Biogenic opal preservation in pelagic sediments of a small area in the eastern tropical Pacific

Abstract

Research Article| September 01, 1976 Biogenic opal preservation in pelagic sediments of a small area in the eastern tropical Pacific THOMAS C. JOHNSON THOMAS C. JOHNSON 1Geological Research Division, Scripps Institution of Oceanography, La Jolla, California 92037 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1976) 87 (9): 1273–1282. https://doi.org/10.1130/0016-7606(1976)87<1273:BOPIPS>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation THOMAS C. JOHNSON; Biogenic opal preservation in pelagic sediments of a small area in the eastern tropical Pacific. GSA Bulletin 1976;; 87 (9): 1273–1282. doi: https://doi.org/10.1130/0016-7606(1976)87<1273:BOPIPS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A 630-km2 area of the sea floor near 14°N, 117°W in the eastern Pacific was surveyed and sampled extensively to determine the pattern of siliceous microfossil preservation, silica concentrations in the sediments and interstitial waters, and clay mineralogy. Siliceous microfossil preservation is uniformly excellent in the surface sediments throughout the area, but deteriorates markedly with depth, to the point where biogenic opal is totally absent within 1 to 2 m below the sea floor. Sediment redistribution by bottom currents concentrates siliceous microfossils in topographic depressions, causing good preservation to extend to greater depths beneath the sea floor in these areas than on surrounding topographic highs. The down-core change in preservation may be due to both an ever-increasing input rate of biogenic opal to the sea floor over the past one-half million years, and to postburial dissolution. Chemical and mineralogical analyses of the sediments indicate that some silica released by postburial dissolution may be used in the formation of authigenic smectite. 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.