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India’s biggest natural arch formed 184 million years ago discovered in Odisha by GSI

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Last Updated17/06/2023

A team of the Geological Survey of India recently discovered India’s biggest natural arch during their survey of coal in Kenduadihi block in Odisha’s Sundargarh district.

The state unit of the Geological Survey of India (GSI) has proposed to declare the ‘Natural Arch’ in the Kanika range of Sundargarh forest division, a Geo Heritage Site.
If it is done, it will be the biggest natural arch of the country to have the Geo Heritage tag.
Apart from the arch at Sundargarh, India has two others- one at Tirumala hills in Tirupati and another at Andaman and Nicobar. However, both of them are smaller compared to the one in Sundargarh.

The Sundargarh natural arch, present in the ferruginous sandstone of the Upper Kamthi formation, dates back to about 184 to 160 million years in the lower to middle Jurassic age.
It is an oval-shaped arch and has a length of 30 metres at the base and is 12 metres high.
The alcove of the natural arch has a maximum height and width of 7 metres and 15 metres, respectively.
The natural arch and its surrounding area are a storehouse of different primary sedimentary structures like planner and cross-bedding along with occasional current ripples signifying high energy fluvial environment during sedimentation.
Formation: Formation of the natural arch could be due to fault activities and the nature of lithotype, which have enhanced the process of sub-aerial weathering over a long period.

Geoheritage sites are sites of rare and unique geological, geo-morphological, mineralogical, petrological, and paleontological significance, including caves and natural rock sculptures of national and international interest.
GSI declares geo-heritage sites/ national geological monuments for protection and maintenance.
GSI or the respective State governments take necessary measures to protect these sites.