Chemical Formula: Pb5Sb8S17
Name Origin: From the Greek, plagios meaning “oblique.”
Discovery date : 1833
Town of Origin : MINE GRAF JOST-CHRISTINA-ZECKE, WOLFSBERG, HARZ
Country of Origin : ALLEMAGNE
Optical and misc. Propertie : Opaque
Reflective Power : 33,2-41% (580)
Hardness : 2,50
Density : 5,54
Color : blackish grey
Luster: metallic
Streak: blackish grey; reddish brown
Break: irregular; conchoidal
Cleavage : yes
The impact of the greenhouse gas CO2 on the Earth’s temperature is well established by climate models and temperature records over the past 100 years, as well as coupled records of carbon dioxide concentration and temperature throughout Earth history. However, past temperature records have suggested that warming is largely confined to mid-to-high latitudes, especially the poles, whereas tropical temperatures appear to be relatively stable: the tropical thermostat model.
The new results, published today in Nature Geoscience, contradict those previous studies and indicate that tropical sea surface temperatures were warmer during the early-to-mid Pliocene, an interval spanning about 5 to 3 million years ago.
The Pliocene is of particular interest because CO2 concentrations then were thought to have been about 400 parts per million, the highest level of the past 5 million years but a level that was reached for the first time last summer due to human activity. The higher CO2 levels of the Pliocene have long been associated with a warmer world, but evidence from tropical regions suggested relatively stable temperatures.
Project leader and Director of the Cabot Institute, Professor Richard Pancost said: “These results confirm what climate models have long predicted – that although greenhouse gases cause greater warming at the poles they also cause warming in the tropics. Such findings indicate that few places on Earth will be immune to global warming and that the tropics will likely experience associated climate impacts, such as increased tropical storm intensity.”
The scientists focussed their attention on the South China Sea which is at the fringe of a vast warm body of water, the West Pacific Warm Pool (WPWP). Some of the most useful temperature proxies are insensitive to temperature change in the heart of the WPWP, which is already at the maximum temperature they can record. By focussing on the South China Sea, the researchers were able to use a combination of geochemical records to reconstruct sea surface temperature in the past.
Not all of the records agree, however, and the researchers argue that certain tools used for reconstructing past ocean temperatures should be re-evaluated.
The paper’s first author, Charlotte O’Brien added: “It’s challenging to reconstruct the temperatures of the ocean many millions of years ago, and each of the tools we use has its own set of limitations. That is why we have used a combination of approaches in this investigation. We have shown that two different approaches agree – but a third approach agrees only if we make some assumptions about how the magnesium and calcium content of seawater has changed over the past 5 million years. That is an assumption that now needs to be tested.”
The work was funded by the UK’s Natural Environment Research Council and is ongoing.
Dr Gavin Foster at the University of Southampton is particularly interested in coupling the temperature records with improved estimates of Pliocene carbon dioxide levels. He said: “Just as we continue to challenge our temperature reconstructions we must challenge the corresponding carbon dioxide estimates. Together, they will help us truly understand the natural sensitivity of the Earth system and provide a better framework for predicting future climate change.”
More information:
Nature Geoscience, dx.doi.org/10.1038/ngeo2194
Note : The above story is based on materials provided by University of Bristol
The Volga is the longest river in Europe; it is also Europe’s largest river in terms of discharge and watershed. It flows through central Russia and is widely viewed as the national river of Russia. Eleven of the twenty largest cities of Russia, including the capital, Moscow, are situated in the Volga’s drainage basin. Some of the largest reservoirs in the world can be found along the Volga. The river has a symbolic meaning in Russian culture and is often referred to as Volga-Matushka (Mother Volga) in Russian literature and folklore.
The Russian hydronym Volga (Волга) derives from Proto-Slavic *vòlga “wetness, moisture”, which is preserved in many Slavic languages, including Ukrainian volóha (воло́га) “moisture”, Russian vlaga (влага) “moisture”, Bulgarian vlaga (влага) “moisture”, Czech vláha “dampness”, Serbo-Croatian vlȁga “moisture”, and Slovene vlaga “moisture” among others.
The Slavic name is a loan translation of earlier Scythian Rā (Ῥᾶ) “Volga”, literally “wetness”, seen also in Avestan Raŋhā “mythical stream” and Sogdian r’k “vein, blood vessel” (*raha-ka), and cognate with Sanskrit rasā́h “liquid, juice; mythical river”. The Scythian name survives in modern Mordvin Rav (Рав) “Volga”.
The Turkic peoples living along the river formerly referred to it as Itil or Atil “big river”. In modern Turkic languages, the Volga is known as İdel (Идел) in Tatar, Атăл (Atăl) in Chuvash, Idhel in Bashkir, Edil in Kazakh, and İdil in Turkish. The Turkic peoples associated the Itil’s origin with the Kama River. Thus, a left tributary to the Kama River was named the Aq Itil “White Itil” which unites with the Kara Itil “Black Itil” at the modern city of Ufa. The name Indyl (Indɨl) is used in Adyge (Cherkess) language.
Among Asians the river was known by its other Turkic name Sarı-su “yellow water”, but Mongols also used their own name: Ijil mörön “adaptation river”. Presently the Mari, another Uralic group, call the river Юл (Jul), meaning “way” in Tatar. Formerly, they called the river Volgydo, a borrowing from Old Russian.
The Volga River is the longest river in Europe. It belongs to the closed basin of the Caspian Sea. Rising in the Valdai Hills 225 meters (738 ft) above sea level northwest of Moscow and about 320 kilometers (200 mi) southeast of Saint Petersburg, the Volga heads east past Lake Sterzh, Tver, Dubna, Rybinsk, Yaroslavl, Nizhny Novgorod, and Kazan. From there it turns south, flows past Ulyanovsk, Tolyatti, Samara, Saratov and Volgograd, and discharges into the Caspian Sea below Astrakhan at 28 meters (92 ft) below sea level. At its most strategic point, it bends toward the Don (“the big bend”). Volgograd, formerly Stalingrad, is located there.
The Volga has many tributaries, most importantly the Kama, the Oka, the Vetluga, and the Sura rivers. The Volga and its tributaries form the Volga river system, which flows through an area of about 1,350,000 square kilometres (521,238 square miles) in the most heavily populated part of Russia. The Volga Delta has a length of about 160 kilometres (99 miles) and includes as many as 500 channels and smaller rivers. The largest estuary in Europe, it is the only place in Russia where pelicans, flamingos, and lotuses may be found. The Volga freezes for most of its length for three months each year.
The Volga drains most of Western Russia. Its many large reservoirs provide irrigation and hydroelectric power. The Moscow Canal, the Volga–Don Canal, and the Volga–Baltic Waterway form navigable waterways connecting Moscow to the White Sea, the Baltic Sea, the Caspian Sea, the Sea of Azov and the Black Sea. High levels of chemical pollution have adversely affected the river and its habitats.
The fertile river valley provides large quantities of wheat, and also has many mineral riches. A substantial petroleum industry centers on the Volga valley. Other resources include natural gas, salt, and potash. The Volga Delta and the nearby Caspian Sea offer superb fishing grounds. Astrakhan, at the delta, is the center of the caviar industry.
Note : The above story is based on materials provided by Wikipedia
Chemical Formula: Zn2Fe(PO4)2·4H2O
Name Origin: Named after its chemical composition containing phosphorus and the Greek fyllon – meaning “leaf.”
Phosphophyllite is a rare mineral composed of hydrated zinc phosphate. Its name derives from its chemical composition (phosphate) and the Greek word for “leaf”, phyllon, a reference to its cleavage. It is highly prized by collectors for its rarity and for its delicate bluish green colour. Phosphophyllite is rarely cut because it is fragile and brittle, and large crystals are too valuable to be broken up.
The finest phosphophyllite crystals come from Potosí, Bolivia, but it is no longer mined there. Other sources include New Hampshire, USA and Hagendorf, Bavaria, Germany. It is often found in association with the minerals chalcopyrite and triphylite.
Discovery date : 1920
Town of Origin: PEGMATITE DE HAGENDORF, OBERPFALZ, BAVIERE
Country of Origin : ALLEMAGNE
Optical and misc. Properties: Transparent – Luminescent, fluorescent – Gemme, pierre fine – Fragile, cassant – Macles possibles –
Refractive Index: from 1,59 to 1,61
Axial angle 2V: 44,3°
Hardness : from 3,00 to 3,50
Density : 3,13
Color : colorless; bluish green; blue green; pale green
Luster: vitreous
Streak: white
Break: irregular
Cleavage: yes
ITHACA, N.Y. – The chemical makeup of wastewater generated by “hydrofracking” could cause the release of tiny particles in soils that often strongly bind heavy metals and pollutants, exacerbating the environmental risks during accidental spills, Cornell University researchers have found.
Previous research has shown 10 to 40 percent of the water and chemical solution mixture injected at high pressure into deep rock strata, surges back to the surface during well development. Scientists at the College of Agriculture and Life Sciences studying the environmental impacts of this “flowback fluid” found that the same properties that make it so effective at extracting natural gas from shale can also displace tiny particles that are naturally bound to soil, causing associated pollutants such as heavy metals to leach out.
They described the mechanisms of this release and transport in a paper published in the American Chemical Society journal Environmental Science & Technology.
The particles they studied are colloids – larger than the size of a molecule but smaller than what can be seen with the naked eye – which cling to sand and soil due to their electric charge.
In experiments, glass columns were filled with sand and synthetic polystyrene colloids. They then flushed the column with different fluids – deionized water as a control, and flowback fluid collected from a Marcellus Shale drilling site – at different rates of flow and measured the amount of colloids that were mobilized.
On a bright field microscope, the polystyrene colloids were visible as red spheres between light-grey sand grains, which made their movement easy to track. The researchers also collected and analyzed the water flowing out of the column to quantify the colloid concentration leaching out.
They found that fewer than five percent of colloids were released when they flushed the columns with deionized water. That figure jumped to 32 to 36 percent when flushed with flowback fluid. Increasing the flow rate of the flowback fluid mobilized an additional 36 percent of colloids.
They believe this is because the chemical composition of the flowback fluid reduced the strength of the forces that allow colloids to remain bound to the sand, causing the colloids to actually be repelled from the sand.
“This is a first step into discovering the effects of flowback fluid on colloid transport in soils,” said postdoctoral associate Cathelijne Stoof, a co-author on the paper.
The authors hope to conduct further experiments using naturally occurring colloids in more complex field soil systems, as well as different formulations of flowback fluid collected from other drilling sites.
Stoof said awareness of the phenomenon and an understanding of the mechanisms behind it can help identify risks and inform mitigation strategies.
“Sustainable development of any resource requires facts about its potential impacts, so legislators can make informed decisions about whether and where it can and cannot be allowed, and to develop guidelines in case it goes wrong,” Stoof said. “In the case of spills, you want to know what happens when the fluid moves through the soil.”
This research was supported by the Cornell University Agricultural Experiment Station’s USDA Hatch funds, as well as the U.S. National Science Foundation and the National Natural Science Foundation of China.
Note : The above story is based on materials provided by Melissa Osgood ” Cornell University “
The Araguaia River is one of the major rivers of Brazil, and the principal tributary of the Tocantins, though it is almost equal in volume at its confluence with the Tocantins. It has a total length of approximately 2,627 km. Araguaia means “river of (red) macaws” in the Tupi language.
Because of the vast number of tributaries, it is not easy to define its source. Important tributaries originate in the Araras mountain range in Mato Grosso as well in the Divisões mountain range situated in Goiás (according to other sources however, the Araguaia comes from the Caiapó Range, at the Goiás-Mato Grosso border). From there it flows northeast to a junction with the Tocantins near the town of São João.
Along its course, the river forms the border between the Brazilian federal states of Goiás, Mato Grosso, Tocantins and Pará. Roughly in the middle of its course, the Araguaia splits into two forks (with the western one retaining the name Araguaia and the eastern one being called Rio Javaés). These later reunite, forming the Ilha do Bananal, the world’s largest river island. The mouth of the Javaés forms a broad inland delta where it pours back into the main Araguaia, a 100,000 hectare expanse of igapó flooded forest, blackwater river channels, and oxbow lakes called Cantão. This is one of the biologically richest areas of the eastern Amazon, with over 700 species of birds, nearly 300 species of fish, large populations of threatened species such as the giant otter, the black cayman, the world’s largest freshwater fish, the pirarucú, and the endemic Araguaian river dolphin (or Araguaian boto) all occurring within a relatively small area.
A large portion of the Araguaia’s course is navigable all year, but the river below the Cantão wetlands is interrupted by rapids.
The combined watershed of Araguaia and Tocantins rivers (named the Araguaia Tocantins Basin) covers approximately 9.5% of Brazil’s national territory. This area is an integral part of the Amazon Basin. However, the Araguaia River is not a tributary of the Amazon.
“Araguaia” means “River of the Macaws” in the native Tupi language.
Its principal tributary is the Rio das Mortes, which rises in the Serra de São Jerônimo, near Cuiabá, Mato Grosso, and is navigable to Pará.
Other important tributaries include the Bonito, Garcas, Cristallino and Tapirape on the west, and the Pitombas, Claro, Vermelho, Tucupa and Chavante on the east.
Note : The above story is based on materials provided by Wikipedia
The name phosgenite was given by August Breithaupt in 1820, from phosgene, carbon oxychloride, because the mineral contains the elements carbon, oxygen and chlorine.
It was found associated with anglesite and matlockite in cavities within altered galena in a lead mine at Cromford, near Matlock: hence its common name cromfordite. Crystals are also found in galena at Monteponi near Iglesias in Sardinia, and near Dundas in Tasmania. It has also been reported from Laurium, Greece; Tarnowitz, Poland; the Altai district, Siberia; the Touissit mine, near Oujda, Morocco; Sidi Amor ben Salem, Tunisia; Tsumeb, Namibia; Broken Hill, New South Wales; and Boleo, near Santa Rosalia, Baja California. In the US it has been reported from the Terrible mine, Custer County, Colorado; the Stevenson-Bennett mine, Organ Mountains, Doña Ana County, New Mexico; and the Mammoth mine, Tiger, Pinal County, Arizona.
Crystals of phosgenite, and also of the corresponding bromine compound Pb2Br2CO3, have been prepared artificially.
Discovery date : 1800
Optical and misc. Properties : Luminescent, fluorescent – Transparent – Translucide – Gemme, pierre fine
Refractive Index: from 2,11 to 2,14
Hardness : from 2,00 to 3,00
Density : 6,13
Color: colorless; white; yellowish white; grey; brown; greenish; pinkish; pale brown
Luster : adamantine; vitreous; greasy; waxy
Streak: white
Break : conchoidal
Cleavage: Yes
New research has revealed the causes and warning signs of rare tsunami earthquakes, which may lead to improved detection measures.
Tsunami earthquakes happen at relatively shallow depths in the ocean and are small in terms of their magnitude. However, they create very large tsunamis, with some earthquakes that only measure 5.6 on the Richter scale generating waves that reach up to ten metres when they hit the shore.
A global network of seismometers enables researchers to detect even the smallest earthquakes. However, the challenge has been to determine which small magnitude events are likely to cause large tsunamis.
In 1992, a magnitude 7.2 tsunami earthquake occurred off the coast of Nicaragua in Central America causing the deaths of 170 people. Six hundred and thirty seven people died and 164 people were reported missing following a tsunami earthquake off the coast of Java, Indonesia, in 2006, which measured 7.2 on the Richter scale.
The new study, published in the journal Earth and Planetary Science Letters, reveals that tsunami earthquakes may be caused by extinct undersea volcanoes causing a “sticking point” between two sections of Earth’s crust called tectonic plates, where one plate slides under another.
The researchers from Imperial College London and GNS Science in New Zealand used geophysical data collected for oil and gas exploration and historical accounts from eye witnesses relating to two tsunami earthquakes, which happened off the coast of New Zealand’s north island in 1947. Tsunami earthquakes were only identified by geologists around 35 years ago, so detailed studies of these events are rare.
The team located two extinct volcanoes off the coast of Poverty Bay and Tolaga Bay that have been squashed and sunk beneath the crust off the coast of New Zealand, in a process called subduction.
The researchers suggest that the volcanoes provided a “sticking point” between a part of Earth’s crust called the Pacific plate, which was trying to slide underneath the New Zealand plate. This caused a build-up of energy, which was released in 1947, causing the plates to “unstick” and the Pacific plate to move and the volcanoes to become subsumed under New Zealand. This release of the energy from both plates was unusually slow and close to the seabed, causing large movements of the sea floor, which led to the formation of very large tsunami waves.
All these factors combined, say the researchers, are factors that contribute to tsunami earthquakes. The researchers say that the 1947 New Zealand tsunami earthquakes provide valuable insights into what geological factors cause these events. They believe the information they’ve gathered on these events could be used to locate similar zones around the world that could be at risk from tsunami earthquakes. Eyewitnesses from these tsunami earthquakes also describe the type of ground movement that occurred and this provides valuable clues about possible early warning signals for communities.
Dr Rebecca Bell, from the Department of Earth Science and Engineering at Imperial College London, says: “Tsunami earthquakes don’t create massive tremors like more conventional earthquakes such as the one that hit Japan in 2011, so residents and authorities in the past haven’t had the same warning signals to evacuate. These types of earthquakes were only identified a few decades ago, so little information has been collected on them. Thanks to oil exploration data and eyewitness accounts from two tsunami earthquakes that happened in New Zealand more than 70 years ago, we are beginning to understand for first time the factors that cause these events. This could ultimately save lives.”
By studying the data and reports, the researchers have built up a picture of what happened in New Zealand in 1947 when the tsunami earthquakes hit. In the March earthquake, eyewitnesses around Poverty Bay on the east coast of the country, close to the town of Gisborne, said that they didn’t feel violent tremors, which are characteristic of typical earthquakes. Instead, they felt the ground rolling, which lasted for minutes, and brought on a sense of sea sickness. Approximately 30 minutes later the bay was inundated by a ten metre high tsunami that was generated by a 5.9 magnitude offshore earthquake. In May, an earthquake measuring 5.6 on the Richter scale happened off the coast of Tolaga Bay, causing an approximate six metre high tsunami to hit the coast. No lives were lost in the New Zealand earthquakes as the areas were sparsely populated in 1947. However, more recent tsunami earthquakes elsewhere have devastated coastal communities.
The researchers are already working with colleagues in New Zealand to develop a better warning system for residents. In particular, new signage is being installed along coastal regions to alert people to the early warning signs that indicate a possible tsunami earthquake. In the future, the team hope to conduct new cutting-edge geophysical surveys over the sites of other sinking volcanoes to better understand their characteristics and the role they play in generating this unusual type of earthquake.
Note : The above story is based on materials provided by Imperial College London.
New research in the journal Nature’s Scientific Reports has provided a major new theory on the cause of the ice age that covered large parts of the Northern Hemisphere 2.6 million years ago.
The study, co-authored by Dr Thomas Stevens, from the Department of Geography at Royal Holloway, University of London, found a previously unknown mechanism by which the joining of North and South America changed the salinity of the Pacific Ocean and caused major ice sheet growth across the Northern Hemisphere.
The change in salinity encouraged sea ice to form which in turn created a change in wind patterns, leading to intensified monsoons. These provided moisture that caused an increase in snowfall and the growth of major ice sheets, some of which reached 3km thick.
The team of researchers analyzed deposits of wind-blown dust called red clay that accumulated between six million and two and a half million years ago in north central China, adjacent to the Tibetan plateau, and used them to reconstruct changing monsoon precipitation and temperature.
“Until now, the cause of the Quaternary ice age had been a hotly debated topic,” said Dr Stevens. “Our findings suggest a significant link between ice sheet growth, the monsoon and the closing of the Panama Seaway, as North and South America drifted closer together. This provides us with a major new theory on the origins of the ice age, and ultimately our current climate system.”
Surprisingly, the researchers found there was a strengthening of the monsoon during global cooling, instead of the intense rainfall normally associated with warmer climates.
Dr Stevens added: “This led us to discover a previously unknown interaction between plate tectonic movements in the Americas and dramatic changes in global temperature. The intensified monsoons created a positive feedback cycle, promoting more global cooling, more sea ice and even stronger precipitation, culminating in the spread of huge glaciers across the Northern Hemisphere.”
Note : The above story is based on materials provided by University of Royal Holloway London.
Discovery date : 1841
Town of Origin: ANTWERP, NEW YORK
Country of Origin : USA
Optical and misc. Properties : Luminescent, fluorescent – Flexible – Elastique – Tenace – Transparent – Translucide – Macles possibles
Refractive Index : from 1,53 to 1,63
Axial angle 2V: 0-15°
Hardness : from 2,00 to 3,00
Density: from 2,78 to 2,85
Color : yellowish brown; brownish red; colorless; white; greenish; grey; brown yellow; blackish; whitish; green
Luster : submetallic; nacreous
Streak : white
Cleavage : Yes
The Tocantins is a river in Brazil, the central fluvial artery of the country. In the Tupi language, its name means “toucan’s beak” (Tukã for “toucan” and Ti for “beak”). It runs from south to north for about 2,640 km. It is not really a branch of the Amazon River, although usually so considered, since its waters flow into the Atlantic Ocean alongside those of the Amazon. It flows through four Brazilian states (Goiás, Tocantins, Maranhão and Pará) and gives its name to one of Brazil’s newest states, formed in 1988 from what was until then the northern portion of Goiás.
It rises in the mountainous district known as the Pireneus, west of the Federal District, but its western tributary, the Araguaia River, has its extreme southern headwaters on the slopes of the Serra dos Caiapós. The Araguaia flows 1,670 km before its confluence with the Tocantins, to which it is almost equal in volume. Besides its main tributary, the Rio das Mortes, the Araguaia has twenty smaller branches, offering many miles of canoe navigation. In finding its way to the lowlands, it breaks frequently into waterfalls and rapids, or winds violently through rocky gorges, until, at a point about 160 km above its junction with the Tocantins, it saws its way across a rocky dyke for 20 km in roaring cataracts.
Two other tributaries, called the Maranhão and Paranatinga, collect an immense volume of water from the highlands which surround them, especially on the south and south-east. Between the latter and the confluence with the Araguaia, the Tocantins is occasionally obstructed by rocky barriers which cross it almost at a right angle.
The Tocantins River Basin (which include the Araguaia River) is the home of several large aquatic mammals such as Amazonian manatee, Araguaian river dolphin and tucuxi, and larger reptiles such as black caiman, spectacled caiman and yellow-spotted river turtle.
The Tocantins River Basin has a high richness of fish species, although it is relatively low by Amazon Basin standards. More than 350 fish species have been registered, including more than 175 endemics. The most species rich families are Characidae (tetras and allies), Loricariidae (pleco catfish and allies) and Rivulidae (South American killifish). While most species essentially are of Amazonian origin, there are also some showing a connection with the Paraná and São Francisco rivers. The Tocantins and these two rivers flow in different directions, but all have their source in the Brazilian Plateau in a region where a low watershed allows some exchange between them. There are several fish species that migrate along the Tocantins to spawn, but this has been restricted by the dams. Following the construction of the massive Tucuruí dam, the flow of the river changed. Some species have been adversely affected and there has been a substantial reduction in species richness in parts of the river.
Downstream from the Araguaia confluence, in the state of Pará, the river used to have many cataracts and rapids, but they were flooded in the early 1980s by the artificial lake created by the Tucuruí dam, one of the world’s largest. When the second phase of the Tucuruí project is completed, there will be a system of locks that will make a long extension of the river navigable. The construction works on the locks have been stalled for many years due to lack of funding, but it is possible that they will be included in a massive development program launched by the Brazilian government in 2007, in which case they could be operational within about four years.
In total there are four dams on the river, of which the largest are the Tucuruí and the Serra da Mesa Dam.
The flat, broad valleys, composed of sand and clay, of both the Tocantins and its Araguaia branch are overlooked by steep bluffs. They are the margins of the great sandstone plateaus, from 300 to 600 m elevation above sea-level, through which the rivers have eroded their deep beds. Around the estuary of the Tocantins the great plateau has disappeared, to give place to a part of the forest-covered, half submerged alluvial plain, which extends far to the north-east and west. The Pará River, generally called one of the mouths of the Amazon, is only the lower reach of the Tocantins. If any portion of the waters of the Amazon runs round the southern side of the large island of Marajó into the river Para, it is only through tortuous, natural canals, which are in no sense outflow channels of the Amazon.
The Tocantins River records a mean discharge rate of 13,598 m³/s and a specific discharge rate of 14.4 l/s/km². The sub-basins have the following specific discharge rates: Tocantins (11 l/s/km²), Araguaia (16 l/s/km²), Pará (17l/s/km²) and Guamá (21l/s/km²).
Note : The above story is based on materials provided by Wikipedia
Methane is a simple molecule consisting of just one carbon atom bound to four hydrogen atoms. But that simplicity belies the complex role the molecule plays on Earth—it is an important greenhouse gas, is chemically active in the atmosphere, is used in many ecosystems as a kind of metabolic currency, and is the main component of natural gas, which is an energy source.
Methane also poses a complex scientific challenge: it forms through a number of different biological and nonbiological processes under a wide range of conditions. For example, microbes that live in cows’ stomachs make it; it forms by thermal breakdown of buried organic matter; and it is released by hot hydrothermal vents on the sea floor. And, unlike many other, more structurally complex molecules, simply knowing its chemical formula does not necessarily reveal how it formed. Therefore, it can be difficult to know where a sample of methane actually came from.
But now a team of scientists led by Caltech geochemist John M. Eiler has developed a new technique that can, for the first time, determine the temperature at which a natural methane sample formed. Since methane produced biologically in nature forms below about 80°C, and methane created through the thermal breakdown of more complex organic matter forms at higher temperatures (reaching 160°C-220°C, depending on the depth of formation), this determination can aid in figuring out how and where the gas formed.
A paper describing the new technique and its first applications as a geothermometer appears in a special section about natural gas in the current issue of the journal Science. Former Caltech graduate student Daniel A. Stolper (PhD ’14) is the lead author on the paper.
“Everyone who looks at methane sees problems, sees questions, and all of these will be answered through basic understanding of its formation, its storage, its chemical pathways,” says Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry at Caltech.
“The issue with many natural gas deposits is that where you find them—where you go into the ground and drill for the methane—is not where the gas was created. Many of the gases we’re dealing with have moved,” says Stolper. “In making these measurements of temperature, we are able to really, for the first time, say in an independent way, ‘We know the temperature, and thus the environment where this methane was formed.'”
Eiler’s group determines the sources and formation conditions of materials by looking at the distribution of heavy isotopes—species of atoms that have extra neutrons in their nuclei and therefore have different chemistry. For example, the most abundant form of carbon is carbon-12, which has six protons and six neutrons in its nucleus. However, about 1 percent of all carbon possesses an extra neutron, which makes carbon-13. Chemicals compete for these heavy isotopes because they slow molecular motions, making molecules more stable. But these isotopes are also very rare, so there is a chemical tug-of-war between molecules, which ends up concentrating the isotopes in the molecules that benefit most from their stabilizing effects. Similarly, the heavy isotopes like to bind, or “clump,” with each other, meaning that there will be an excess of molecules containing two or more of the isotopes compared to molecules containing just one. This clumping effect is strong at low temperatures and diminishes at higher temperatures. Therefore, determining how many of the molecules in a sample contain heavy isotopes clumped together can tell you something about the temperature at which the sample formed.
Eiler’s group has previously used such a “clumped isotope” technique to determine the body temperatures of dinosaurs, ground temperatures in ancient East Africa, and surface temperatures of early Mars. Those analyses looked at the clumping of carbon-13 and oxygen-18 in various minerals. In the new work, Eiler and his colleagues were able to examine the clumping of carbon-13 and deuterium (hydrogen-2).
The key enabling technology was a new mass spectrometer that the team designed in collaboration with Thermo Fisher, mixing and matching existing technologies to piece together a new platform. The prototype spectrometer, the Thermo IRMS 253 Ultra, is equipped to analyze samples in a way that measures the abundances of several rare versions, or isotopologues, of the methane molecule, including two “clumped isotope” species: 13CH3D, which has both a carbon-13 atom and a deuterium atom, and 12CH2D2, which includes two deuterium atoms.
Using the new spectrometer, the researchers first tested gases they made in the laboratory to make sure the method returned the correct formation temperatures.
They then moved on to analyze samples taken from environments where much is known about the conditions under which methane likely formed. For example, sometimes when methane forms in shale, an impermeable rock, it is trapped and stored, so that it cannot migrate from its point of origin. In such cases, detailed knowledge of the temperature history of the rock constrains the possible formation temperature of methane in that rock. Eiler and Stolper analyzed samples of methane from the Haynesville Shale, located in parts of Arkansas, Texas, and Louisiana, where the shale is not thought to have moved much after methane generation. And indeed, the clumped isotope technique returned a range of temperatures (169°C-207°C) that correspond well with current reservoir temperatures (163°C-190°C). The method was also spot-on for methane collected from gas that formed as a product of oil-eating bugs living on top of oil reserves in the Gulf of Mexico. It returned temperatures of 34°C and 48°C plus or minus 8°C for those samples, and the known temperatures of the sampling locations were 42°C and 48°C, respectively.
To validate further the new technique, the researchers next looked at methane from the Marcellus Shale, a formation beneath much of the Appalachian basin, where the gas-trapping rock is known to have formed at high temperature before being uplifted into a cooler environment. The scientists wanted to be sure that the methane did not reset to the colder temperature after formation. Using their clumped isotope technique, the researchers verified this, returning a high formation temperature.
“It must be that once the methane exists and is stable, it’s a fossil remnant of what its formation environment was like,” Eiler says. “It only remembers where it formed.”
An important application of the technique is suggested by the group’s measurements of methane from the Antrim Shale in Michigan, where groundwater contains both biologically and thermally produced methane. Clumped isotope temperatures returned for samples from the area clearly revealed the different origins of the gases, hitting about 40°C for a biologically produced sample and about 115°C for a sample involving a mix of biologically and thermally produced methane.
“There are many cases where it is unclear whether methane in a sample of groundwater is the product of subsurface biological communities or has leaked from petroleum-forming systems,” says Eiler. “Our results from the Antrim Shale indicate that this clumped isotope technique will be useful for distinguishing between these possible sources.”
One final example, from the Potiguar Basin in Brazil, demonstrates another way the new method will serve geologists. In this case the methane was dissolved in oil and had been free to migrate from its original location. The researchers initially thought there was a problem with their analysis because the temperature they returned was much higher than the known temperature of the oil. However, recent evidence from drill core rocks from the region shows that the deepest parts of the system actually got very hot millions of years ago. This has led to a new interpretation suggesting that the methane gas originated deep in the system at high temperatures and then percolated up and mixed into the oil.
“This shows that our new technique is not just a geothermometer for methane formation,” says Stolper. “It’s also something you can use to think about the geology of the system.”
More information:
Formation temperatures of thermogenic and biogenic methane, by D.A. Stolper et al. www.sciencemag.org/lookup/doi/… 1126/science.1254509
Note : The above story is based on materials provided by California Institute of Technology
Chemical Formula: (Ca,Na2,K2)3Al6Si10O32·12H2O
Name Origin: Named after William Phillips (1775-1829), English mineralogist and founder of the Geological Society of London. Na modifier added by zeolite nomenclature committee.
Phillipsite is a mineral series of the zeolite group; a hydrated potassium, calcium and aluminium silicate, approximating to (Ca,Na2,K2)3Al6Si10O32·12H2O. The members of the series are phillipsite-K, phillipsite-Na and phillipsite-Ca. The crystals are monoclinic, but only complex cruciform twins are known, these being exactly like twins of harmotome which also forms a series with phillipsite-Ca. Crystals of phillipsite are, however, usually smaller and more transparent and glassy than those of harmotome. Spherical groups with a radially fibrous structure and bristled with crystals on the surface are not uncommon. The Mohs hardness is 4.5, and the specific gravity is 2.2. The species was established by A. Lévy in 1825 and named after William Phillips. French authors use the name Christianite (after Christian VIII of Denmark), given by A. Des Cloizeaux in 1847.
Phillipsite is a mineral of secondary origin, and occurs with other zeolites in the amygdaloidal cavities of mafic volcanic rocks: for example in the basalt of the Giants Causeway in County Antrim, and near Melbourne in Victoria; and in Lencitite near Rome. Small crystals of recent formation have been observed in the masonry of the hot baths at Plombires and Bourbonne-les-Bains, in France. Minute spherical aggregates embedded in red clay were dredged by the Challenger from deep sea sedimenary deposits in the Pacific Ocean.
Discovery date : 1825
Town of Origin: ACI CASTELLO, SICILE
Country of Origin : ITALIE
Optical and misc. Properties: Fragile, cassant – Transparent – Translucide – Opaque – Macles possibles
Refractive Index : from 1,48 to 1,51
Axial angle 2V: 60-80°
Hardness : from 4,00 to 4,50
Density : 2,20
Color : colorless; white; reddish yellow; reddish; yellow; yellowish; yellowish white
Luster : vitreous
Streak : white
Break : irregular
Cleavage : Yes
Researchers from the CNRS and the Université de Poitiers, working in collaboration with teams from the Université de Lille 1, Université de Rennes 1, the French National History Museum and Ifremer, have discovered, in clay sediments from Gabon, fossils of the oldest multicellular organisms ever found (Nature, 2010). In total, more than 400 fossils dating back 2.1 billion years have been collected, including dozens of new types. The detailed analysis of these finds, published on June 25, 2014 in PLoS One, reveals a broad biodiversity composed of micro and macroscopic organisms of highly varied size and shape that evolved in a marine ecosystem.
The discovery in 2010 of 250 fossils of complex multicellular organisms dating back 2.1 billion years in a sedimentary bed close to Franceville, in Gabon, drastically changed the scenario of the history of life on Earth. Until then, the oldest known fossils of complex organisms were 600 million years old (Vendobionta from Ediacara in Australia) and it was commonly accepted that, before that period, life on our planet was exclusively made up of unicellular organisms (bacteria, unicellular algae, etc.). With the Franceville discovery, complex life forms made a leap of 1.5 billion years back in time.
The excavations carried out since 2008 by the team of Professor Abderrazak El Albani, geologist at the Institut de chimie des milieux et matériaux in Poitiers (CNRS/Université de Poitiers), have uncovered 400 fossils. The organic origin (biogenicity) of the samples was confirmed using an ion probe to measure the different sulfur isotopes, while X-ray microtomography revealed their internal and external structures. The rapid fossilization of these individuals by the pyritization phenomenon (replacement of their organic matter by pyrite, brought about by bacterial action) conserved their original forms very well.
Several new morphotypes, e.g. circular, elongated, lobed, etc. have been catalogued by the researchers, each including individuals of different size. Their analyses reveal organisms with radial texture and soft gelatinous bodies. Their forms can be smooth or folded, their texture uniform or knobby and their material in one whole piece or partitioned. The highly organized structure and varied sizes of the macroscopic specimens (up to 17 centimeters) suggest an extremely sophisticated means of growth for the period. This complete marine ecosystem was therefore composed of micro and macroscopic organisms, extremely varied in shape and form, living in a shallow marine environment.
Like the biota* of Ediacara in Australia, whose emergence coincided with a sudden increase in oxygen levels in the atmosphere 800 million years ago, the appearance and diversity of the biota in Gabon corresponds to the first peak in oxygen observed between — 2.3 and — 2 billion years ago. This biodiversity apparently died out after this oxygen level suddenly fell. This Gabonese biota raises questions about the history of the biosphere at a planetary scale. The diversity and highly organized structure of the specimens studied suggest that they were already evolved. It is also possible that other forms of life just as old may exist elsewhere on the planet
This study was performed with the support of the Institut de Chimie des Milieux et des Matériaux de Poitiers (CNRS/Université de Poitiers), the Laboratoire Géosystèmes (CNRS/Université Lille 1), the Centre de Recherches Pétrographiques et Géochimiques (CNRS/Université de Lorraine), the Laboratoire Histoire Naturelle de l’Homme Préhistorique (MNHN/CNRS), the Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (CNRS/UMPC/MNHN/IRD), the Laboratoire de Géosciences de Rennes (CNRS/Université de Rennes 1) which is part of the Observatoire des Sciences de l’Univers de Rennes, the Laboratoire d’Hydrologie et de Géochimie, Strasbourg (CNRS/Université de Strasbourg), and the Ressources Physiques et Ecosystèmes de Fond de Mer department at the lnstitut Carnot Ifremer Edrome.
*A biota is a community of living organisms historically established in a particular geographic region.
Note : The above story is based on materials provided by CNRS.
Geologists have discovered three previously unrecorded volcanoes in volcanically active southeast Australia.
The new Monash University research, published in the Australian Journal of Earth Sciences, gives a detailed picture of an area of volcanic centres already known to geologists in the region.
Covering an area of 19,000 square kilometres in Victoria and South Australia, with over 400 volcanoes, the Newer Volcanics Province (NVP) features the youngest volcanoes in Australia including Mount Schank and Mount Gambier.
Focusing on the Hamilton region, lead researcher Miss Julie Boyce from the School of Geosciences said the surprising discovery means additional volcanic centres may yet be discovered in the NVP.
“Victoria’s latest episode of volcanism began about eight million years ago, and has helped to shape the landscape. The volcanic deposits, including basalt, are among the youngest rocks in Victoria but most people know little about them,”Miss Boyce said.
“Though it’s been more than 5000 years since the last volcanic eruption in Australia, it’s important that we understand where, when and how these volcanoes erupted. The province is still active, so there may be future eruptions.”
The largest unrecorded volcano is a substantial maar-cone volcanic complex — a broad, low relief volcanic crater caused by an explosion when groundwater comes into contact with hot magma — identified 37 kilometres east of Hamilton.
Miss Boyce said the discoveries were made possible only by analysing a combination of satellite photographs, detailed NASA models of the topography of the area and the distribution of magnetic minerals in the rocks, alongside site visits to build a detailed picture of the Hamilton region of the NVP.
“Traditionally, volcanic sites are analysed by one or two of these techniques. This is the first time that this multifaceted approach has been applied to the NVP and potentially it could be used to study other volcanic provinces worldwide.”
The NVP is considered active, as carbon dioxide is released from Earth’s mantle in several areas, where there is a large heat anomaly at depth. With an eruption frequency of one volcano every 10,800 years or less, future eruptions may yet occur.
It’s hoped that this multifaceted approach will lead to a better understanding of the distribution and nature of volcanism, allowing for more accurate hazard analysis and risk estimates for future eruptions.
Note : The above story is based on materials provided by Monash University.
Chemical Formula: Be2SiO4
Locality: Takovaya, Ekaterinburg (Sverdlovsk), Ural Mts, Russia
Name Origin: From the Greek phenakos – “deceiver”, in allusion to its similarity to quartz when colorless.
Phenakite or phenacite is a fairly rare nesosilicate mineral consisting of beryllium orthosilicate, Be2SiO4. Occasionally used as a gemstone, phenakite occurs as isolated crystals, which are rhombohedral with parallel-faced hemihedrism, and are either lenticular or prismatic in habit: the lenticular habit is determined by the development of faces of several obtuse rhombohedra and the absence of prism faces. There is no cleavage, and the fracture is conchoidal. The Mohs hardness is high, being 7.5 – 8; the specific gravity is 2.96. The crystals are sometimes perfectly colorless and transparent, but more often they are greyish or yellowish and only translucent; occasionally they are pale rose-red. In general appearance the mineral is not unlike quartz, for which indeed it has been mistaken.
Phenakite is found in high-temperature pegmatite veins and in mica-schists associated with quartz, chrysoberyl, apatite and topaz. It has long been known from the emerald and chrysoberyl mine on the Takovaya stream, near Yekaterinburg in the Urals of Russia, where large crystals occur in mica-schist. It is also found with topaz and amazon-stone in the granite of the Ilmen Mountains in the southern Urals and of the Pikes Peak region in Colorado (USA). Large crystals of prismatic habit have been found in a feldspar quarry at Kragero in Norway. Framont near Schirmeck in Alsace is another well-known locality. Still larger crystals, measuring 1 to 2 in. in diameter and weighing 28 lb (13 kg). have been found at Greenwood in Maine, but these are pseudomorphs of quartz after phenakite.
For gem purposes the stone is cut in the brilliant form, of which there are two fine examples, weighing 34 and 43 carats (6.8 and 8.6 g), in the British Museum. The indices of refraction are higher than those of quartz, beryl or topaz; a faceted phenakite is consequently rather brilliant and may sometimes be mistaken for diamond.
It is a remarkable survivor of an ancient aquatic world — now a new study sheds light on how one of Earth’s oldest reefs was formed.
Researchers have discovered that one of these reefs — now located on dry land in Namibia — was built almost 550 million years ago, by the first animals to have hard shells.
Scientists say it was at this point that tiny aquatic creatures developed the ability to construct hard protective coats and build reefs to shelter and protect them in an increasingly dangerous world.
They were the first animals to build structures similar to non-living reefs, which are created through the natural processes of erosion and sediment deposition.
The study reveals that the animals attached themselves to fixed surfaces — and to each other — by producing natural cement composed of calcium carbonate, to form rigid structures.
The creatures — known as Cloudina — built reefs in ancient seas that now form part of Namibia. Their fossilised remains are the oldest reefs of their type in the world.
Cloudina were tiny, filter-feeding creatures that lived on the seabed during the Ediacaran Period, which ended 541 million years ago. Fossil evidence indicates that animals had soft bodies until the emergence of Cloudina.
Findings from the study — led by scientists at the University of Edinburgh — support previous research which suggested that environmental pressures caused species to develop new features and behaviours in order to survive.
Researchers say animals may have developed the ability to build reefs to protect themselves against increased threats from predators. Reefs also provided access to nutrient-rich currents at a time when there was growing competition for food and living space.
Scientists say the development of hard biological structures — through a process called biomineralisation — sparked a dramatic increase in the biodiversity of marine ecosystems.
The study, published in the journal Science, was carried out in collaboration with University College London and the Geological Survey of Namibia. The work was supported by the Natural Environment Research Council, the University of Edinburgh and the Laidlaw Trust.
Professor Rachel Wood, Professor of Carbonate GeoScience at the University of Edinburgh, who led the study, said: “Modern reefs are major centres of biodiversity with sophisticated ecosystems. Animals like corals build reefs to defend against predators and competitors. We have found that animals were building reefs even before the evolution of complex animal life, suggesting that there must have been selective pressures in the Precambrian Period that we have yet to understand.”
Note : The above story is based on materials provided by University of Edinburgh.
For decades, climate scientists have tried to explain why ice-age cycles became longer and more intense about 900,000 years ago, switching from 41,000-year cycles to 100,000-year cycles. In a new study in the journal Science, researchers found that the deep ocean currents that move heat around the globe stalled or even stopped, possibly due to expanding ice cover in the north. The slowing currents increased carbon dioxide storage in the ocean, leaving less in the atmosphere, which kept temperatures cold and kicked the climate system into a new phase of colder but less frequent ice ages, they hypothesize.
“The oceans started storing more carbon dioxide for a longer period of time,” said Leopoldo Pena, the study’s lead author, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory. “Our evidence shows that the oceans played a major role in slowing the pace of ice ages and making them more severe.”
The researchers reconstructed the past strength of earth’s system of deep-ocean currents by sampling deep-sea sediments off the coast of South Africa, where powerful currents originating in the North Atlantic Ocean pass on their way to Antarctica. How vigorously those currents moved in the past can be inferred by how much North Atlantic water made it that far, as measured by isotope ratios of the element neodymium bearing the signature of North Atlantic seawater. Like a tape recorder, the shells of ancient plankton incorporate this seawater signal through time, allowing scientists to approximate when the currents grew stronger and weaker off South Africa.
They confirmed that over the last 1.2 million years, the conveyor-like currents strengthened during warm periods and weakened during ice ages, as previously thought. But they also discovered that at about 950,000 years ago, ocean circulation weakened significantly and stayed weak for 100,000 years; during that period the planet skipped an interglacial — the warm interval between ice-ages–and when the system recovered it entered a new phase of longer, 100,000-year ice age cycles. After this turning point, the deep ocean currents remain weak during ice ages, and the ice ages themselves become colder, they find.
“Our discovery of such a major breakdown in the ocean circulation system was a big surprise,” said study coauthor Steven Goldstein, a geochemist at Lamont-Doherty. “It allowed the ice sheets to grow when they should have melted, triggering the first 100,000-year cycle.”
Ice ages come and go at predictable intervals based on the changing amount of sunlight that falls on the planet due to variations in earth’s orbit around the sun. Orbital changes alone, however, are not enough to explain the sudden switch to longer ice age intervals.
According to one earlier hypothesis for the transition, advancing glaciers in North America stripped away soils in Canada, causing thicker, longer-lasting ice to build up on the remaining bedrock. Building on that idea, the researchers hypothesize that the advancing ice might have triggered the slowdown in deep ocean currents, leading the oceans to vent less carbon dioxide, which suppressed the interglacial that should have followed. A 2009 study in Science led by Lamont’s Bärbel Hönisch confirmed that carbon dioxide levels dropped sharply at the time.
“The ice sheets must have reached a critical state that switched the ocean circulation system into a weaker mode,” said Goldstein.
A key ingredient in cellphones, headphones, computers and wind turbines, neodymium, it turns out, is also a good way of measuring the vigor of ancient ocean currents at depth. In a 2000 study in Nature, Goldstein and colleagues used neodymium ratios in deep-sea sediment samples to show that ocean circulation slowed during past ice ages. In a follow-up study in Science, they used the same method to show that changes in climate preceded changes in ocean circulation. A trace element in earth’s crust, neodymium washes into the oceans through erosion from the continents, where natural radioactive decay leaves a signature unique to the land mass where it originated.
When Goldstein and his Lamont colleague Sidney Hemming were pioneering this method in the late 1990s, they rarely worried about surrounding neodymium contaminating their samples. The rise of consumer electronics has changed that. “I used to say you could do sample processing for neodymium analysis in a parking lot,” said Goldstein. “Not anymore.”
Note : The above story is based on materials provided by The Earth Institute at Columbia University.
Chemical Formula: LiAl(Si4O10)
Name Origin: From the Greek petalon – “leaf” in allusion to the perfect basal cleavage.
Petalite, also known as castorite, is a lithium aluminium phyllosilicate mineral LiAl(Si4O10), crystallizing in the monoclinic system. Petalite is a member of the feldspathoid group. It occurs as colourless, grey, yellow, yellow grey, to white tabular crystals and columnar masses. Occurs in lithium-bearing pegmatites with spodumene, lepidolite, and tourmaline.
Petalite is an important ore of lithium, and is converted to spodumene and quartz by heating to ~500 °C and under 3 kbar of pressure in the presence of a dense hydrous alkali borosilicate fluid with a minor carbonate component. The colorless varieties are often used as gemstones.
Discovered in 1800, type locality: Utö Island, Haninge, Stockholm, Sweden. The name is derived from the Greek word petalon, which means leaf.
Economic deposits of petalite ahre found near Kalgoorlie, Western Australia; Aracuai, Minas Gerais, Brazil; Karibib, Namibia; Manitoba, Canada; and Bikita, Zimbabwe.
The first important economic application for petalite was as a raw material for the glass-ceramic cooking ware CorningWare. It has been used as a raw material for ceramic glazes.
Discovery date : 1800
Town of Origin : ILE UTO
Country of Origin : SUEDE
Refractive Index: from 1,50 to 1,52
Axial angle 2V: 82-84°
Hardness: 6,50
Density : from 2,41 to 2,42
Color : colorless; white; grey; yellowish grey; yellow; reddish; greenish; pink
Luster: vitreous; nacreous
Streak : white
Break: sub-conchoidal
Cleavage : Yes
Researchers from the University of Bonn and from China have discovered a fossil fly larva with a spectacular sucking apparatus.
Around 165 million years ago, a spectacular parasite was at home in the freshwater lakes of present-day Inner Mongolia (China): A fly larva with a thorax formed entirely like a sucking plate. With it, the animal could adhere to salamanders and suck their blood with its mouthparts formed like a sting. To date no insect is known that is equipped with a similar specialised design. The international scientific team is now presenting its findings in the journal eLIFE.
The parasite, an elongate fly larva around two centimeters long, had undergone extreme changes over the course of evolution: The head is tiny in comparison to the body, tube-shaped with piercer-like mouthparts at the front. The mid-body (thorax) has been completely transformed underneath into a gigantic sucking plate; the hind-body (abdomen) has caterpillar-like legs. The international research team believes that this unusual animal is a parasite which lived in a landscape with volcanoes and lakes what is now northeastern China around 165 million years ago. In this fresh water habitat, the parasite crawled onto passing salamanders, attached itself with its sucking plate, and penetrated the thin skin of the amphibians in order to suck blood from them.
“The parasite lived the life of Reilly,” says Prof. Jes Rust from the Steinmann Institute for Geology, Mineralogy and Palaeontology of the University of Bonn. This is because there were many salamanders in the lakes, as fossil finds at the same location near Ningcheng in Inner Mongolia (China) have shown. “There scientists had also found around 300,000 diverse and exceptionally preserved fossil insects,” reports the Chinese scientist Dr. Bo Wang, who is researching in palaeontology at the University of Bonn as a PostDoc with sponsorship provided by the Alexander von Humboldt Foundation. The spectacular fly larva, which has received the scientific name of “Qiyia jurassica,” however, was a quite unexpected find. “Qiyia” in Chinese means “bizarre”; “jurassica” refers to the Jurassic period to which the fossils belong.
For the international team of scientists from the University of Bonn, the Linyi University (China), the Nanjing Institute of Geology and Palaeontology (China), the University of Kansas (USA) and the Natural History Museum in London (England), the insect larva is a spectacular find: “No insect exists today with a comparable body shape,” says Dr Bo Wang. That the bizarre larva from the Jurassic has remained so well-preserved to the present day is partly due to the fine-grained mudstone in which the animals were embedded. “The finer the sediment, the better the details are reproduced in the fossils,” explains Dr Torsten Wappler of the Steinmann-Institut of the University of Bonn. The conditions in the groundwater also prevented decomposition by bacteria.
Astonishingly, no fossil fish are found in the freshwater lakes of this Jurassic epoch in China. “On the other hand, there are almost unlimited finds of fossilised salamanders, which were found by the thousand,” says Dr Bo Wang. This unusual ecology could explain why the bizarre parasites survived in the lakes: fish are predators of fly larvae and usually hold them in check. “The extreme adaptations in the design of Qiyia jurassica show the extent to which organisms can specialise in the course of evolution,” says Prof. Rust.
As unpleasant as the parasites were for the salamanders, their deaths were not caused by the fly larvae. “A parasite only sometimes kills its host when it has achieved its goal, for example, reproduction or feeding ,” Dr Wappler explains. If Qiyia jurassica had passed through the larval stage, it would have grown into an adult insect after completing metamorphosis. The scientists don’t yet have enough information to speculate as to what the adult it would have looked like, and how it might have lived.
Note : The above story is based on materials provided by Universität Bonn.
