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

Gauri Dole ¹, V. V. Peshwa ¹, Vivek S. Kale ¹

Affiliations
1 Department of Geology, University of Pune, Pune 411007, IN

Abstract

Palaeoseismic evidence is recorded for the first time from the upland region near the crest of the Deccan plateau. Some of the soft-sediment deformation structures from Quaternary sediments in the Chandanapuri valley are interpreted as seismites. These sediments rest nonconformably upon the Deccan Traps and are inherently anomalous vis-a-vis their location in the river valley. Based on various features and their position in the succession of the sediments, these seismites are provisionally attributed to a single event with an inferred magnitude > 6.5 M, which occurred 5000 - 7000 years ago. This report highlights the need to re-evaluate the traditional perception of the aseismic nature of the main Deccan plateau.

Keywords

Palaeoseismology, Deccan Plateau, Quaternary Sediments, Seismites.

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V. V. Peshwa , Vivek S. Kale

Abstract

No Abstract.

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Vivek S. Kale ¹, Vaishali Ghunakikar ¹, P. Paul Thomas ¹, V. V. Peshwa ¹

Affiliations
1 Department of Geology, University of Pune, Pune-411 007, IN

Abstract

The lowest sequence of the Lokapur Subgroup from the Bagalkot Group manifests the earliest transgression in the Meso-Neoproterozoic Kaladgi Basin. It is characterised by four sedimentary lithofacies namely, (i) sandstone facies (dominantly quartzose-arenites with minor interbedded conglomerates and gravel beds), (ii) argillite facies (including siltstones and shales), (iii) carbonate facies (primarily dolomites which are often cherty and stromatolitic) and, (iv) chertbreccia facies (poorly bedded and silicified).

These four macrofacies have been studied in the gently folded and faulted exposures along the southern margin of the Kaladgi Basin. An unfolded fence of their distribution and mutual dispositions is reconstructed so as to enable the visualization of their syndepositional architecture. Modifications of the existing classification of the examined sequence of the Lokapur Subgroup are suggested on the basis of this restoration and in context of process responsive lithostratigraphy.

The Kaladgi Basin is interpreted to have been initiated in an extensional tectonic regime. All the four recognised macrofacies were deposited more or less simultaneously during the earliest transgression in this basin and their architecture was governed by synsedimentary events of sagging of the uneven basin floor along an array of East-West trending growth faults with northern downthrows.

Keywords

Sedimentology, Meso-Neoproterozoic, Kaladgi Basin, Karnataka.

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Shilpa Patil Pillai ¹, V. V. Peshwa ¹, Sushma Nair ¹, Mukund Sharma ², Manoj Shukla ², Vivek S. Kale ¹

Affiliations
1 Department of Geology, University of Pune, Pune 411007, IN
2 Birbal Sahni Institute of Palaeobotany, Lucknow 226007, IN

Abstract

A manganiferous horizon was recorded near Niralkeri, in an intricately folded quartzite-chert breccia-mudstone sequence of the Simikeri Subgroup in the Kaladgi Basin of Karnataka. The nodules collected from this horizon show the presence of todorokite, vemadite and lithophorite in association with quartz and hematite; with MnO-58%.

Keywords

Economic Geology, Manganese, Proterozoic, Kaladgi Basin, Karnataka.

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