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.

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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.

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Ronak Jain ¹, Harsh Bhu ¹, Ritesh Purohit ¹

Affiliations
1 Department of Geology, Faculty of Earth Sciences, Mohanlal Sukhadia University, Udaipur 313 001, IN

Abstract

In the present study, thermal remote sensing technique and ASTER data have been used to delineate ultramafic, carbonate and siliceous rocks. The study gains importance as mineralized carbonate and ultramafic rocks are present in the southern region of Rajasthan, India between Udaipur and Dungarpur districts. The rocks in the study area include phyllites, mica schist, chlorite schist, quartzite, dolomite, granite, granitoids, gneiss and intrusive serpentinite. ASTER thermal bands were used to map ultramafics, siliceous and carbonate rocks on a scale of 1 : 380,000. Delineation of ultramafics was done using MRI-AV and MI-N indices, however the former provided a more informative map compared to the latter. QRIAV, QI-N and QI-RH indices were used for mapping siliceous rock. QI-RH provided a more informative map compared to QRI-AV and QI-N. The index used for carbonate rocks was CI-N, but this did not provide a satisfactory map.

Keywords

ASTER TIR, Carbonate and Siliceous Rocks, Thermal Indices, Thermal Remote Sensing, Ultramafics.

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