Meteorite-Mineralien-Gold-Forum.de
Meteoriten => Tektite ... => Thema gestartet von: karmaka am Februar 26, 2013, 21:57:42 Nachmittag
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Kleinere Impaktkrater als mögliche 'Brutstätten' bakteriellen Lebens auf der frühen Erde
Die Abkühlung des Lappajärvi-Kraters dauerte länger als vermutet
Earlier estimates for the duration of cooling in smaller impact craters were based on theoretical simulations and suggested a relatively short cool-down period of about 10,000 years after the impact. Drs Schmieder and Jourdan used the so-called argon-argon dating technique based on the natural radioactive decay of potassium to argon to measure the age of different minerals formed on impact.
"Our new argon-argon data tell us that the Lappajärvi crater did not cool down as rapidly as expected but within at least several 100,000 years, and perhaps more than a million years," Dr Jourdan said.
"Cooling impact craters are hot natural laboratories in which hot hydrothermal fluids circulate. We think they provided ideal starting conditions for the origin and evolution of microbial life on early Earth more than two billion years ago."
http://phys.org/news/2013-02-impact-craters-cradles-life.html
http://www.sciencedirect.com/science/article/pii/S0016703713001105