Discussion on ‘Acheulian and Tephra from Upland Western Maharashtra, (Deccan Volcanic Province), Peninsular India’, by Deo et al. 2021 (SP 515)

Acheulean artefacts are widely known from archaeological complexes in India and commonly comprise handaxes, picks and cleavers. These provide information on human occupation and evolution across India, and have been the subject of much research on stone technology. In some of these sites, artefacts are associated with a Pleistocene volcanic ash layer derived from the Toba caldera in Sumatra, but various studies have derived a wide range of ages from this deposit leading to differing schools of thought as to the age of the tephra. Recent trace element, fission track and mineralogical studies (since 2011), have enabled accurate recognition of each Toba eruptive unit across their fall out, but these approaches continue to be overlooked in some studies where artefacts and Toba tephra co-exist in India. This leads to significant errors in tephra identification, and thus hampers any derived age interpretations. Most recently, this includes the study by Deo et al. (2021) who, in Geological Society Special Publication 515 (Tiwari et al. 2021) report ages for artefacts and tephra from two sites in the Deccan Volcanic Province which have become pivotal in many arguments, namely Morgaon and Bori. Here we address these issues and reiterate the methods for identification of the three main Toba tephra deposits.