A storm event during the Maastrichtian in the Cauvery basin, South India

Mu Ramkumar

doi:10.2298/gabp0667035r

Abstract

Sedimentary structures in the Kallankurichchi Formation of the Ariyalur Group, South India have been examined with a view of assessing the depositional setting of these rocks. Of the different sedimentary structures such as cross bedding, cut and fill, etc., hummocky cross stratification is significant as it resulted from a major storm event. This paper deals with the recognized sedimentary structures, their genesis and environmental implications.

Highlights

Sedimentary structures play a vital role in the interpretation of depositional conditions and an attempt was made to understand the depositional environment of the Kallankurichchi Formation of the Ariyalur Group, Tamil Nadu based on its sedimentary structures
Based on the faunal composition, Maastrichtian age has been assigned by SASTRY et al (1972) and later refined to Lower Maastrichtian by RAMAMOORTHY (1991) & RADULOVI] and RAMAMOORTHY (1992)
Hummocky cross stratification is commonly associated with storm deposits (“Tempstites” of AGER, 1973; KREISA & BAMBACH, 1982; LOOPE & WATKINS, 1989; MENG et al, 1997)

Summary

Introduction

Sedimentary structures play a vital role in the interpretation of depositional conditions and an attempt was made to understand the depositional environment of the Kallankurichchi Formation of the Ariyalur Group, Tamil Nadu based on its sedimentary structures. The maximum thickness of the cross bedded unit is of the order of 1.8 meters. The cross bedding structure is found in a limited region within finely fragmented limestone and can be seen in the southwest wall of mine pit I of the Tancem mine (located west of Kallankurichchi Village and north of the Ariyalur–Kallankurichchi road – Fig. 1).

Results

Conclusion