(Table 1) Mineralogical composition of sediments from DSDP Sites 69-504 and 69-505


We discuss the provenance of minerals detected by X-ray-diffraction analyses of sediments of Sites 504 and 505 of Deep Sea Drilling Project Leg 69. These are X-ray-amorphous material, opal-CT, calcite, quartz, feldspar, apatite, smectite, illite, kaolinite, magnetite, maghemite, pyrite, marcasite, barite, sepiolite, and clinoptilolite. Authigenic marcasite and clinoptilolite together with opal-CT are restricted to Site 504, indicating the special diagenetic conditions related to relatively high sediment temperatures at this site. Marcasite formation is likely dependent on the relatively low pH values of <7.1 found in interstitial waters of Site 504 sediments below 50 meters sub-bottom. Clinoptilolite evidently was formed by diagenetic alteration of rhyolitic volcanic glass or smectite plus biogenic silica within the chalk-limestone-chert sequence of Site 504, where opal-CT also reflects a high degree of silica dissolution and reprecipitation. This was a consequence of high temperatures (50-55 °C) at the base of the sediment column.

Supplement to: Beiersdorf, Helmut; Rösch, Heinrich (1983): Mineralogy of sediments encountered during Deep Sea Drilling Project Leg 69 (Costa Rica Rift, Panama Basin), as determined by x-ray diffraction. In: Cann, JR; Langseth, MG; Honnorez, J; Von Herzen, RP; White, SM; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 69, 385-393

DOI https://doi.org/10.1594/PANGAEA.816252
Related Identifier https://doi.org/10.2973/dsdp.proc.69.115.1983
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.816252
Creator Beiersdorf, Helmut; Rösch, Heinrich
Publisher PANGAEA
Publication Year 1983
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 3418 data points
Discipline Earth System Research
Spatial Coverage (-83.790W, 1.226S, -83.730E, 1.913N); North Pacific/GRABEN
Temporal Coverage Begin 1979-09-20T00:00:00Z
Temporal Coverage End 1979-10-07T00:00:00Z