"If extrasolar giant gas planets are in the habitable zone around their star, and if they have moons, can they supoort complex life?"
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Jack Hills Zircons: New Information About Earth's Earliest Crust
Members of NAI’s University of Wisconsin, Madison team have a new paper in Earth and Planetary Science Letters presenting their analyses of 4.35 – 3.36 billion year old detrital zircons from the Jack Hills, Western Australia. Their data reveal relatively high lithium abundances compared to other zircons, as well as lithium isotope ratios that are similar to continental crust weathering products rather than ocean floor basalts. The results support the hypothesis that continental-type crust and oceans existed by 4.3 billion years ago, and suggest that weathering was extensive in the early Archean.
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Wandering Geologist said:
I read this paper and it made no sense to me. When I asked my geochemist friends to explain what structural/chemical role lithium has in zircon, they said: “What? It doesn’t have any. It’s a contaminant.” After I pointed this paper out to them, ALL said that the study was deeply flawed.
So, what does this mean for this work? My impression is that it their lithium values don’t tell us anything about the early earth. Hey, what happened to the peer-review process on this one!??
curious said:
if lithium can move in and out of this mineral then what does it tell us about anything