Other
Scientific paper
Jun 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001e%26psl.188..369r&link_type=abstract
Earth and Planetary Science Letters, Volume 188, Issue 3-4, p. 369-381.
Other
15
Scientific paper
Umbers from 8 of 11 localities studied yield 187Os/188Os ratios that range from 0.51 to 0.57. We interpret this range as reflecting the Os isotopic composition of mid-Cretaceous seawater. 187Os/188Os measured in samples from the remaining three localities fall above and below this range and are believed to result from post-depositional redistribution of Os. Extremely large 187Os/188Os ratios occur in hydrothermal sulfides (>200) and in their oxidation products, ochres (3.6-13.2). Measured Re/Os ratios in these samples require open system behavior. Model age calculations indicate that ochre formation occurred over a 1-5 million year interval after sulfide precipitation. In most samples >99% Re loss occurred during sulfide oxidation. Comparison of element ratios in Cyprus umbers to those of modern seawater suggest the following sequence of scavenging efficiency by hydrothermal Fe-oxides: Ir>Pt>Os>Re. Cyprus sulfides exhibit the opposite pattern of element enrichment. These patterns of aqueous platinum-group element (PGE) fractionation are potentially relevant to study of recycled Os in mantle-derived rocks because they give rise to the following phenomena: (1) ephemeral Re enrichment within the basal sediments of the oceanic crust, (2) PGE concentrations in metalliferous sediments (Os up to 1 ppb and Pt up to 22 ppb) that are comparable to those in the mantle, and (3) Pt/Re ratios in Cyprus umbers that exceed those required to explain the coupled 186Os-187Os variations in Hawaiian basalts.
Blusztajn Jerzy
Prichard Hazel M.
Ravizza Greg
No associations
LandOfFree
Re-Os systematics and platinum-group element distribution in metalliferous sediments from the Troodos ophiolite does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Re-Os systematics and platinum-group element distribution in metalliferous sediments from the Troodos ophiolite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Re-Os systematics and platinum-group element distribution in metalliferous sediments from the Troodos ophiolite will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1131345