Mineralogy and geochemistry of Bay of Bengal deep-sea fan sediments, ODP Leg 116: evidence for an Indian subcontinent contribution to distal fan sedimentation
Crowley, S.F.; Stow, D.A.V.; Croudace, I.W. (1998). Mineralogy and geochemistry of Bay of Bengal deep-sea fan sediments, ODP Leg 116: evidence for an Indian subcontinent contribution to distal fan sedimentation, in: Cramp, A. et al. Geological evolution of ocean basins: results from the Ocean Drilling Program. Geological Society Special Publication, 131: pp. 151-176. https://dx.doi.org/10.1144/GSL.SP.1998.131.01.11
In: Cramp, A. et al. (1998). Geological evolution of ocean basins: Results from the Ocean Drilling Program. Geological Society Special Publication, 131. Geological Society: London. ISBN 1-86239-003-7. XI, 323 pp., more
In: Hartley, A.J. et al. (Ed.) Geological Society Special Publication. Geological Society of London: Oxford; London; Edinburgh; Boston, Mass.; Carlton, Vic.. ISSN 0305-8719; e-ISSN 2041-4927, more
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| Keywords |
Bay of Bengal
Chemistry > Geochemistry
Fans
Hydrographic features > Bays > Marine areas > Marine bays > Eastern indian ocean > Bay of bengal
India, West Bengal
Mineralogy
Minerals > Silicate minerals > Clay minerals > Kaolinite
Minerals > Silicate minerals > Clay minerals > Smectite
Sedimentation
Sediments > Clastics > Turbidites
Trace elements
Water > Deep water
Midnapur [Marine Regions]
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| Authors | | Top |
- Crowley, S.F.
- Stow, D.A.V.
- Croudace, I.W.
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| Abstract |
Sediments recovered during Ocean Drilling Program Leg 116 (Bay of Bengal deep-sea fan) fall into three mineralogically and geochemically distinct groups. The first of these groups (Group I), characterized by quartz-mica-rich turbidites, constitutes the largest proportion of distal fan sediments. Trace element patterns are similar to modern River Ganges suspended sediment and are consistent with a Himalayan (meta)sedimentary/granitic source. The second group of sediments (Group II) is represented by organic carbon-rich, smectite-kaolinite turbidites. Trace element data reveal significant enrichment in compatible and ferromagnesian elements consistent with a significant contribution from a basaltic crustal source. Although mixing of a basaltic source with granitic crust can account for specific geochemical relationships, mixing of these components cannot account for observed rare earth element (REE) patterns. REE data are best explained by mixing of basaltic detritus (e.g. Deccan Trap basalts of central India) with Precambrian tonalitic crust of the Indian subcontinent. A third group of carbonate-rich sediments (Group III), containing a low-latitude marine fauna, is characterized by a clastic component similar in composition to smectite-kaolinite turbidites. Although carbonate-rich sediments are superficially similar to Group II turbidites, geochemical data indicate a reduced contribution from basaltic crustal sources compared with smectite-kaolinite turbidites. A possible southern India/Sri Lankan provenance has been assigned to Group III turbidites on the basis of faunal content and geochemical composition, although insufficient information exists to substantiate this using geochemical data alone. |
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