Archives de catégorie : only geology

Methane-munching microbes living in the deep biosphere for 400 million years: An analogue for extra-terrestrial life

by Linnaeus University, May 9, 2017 in ScienceDaily


It is becoming more and more appreciated that a major part of the biologic activity is not going on at the ground surface, but is hidden underneath the soil down to depths of several kilometres in an environment coined the « deep biosphere ». Studies of life-forms in this energy-poor system have implications for the origin of life on our planet and for how life may have evolved on other planets, where hostile conditions may have inhibited colonization of the surface environment. The knowledge about ancient life in this environment deep under our feet is extremely scarce.

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Oldest evidence of life on land found in 3.48 billion-year-old Australian rocks

by UNSW Sydney, May 9, 2017 in ScienceDaily


Fossils discovered by UNSW scientists in 3.48 billion year old hot spring deposits in the Pilbara region of Western Australia have pushed back by 580 million years the earliest known existence of microbial life on land.

he Pilbara deposits are the same age as much of the crust of Mars, which makes hot spring deposits on the red planet an exciting target for our quest to find fossilised life there.”

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New theory on how Earth’s crust was created

by McGill University , EPSL,  May 5, 2017, in ScienceDaily


Conventional theory holds that all of the early Earth’s crustal ingredients were formed by volcanic activity. Now, however, earth scientists have published a theory with a novel twist: some of the chemical components of this material settled onto Earth’s early surface from the steamy atmosphere that prevailed at the time.

More than 90% of Earth’s continental crust is made up of silica-rich minerals, such as feldspar and quartz. But where did this silica-enriched material come from? And could it provide a clue in the search for life on other planets?

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Earth probably began with a solid shell

by University of Maryland, in Nature, February 27, 2017

in ScienceDaily


New research suggests that plate tectonics began later in Earth’s history

But new research suggests that this was not always the case. Instead, shortly after Earth formed and began to cool, the planet’s first outer layer was a single, solid but deformable shell. Later, this shell began to fold and crack more widely, giving rise to modern plate tectonics.

see also in French

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