Occurrence of rhyolytic tuffs at deep sea drilling project site 219 on the Laccadive Ridge
DRS at CSIR-National Institute of Oceanography
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Title |
Occurrence of rhyolytic tuffs at deep sea drilling project site 219 on the Laccadive Ridge
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Creator |
Siddiquie, H.N.
Sukheswala, R.N. |
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Subject |
Geology and Geophysics
Geology and Geophysics deep sea drilling petrology mineralogy texture palaeo studies ISW, Laccadive |
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Description |
A study of thin sections from the lower and middle parts of Unit 5 (Paleocene) from Site 219 shows that these largely consist of acidic or rhyolitic tuffs. The overlying limestones in Unit 5 (Paleocene) and Unit 4 (Lower Eocene) also contain tuffaceous material in varying proportions. Albite/oligoclase forms the phenocrysts as also needles in the groundmass of these tuffs and tuffaceous material in limestones. The euhedral fresh felspars suggest that the source of activity was nearby and possibly most of the activity was subaqueous rather than subaerial. Similar acidic tuffs in the Deccan Traps have been reported particularly from the West Coast of India. The acidic tuffs at site 219 are of the same age as the Deccan Traps and may represent a late phase of Deccan Trap activity on the Laccadive Ridge before its subsidence and separation from peninwular India
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Date |
1997-11-26T09:56:51Z
2017-09-29T13:47:05Z 1997-11-26T09:56:51Z 2017-09-29T13:47:05Z 1976 |
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Type |
Journal Article
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Identifier |
Journal of the Geological Society of India, vol.17(4); 1976; 539-546
0016-7622 http://drs.nio.org/drs/handle/2264/5516 |
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Language |
en
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Relation |
J Geol Soc India
SCI |
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Publisher |
Geological Society of India
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