A DETRITAL ZIRCON TRANSECT ACROSS THE SON VALLEY SECTOR OF THE VINDHYAN BASIN, INDIA: FURTHER CONSTRAINTS ON BASIN EVOLUTION

The Vindhyan Supergroup is one of the largest and thickest Precambrian sedimentary successions of the world, located in central peninsular India, that outcrops over an area of over 104,000 km². The Vindhyan is the largest of the so-called “Purana” basins in India. Sedimentary units in the Vindhyan Basin can be subdivided into four groups: The Semri Group(Lower Vindhyan) and the Kaimur, Rewa and Bhander Groups (Upper Vindhyan). Lower Vindhyan Semri Group ages are generally well constrained, while the ages of the Upper Vindhyan are controversial. Malone et al. (2008) and Gregory et al. (2006) argued for an early Neoproterozoic closure (~1050 Ma) of Upper Vindhyan sedimentation whereas Azmi et al. (2009) argue for an Ediacaran-Cambrian age. Malone et al. (2008) cited evidence from detrital zircon spectra in the Rajasthan sector and the Marwar Supergroup along with paleomagnetic data from the Majhgawan kimberlite and Vindhyan strata. The older closure age is also in agreement with new ages from the nearby Chhattisgarh basin (Patranabis-Deb et al., 2007, Bickford et al., 2009).

In an effort to further constrain the age of the Upper Vindhyan strata, we sampled a transect across the Son Valley sector from different levels within the Upper Vindhyan along with additional samples from the Marwar Supergroup in Rajasthan. We will report our preliminary results from this study.