrangular shape, cutting of the rock in successive stages, such are the characteristics of these particularly well organized mining works.

This resumption of the works at the end of Classical period (4th century BC) is dated by the tool marks in the galleries and the ceramic remains. Shafts discovered inside this network connect two main levels of mineralization’s, and hence of extraction. Of perfect geometrical architecture, executed to the millimeter, their technique of construction is still investigated by the archaeologists.

Today, these shafts are only accessible using techniques of alpine caving. A certain number of these abandoned galleries has remained untouched over the last 5000 years. Others, which are now inaccessible, had been entirely banked up during successive phases of mining. Progressing in these galleries remains difficult for the experienced archaeologists, wearing high-tech equipment, in a stifling atmosphere with temperatures up to 21°C.

The mine that has been discovered in Thorikos is exceptional in its lay-out and extension. Up to now mining archaeologists working in the Laurion area did not explore such a complex network of galleries and mining infrastructure. They show the physical capacities and skills of the ancient miners to exploit these complex ore deposits and to assure ore dressing activities outside the mine from the Prehistory on. It testifies to a deliberate strategy and to perfect technological and spatial control over the process: an exceptional concentration of means to extract silver and a sophisticated technical system that in its scale is unique within the ancient world.

Already exploited since the 4th / 3rd millennium BC, by the 5th and 4th centuries BC these silver mines constituted the most important mining district of Greece, laying at the basis of Athens’ domination of the Aegean world.

The 2015 underground survey campaign brought new information on the mining techniques developed since the first metal ages in this strategic zone of the eastern Mediterranean. The ongoing research not only aims to survey these subterranean remains, but it will also allow to understand the mining technologies of these early periods, the management of mineral resources, their extraction and processing as well as the circulation of the end products… These achievements of human ingenuity already foreshadow the technological advances of the Middle Ages.

Note: The above post is reprinted from materials provided by Ghent University.

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