Geochemistry of inorganic and organic sulphur in organic-rich sediments from the Peru margin

Online Access: Get full text
doi: 10.1016/0016-7037(91)90057-C
Author(s): Mossmann, Jean-Remi; Aplin, Andrew C.; Curtis, Charles D.; Coleman, Max L.
Author Affiliation(s): Primary:
Univ. Manchester, Dep. Geol., Manchester, United Kingdom
Br. Pet. Res. Int., United Kingdom
Volume Title: Geochimica et Cosmochimica Acta
Source: Geochimica et Cosmochimica Acta, 55(12), p.3581-3595. Publisher: Pergamon, Oxford, International. ISSN: 0016-7037 CODEN: GCACAK
Note: In English. 68 refs.; illus. incl. 4 tables, sects.
Summary: The abundance and isotopic composition of pyrite, monosulphide, elemental S, organically-bound S (OBS) and dissolved sulphate, the partition of Fe(III) and Fe(II), and the organic C contents, are reported for sediment samples from Sites 680, 686 drilled on ODP Leg 112. OBS comprises <= 50% of the total sedimentary S and comprises <= 1% of the bulk sediment; S:C in organic matter ranges (by weight) 0.07-0.15, which is similar to petroleum source rocks in the Monterey and Sisquoc formations of California. Isotopic analyses indicate that S is incorporated into organic matter within 1 m of the sediment surface. Most inorganic S is held in pyrite which forms in surface sediments. Despite highly reducing sulphidic conditions, only 35-65% of the total Fe is converted to sulphide with 10-30% occurring as Fe(III). It is suggested that polysulphides are important sulphurizing agents and the early diagenetic availability of polysulphides is an important control on the S content of sedimentary organic matter. Polysulphides are suggested also to be the link between FeS and FeS2. Acid- volatile S forms by direct reaction between dissolved sulphide and detrital Fe minerals, and some pyrite may have formed in this way.
Year of Publication: 1991
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; Continental margin; Geochemistry; Isotopes; Leg 112; Marine sediments; ODP Site 680; ODP Site 686; Ocean Drilling Program; Offshore; Organic compounds; Organic materials; Organic sulfur; Pacific Ocean; Peru; Ratios; S-34/S-32; Sediments; South America; Stable isotopes; Sulfur
Coordinates: S110354 S110354 W0780436 W0780436
S132849 S132848 W0765329 W0765329
Record ID: 1992001801
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom