Ramgarh crater. 3.5 kilometres (2.2 mi) in diameter, is a potential meteor crater in Kota plateau of Vindhya range located near Ramgarh village, Mangrol tehsil of Baran district in Rajasthan state of India. If confirmed, its diameter size would be between the two confirmed Indian craters, 14 kilometres (8.7 mi) Dhala and 1.8 kilometres (1.1 mi) Lonar. As of January 2017, it is being considered by geological Survey of India for listing as a national geological monument. Glass resembling rock samples were collected and investigated. These spherules contain very high percentage of iron, along with very high ratios of nickel and cobalt. This high ratios suggests a meteorite strike or extraterrestrial rocks.
The crater is yet to be fully investigated in a systematic way. It was first visited in 1869 by Mallet of Geological Survey of India. Later studies include by those of Coulson (1927–28), Sharma and Singh and Jaganathan and Rao (1969–70), Crowford (1972), Rakshit (1973), Ramaswamy (1981), Vimal Kumar Reddy(1984) etc.
Appearance and present status
The crater is visible from a distance of 40 to 50 km, as it is located on a circular hill of about 400 mts high. The structure has a diameter of 3.2 km and forms a part of drainage of small river named Parvathi river. It was called in different names like Ramgarh structure, Ramgarh Dome, Ramgarh astrobleme etc. A rootless mass of sheared sandstone found near Bandewara temple in the crater indicates a fall back material.
Located on a 240m MSL high plateau, the 3.2 kilometres (2.0 mi) diameter Ramgarh ring crater rise further 150 to 200 m above the surrounding plateau. Located in Vindhya Range it is part of 'Bhander Group of Vindhyan Supergroup it has a raised rim and a circular depression in its centre forming a plain with average elevation of 260 m above MSL. Ramgarh rivulet flows from the south-west chasm of the crater and it becomes a tributary of Parvati river 4 km in the west. There are several other gullies (deeper channel and ditches cut into rocks and soil by the erosive action of fast flowing forceful water) and rills (shallow channel cut into soil by the erosive action of flowing water) with formed with radial (flowing out of crater) and centripetal (flowing in to crater) drainage.
- GSI. "The curious ring structure of Ramgarh in Vindhyas of Rajastan". Geological Survey of India. Geological Survey of India. Retrieved 27 July 2015.
- Misra, S; G. Lashkari; D. Panda; A. Dube; M. S. Sisodia; H. E. Newsom; D. Sengupta (2008). "Geochemical Evidence for the Meteorite Impact Origin of Ramgarh Structure, India" (PDF). Lunar and Planetary Science XXXIX. Houston, Texas: Lunar and Planetary Institute. Retrieved 2009-08-25.
- Misra, S; A. Dube; P. K. Srivastava; H. E. Newsow (2008). "Time of Formation of Ramgarh Crater, India – Constraints from Geological Structures" (PDF). Lunar and Planetary Science XXXIX. Houston, Texas: Lunar and Planetary Institute. Retrieved 2009-08-25.
- Sisodia, M.S; G. Lashkari; N.Bhandari (2006). "Impact Origin Of the Ramgarh Structure, Rajasthan : Some New Evidences". Journal of the Geological Society of India vol 67 pp 423–431. Retrieved 2011-07-06.
- Aabshar H Quazi, "Ramgarh crater likely to get national geological monument tag.", Hindustan Times, 5 January 2017.