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Javed N. Malik ¹, Parag S. Sohoni ¹, R. V. Karanth ¹, S. S. Merh ¹

Affiliations
1 Department of Geology, M. S. University of Baroda, Vadodara - 390 002, IN

Abstract

No Abstract.

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Parag S. Sohoni ¹, R. V. Karanth ¹

Affiliations
1 Department of Geology, Faculty of Science, M. S. University of Baroda, Vadodara - 390002, IN

Abstract

The studies carried out at different locations in Central Kachchh Mainland indicate that prolific jointing is conspicuous in Mesozoic and Cenozoic rocks. The present investigation aims at documenting the characteristic joint sets cutting the rocks of different age groups and explore their possible genetic implications. Detailed lineament analysis has been carried out to compare major lineament patterns in the area and the characteristic joint sets observed in the field. Rocks of all age groups are highly jointed, but most intensive jointing is seen in the Mesozoic litho·units. Five different joint sets can be deciphered by their average azimuthal distribution, i.e., N125°±10°, N60°±100, NI50°±100, N180°±100 and N90°±10°. The directional analysis shows that there are three general trends i.e. NNE-SSW, NW-SE and ESE-WNW, with other subsidiary directions. The length-azimuth relationship shows that the highest density of lineaments correspond to the length inbetween 800 m and 3000 m. NNE-SSW and NW-SE trending lineaments are dominant in the length range of 800 m to 3000 m. The most significant part of the length-azimuth analysis is that WNWESE lineaments are increasingly prominent as length increases. This is because of the fact that most of the major structures in Central Kachchh Mainland are oriented in WNW-ESE and E-W directional domains.

The genesis of NNE-SSW and NNW-SSE lineaments can broadly be correlated with the faults and fractures developed transverse to the major east-west trending structures. The occurrence of nearly E-W and N-S sets suggest their close association with the flexuring activity along the major and minor faults within the Katrol Hill Zone (KHZ). Presence of NNE-SSW, NNW-SSE, E-Wand N-S sets in the Mesozoic sediments of KHZ in general and in the Quaternary sediments along the eastern extremity of KHZ in particular suggests sustained tectonic instability in this region during the Quaternary.

Keywords

Tectonism, Jointing, Kachchh, Gujarat.

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Manoj A. Limaye ¹, Parag S. Sohoni ¹

Affiliations
1 Department of Geology, Faculty of Science, M. S. University of Baroda, Vadodara - 390 002, IN

Abstract

No Abstract.

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Parag S. Sohoni ¹, R. V. Karanth ¹

Affiliations
1 Department of Geology, M S University of Baroda, Vadodara - 390002, IN

Abstract

Kachchh regiOn of western India has been a site for successive deformatiOnal events since the advent of Mesozoic leading to a considerable amount of structural deformation of the rocks Faulting forms as one of the most conspicuous groups of structures that developed 10 Central Kachchh Mainland (CKM) Normal faults in particular are very well exposed throughout the region These provide an avenue to study then geometry and morphology both in dip section and plan The present study revolves around the geometry and morphology of normal faults exposed in late Cretaceous Bhuj FormatiOn constituting an itercalating sequence of sandtones and shales

The observed morphology of faulting is quite varied, the most interesting being oversteps and bends Both the extensional as well as the contractional offsets of the faults have been observed and are analysed in detail Several morphologic attributes recorded, include the pull-apart structures, fault refraction in the dip section, segmented fault scarps and conjugate faults This note in general is aimed at documenting a variety of normal fault geometry occuring 10 Central Kachchh Mainland and thereby focus on the fact that the zones of oversteps and bends are vulnerable to renewed faulting activity and may serve as potential sites for the earthquake foci in the future

Looking at the extent and type of deformatiOn, it is envisaged that there must be several zones of oversteps and bends existing in Central Kachchh Mainland A careful and proper documentation of such weak zones may go a long way to help proper urban planning and to evaluate perceptible seismic hazard in the area.

Keywords

Morphology, Normal faults, Central Kachchh Mainland, Gujarat.

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R. V. Karanth ¹, Parag S. Sohoni ¹, George Mathew ¹, Anirudhha S. Khadkikar ¹

Affiliations
1 Department of Geology, M. S. University of Baroda, Vadodara - 390 002, IN

Abstract

The entire Gujarat State in general and Kachchh region in particular experienced one of the most devastating earthquakes in the Indian shield on 26^th January 2001. This earthquake has caused significant damage to life and property and is one of the most important seismic events that can serve as a modern analogue for studying ground deformation caused on account of large magnitude earthquake in the stratigraphic record. Mainly four different kinds of ground deformation have been observed in Kachchh: (a) large scale ground fissuring, (b) lateral spreads/Faulting, (c) rock falls and slumping and (d) liquefaction and fluidization. Intense ground deformation is seen in the domain of Kachchh Mainland Fault (KMF). Most of the intense liquefaction and ground-Rupture sites fall along the extent of KMF which indicates that a part of Kachchh Mainland Fault has been activated between Kunaria in the west to Adhoi in the east during this earthquake.

Keywords

Earthquakes, Seismicity, Kachchh Mainland Fault, Bhuj, Gujarat.

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Parag S. Sohoni ¹

Affiliations
1 Department of Geology, Faculty of Science, M. S. University of Baroda, Vadodara - 390 002, IN

Abstract

No Abstract.

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