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Toba Ash on the Indian Subcontinent and Its Implications for Correlation of Late Pleistocene Alluvium

Published online by Cambridge University Press:  20 January 2017

Subhrangsu Kanta Acharyya
Affiliation:
Geological Survey of India Shillong-793003, India
Prabir Kumar Basu
Affiliation:
Geological Survey of India Calcutta-700016, India

Abstract

The Toba ash occurs extensively in the Indian subcontinent and marks a ca. 74,000-yr-old event. In the Bay of Bengal and Indian Ocean it is about 10 cm thick, whereas in several alluvial basins, it is usually 1-3 m thick. The latter occurs in a partly reworked state but as nearly chemically pure first-cycle sediments, The ash has a broad northwesterly dispersal pattern. Samples of ash from the Indian subcontinent compare closely with the youngest (74,000 yr B.P.) Toba Tuff and the deep-sea Toba ash in bulk chemical composition, REE signature, and bubble-wall shard morphology. However, a more proximally located and thicker (2-5 m) ash-bed, from the alluvial basins in the gneissic area and close to east coast, has a lower magnitude negative Eu anomaly, possibly because of minor contamination by feldspathic silt. Quaternary sediments in the central Narmada and middle Son basins contain rich late and middle Pleistocene mammalian and cultural records. Based on the presence of the ash layer marker and stratigraphic relations, late Pleistocene sediments within the subcontinent can be correlated with those from central India and the deep sea.

Type
Research Article
Copyright
University of Washington

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References

Anonymous, (1989). Late Quaternary ash bed in the Barakar River section, Bihar. News Geological Survey of India, Centra! Headquarters 20(1), 18.Google Scholar
Anonymous, (1990). Late Quaternary ash bed and Acheulian imple-ments from Orissa—The implication. News Geological Survey of India, Eastern Region 10(1), 7.Google Scholar
Anonymous, (1991). Volcanic ash in the Quaternary formations Sagileru valley. News Geological Survey of India, Southern Region 9(2), 9.Google Scholar
Basu, P. K., and Biswas, S. (1991). Quaternary ash bed from eastern India. In “A decade of scanning electron microscopy in GSI”, Geological Survey of India, Special Publication 16, 6568.Google Scholar
Basu, P. K. Biswas, S., and Acharyya, S. K. (1987). Late Quaternary ash beds from Son and Narmada basins, Madhya Pradesh. Indian Minerals 41, 6672.Google Scholar
Biswas, S., and Dassarma, D. C. (1986). Stratigraphy of the Quaternary alluvial deposits of the Central Narmada valley in Madhya Pradesh, India. Proceeding of the XI Indian Colloquium on Micropalaeontol-ogy and Stratigraphy, Bulletin Geological Mining Mettalurgical Society of India 54, 1827.Google Scholar
Biswas, S. Basu, P. K., and Sarkar, G. P. (1989). Biostratigraphy of the Quaternary alluvial sediments in the Central Narmada Basin and the Middle Son Basin in Eastern Madhya Pradesh. Unpublished report. Geological Survey of India 38P.Google Scholar
Chesner, C. A. (1985). Geochemistry of the Toba ignimbrites: Implications on silicic magma bodies, outflow patterns, and caldera collapse. EOS (American Geophysical Union Transactions) 66, 1141.Google Scholar
Chesner, C. A. Rose, W. I. Drake, A. D. R., and Westgate, J. A. (1991). Eruptive history of Earth’s largest Quaternary caldera (Toba Indonesia) clarified. Geology, 19, 200203.2.3.CO;2>CrossRefGoogle Scholar
Clark, J. D., and Sharma, G. R. (1983). A discussion of preliminary results and assessment of future research potential. In “Palaeoenvi-ronment and Prehistory in the Middle Son Valley” (G. R., Sharma and J. D., Clark, Eds.), pp. 261273. Department of Ancient History, Culture and Archaeology, Allahabad University A. H. Wheeler & Co., Allahabad.Google Scholar
Dehn, J. Farrel, J. W., and Schmincke, H.-U. (1991). Neogene Teph-rochronology from site 758 on northern Ninety east Ridge: Indonesian arc volcanism of the past 5 ma. Proceedings of the Ocean Drilling Programme, Scientific Results 121, 273295.Google Scholar
Devdas, V., and Meshram, S. N. (1991). Search for Quaternary ash bed in the Quaternary basins of Orissa. Records Geological Survey of India 124(3), 4042.Google Scholar
Korisettar, R. Venkatesan, T. R. Misra, S. Rajaguru, S. N. Somaya-julu, B. L. K. Tandon, S. K. Gogte, V. D. Ganjoo, R. K., and Kale, V. S. (1989). Discovery of a tephra bed in the Quaternary alluvial sediments of Pune district (Maharashtra). Peninsular India. Current Science 58, 564567.Google Scholar
Mandal, D. (1983). A note on the radiocarbon dates from the Middle Son valley. In ‘“Palaeonvironment and Prehistory in the Middle Son valley” (G. R., Sharma and J. D., Clark, Eds.), Appendix B, pp. 285289. Department of Ancient History, Culture & Archaeology, Allahabad University A. H. Wheeler & Co., Allahabad.Google Scholar
Ninkovitch, D. Shakleton, N. I. Obradovich, J. D., and Izett, G. (1978). K-Ar age of the late Pleistocene eruption of Toba, north Sumatra. Nature 276, 574577.Google Scholar
North American Commission on Stratigraphic Nomenclature (NACSN) (1983). North American Stratigraphic Code. Bulletin American Association of Petroleum Geologists 67, 841875.Google Scholar
Poddar, B. C Verma, K. K. Tewari, M. P. Rahate, D. N. Khan, A. A. Sonakia, A. Biswas, S. Nandi, A. Krishna, S. G. Dubey, U. S. Bhai, H. Y. Fahim, M., and Sitaramaiah, Y. (1991). Narmada valley project. Records Geological Survey of India 124(6), 245246.Google Scholar
Rose, W. I., and Chesner, C. A. (1987). Dispersal of ash in the great Toba eruption, 75 ka. Geology 15, 913917.Google Scholar
Rose, W. I., and Chesner, C. A. (1990). Worldwide dispersal of ash and gases from earth’s largest known eruption: Toba, Sumatra, 75 ka. Palaeogeography. Palaeoclimatology, Palaeoecoiogy 89, 269275.Google Scholar
Sonakia, A. (1984). The skullcap of early man and associated mammalian fauna from Narmada valley alluvium. Hoshangabad area, Mad-hya Pradesh (India). Records of the Geological Survey of India 113(6), 159172.Google Scholar
Sparks, R. S. J., and Wilson, L. (1976). A model for the formation of ignimbrite by gravitational column collapse. Journal of the Geological Society of London 132, 441451.CrossRefGoogle Scholar
Woods, A. W., and Wohletz, K. (1991). Dimensions and dynamics of co-ignimbrite eruption columns. Nature 350, 225227.CrossRefGoogle Scholar
Williams, M. A. J., and Royce, K. (1982). Quaternary geology of the Middle Son valley, North Central India: Implications for prehistoric Archaeology. Palaeogeography, Palaeoclimatology, and Palaeoecoiogy 38, 139162.Google Scholar
Williams, M. A. J., and Royce, K. (1983). Alluvial history of the Middle Son valley, North Central India. In “Palaeoenvironment and prehistory in the Middle Son valley” (Sharma, G. R. and Clark, J. D., Eds.), pp. 921, Department of Ancient History, Culture & Archaeology, Allahabad University A. H. Wheeler & Co., Allahabad.Google Scholar
Williams, M. A. J., and Clarke, M. F. (1984). Late Quaternary environments in north-central India. Nature 308, 633635.Google Scholar