(Table 1) Comparison of adjacent Cenomanian black shales with green claystones from DSDP Hole 75-530A, supplement to: Meyers, Philip A; Leenheer, M J; Kawka, Orest E; Trull, Tom W (1984): Enhanced preservation of marine-derived organic matter in Cenomanian black shales from the southern Angola Basin. Nature, 312(5992), 356-359


Black shales possessing high concentrations of organic carbon (Foresman, 1978, doi:10.2973/dsdp.proc.40.111.1978) were deposited in many parts of the proto South Atlantic Ocean during the Cretaceous period (Bolli et al., 1978, doi:10.2973/dsdp.proc.40.104.1978). The way such sediments accumulated is not fully understood, but is likely to have occurred through a combination of low oxygen availability and abundant supply of organic matter. Thin, centimetre-thick layers of black shales are commonly interbedded with thicker layers of organic carbon-deficient, green claystones, as found in strata of Aptian to Coniacian age, at Deep Sea Drilling Project (DSDP) Site 530, in the southern Angola Basin (Hay et al., 1982, doi:10.1130/0016-7606(1982)932.0.CO;2) and elsewhere. These differences in carbon content and colour reflect the conditions of deposition, and possibly variations in the supply of organic matter (Summerhayes and Masran, 1983, doi:10.2973/dsdp.proc.76.116.1983; Dean and Gardner, 1982). We have compared, using organic geochemical methods the compositions of organic matter in three pairs of closely-bedded black and green Cenomanian claystones obtained from Site 530. Kerogen analyses and distributions of biological markers show that the organic matter of the black shales is more marine and better preserved than that of the green claystones.

DOI https://doi.org/10.1594/PANGAEA.770032
Related Identifier https://doi.org/10.1038/312356a0
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.770032
Creator Trull, Tom W; Meyers, Philip A; Leenheer, M J; Kawka, Orest E
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1984
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 72 data points
Discipline Earth System Research
Spatial Coverage (9.386 LON, -19.188 LAT); South Atlantic/RIDGE