Cenozoic biogenic silica sedimentation in the Antarctic Ocean

Abstract

Research Article| June 01, 1980 Cenozoic biogenic silica sedimentation in the Antarctic Ocean NANCY ANN BREWSTER NANCY ANN BREWSTER 1School of Oceanography, Oregon State University, Corvallis, Oregon 97331. Present address: Union Oil Company of California, P. O. Box 6176, Ventura, California 93003 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1980) 91 (6): 337–347. https://doi.org/10.1130/0016-7606(1980)91<337:CBSSIT>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation NANCY ANN BREWSTER; Cenozoic biogenic silica sedimentation in the Antarctic Ocean. GSA Bulletin 1980;; 91 (6): 337–347. doi: https://doi.org/10.1130/0016-7606(1980)91<337:CBSSIT>2.0.CO;2 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 The Antarctic Ocean during Cenozoic time experienced four periods of enhanced siliceous productivity. The beginning of the Miocene and the Pliocene-Quaternary are the two major periods. The Pliocene-Quaternary increase in productivity began 5 m.y. ago and has progressively increased to the present level of intense surface productivity. Two short-lived periods of slightly increased surface productivity were the middle Eocene and the middle Miocene.The major control of Antarctic surface productivity through the Cenozoic has been climate. Climate in the Southern Ocean is ultimately controlled by tectonic changes in the Antarctic Ocean basin, which altered the patterns of surface and thermohaline circulation. Antarctic surface waters became more conducive to siliceous biological productivity with the progressive latitudinal and thermal isolation of Antarctica. Opal production during the Neogene increased particularly during globally cooler times, due to the intensification of upwelling south of the Polar Front. This intensification was caused by accelerated atmospheric circulation and an increased volume production of Antarctic Bottom Water.Since the Oligocene, times of increasing productivity in the Antarctic correspond to periods of decreasing productivity in the central equatorial Pacific Ocean. It appears that high concentrations of limiting nutrients upwelling in the Southern Ocean have enabled the region to successfully “compete” for silica. The efficiency of the biological cycling of silica has progressed to the extent in the Antarctic that much of the silica assimilation and accumulation has transferred to the Antarctic at the expense of other productive oceanic regions such as the central equatorial Pacific. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.