Stromatolites of the Kaladgi Basin, Karnataka, India: Systematics, biostratigraphy and age implications

Abstract

Systematics of the stromatolites of the Proterozoic Kaladgi Basin is attempted. The main purpose is to document the diversity and distribution of the various stromatolite forms occurring in the Bagalkot Group of the Kaladgi Supergroup. An assemblage of six taxa is recognized from the Bagalkot Group. The forms Asperia digitata (=Yelma digitata), Ephyaltes edingunnensis, Eucapsiphora leakensis, Kussoidella karalundiensis, Pilbaria deverella and Yandilla meekatharrensis are described. These forms are not recorded from any other Proterozoic Sequence of India of the Palaeoproterozoic age. Similar forms are recorded from Africa, Australia, Canada and China. Asperia digitata, a digitate stromatolite, is known from the Proterozoic Sequence of the Palaeoproterozoic age in other parts of the world. Poorly constrained age of the Bagalkot Group of the Kaladgi Supergroup can be ascertained on the basis of the reported assemblage as Late Palaeoproterozoic to Early Mesoproterozoic (Orosirian-Statherian to Calymmian Period).