Organic geochemistry of Cretaceous black shales at DSDP Hole 75-530A


Autoria(s): Deroo, Gerard; Herbin, Jean-Paul; Huc, Alain Y
Cobertura

LATITUDE: -19.187700 * LONGITUDE: 9.385800 * DATE/TIME START: 1980-07-29T00:00:00 * DATE/TIME END: 1980-07-29T00:00:00

Data(s)

12/04/1984

Resumo

Five-hundred ten meters of Cretaceous sediments were drilled north of the Walvis escarpment in Hole 530A during Leg 75. An immature stage of evolution for organic matter can be assigned to all the samples studied. Black shales are interbedded with red and green claystone in the bottom sedimentary unit, Unit 8, which is of Coniacian to late Albian age. The richest organic carbon contents and petroleum potentials occur in the black shales. Detrital organic matter is present throughout the various members of a sequence, mixed with largely oxidized organic matter in the gray and green claystone or marlstone members on both sides. Detrital organic matter also characterizes the black streaks observed in the claystones. Vertical discontinuities in organic matter distribution are assigned to slumping. Several types of black shales can be identified, according to their content of detrital organic matter, the more detrital black levels corresponding to the Albian-Cenomanian period. Cyclic variations of organic matter observed for a sequence can occur for a set of sequences and even for some consecutive sets of sequences. Climatic factors are proposed to account for the cyclic sedimentation and distribution of organic matter for every sequence that includes a black bed.

Formato

application/zip, 5 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.810178

doi:10.1594/PANGAEA.810178

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Deroo, Gerard; Herbin, Jean-Paul; Huc, Alain Y (1984): Organic geochemistry of Cretaceous black shales from Deep Sea Drilling Project Site 530, Leg 75, eastern South Atlantic. In: Hay, WW; Sibuet, J-C; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 75, 983-999, doi:10.2973/dsdp.proc.75.130.1984

Palavras-Chave ## = OGP sample; 75-530A; AOM; Aromatic hydrocarbon fraction; Arom HC; Ash; Ash-free; Atomic; Black coal; C; Carbon; Carbon, organic, total; Carbon, pyrolysis mineral; Carbon dioxide yield, S3 per unit sediment mass; Chlf; Chloroform extract; Cloudy; Coal fragm; Debris; Deep Sea Drilling Project; Depth; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; Element analyser CHN, LECO; Extract; Facies; Facies name/code; Fe; Fragments, coal; Gas chromatography; Glomar Challenger; Granulous; H; H/C; HC/sed; HI, HC/TOC; Hydrocarbon per unit sediment; Hydrogen; Hydrogen/Carbon ratio; Hydrogen index, mass HC per unit mass total organic carbon; Iron; Label; Label 2; Leg75; Lignoeus; Lithology; Lithology/composition/facies; Main organic; mbsf; Nitrogen, total; NSO fraction; NSO-fraction (fraction of polar compounds); O; O/C; ODP sample designation; OI, CO2/TOC; Optical microscopy; Organic matter, amorphous; Oxygen; Oxygen/Carbon ratio; Oxygen index, mass CO2 per unit mass total organic carbon; Py; Pyrite, FeS2; Pyrolysis temperature maximum; pyroMinC; Related to OC; Related to rock; Rock eval pyrolysis (Espitalié et al. 1977); S; S3/sed; Sample code/label; Sample code/label 2; Sat HC; Saturated hydrocarbon fraction; South Atlantic/RIDGE; Spores; Sulfur, total; TAI; Thermal alteration index, description; Tmax; TN; TOC
Tipo

Dataset