LUCKNOW, March 17 -- The hill area around the historic Kalinjar Fort in Banda district has been declared a National Geo-Heritage Site by the Geological Survey of India (GSI). The recognition highlights the region's rare geological formation known as the Eparchaean Unconformity, which records a long gap in Earth's geological history.

The site was inaugurated by Rajinder Kumar, additional director general and head of GSI's Northern Region, who said the rocks found in the Kalinjar area represent geological events that occurred billions of years apart.

According to the press release, the hill exposes nearly 2.5 billion year old Bundelkhand granite overlain by 1.2 billion year old Kaimur sandstone, making it an important record of Earth's ev...