Lower and Early Middle Pleistocene Acheulian in the Indian sub-continent

Methods for determination of the age of Pleistocene tephra, derived from eruption of Toba, in central India

“…The age assignment deduced from our analysis is slightly high for this interpretation, since Dehn et al (1991) placed the eruption at the MIS 14 to MIS 13 transition, or ∼530 ka. This site can thus be inferred on this basis to be younger than that deduced by Gaillard et al (2009) and others using magnetostratigraphy. Such a reassignment in age would require the reverse geomagnetic polarities recorded here (Sangode et al 2007) to indicate one or more of the reverse-polarity excursions within the Brunhes chron, rather than the Matuyama chron.…”

“…Subsequent investigations have led to the conclusion that other Lower Palaeolithic sites in India, associated with deposits of Toba tephra, also date from the Early Pleistocene or early Middle Pleistocene, on the basis of stratigraphic relations, magnetostratigraphy, and limited evidence from numerical dating. The current state of knowledge on this topic was reviewed by Gaillard et al (2009), notwithstanding Chauhan's (2010) comment that the story is 'based entirely on circumstantial and inconclusive evidence' (cf. Gaillard et al 2010); Gaillard et al (2009) concluded that there is a strong weight of evidence, from the presence of Acheulian artefacts, for human occupation of the region in the late Early Pleistocene.…”

“…The current state of knowledge on this topic was reviewed by Gaillard et al (2009), notwithstanding Chauhan's (2010) comment that the story is 'based entirely on circumstantial and inconclusive evidence' (cf. Gaillard et al 2010); Gaillard et al (2009) concluded that there is a strong weight of evidence, from the presence of Acheulian artefacts, for human occupation of the region in the late Early Pleistocene. For example, Sangode et al (2007) have reported reversed magnetization in sediments associated with Acheulian artefacts and the tephra at Morgaon, Maharashtra, and at Bori, implying ages within the Matuyama chron (i.e., within the Early Pleistocene).…”

“…This paper will summarize the history of previous studies on this topic, before presenting the results of our own analysis of five tephra samples, four of which will be shown to have yielded meaningful numerical ages. However, no attempt will be made to review the Pleistocene stratigraphy of any sites; the existing literature (e.g., Mishra et al 1995;Tiwari et al 1996;Petraglia et al 1999Gaffer et al 2001;Westaway et al 2003;Shete 2006;Mishra 2007Mishra , 2008Sangode et al 2007;Gaillard et al 2009;Jones and Pal 2009;and references therein) includes detailed site maps, cross-sections and discussions of stratigraphic relations. The five sites for which tephra samples are analysed are Morgaon, Bori, Gandhigram, Simbhora and Pawla (figure 2).…”

A high-precision 40Ar/39Ar age for the Young Toba Tuff and dating of ultra-distal tephra: Forcing of Quaternary climate and implications for hominin occupation of India

“…The YTT ash deposits associate with Middle Palaeolithic assemblages in the Son Valley (Jones and Pal, 2009;Petraglia et al, 2012) and the Jurreru Valley Petraglia et al, 2012). The implication is that claims for an association between Acheulean artefacts and ash (Sangode et al, 2007;Gaillard et al, 2010) are likely to be a product of redeposition and erroneous dating. While allowing for chronometric dating gaps in the Late Pleistocene of India, the presence of Middle Palaeolithic hominins between c. 77 and 38 ka implies continuity of human populations, and is thus consistent with some genetic studies which suggest a pre-Toba colonisation (Oppenheimer, 2012).…”