Pore-fluid Fe isotopes reflect the extent of benthic Fe redox recycling: evidence from continental shelf and deep-sea sediments


Homoky, W.B., Severmann, S., Mills, R.A., Statham, P.J. and Fones, G.R. (2009) Pore-fluid Fe isotopes reflect the extent of benthic Fe redox recycling: evidence from continental shelf and deep-sea sediments Geology, 37, (8), pp. 751-754. (doi:10.1130/G25731A.1).

Download

[img] PDF Homoky_et_al.pdf - Version of Record
Restricted to Repository staff only

Download (409kB)

Description/Abstract

Pore-fluid Fe isotopes may be a unique tracer of sediment respiration by dissimilatory Fe reducing bacteria, but to date, pore-fluid Fe isotope measurements have been restricted to continental shelf settings. Here, we present ?56Fe values of pore fluids from two distinct sedimentary
settings: (1) a riverine-dominated site on the northern California margin (Eel River shelf; 120 m water depth) and (2) biogenic opal-rich volcaniclastic deep-sea sediments from the Southern Ocean (north and south of the Crozet Plateau; 3000–4000 m water depth). The Fe isotope compositions of Crozet region pore fl uids are signifi cantly less fractionated (?56Fe = +0.12‰ to –0.01‰) than the Eel River shelf (?56Fe = –0.65‰ to –3.40‰) and previous studies of pore-fluid Fe isotopes, relative to average igneous rocks. Our data represent the fi rst measurements of Fe isotope compositions in pore fl uids from deep-sea sediments.

A comparison of pore-fluid ?56Fe with the relative abundance of highly labile Fe in the reactive sedimentary Fe pool demonstrates that the composition of Fe isotopes in the pore fluids reflects the different extent of sedimentary Fe redox recycling between these sites.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1130/G25731A.1
ISSNs: 0091-7613 (print)
Related URLs:
Subjects:
ePrint ID: 148815
Date :
Date Event
August 2009Published
Date Deposited: 29 Apr 2010 08:01
Last Modified: 18 Apr 2017 14:32
Further Information:Google Scholar
URI: http://eprints.soton.ac.uk/id/eprint/148815

Actions (login required)

View Item View Item