d) None of these
The scientists used luminescence dating method to understand when quartz grains in the river sands were buried. New Delhi: A “lost” river that ran through the central Thar desert, near Bikaner, about 1,72,000 years ago has been found by researchers. It may have been a life-line for humans inhabiting the region. Thar Desert, also called Great Indian Desert, arid region of rolling sand hills on the Indian subcontinent. It is located partly in Rajasthan state, northwestern India, and partly in Punjab and Sindh (Sind) provinces, eastern Pakistan.