Posted on 08/19/2010 1:54:18 PM PDT by decimon
In The Sign of the Four Sherlock Holmes tells Watson he has written a monograph on 140 forms of cigar-, cigarette-, and pipe-tobacco, with colored plates illustrating the difference in the ash." He finds the ash invaluable for the identification of miscreants who happen to smoke during the commission of a crime.
But Sherlock Holmes and his cigarette ash and pipe dottle dont have a patch on geologists and the redox proxies from which they deduce chemical conditions early in Earth's history.
Redox proxies, such as the ratio of chromium isotopes in banded iron formations or the ratio of isotopes in sulfide particles trapped in diamonds, tell geologists indirectly whether the Earth s atmosphere and oceans were reducing (inclined to give away electrons to other atoms) or oxidizing (inclined to glom onto them).
It makes all the difference: the bacterium that causes botulism, and the methanogens that make swamp gas are anaerobes, and thrive in reducing conditions. Badgers and butterflies, on the other hand, are aerobes, and require oxygen to keep going.
In the July issue of Nature Geoscience Washington University in St. Louis geochemist David Fike gives an unusually candid account of the difficulties his community faces in correctly interpreting redox proxies, issuing a call for denser sampling and more judicious reading of rock samples.
The world ocean Fike, assistant professor of earth and planetary sciences in Arts & Sciences, focuses on the dramatic change from anoxic to oxygenated conditions in the worlds oceans that preceded the Ediacaran period (from 635 to 542 million years ago) when the first multicellular animals appeared.
(Excerpt) Read more at news.wustl.edu ...
Story of O ping.
Shouldn’t they be studying CO2 like everyone else?
Well, the C did have to be Oed.
Seems like the O gangs up on the poor C. It’s not fair.
Not so. The carbon is the happy participant in a three-way with the two oxygens.
Many O’s seem happy in a monogamous gay union. Where’s the chemical justice?
I knew a guy, Chert Jasper, from Flint. A geologist, he had his faults. He took his girlfriend to the quarry to get a little boulder.
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Heh.... I’m not ENTIRELY convinced of their explanation for where our water came from. (of course, I know nothing. I’m a mere idiot on the intrawebs, and I never found a Holiday Inn Express to stay at)
There is A LOT of water on our planet, perhaps even more than we can see. It’s just remarkable to me how when you look at other planets, they are all bone dry for the most part, and here we are with all of this water. Our Moon is even bone dry, and it’s only 250,000 miles next door. If find it difficult to believe that all of it came from ice via comets, or by condensation. If our water came from bombardment by Comets, how come the Moon didn’t also get bombarded? Even if it woudn’t have been covered with liquid water as we are, there should be a BUNCH of ice all over it.
According to evidence found in some of the oldest Zircon crystals, water was indeed here not very long after the planet cooled. Where it came from may be one of those questions that will never be answered. Our best chance may be if we can somehow see it happening on another planet somewhere.
Did they drive there in a Topaz?
Now thats a breath of fresh air.
Very true! After thinking about it some after posying, I did consider the Moon having no atmosphere. That would certainly explain the lack of liquid water, unlike our planet... Even if both were exposed to the same things over time. Even with the super cold temperatures, even the ice would evaporate away if exposed to the Sun. I read somewhere awhile back that in shadowy areas on the Moon, lots of ice could still be there. Those areas could be a time capsule of sorts, dating back to the formation of our Solar System. Would be awesome if we could get some core samples from those areas. We could probably learn a LOT from them.
For the Kola Peninsula Borehole:
http://www.freerepublic.com/perl/post?id=2573879%2C1
“To scientists, one of the more fascinating findings to emerge from this well is that the change in seismic velocities was not found at a boundary marking Harold Jeffreys’s hypothetical transition from granite to basalt; it was at the bottom of a layer of metamorphic rock that extended from about 5 to 10 kilometers beneath the surface. The rock there had been thoroughly fractured and was saturated with water, which was surprising. This water, unlike surface water, must have come from deep-crust minerals and had been unable to reach the surface because of a layer of impermeable rock.[9]
Another unexpected discovery was the large quantity of hydrogen gas, with the mud flowing out of the hole described as “boiling” with hydrogen.[10]”
Trapped in the Earth
O, the inhumanity!
I guess we’ve flogged that subject.
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