Hostname: page-component-76fb5796d-45l2p Total loading time: 0 Render date: 2024-04-30T02:11:41.567Z Has data issue: false hasContentIssue false

New Geochemical Evidence for the Youngest Toba Tuff in India

Published online by Cambridge University Press:  20 January 2017

Phil Shane
Affiliation:
Department of Geology, University of Toronto, Toronto, Ontario M5S3B1, Canada
John Westgate
Affiliation:
Department of Geology, University of Toronto, Toronto, Ontario M5S3B1, Canada
Martin Williams
Affiliation:
Mawson Graduate Centre for Environmental Studies, University of Adelaide, Adelaide, SA 5005, Australia
Ravi Korisettar
Affiliation:
Department of History and Archaeology, Karnatak University, Dharwad 580 003, India

Abstract

New geochemical data on tephra samples from a layer present at several archeological sites in India support correlation of this layer to the Youngest Toba Tuff, erupted from northern Sumatra about 74,000 yr ago. The data show that the Indian tephra layer is not a correlative of older tephra erupted from Toba, as has been suggested on the basis of artifact assemblages. Previously published geochemical data on the Indian tephra beds was based on bulk ash samples containing mineral and clay contaminants, and the resulting variability in analyses did not allow identification or discrimination of individual eruptive events. Our new data were collected on individual glass shards and small, purified glass separates which have greater resolving power in fingerprinting. Acheulian and Paleolithic artifacts found at some of the Indian tephra sites do not reflect the antiquity of the tephra bed, as they occur in fluvial sediments and may be reworked.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Acharyya, S. K., and Basu, P. K. (1993). Toba ash on the Indian Subcontinent and its implications for correlation of late Pleistocene alluvium. Quaternary Research 40 , 1019.Google Scholar
Badam, G. L., and Rajaguru, S. N. (1994). Comment on “Toba ash on the Indian subcontinent and its implication for the correlation of late Pleistocene alluvium.” Quaternary Research 41 , 398399.Google Scholar
Barnes, S., and Gorton, M. P. (1984). Trace element analysis by neutron activation with a low flux reactor (Slowpoke-II); Results for international reference rocks. Geostandards Newsletter 8 , 177223.Google Scholar
Chesner, C. A. Rose, W. I. Deino, A. Drake, A. D. R., and Westgate, J. A. (1991). Eruptive history of Earth’s largest Quaternary caldera (Toba, Indonesia) clarified. Geology 19 , 200203.Google Scholar
Dehn, J. Farrel, J. W., and Schmincke, H.-U. (1991). Neogene tephrochronology from site 758 on Ninety east Ridge: Indonesian arc volcanism of the past 5 Ma. Proceedings of the Ocean Drilling Program, Scientific Results 121 , 273295.Google Scholar
Korisettar, R. Venkatesan, T. R. Misra, S. Rajaguru, S. N. Somayajulu, 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
Mishra, S., and Rajaguru, S. N. (1994). Comment on “Toba ash on the Indian subcontinent and its implication for the correlation of late Pleistocene alluvium.” Quaternary Research 41 , 396397.Google Scholar
Ninkovich, D. Shackleton, N. J. Abdel-Monem, A. A. Qbradovich, J. D., and Izett, G. (1978a). K-Ar age of the late Pleistocene eruption of Toba, north Sumatra. Nature 276 , 574577.Google Scholar
Ninkovich, D. Sparks, R. S. J., and Ledbetter, M. T. (1978b). The exceptional magnitude and intensity of the Toba eruption, Sumatra: An example of the use of deep-sea tephra layers as a geological tool. Bulletin Volcanologique 41-3 , 113.Google Scholar
Rampino, M. R., and Self, S. (1993). Climate-volcanism feedback and the Toba eruption of -74,000 years ago. Quaternary Research 40 , 269280.Google Scholar
Rose, W. I., and Chesner, C. A. (1987). Dispersal of ash in the great Toba eruption. Geology 15 , 913917.Google Scholar
Shane, P. A. R., and Froggatt, P. C. (1994). Discriminant function analysis of glass chemistry of New Zealand and North American tephra deposits. Quaternary Research 41 , 7081.Google Scholar
Sama-Wojcicki, A. M., and Davis, J. O. (1991). Quaternary tephrochronology. In “Quaternary Nonglacial Geology: Conterminous U.S.” (Morrison, R. B., Ed.), The Geology of North America, K-2, pp. 93116. Geological Society of America, Boulder, CO.Google Scholar
Stauffer, P. H., and Batchelor, B. (1978). Quaternary volcanic ash and associated sediments at Serdang, Selangor. Warta Geologi 4 , 711.Google Scholar
Westgate, J. A. Perkins, W. T. Fuge, R. Pearce, N. J. G., and Wintle, A. G. (1994). Trace-element analysis of volcanic glass shards by laser ablation inductively coupled plasma mass spectrometry: Application to tephrochronological studies. Applied Geochemistry 9 , 323335.Google Scholar
Westgate, J. A., and Gorton, M. P. (1981). Correlation techniques in tephra studies. In “Tephra Studies” (Self, S. and Sparks, R. S. J., Eds.) pp. 7394, Reidel, Dordrecht.Google Scholar
Williams, M. A. J., and Royce, K. (1982). Quaternary geology of Middle Son valley, North Central India: Implications for prehistoric archaeology. Palaeogeography, Palaeoclimatology and Palaeoecology 38 , 139162.Google Scholar