Abstract The two Early Acheulian sites of Bori and Morgaon in the Deccan Volcanic Province in Upland Maharashtra, India bear some association with an acidic tephra deposit in a fluvial context. Acheulian artefacts in association with tephra were first reported in India from the Bori site and numerous efforts to date this tephra have since been undertaken. These efforts employed various dating methods and produced a total of 10 absolute dates ranging from the Early Pleistocene with a maximum age of 1.4 Ma to the Late Pleistocene with a minimum age of 23.4 ± 2.4 ka. However, field observations and a typo-technological analysis strongly suggests that these Early Acheulian artefacts occur in a semi-primary context, and thus contest the Late Pleistocene age of the tephra and redeposition of the artefacts as argued by some scholars. At Morgaon, the Acheulian artefacts have been recovered from basal fluvial sediments that contain clasts of laterite. These sediments are capped by two low-energy clay facies that are separated by high-energy gravel lenses. The tephra at Morgaon has been reported from the upper clay facies and has produced absolute dates ranging from the Matuyama period (>0.78 Ma) to the Late Pleistocene (41 ka). After more than two decades of investigation at these sites, the number of absolute dates procured through methods such as electron spin resonance (ESR), 39 Ar– 40 Ar, U–Th and palaeomagnetism, although encouraging, are inconclusive. This paper is therefore an attempt to gauge the nature of the palaeolandscapes that most probably existed during the Early Quaternary. This will be achieved by studying local geomorphological variability between the two sites, along with a preliminary analysis of lithic morphology.

Abstract The formal beginning of geoarchaeology in India can be traced back to 1863 when the first palaeolith was documented and collected by Robert Bruce Foote in Tamil Nadu and later described in a detailed geological context. Today, various geological tools such as geospatial analytical tools are available to provide extra mileage to geoarchaeological investigations. They supplement field evidence and enable researchers to display, manipulate, and model geological data and the associated archaeological evidence. The present paper attempts to summarize the current status of understanding of the Quaternary geoarchaeology of the Tapi River basin in west-central India. The aspects considered include geomorphology, landform evolution, morphometric parameters, relationships between climate and basin evolution and Palaeolithic and Mesolithic evidence. This present study uses Landsat imagery, locational data, Survey of India topographic sheets and Shuttle Radar Topography Mission data in ArcGIS software. The study is the first comprehensive attempt to summarize the issue of prehistoric human adaptations (dominated mainly by Late Pleistocene evidence) through changing environments, with an assumption that the two occurred in synchronization. Another assumption is that the reported lithic and fossil sites and the surrounding areas have preserved signatures of original landforms and sedimentary contexts. Through these perspectives and visual integration of topography, drainage networks and Landsat image parameters in a Geographic Information System platform, along with other variable field inputs, a testable hypothetical model of the Quaternary evolution of Central Tapi valley is proposed. Additionally, an accelerator mass spectrometry (AMS) date of 47 145 cal BP for a newly discovered ostrich eggshell fragment from Sakegaon near Bhusawal is presented and its palaeoanthropological implications are discussed. Altogether, our observations from the study area, such as an expansion of land use from the Acheulean onwards, signatures of arid phases and the oldest reported ostrich eggshell, warrant further detailed multidisciplinary research. An in-depth understanding of the first-to-last occurrences of ostriches in the region and comprehensive picture of their pan-South Asian distribution in general will help address the issue of prehistoric human adaptations through changing environments.

Abstract An understanding of long-term climate variability may provide a valuable perspective on the possible response of human societies to modern climate change. The present study, based on geochemical and sedimentological analyses on well dated (using AMS 14 C and optically stimulated luminescence (OSL) dates) alluvial sediments from Sina River basin (in Maharashtra, central India), provides a detailed understanding of the complex interplay between climate and cultural dynamics during the Late Holocene. The radiocarbon dates of the organic residues from the potsherds represent the Medieval period ( c. 1.6–0.95 cal ka BP), whereas the OSL sample shows an age of c. 7.5 ± 0.4 ka. Further, several cultural objects (e.g. potsherds, shell bangles, and copper artefacts) available at the site were also investigated in order to understand the extent of human activity in the region. The temporal changes in the proxies along with the abundance of cultural materials in the fluvial section during the Medieval period suggest that the human population attempted to adapt against the fluctuating climate conditions. The regional comparison of geo-archaeological datasets shows that the pronounced weakening of the monsoonal rainfall during the Late Holocene coincides with the disruption, migration and resettlement of indigenous societies, deciphering the possible impact of climate on human settlement.

Abstract Rivers and river-borne deposits have always been a major attraction for hominins as an important source of sustenance and settlements. Hence, fluvial deposits have long been an important source of evidence for early human occupation throughout the Old World. Apart from being an important palaeoclimatic marker, fluvial sequences have provided archaeologists with frameworks for correlation, along with Palaeolithic markers discovered within them. Moreover, given the influx of sediments eroded and deposited by Indian rivers, these could have acted as a centre of hominin activities. Palaeolithic research in India has been concentrated around some of its major river valleys, which have yielded a rich record of hominin occupation. So far, 305 Palaeolithic sites have been reported from a gravel context throughout the country, yielding Lower to Upper Palaeolithic, Mesolithic and Neolithic evidence. However, most of the derived evidence is secondary deposits and stands contested based on its contextuality. Nevertheless, its importance as a source of information about hominin activity cannot be underestimated. This review presents a provisional synthesis of all of the Indian Palaeolithic sites reported from gravel contexts, thereby presenting scope for future multidisciplinary research at these localities.

ABSTRACT Rampart craters are omnipresent features on volatile-rich solid planetary surfaces. This raises the question whether, and how many, rampart craters are present on Earth. We reviewed the terrestrial impact crater record with regard to possible rampart morphologies and present detailed morphological analyses of these terrestrial craters here. Our results show that the Ries crater in Germany, Bosumtwi crater in Ghana, Tenoumer crater in Mauritania, Lonar crater in India, and Meteor crater in the United States are terrestrial rampart craters. The Ries and Bosumtwi craters can be classified as double-layer ejecta (DLE) craters, whereas Tenoumer, Lonar, and Meteor craters can be classified as single-layer ejecta (SLE) craters. Tenoumer and Meteor craters show rampart as well as common lunar-like ejecta characteristics within their ejecta blankets and, thus, appear to be hybrid craters. In addition, we discuss seven crater structures that show at least some morphological or lithological peculiarities that could provide evidence for possible ejecta ramparts. Considering the low number of terrestrial impact craters with well-preserved ejecta blankets, the relatively high proportion of rampart craters is astonishing. Obviously, the formation of layered or rampart craters is a common and not a rare process on Earth.

Abstract Archaeointensity and rock-magnetic studies were undertaken on 49 baked clay artefacts from four archaeological sites (Ter, Junnar, Nalasopara and Kanheri) in Maharashtra, India. Rock-magnetic properties, including bulk magnetic susceptibility, magnetic remanence and thermomagnetic analysis, indicate the presence of a low-coercivity magnetite in fine (superparamagnetic, single domain) grain-sizes. The ratio of anhysteretic remanent magnetization to saturation isothermal remanent magnetization, the reversible high-temperature susceptibility curves and the 3-axes isothermal remanent magnetization tests also indicate that the artefacts dominantly possess fine-grained magnetic particles, carrying a stable thermoremanent magnetization (TRM). Archaeointensity was estimated using Coe's modified Thellier method corresponding to the linear behaviour of natural remanent magnetization loss and TRM gained plots, which were evaluated with ThellierTool4.0 software. Cooling rate and anisotropy of the TRM corrections were applied and the corrected intensities were used to calculate a mean archaeointensity value for each one of the four sites. The new archaeointensity values were plotted along the existing Indian archaeointensity values derived only from archaeological artefacts, and were compared with the SHA.DIF.14k and ARCH10k.1 global models’ predictions. The present study aims to improve the overall understanding of Indian geomagnetic field variation in the past by providing new high-quality archaeointensity results. However, still more archaeointensity values are required to develop a reliable secular variation curve for India.

Abstract A relative palaeointensity determination was obtained using the pseudo-Thellier technique on sediment from Ther, Tirna Basin, Latu-Osmanabad District, Maharashtra, India. The stability of the natural remanent magnetization was investigated by alternating field (AF) demagnetization. Rock magnetic studies suggest that the main carriers of magnetization are ferrimagnetic minerals, predominantly pseudo-single-domain magnetite. To varying degrees, the smoothed palaeoinclination and palaeodeclination patterns of the Tirna Basin are similar to other Asian palaeosecular variation records CALS3k.4, CALS10k.1 and SED3k.1, with an age offset. Measurements of intensity of the natural remanent magnetization left after AF demagnetization v. intensity of anhysteric remanent magnetization gained at the same peak were carried out on a set of samples. A jackknife re-sampling scheme provides error estimates for the palaeointensity. A good agreement pattern can be observed between the Tirna Basin relative palaeointensity proxy and other global curves with an age shift. Although some temporal offsets of palaeointensity features between different records have been recognized, their similar shape suggests that the palaeointensity can give a globally coherent signal and may be used as a relative dating technique. For the first time, relative palaeointensity data for the past 2 kyr from India is presented here, which complement the existing archaeological records but with an additional input.