Posted by
michael
on from the just-missed-it dept.
An anonymous reader writes "If you're looking to strike it rich, then perhaps this article in Nature magazine will be of assistance. It seems that three billion years ago there was no life on land and no oxygen in the atmosphere. But the rivers ran with gold."
a meteorite struck the basin about 2 billion years ago.
And they don't seem to think this might have had something to do with it too? The Sudbury Basin around Sudbury, Ontario was formed by meteor impact (about 1.85 billion years ago), and is one of the world's largest sources of nickel and other metals like copper, silver, platinum group and gold. Coincidence? What other metals are found at the South Africa site?
-- -- Alastair
Re:Reducing atmosphere
by
fluffy666
·
· Score: 4, Interesting
Given that many deposits of Archean age show evidence of being deposited in a reducing environment - the oxidation states of iron, for example.
http://gsa.confex.com/gsa/2001ESP/finalprogram/s es sion_182.htm
*how* reducing, and for how long, is another matter. This is called 'an area of scientific research'.
Reducing Atmosphere?
by
blitz77
·
· Score: 4, Interesting
Most scientists nowadays agree that the atmosphere was not reducing. Take a read of the following: -
For a long time it was thought that the early Earth had a reducing atmosphere. A reducing atmosphere contains reductants, or molecules saturated with hydrogen atoms, which are able to reduce other molecules. Many scientists believed that the atmosphere consisted of CH4, NH3, and H2. This is the mixture of gases Miller and Urey used in 1953 to mimic the conditions of the early earth. Their experiment showed that abiotic molecules could be used to create important biotic compounds thought to be necessary for the origin of life.
from http://www.chem.duke.edu/~jds/cruise_chem/Exobiolo gy/PBearth.html
Re:Reducing atmosphere
by
aminorex
·
· Score: 3, Insightful
And at the same conference, you will find overwhelming evidence of oxygenated oceans 4 billion years ago.
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a meteorite struck the basin about 2 billion years ago.
And they don't seem to think this might have had something to do with it too? The Sudbury Basin around Sudbury, Ontario was formed by meteor impact (about 1.85 billion years ago), and is one of the world's largest sources of nickel and other metals like copper, silver, platinum group and gold. Coincidence? What other metals are found at the South Africa site?
-- Alastair
Given that many deposits of Archean age show evidence of being deposited in a reducing environment - the oxidation states of iron, for example.
s es sion_182.htm
http://gsa.confex.com/gsa/2001ESP/finalprogram/
*how* reducing, and for how long, is another matter. This is called 'an area of scientific research'.
Most scientists nowadays agree that the atmosphere was not reducing. Take a read of the following: - For a long time it was thought that the early Earth had a reducing atmosphere. A reducing atmosphere contains reductants, or molecules saturated with hydrogen atoms, which are able to reduce other molecules. Many scientists believed that the atmosphere consisted of CH4, NH3, and H2. This is the mixture of gases Miller and Urey used in 1953 to mimic the conditions of the early earth. Their experiment showed that abiotic molecules could be used to create important biotic compounds thought to be necessary for the origin of life. from http://www.chem.duke.edu/~jds/cruise_chem/Exobiolo gy/PBearth.html
And at the same conference, you will find overwhelming evidence of oxygenated oceans 4 billion years ago.
a bs tract_7459.htm
http://gsa.confex.com/gsa/2001ESP/finalprogram/
Hint: The oxygenation state of the atmosphere is
much more closely linked to that of the oceans
than that of rocks.
-I like my women like I like my tea: green-