Archives par mot-clé : Geology

NASA – Supervolcano may be melting Antarctic ice sheet from below

by Robert, November 10, 2017 in NASA


Confirms what I’ve been saying all along!
NASA scientists admit that a massive heat source almost as hot as the Yellowstone supervolcano may be melting the Antarctic ice sheet from below. 

It seems like a no-brainer to me. I mean, how can lakes and rivers be flowing beneath the ice unless there’s a heat source down there? And if sub-glacial volcanoes can be melting the ice, why couldn’t underwater volcanoes be heating the sea

Site of asteroid impact changed the history of life

by Tohoku University, November 10, 2017 in ScienceDaily


An asteroid, also known as the Chicxulub Impactor, hit Earth some 66 million years ago, causing a crater 180 km wide. The impact of the asteroid heated organic matter in rocks and ejected it into the atmosphere, forming soot in the stratosphere.

According to the study, soot from hydrocarbon-rich areas caused global cooling of 8-11°C and cooling on land of 13-17°C. It also caused a decrease in precipitation by approximately 70-85 percent on land and a decrease of approximately 5-7°C in seawater temperature at a 50-m water depth, leading to mass extinction of life forms including dinosaurs and ammonites

Oxygen-18 Stability in Foraminifera fossils, implications in paleoclimatology

by Andy May, November 4, 2017


18O is a rare isotope of oxygen. The ratio of 18O to the normal 16O in foraminifera fossils (“forams”) can be used to estimate paleo-ocean temperatures. Higher values mean lower temperatures. A recent article on geologypage.com (here) led me to Bernard, et al., 2017, which has experimental data that suggest 18O concentrations can be altered in fossils by solid-state diffusion after fossilization. This can corrupt the measurement and the resulting calculated temperature

Retrograde Accretion of a Caribbean Fringing Reef Controlled by Hurricanes and Sea-level Rise

by P. Blanchon et al., October 12, 2017 in Front.Earth.Sci


Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales

Global nickel anomaly links Siberian Traps eruptions and the latest Permian mass extinction

by Michael R. Rampino et al., October 2017, in Nature


Anomalous peaks of nickel abundance have been reported in Permian-Triassic boundary sections in China, Israel, Eastern Europe, Spitzbergen, and the Austrian Carnic Alps. New solution ICP-MS results of enhanced nickel from P-T boundary sections in Hungary, Japan, and Spiti, India suggest that the nickel anomalies at the end of the Permian were a worldwide phenomenon.

See also here and here

Did life on Earth start due to meteorites splashing into warm little ponds?

by McMaster University, October 2, 2017 in ScinceDaily


Life on Earth began somewhere between 3.7 and 4.5 billion years ago, after meteorites splashed down and leached essential elements into warm little ponds, say scientists. Their calculations suggest that wet and dry cycles bonded basic molecular building blocks in the ponds’ nutrient-rich broth into self-replicating RNA molecules that constituted the first genetic code for life on the planet.

Lost continent of Zealandia: Scientists return from expedition to sunken land

by National Science Foundation, September 26, 2017  in ScienceDaily


Expedition co-chief scientist Rupert Sutherland of Victoria University of Wellington in New Zealand said researchers had believed that Zealandia was submerged when it separated from Australia and Antarctica about 80 million years ago.

Big geographic changes across northern Zealandia, which is about the same size as India, have implications for understanding questions such as how plants and animals dispersed and evolved in the South Pacific.

Diamonds show Earth still capable of ‘superhot’ surprises

by Europlanet Media Centre, September 21, 2017 in ScienceDaily


Diamonds may be ‘forever’ but some may have formed more recently than geologists thought. A study of 26 diamonds, formed under extreme melting conditions in the Earth’s mantle, found two populations, one of which has geologically ‘young’ ages. The results show that certain volcanic events on Earth may still be able to create super-heated conditions previously thought to have only existed early in the planet’s history before it cooled. The findings may have implications for diamond prospecting.

See also here