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| Main Authors: | , |
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| Format: | Dataset Open Access |
| Language: | en |
| Published: |
PANGAEA
1984
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| Subjects: | |
| Online Access: | https://doi.org/10.1594/PANGAEA.810102 |
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| _version_ | 1867171815123582976 |
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| author | Stow, Dorrik A V Dean, Walter E |
| author_facet | Stow, Dorrik A V Dean, Walter E |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The middle Cretaceous black shale interval at Site 530 is 170 m thick and late Albian to Coniacian in age. The organic-carbon-rich sediments occur as 260 separate beds (average 4 cm, maximum 60 cm thick) and make up less than 10% of the recovered section. Associated lithologies are greenish, grayish, and reddish mudstones, marlstones, and rare limestones. Organic-carbon contents of the black shales average about 5% (maximum 16%), and of the interbedded sediments, less than 0.5%. Careful study of the sedimentary and biogenic structures and composition and review of paleoceanographic conditions in the Angola Basin indicate that a complex interplay of processes controlled black shale accumulation. Relatively low oxygen concentrations in sediment and bottom waters occurred periodically, and conditions locally may have been anoxic or near anoxic both in the basin and on the continental margin. Pelagic, hemipelagic, and turbiditic depositional processes all operated to varying degrees at different times. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_810102 |
| institution | PANGAEA |
| language | en |
| publishDate | 1984 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 1) Black shale characteristics at DSDP Hole 75-530A Stow, Dorrik A V Dean, Walter E 75-530A; Carbon, organic, total; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Glomar Challenger; Leg75; Length Recovered; Number of beds; Percentage; Sample code/label; Sample thickness; South Atlantic/RIDGE; Standard deviation The middle Cretaceous black shale interval at Site 530 is 170 m thick and late Albian to Coniacian in age. The organic-carbon-rich sediments occur as 260 separate beds (average 4 cm, maximum 60 cm thick) and make up less than 10% of the recovered section. Associated lithologies are greenish, grayish, and reddish mudstones, marlstones, and rare limestones. Organic-carbon contents of the black shales average about 5% (maximum 16%), and of the interbedded sediments, less than 0.5%. Careful study of the sedimentary and biogenic structures and composition and review of paleoceanographic conditions in the Angola Basin indicate that a complex interplay of processes controlled black shale accumulation. Relatively low oxygen concentrations in sediment and bottom waters occurred periodically, and conditions locally may have been anoxic or near anoxic both in the basin and on the continental margin. Pelagic, hemipelagic, and turbiditic depositional processes all operated to varying degrees at different times. |
| title | (Table 1) Black shale characteristics at DSDP Hole 75-530A |
| topic | 75-530A; Carbon, organic, total; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Glomar Challenger; Leg75; Length Recovered; Number of beds; Percentage; Sample code/label; Sample thickness; South Atlantic/RIDGE; Standard deviation |
| url | https://doi.org/10.1594/PANGAEA.810102 |