(Table 1) Comparison of adjacent Cenomanian black shales with green claystones from DSDP Hole 75-530A ...

• Main Authors: Trull, Tom W, Meyers, Philip A, Leenheer, M J, Kawka, Orest E
• Format: Dataset
• Language: English
• Published: PANGAEA 1984
• Subjects: Sample code/label; Color description; Calcium carbonate; Pyrite, FeS2; Carbon, organic, total; Carbon/Nitrogen ratio; Kerogen, amorphous; Vitrinite; Aliphatic hydrocarbons; Polycyclic aromatic hydrocarbons; n-Alkanoic acid, total per unit sediment mass; n-Alkanol, total per unit sediment mass; Drilling/drill rig; Leg75; Glomar Challenger; Deep Sea Drilling Project DSDP; South Atlantic Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.770032; https://doi.pangaea.de/10.1594/PANGAEA.770032

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)93<1038:SAAOOC>2.0.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, ... : 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 ...