Rates of reaction between silicate iron and dissolved sulfide in Peru Margin sediments

Details Rates of reaction between silicate iron and dissolved sulfide in Peru Margin sediments Rates of reaction between silicate iron and dissolved sulfide in Peru Margin sediments

Aug 1996

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996gecoa..60.2777r&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 60, Issue 15, pp.2777-2787

Computer Science

13

Scientific paper

Porewaters in site 680 Peru Margin sediments contain dissolved sulfide over a depth of approximately 70 m which, at a sedimentation rate of 0.005 cm yr -1 , gives a sediment exposure time to dissolved sulfide of about 1.4 × 10 6 yr. Reactions with dissolved sulfide cause the site 680 sediments to show a progressive decrease in a poorly-reactive silicate iron fraction, defined as the difference between iron extracted by dithionite (FeD) at room temperature and that extracted by boiling concentrated HCl (FeH), normalised to the total iron content (FeT). Straight line plots are obtained for 1n [(FeH - FeD)/FeT] against time of burial, from which a first order rate constant of 0.29 × 10 -6 yr -1 (equivalent to a half-life of 2.4 × 106 yr) can be derived for the sulfidation of this silicate iron. Comparable half-lives are also found for the same poorly-reactive iron fraction in the nearby site 681 and 684 sediments. This silicate Fe fraction comprises 0.8-1.0% Fe, only 30-60% of which reacts even with 1.5-3 million years exposure to dissolved sulfide. Diagenetic models based on porewater concentrations of sulfate and sulfide, and solid phase iron contents, at site 680 are consistent in indicating that this poorly-reactive iron fraction is only sulfidized on a million year time scale. Silicate iron not extracted by HCl can be regarded as unreactive towards dissolved sulfide on the time scales encountered in marine sediments.

Affiliated with

Also associated with

No associations

Rating

Rates of reaction between silicate iron and dissolved sulfide in Peru Margin sediments 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 Rates of reaction between silicate iron and dissolved sulfide in Peru Margin sediments, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rates of reaction between silicate iron and dissolved sulfide in Peru Margin sediments will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1450294