Biogenic Silica Accumulation in the Central Equatorial Pacific and its Implications for Cenozoic Paleoceanography

Abstract

Research Article| September 01, 1979 Biogenic Silica Accumulation in the Central Equatorial Pacific and its Implications for Cenozoic Paleoceanography Margaret Leinen Margaret Leinen 1Graduate School of Oceanography, University of Rhode Island. Kingston, Rhode Island 02883 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1979) 90 (9_Part_II): 1310–1376. https://doi.org/10.1130/GSAB-P2-90-1310 Article history received: 26 Dec 1978 accepted: 25 Apr 1979 rev-recd: 02 May 1979 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Margaret Leinen; Biogenic Silica Accumulation in the Central Equatorial Pacific and its Implications for Cenozoic Paleoceanography. GSA Bulletin 1979;; 90 (9_Part_II): 1310–1376. doi: https://doi.org/10.1130/GSAB-P2-90-1310 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Since the Deep Sea Drilling Project (DSDP) has made available long cores through Cenozoic deep-sea sediments, geologists have begun to study the history of sedimentation in the world ocean and to infer the oceanographic conditions which have influenced deposition of the sediment. During this time, the central equatorial Pacific Ocean has become one of the most intensively studied geologic provinces in the world ocean. This area lies beneath the biologically productive equatorial current system which supplies great quantities of calcium carbonate and amorphous silica (opal) to the sediment in the form of skeletal tests. This biogenic debris, together with terrigenous, authigenic, and hydrothermal sediment, has produced an unusually thick and complete marine record which was cored by four DSDP Legs (5, 8, 9, and 16). Because the productivity of the equatorial Pacific is a direct consequence of large nutrient concentrations associated with upwelling in the complex equatorial current system, the sedimentary section can be used to interpret the paleoceanography as well as the history of productivity in the equatorial Pacific.The history of carbonate sedimentation in the central equatorial Pacific is well known from the Initial Reports of DSDP Legs 8, 9, and 16 (Tracey and others, 1971; Hays and others, 1972; van Andel and Heath, 1973), as well as from a wealth of published information (Hays and others, 1969; McManus and others, 1972; Berger, 1973; Winterer, 1973; van Andel and others, 1975). There are limitations, however, to the use of carbonate sediments for interpreting the paleoceanography and productivity of surface waters. The patterns of distribution and accumulation of calcareous sediments in the deep ocean are modified by the dissolution of carbonate in undersaturated bottom Waters at rates which vary with depth (Peterson, 1966; Berger, 1973) and with time (van Andel and others, 1975). Because we are, at present, unable to determine past rates of carbonate dissolution in bottom waters unambiguously (van Andel and others, 1975; Heath and others, 1977), we are also unable to assess accurately the rate of supply of carbonate to an area in the past. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not currently have access to this article.