The geochemical cycle of rhenium: a reconnaissance

Details The geochemical cycle of rhenium: a reconnaissance The geochemical cycle of rhenium: a reconnaissance

May 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993e%26psl.117..205c&link_type=abstract

Earth and Planetary Science Letters, Volume 117, Issue 1-2, p. 205-221.

Computer Science

37

Scientific paper

Rhenium (Re) is one of a suite of elements (including uranium and molybdenum) that display conservative behavior in seawater and are enriched in anoxic sediments. The decay of 187Re to 187Os provides a geochronometer in ancient sedimentary rocks and gives rise to Os-isotopic variations in nature. In order to better characterize its sources to seawater, Re was measured in three major rivers (Amazon, Orinoco, Ganges-Brahmaputra) and some of their tributaries. Re concentrations span four orders of magnitude (from < 0.02 to 400 pmol/kg), with the highest concentrations found in rivers draining black shales in the Venezuelan Andes. Mainstream Re levels in the three rivers are between 1 and 10 pmol/kg, with a flux weighted average of 2.3 pmol/kg. The residence time for Re in the oceans is estimated to be 750,000 yr with respect to river inputs.
Re profiles from the Atlantic and Pacific Oceans confirm that Re behaves conservatively in seawater, with no significant uptake onto particles and/or recycling within the water column. This is also true in the anoxic water column of the Black Sea. Re removal into anoxic sediments occurs at or below the sediment water interface, as demonstrated in sediment pore waters from Chesapeake Bay. In oxic sediments, Re is not cycled with manganese oxides, and it is not enriched in very slowly accumulating pelagic sediments with a large hydrogenous iron and manganese component, or in manganese nodules. Burial of Re in anoxic sediments, which accumulate on 0.3% of the ocean floor, removes approximately 50% of the riverine Re flux to the oceans. Hence, oceanic Re concentrations may be very sensitive to changes in the area of anoxic sedimentation.

Affiliated with

Also associated with

No associations

Rating

The geochemical cycle of rhenium: a reconnaissance 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 The geochemical cycle of rhenium: a reconnaissance, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The geochemical cycle of rhenium: a reconnaissance will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1853224