Oceans 1.84 Billion Years Ago....or so they Say

Our experts in geology and any interested in geological matters for comparing with their Flood model will want to look at "The transition to a sulphidic ocean ~1.84 billion years ago" by Poulton, Fralick, & Canfield, Nature v. 431, 9 Sept. '04, p. 173.

The abstract (opening paragraph) dates the "largely anoxic" (free-oxygen free) Archean aeon to >2.5 Gyr ago (more than 2 and a half billion aka thousand million years ago), "and the dominantly oxic world" that we live in "of the Phanerozoic" to <0.54 Gyr (less than 540 million years, about the time of the Cambrian explosion) ago. This makes the Proterozoic aeon in between of special interest to evolutionists.

"Traditionally" they've thought that "an increase in atmospheric oxygen around 2.3 Gyr ago" lead to increased oxygen levels in the ocean. The big geologic clue to when the oxygenation had increased to a significant amount is the absence of banded iron formations in strata dated younger than "around 1.8 Gyr ago." This article claims that what really ended the iron deposits was an indirect effect as oxygen in the air caused increased "sulphide weathering" of the barren rocks of the dry land, and it was the level of suphides in the water that stopped the iron deposition by turning it into pyrite.

The researchers studied "sediments from the ~1.8-Gyr-old Animikie group, Canada" and using "iron-sulphur-carbon (Fe-S-C) systematics" they claim to "demonstrate continued ocean anoxia after the final global deposition of BIF and show that a transition to sulphidic bottom waters was ultimately responsible for the termination of BIF deposition." I didn't wade through the article itself to see how they ruled out the possibility that these conditions (if they're interpreting the data correctly) were merely local.

Until Next Time,

David Bump
Philippians 3: 13 Brethren, I
count not myself to have
apprehended: but [this] one thing
[I do], forgetting those things
which are behind, and reaching
forth unto those things which are
before, 14 I press toward the
mark for the prize of the high
calling of God in Christ Jesus.

http://home.att.net/~david.bump