Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean ...
The upper Miocene to Pleistocene sediments recovered at ODP Sites 745 and 746 in the Australian-Antarctic Basin are characterized by cyclic facies changes. Sedimentological investigations of a detailed Quaternary section reveal that facies A is dominated by a high content of siliceous microfossils,...
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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PANGAEA
1991
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| Online Access: | https://dx.doi.org/10.1594/pangaea.587844 https://doi.pangaea.de/10.1594/PANGAEA.587844 |
| Summary: | The upper Miocene to Pleistocene sediments recovered at ODP Sites 745 and 746 in the Australian-Antarctic Basin are characterized by cyclic facies changes. Sedimentological investigations of a detailed Quaternary section reveal that facies A is dominated by a high content of siliceous microfossils, a relatively low terrigenous sediment content, an ice-rafted component, low concentrations of fine sediment particles, and a relatively high smectite content. This facies corresponds to interglacial sedimentary conditions. Facies B, in contrast, is characteristic of glacial conditions and is dominated by a large amount of terrigenous material and a smaller opaline component. There is also a prominent ice-rafted component. The microfossils commonly are reworked and broken. The clay mineral assemblages show higher proportions of glacially derived illite and chlorite. A combination of four different processes, attributed to glacial-interglacial cycles, was responsible for the cyclic facies changes during Quaternary ... : Supplement to: Ehrmann, Werner; Grobe, Hannes (1991): Cyclic sedimentation at sites 745 and 746. In: Barron, J; Larsen, B; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 119, 225-237 ... |
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