MAGNETOSTRATIGRAPHY AND GEOCHRONOLOGY OF THE VINDHYANCHAL BASIN, INDIA

Paleomagnetic and geochronologic research on the Indian subcontinent provides an important window into the problem of Rodinia assembly and breakup, as well as adding insight into the subsequent assembly of East Gondwana. The Vindhyanchal basin, located in the central peninsular region of India, provides an excellent area to conduct the paleomagnetic and geochronologic studies of Meso- to Neoproterozoic rock formed contemporaneously with these supercontinent events. High-resolution paleomagnetic data is provided for the basin from dense sampling of both the Upper Vindhyan and Lower Vindhyan systems of Rajasthan and Madhya Pradesh. Selected units of the Lower Vindhyan have been studied, seeking to utilize magnetic directions as a tool in correlating units across the separated sections in Rajasthan and the Son Valley. Special attention has been paid to the Bhander and Rewa red-bed and limestone units of the Upper Vindhyan in an effort to better constrain both their directions and their age. Previous work has been conducted on these units, but were lacking in density and age control. Previous age control is poorly constrained, ranging from 1073.5 +/- 13.7 Ma for the Majhgawan kimberlite (Intruding into the Kaimur sandstone, age from this study) to ~650 Ma minimum age, based on Strontium isotopes from the Bhander limestone. Ash beds within the Rewa group aid in further constraining the age of the Upper Vindhyan. We will present the resulting paleomagnetic data and ages from this project.