Current Science

A. B. Roy ¹, Harsh Bhu ², Pankaj Sharma ², Kishan Vaishnav ²

Affiliations
1 Niloy Apartment, Flat 3/2G, 46A, R.N. Das Road, Kolkata 700 031, IN
2 Department of Geology, Mohanlal Sukhadia University, Udaipur 313 001, IN

Abstract

Seismicity or seismic susceptibility implies proneness to earthquake incidence in a region. For this we cannot depend entirely on instrumental records, because this facility was almost unknown about 70-odd years ago, whereas the 'period of quiescence' between two successive major earthquakes in a region may be hundreds of years and sometimes more. This places a severe constraint on the understanding of the regional variability of seismic susceptibility or the proneness of any particular region to the occurrence of an earthquake. In such cases, the necessity is to look for evidence of palaeoseismicity in historic/pre-historic and archaeological records, and for much older events the different fault features preserved in geomorphic features. Here we cite an incidence of seismic event based on the examination of a large number of deserted early nineteenth century houses scattered around Jaisalmer region in western Rajasthan, India. Lying unoccupied for about 190 years or more, evidence of destruction is observed in each and every house, which is not generally witnessed in disused old houses standing for hundred years or more. Looking into the nature of collapse-related flattening features such as collapsed roofs, fallen joists, lintels and pillars in all these houses, we suggest that these are manifestations of earthquake-related destruction. Such an assumption finds strong support from the observed evidence of recent tectonic activities and from the observed ground movements along several major faults in the region covering Jaisalmer and the adjoining areas.

Keywords

Deserted Paliwal Villages, Evidence of Recent Tectonics, Earthquake Related Destruction, Historical Evidence of Earthquake, Palaeoseismicity.

Full Text

   

A. B. Roy ¹, Harsh Bhu ¹, Pankaj Sharma ¹, Kishan Vaishnav ¹

Affiliations
1 Niloy Apartment, Flat 3/2G, 46A, R.N. Das Road, Kolkata 700 031, IN

Abstract

We must thank Bahadur et al. for mentioning the date of what they consider as the ‘Great migration’. Our suggestion about earthquake-related devastation was based on the field examination of different villages where the Paliwal Brahmins lived. We presented some telltale evidence of destruction of houses made of blocks of rocks without using any cementing materials. The earthquake-related destruction features in the poorly constructed stone-block houses of Kuldhar and other Paliwal villages were similar to those destroyed during the Latur earthquake in the recent past, and at about 4000 years ago site at the historical Mohenjodaro.

Full Text

   

Pradeep Srivastava ¹, Anil Kumar ¹, Randheer Singh ², Oshin Deepak ³, Arjit M. Kumar ³, Yogesh Ray ⁴, R. Jayangondaperumal ¹, Binita Phartiyal ², Poonam Chahal ¹, Pankaj Sharma ¹, Rupa Ghosh ¹, Naresh Kumar ⁵, Rajesh Agnihotri ²

Affiliations
1 Wadia Institute of Himalayan Geology, Dehradun 248 001, IN
2 Birbal Sahni Institute of Palaeosciences, Lucknow 226 007, IN
3 Department of Geology, Lucknow University, Lucknow 226 007, IN
4 National Centre for Polar and Ocean Research, Goa 403 802, IN
5 Department of Geology, HNB Garhwal University, Srinagar 249 161, IN

Abstract

Pangong Tso is a brackish water lake that lies along Pangong strand of the Karakoram strike–slip fault in arid Trans Himalayan region. The geomorphic mapping along the periphery of the lake suggested the presence of four palaeolake level strands located at 6, 4.8, 3.8 and 1.25 m above the present lake level. The gullied periphery expose relict deltaic sediments where sedimentological study enabled us to identify four deltaic lobes that make a classic Gilbert-type delta with well-developed top-set, fore-set and bottom-set. The top-set of the stratigraphically oldest delta lobe that corresponds to the highest lake level shows the presence of freshwater molluscs identified as Radix and a burnt sediment layer (hearth). The charcoal derived from this layer yielded 14C date as 1.7 ka BP and six luminescence ages from different delta lobes suggested that delta evolution and lake level fall of ~6 m took place between ~2–1 ka. Review of palaeoclimate record available from NW Himalaya and Pangong Tso suggests that late Holocene aridity might be responsible for this rapid lake level fall. Sclerochronological analysis carried out on 54 subsamples from three Radix specimens suggested that the modern type of seasonal conditions may have prevailed at ~1.7 ka BP.

Keywords

Ladakh Himalaya, Lake-Delta, Late Holocene Aridity, Pangong Tso, Sclerochronological Analysis.

Full Text