geochemist – Shamskm: A site to exchange knowledge and solutions

Ancient Fossilized Sea Creatures Yield Oldest Biomolecules Isolated Directly from a Fossil

By Guest PostFebruary 21, 2013Nature, Scienceamerican midwest, analytical tools, ancient, aquatic sea creatures, aromatic compounds, biological signal, biomarkers, calcite crystal, carboniferous period, christina omalley, complex organic molecules, crinoids, crinoids today, DNA, feathery arms, fine grained sediment, fossil, fossilization, fossilized sea creatures, function, gas chromatograph, geochemist, geologic time, geologists, hard calcite shell, Indiana, iowa, layer, living tissue, mass spectrometer, midwest, mountain chains, North America, ohio, ohio state, ohio state geologists, ohio state university, oldest biomolecules, organic matter, organic molecules, pigments, pores, predators, quinines, sand dollars, sea lily, spindly animals, toxins, vast inland seas, volcanism, william ausich, yu ping chin

COLUMBUS, Ohio — Though scientists have long believed that complex organic molecules couldn’t survive fossilization, some 350-million-year-old remains of aquatic sea creatures uncovered in Ohio, Indiana, and Iowa have challenged that assumption.

The spindly animals with feathery arms—called crinoids, but better known today by the plant-like name “sea lily”—appear to have been buried alive in storms during the Carboniferous Period, when North America was covered with vast inland seas. Buried quickly and isolated from the water above by layers of fine-grained sediment, their porous skeletons gradually filled with minerals, but some of the pores containing organic molecules were sealed intact. (more…)

UMD Finding May Hold Key to Gaia Theory of Earth as Living Organism

By Guest PostMay 16, 2012Scienceatmosphere, dimethylsulfide, dimethylsulfide emission, dimethylsulfoniopropionate, earth, gaia hypothesis, gaia theory, geochemist, harry oduro, isotopic composition, james farquhar, james lovelock, kathryn van alstyne, key, living organism, lynn margulis, ocean, oxidation, sulfur compound, sulfur cycle, umd finding, university of maryland, western washington university

Discovery ultimately could lead to better climate understanding and prediction

COLLEGE PARK, Md. Is Earth really a sort of giant living organism as the Gaia hypothesis predicts? A new discovery made at the University of Maryland may provide a key to answering this question. This key of sulfur could allow scientists to unlock heretofore hidden interactions between ocean organisms, atmosphere, and land — interactions that might provide evidence supporting this famous theory.

The Gaia hypothesis — first articulated by James Lovelock and Lynn Margulis in the 1970s — holds that Earth’s physical and biological processes are inextricably connected to form a self-regulating, essentially sentient, system.

One of the early predictions of this hypothesis was that there should be a sulfur compound made by organisms in the oceans that was stable enough against oxidation in water to allow its transfer to the air. Either the sulfur compound itself, or its atmospheric oxidation product, would have to return sulfur from the sea to the land surfaces. The most likely candidate for this role was deemed to be dimethylsulfide. (more…)

Yale-led Team Finds CO2 Levels Plunged as Antarctica Froze

By Guest PostDecember 3, 2011Environmentalgae, atmosphere, carbon dioxide levels, climate transition, co2 and climate change, critical condition, cryosphere, earth, eocene epoch, eocene to oligocene, freezing of antarctica, fundamental link, geochemist, global climate change, global cooling, greenhouse gases, ice sheets, icing of antarctica, mark pagani, matthew huber, molecules, oligocene, polar ice caps, robert m deconto, sea level, temperatures, yale university, zhonghui liu

A Yale University-led research team has found evidence that carbon dioxide levels in Earth’s atmosphere plunged prior to and during the initial icing of Antarctica, about 34 million years ago. The new findings provide further evidence of atmospheric carbon dioxide’s role as a major trigger of global climate change.

“CO2 is tracking global cooling at that time,” said Yale geochemist Mark Pagani, lead author of a paper published online Dec. 1 in the journal Science. “It’s important to demonstrate that there are obvious linkages between CO2 and climate change. It’s one more piece of evidence that CO2 is a primary lever on climate.” (more…)

Six Million Years of African Savanna

By Guest PostAugust 6, 2011Environment, Scienceancient soil, anthony macharia, ape, ardipithecus, australopithecus, bipedalism, c3 pathway of photosynthesis, c4 photosynthesis, carbon isotope ratios in fossil soils, chemical isotopes, david kimutai korir, early human fossils, east african, environments, fossils of human ancestors, geochemist, geological past, homo, human ancestors, kenya wildlife service, michael bird, national science foundation, omo turkana basin of ethiopia and kenya, open grasslands, paleo shade proxy for soil temperature and woody cover, paleosols, paranthropus, prehistoric tree cover, ratio of rare carbon 13 to common carbon 12, richard lane, samuel andanje, savanna, savanna landscape, scattered trees, thure cerling, tropical landscapes, university of utah, vegetation chronologies of the awash valley of ethiopia, woody cover and hominin environments in the past 6 million years

*Open, grassy environments accompanied human evolution*

Scientists using chemical isotopes in ancient soil to measure prehistoric tree cover–in effect, shade–have found that grassy, tree-dotted savannas prevailed at most East African sites where human ancestors and their ape relatives evolved during the past six million years.

“We’ve been able to quantify how much shade was available in the geological past,” says University of Utah geochemist Thure Cerling, lead author of a paper titled “Woody cover and hominin environments in the past 6 million years” on the results in this week’s issue of the journal Nature. (more…)

Tag Archives: geochemist

Ancient Fossilized Sea Creatures Yield Oldest Biomolecules Isolated Directly from a Fossil

UMD Finding May Hold Key to Gaia Theory of Earth as Living Organism

Yale-led Team Finds CO2 Levels Plunged as Antarctica Froze

Six Million Years of African Savanna