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

Vivek S. Kale ¹, Sushma Nair ¹, Shilpa Patil ¹

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

Abstract

Detailed measurements of a more than 55 m wide tract of the Chikshellikeri Limestone, immediately underlying the Muchkundi Quartzite were undertaken in the Kaladgi Basin. This sequence is constituted of 3218 measured laminations from more than 1550 mudstone - packstone couplet. They are interrupted by 57 horizons of Intraformational Limestone Breccias. The distribution pattern of these horizons within the sequence is evaluated within the framework of the depositional environments which yielded the limestone sequence and they are recognised as products of events of penecontemporaneous basin-floor instability. It is shown that disconformity separating the Bagalkot Group into two Subgroups (earlier attributed to two separate transgresive events) was formed as a result of reorganisation of the basin configuration in response to synsedimentary tectonics and not as a result of a second transgression of the contemporary sea.

Keywords

Sedimentology, Kaladgi Basin, Disconformity, Meso- Neoproterozoic, Basin Evolution, 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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