Authigenic gypsum in marine sediments

An Authigenic Gypsum, Pyrite, and Glauconite Association in a Miocene Deep Sea Biogenic Ooze from the Falkland Plateau, Southwest Atlantic Ocean

“…The problem of reworked and secondary gypsum in deep sea cores has been discussed in detail by Briskin and Schreiber (1978). Reworking of gypsum from older units was initially considered a possibility for the Falkland Plateau sediments because erosion along this feature during the Miocene was extensive and some reworking of older Tertiary microfossils has been noted (Ciesielski and Wise, 1977;Wise et al, 1982).…”

“…1; Timofeev, this volume). Briskin and Schreiber (1978), however, note that where gypsum is a product of reworking, some of the crystals should show signs of breakage or abrasion. This is not generally the case for the specimens we examined, since most of the delicate crystal margins are unabraded and intact.…”

“…Gypsum in turn was formed by the reaction of sulfate ions introduced during pyrite formation with biogenic carbonate of the sediment. Briskin and Schreiber (1978) tabulated three modes of gypsum occurrence in deep sea sediments, citing examples primarily from piston cores they examined. They tabulated examples in the following categories: (A) reworked clastic (nonauthigenic), (B) tabular authigenic, and (C) prismatic or acicular authigenic.…”

“…In the typical carbonate deep sea oozes studied by Briskin and Schreiber (1978), the gypsum had precipitated in the absence of pyrite. Unlike the sediments described by Siesser and Rogers (1976) and by Robert and Chamley (1974), their sediments were neither highly anoxic nor rich in sulfur and detrital minerals.…”

The Sedimentary Deposits of Suiko Seamount (Leg 55, Site 433): From the Reef Environment to the Pelagic Sedimentation

“…Organic activity in a reducing environment is the commonly hypothesized mechanism for framboidal pyrite formation; different explanations of the process are given by Rickard (1970); Sweeney and Kaplan (1973);and Goldhaber and Kaplan (1974). High organic content of the calcareous deposits is also responsible for the very small amount of gypsum present (Arrhenius, 1963;Siesser and Rogers, 1976;Briskin and Schreiber, 1978). The source of S and SO 4 2~ could be steams migrating through the volcanic terrace.…”