Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

D. K. Bhatt ¹, Ravindra Kumar ¹

Affiliations
1 Geological Survey of India, Jaipur 302 004, IN

Abstract

The data contained in this paper pertain to the record of microfauna that indicates the presence of sediments of Miocene-Quaternary age in western Rajasthan. The recovered microfauna consist mainly of foraminifera and ostracoda. The dwarf nature of microfauna indicates stressed palaeoenvironment.

Keywords

Forminifera, Ostracoda, Neogene-Quaternary, Rajasthan.

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Ravindra Kumar ¹, A. N. Shah ¹, D. K. Bingham ¹

Affiliations
1 Department of Geology, Tribhuvan University, Kathmandu, NP

Abstract

An angular unconformity between fossiliferous Early-Middle Palaeozoic and Precambrian rocks, yet not known in the Himalaya, has been discovered in Central Nepal. The underlying Precambrian rocks show at least one additional distinct foliation and lineation than the overlying Early-Middle Palaeozoic rocks. This deformation is attributed to a Precambrian tectonic phase.

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V. Sharma ¹, Ravindra Kumar ¹

Affiliations
1 Department of Geology, University of Delhi, IN

Abstract

A sequence of clayey to sandy limestone exposed on the eastern coast of Interview Island, Bay of Bengal is studied for foraminiferal content. Twenty-seven species of planktonic foraminifera are reported. The species assemblage consisting of Globorotalia plesiotumida, Globigerinoides extremus, Neogloboquadrina acostaensis and Globorotalia (Tenuitella) anfracta suggests a Late Miocene age for the limestone unit. The assemblage is referable to Zone 17 of Blow (1969) and Zone 17A of Srinivasan and Kennett (1983) and represents the Neillian Stage (Srinivasan, 1978).

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Ravindra Kumar ¹

Affiliations
1 CAS in Geology Panjab University Chandigarh-160014, IN

Abstract

No Abstract.

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Ravindra Kumar ¹, G. S. Gill ¹, L. N. Gupta ¹

Affiliations
1 Centre of Advanced Study in Geology, Panjab University, Chandigarh - 160 014, IN

Abstract

Soft sediment deformational structures have been observed in three sections of the basal Pinjor Formation exposed in the frontal Himalayan foothills in northern Haryana. The Nadah Choe section (A) shows contortion, Thinning-Thickening and faulting within 5 m thick sequence of sandstone, sandy shale and calcareous siltstone. The section (B) in a stream in the southwest of Nadah shows autoclasts, contortions around clay ball and faulting about 2 m thick Fluvio-Lacustrine sequence. The third section © is exposed in the Ghaggar river shows diapiric, Flame-Like intrusion of mud into the overlying beds of siltstone. The three sections are about 1.5 km strike length of gently dipping beds of basal Pinjor Formation. These structures were formed by liquefaction attending shear stress and can be related to major seismic events in this region during the deposition of the basal Pinjor Formation.

Keywords

Earthquakes, Pinjor Formation, Nadah, Haryana.

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D. K. Bhatt , Ravindra Kumar , P. K. Kathal ¹

Affiliations
1 Centre of Advanced Study in Geology, Dr. H.S. Gour University, Sagar - 470 003, IN

Abstract

No Abstract.

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K. S. Raghav ¹, D. K. Bhat , Ravindra Kumar

Affiliations
1 228, Shree ji Nagar, Durgapura, Jaipur - 302 018, IN

Abstract

No Abstract.

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Tejpal Singh ¹, Umakant Sharma ², A. K. Awasthi ³, N. S. Virdi ⁴, Ravindra Kumar ²

Affiliations
1 CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore - 560 037, IN
2 Department of Geology, Panjab University, Chandigarh - 160 014, IN
3 Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee - 247 667, IN
4 Wadia Institute of Himalayan Geology, Dehradun – 248 001, IN

Abstract

Neotectonism in the Sub-Himalayan belt is not new. Moreover, the word 'Sub-Himalaya' is almost synonymous with 'neotectonic activity'. In the present paper, we report some of the most convincing geomorphic and structural evidences of neotectonic activity from the Sub-Himalayan belt in the Nahan Salient. The geomorphic evidences mainly include the four geomorphic surfaces identified from the transverse topographic profiles drawn parallel to the Himalayan front. These surfaces are commonly covered with terrace deposits that are tilted as well as faulted at a number of places. A number of faults, directly observable in the field, are normal in nature and they are oriented at high angles to the Himalayan Frontal Thrust (HFT). These faults are similar to the E-W extension in southern Tibet in response to the oblique convergence of India at ∼N20°E in the NW Himalaya. They are attributable to the kinematics of neotectonic compression along the HFT, the frontal ramp-oblique ramp-frontal ramp geometry of the thrust fault and related adjustments.

Keywords

Geomorphology, Neotectonics, Nahan Salient, Sub-Himalaya.

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