Editorial

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Local diversity in settlement, demography and subsistence across the southern Indian Neolithic-Iron Age transition: site growth and abandonment at Sanganakallu-Kupgal

The Southern Indian Neolithic-Iron Age transition demonstrates considerable regional variability in settlement location, density, and size. While researchers have shown that the region around the Tungabhadra and Krishna River basins displays significant subsistence and demographic continuity, and intensification, from the Neolithic into the Iron Age ca. 1200 cal. BC, archaeological and chronometric records in the Sanganakallu region point to hilltop village expansion during the Late Neolithic and ‘Megalithic’ transition period (ca. 1400–1200 cal. BC) prior to apparent abandonment ca. 1200 cal. BC, with little evidence for the introduction of iron technology into the region. We suggest that the difference in these settlement histories is a result of differential access to stable water resources during a period of weakening and fluctuating monsoon across a generally arid landscape. Here, we describe well-dated, integrated chronological, archaeobotanical, archaeozoological and archaeological survey datasets from the Sanganakallu-Kupgal site complex that together demonstrate an intensification of settlement, subsistence and craft production on local hilltops prior to almost complete abandonment ca. 1200 cal. BC. Although the southern Deccan region as a whole may have witnessed demographic increase, as well as subsistence and cultural continuity, at this time, this broader pattern of continuity and resilience is punctuated by local examples of abandonment and mobility driven by an increasing practical and political concern with water

Optically stimulated luminescence dating as a geochronological tool for late quaternary sediments in the Red Sea region

This chapter concerns the use of luminescence methods as geochronological tools for dating Late Quaternary sediments in the Red Sea region. The dating methods all use stimulated luminescence to register signals developed in mineral systems in response to long term exposure to ionising radiation in the environment. The principles of luminescence dating are outlined followed by discussion of its application to the Arabian Peninsula, where, particularly in SE Arabia and parts of the interior, a growing corpus of work is emerging, which is helping to define past arid or humid periods of importance to palaeoclimatology and to archaeology. Turning to the Red Sea, studies conducted within the DISPERSE project are presented both in marine and terrestrial settings. The motivation for much of this work concerns definition of the environmental conditions and chronologies for hominin and human dispersion through Arabia. Data are presented which identify, for the first time, late Pleistocene evidence on the inner continental shelf near the Farasan Islands, using material from the 2013 cruise of RV AEGAEO . Results are also presented from the littoral fringe of southwest Saudi Arabia, identifying units associated with MIS5 which have palaeo-environmental and archaeological significance. It is to be hoped that further research in coming decades will continue to extend the regional chronology for the littoral fringe of the Red Sea. In this respect luminescence dating has potential to help define the environmental history of this important area, to assist with assigning marine and terrestrial features into unique stages of Quaternary climate cycles, and to promote better understanding of human-environment interactions in this dynamic area

Luminescence chronometry and geomorphic evidence of active fold growth along the Kachchh Mainland Fault (KMF), Kachchh, India: Seismotectonic implications

The Kachchh region of Western India is a pericratonic basin experiencing periodic high magnitude earthquakes events. In 2001 a catastrophic seismic event occurred at Bhuj measuring M-w=7.7. The epicenters of both the 1956 and 2001 earthquakes were along the Kachchh Mainland Fault (KMF), proximal to the eastern end of the Northern Hill Range (NHR). The latter is a topographic expression of an active fault related fold on the hanging wall, and is controlled by a south dipping blind thrust. The present study deals with the eastern sector of NHR and uses optical dating to reconstruct the chronology of tectonically caused incisions. Along the backlimb of the NFIR, incision ages on, channel fills and valley fill terraces progressively decrease from similar to 12 ka to 4.3 ka. This age progression along with geomorphic evidences (decrease in topographic relief, drainage capture and drainage migration across the fold nose) suggests an active vertical and lateral fold growth along the KMF. Optical ages suggest that during the Late Holocene, the average uplift rate along the eastern NHR was 10 +/- 1 mm/a. Recent GPS based estimates on crustal shortening are similar to 12 mm/a. The KMF and the South Wagad Fault (SWF) represent the bounding faults of a transtensional basin that formed during the initial rifling. This basin is termed as the Samakhiali basin. The compressive stresses on account of structural inversion from normal to reverse phase resulted in lobate-shaped anticlines along KMF and SWF zone. These anticlines subsequently coalesced and formed linked and overlap segments. The present study suggests that eastward lateral deformation across the eastern portion of KMF has continued and has now resulted in its interaction with a left step over transfer fault called the;South Wagad Master Fault (SWMF). This implies an increasing transpersional deformation of the Samakhiali basin. We therefore, suggest that the eastward NFIR ridge propagation along KMF resulted in the thrust faulting on the south dipping SWMF resulting in the Bhuj 2001 event. The increasing strain on this basin may cause enhanced seismicity in the future along the eastern KMF and Wagad region. (c) 2006 Elsevier B.V

Quartz thermoluminescence: Dose and dose-rate effects and their implications

Laboratory dose-induced thermoluminescence (TL) sensitivity changes have been observed in natural quartz at doses in excess of 250 Gy. This observation has a direct Implication for environmental dosimetry and luminescence geochronology. We suggest a new variant of thermoluminescence dating based on dose-dependent sensitivity changes. When established fully, this approach can potentially extend the quartz-based TL chronology up to a million years. Electron spin resonance studies on the same samples and using the same irradiation schedule indicate growth of a new centre at g = 2.0033. A conceptual framework to explain these observations has been attempted. (C) 1998 .

Drainage migration and out of sequence thrusting in Bhalukpong, Western Arunachal Himalaya, India

In the foreland regions of the Western Arunachal Himalaya (WAH), geological studies along the Kameng river (between Tipi village and the Himalayan Frontal Thrust (HFT)) reveal four levels of unpaired terraces and a paired terrace. In WAH, wrench deformation of HFT zone resulted in a SE propagation of the Balipara anticline and it is suggested that the Mikir high basement controls its orientation. Ages of terrace surfaces from Siwaliks suggest that since the Late Pleistocene, Kameng River migrated at a rate varying between similar to 7.5 cm/yr in upper reaches and similar to 13.5 cm/yr towards northeast due to HFT related uplift. In the Brahmaputra plains, luminescence ages of abandoned paleochannel deposits suggest eastward shifting of the Kameng river at an average rate of similar to 1 m/yr. Field evidences between Bhalukpong and Tipi villages show Pliocene strath and Quaternary terrace surfaces, displaced by faults that do not correspond to the mapped faults in the foreland region. We interpret them as out-of-sequence thrusts (00STs). This is the first such report of OOST in the NE Himalaya. Presence of active COST is inferred by similar age (similar to 1 ka) and differing incision rates of the surface of same terrace (T-2b) in adjacent locations. This suggests that OOSTs in the western Arunachal Siwalik are <1 ka. Average slip rate and horizontal shortening rate on OOST during the Holocene, are calculated as similar to 12 mm/yr and 7 mm/yr respectively. Thus any estimation of Holocene shortening in the Siwalik therefore, needs to incorporate slip along the OOSTs given that it accommodates a significant amount of N-S compression of the Himalayan fold-and-thrust belt. The reason for COST in the WAH Siwalik foreland is discussed in terms of the critical wedge dynamics arising from erosion via tectonics-climate interaction. We estimate a minimum slip rate of Siwalik as 27 mm/yr during the Holocene and suggest acceleration in shortening rates east of Bhutan. (C) 2014 Elsevier Ltd. All rights reserved

Rapid denudation of Higher Himalaya during late Pliestocence, evidence from OSL thermochronology

Optically Stimulated Luminescence (OSL) of quartz, with closure temperatures of 30-35A degrees C in conjunction with Apatite Fission Track (AFT; closure temp. similar to 120A degrees C) and Ar-40-Ar-39 (biotite closure temperature similar to 350A degrees C), were used to obtain cooling ages from Higher Himalayan crystalline rocks of Western Arunachal Himalaya (WAH). Cooling age data based on OSL, AFT and Ar-Ar thermochronology provide inference on the exhumation - erosion history for three different time intervals over million to thousand year scale. Steady-state exhumation of similar to 0.5 mm/yr was observed during Miocene (> 7.2 Ma) till Early Pleistocene (1.8 Ma). Onset of Pleistocene glacial/interglacial conditions from similar to 1.8 Ma formed glaciated valleys and rapid erosion with rivers incising deep valleys along their course. Erosion enables midcrustal partial melts to move beneath the weak zone in the valley and causes an erosion-induced tectonic uplift. This resulted in a rapid increase in exhumation rate. The OSL thermochronology results suggest increased erosion over similar to 21 ka period from Late Pleistocene (2.5 mm/yr) to Early Holocene (5.5 mm/yr) and these are to be contrasted with pre 1.8 Ma erosion rate of 0.5 mm/yr. Enhanced erosion in the later stage coincides with the periods of deglaciation during Marine Isotope Stages (MIS) 1 and 2. The results of the present study suggest that in the present setting OSL thermochronology informed on the short-term climatic effect on landscape evolution and techniques like the AFT and Ar-40-Ar-39 provided longer-term exhumation histories

Electron spin resonance characterization of calcretes from Thar desert for dating applications

Results of a study to characterize electron spin resonance (ESR) signals from naturally occurring carbonates from Thar desert are reported. Three radiation induced signals at g = 2.0071 (signal A, very weak), g = 2.0012 (signal B) and g = 2.0003 (signal C) with linewidths ranging from 0.5-2 G are seen. A broad signal (BL) with linewidth 7 G is also seen at 2,0038, Detailed ESR experiments involving (1) sensitivity of ESR signals to ionizing radiation, (2) intensity variation of ESR signals with microwave power at different temperatures, (3) analysis of acid insoluble residue to estimate the interference from ESR signals of silicate fraction, and (4) X-ray diffraction analysis (to study possible phase changes on heating), led to the choice of signal BL for dating. Experiments on acid insoluble residue revealed that signal C has a contribution from the E-1' centre of quartz and signal B is the parallel component (g(parallel to)) of the E-1' centre, Paleodose estimates based on signal BL are stratigraphically consistent. (.

Luminescence dating in archaeology, anthropology and geoarchaeology: an overview

The field of Luminescence Dating has reached a level of maturity. Both research and applications from all fields of archaeological science, from archaeological materials to anthropology and geoarchaeology, now routinely employ luminescence dating. The advent of optically stimulated luminescence (OSL) techniques and the potential for exploring a spectrum of grain aliquots enhanced the applicability, accuracy and the precision of luminescence dating. The present contribution reviews the physical basis, mechanisms and methodological aspects of luminescence dating; discusses advances in instrumentations and facilities, improvements in analytical procedures, and statistical treatment of data along with some examples of applications across continents, covering all periods (Middle Palaeolithic to Medieval) and both Old and New World archaeology. They also include interdisciplinary applications that contribute to palaeo-landscape reconstruction

Multiple episodes of aggradation and calcrete formation in Late Quaternary aeolian sands, Central Thar Desert, Rajasthan, India

A 12 m thick section in a dune-sandy plain terrain of the Central Thar in Rajasthan, has provided a near continuous record of environmental change for the past 160 ka. The site presently receives 280 mm rainfall, almost entirely from the summer monsoon. The base of this section comprises a gravel bed of an ephemeral stream and the overlying six litho-units, each with discrete boundaries, comprise a succession of aeolian sands. Luminescence dating provided an estimate of the timing of the sand aggradation periods to 160, 90, 60, 27 and 17–14 ka and helped constrain the timing of calcrete formation periods. In each aggradation unit, discrete nodular calcretes formed by the leaching of carbonate from the overlying solum. This is analogous to present-day conditions in sandy plains during periods of increased rainfall and landscape stability. Several of these calcretes are, however, devoid of their donor solum, suggesting solum removal during a subsequent period of decreased rainfall and resultant surface instability. This is supported by the presence of reworked nodules on the surfaces of some calcretes. A prominent phase of calcrete development followed the aeolian sand aggradation at 60 ka, suggesting climate amelioration that also caused the formation of groundwater-related calcrete and mottling. The study suggests that stage II calcrete nodules form in a time frame of 10–20 ka, and confirms limited data on the duration and stage of calcrete development in the literature. The d13C values of calcrete carbonate lie in a narrow range (+0.5 to -1.1‰) suggesting formation under soils with C4 vegetation. This implies that even during phases of climatic amelioration, the high temperatures and increased seasonality of rainfall did not permit significant development of C3 plants in the Central Thar