The Ramgarh Terrestrial Impact Structure in Rajasthan State: a ‘Geoheritage Site and Geopark’ Candidate from North-Central India

Manoj K. Pandit & Sharad Master

Geoheritage, Volume 13, Article number: 81 (2021)

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“A nearly complete, 3.5–4 km diameter, circular topographic high structure occurs as a solitary geomorphic high landform at Ramgarh village in Rajasthan State in north-central India, amidst vast agricultural plains. Known as the Ramgarh (impact) structure, this landform was first noticed in 1869. Although the possibility of its meteorite impact origin was mentioned as early as 1972, it was described as a tectonic “dome structure,” in the absence of any clinching evidence. Geological and geophysical investigations carried out during the last decades have pointed out features typical of a terrestrial meteorite impact, such as a well-preserved circular shape with an uplifted central depression, steep inner slopes of the ridge compared to outer slopes, intense brecciation, fracturing, and faulting, and most important, identification of planar deformation features in quartz, diagnostic of shock metamorphism. Therefore, the structure has recently been recognized as a confirmed “meteorite impact structure” from India and listed in the global database on impact structures. The central depression of the structure is also the site for a tenth century Khajuraho-style temple complex. Besides, there are two cave temples on the inner slope of the eastern rim of the structure, a cultural cum pilgrimage center. The ruins of a fort at the southern outer slope of the structure represent yet another object of archeological/historic interest. The two water bodies in the central depression, filled with the rainwater drained from the surrounding slopes, are the abode for several species of migratory birds. Thus, the “impact structure” provides scientific, archeological, historical, cultural, and biodiversity features of common interest in a unified geographic domain, making an appropriate case for consideration and accreditation as “geopark.” Although the structure is listed amongst 34 geoheritage sites/geological monuments by the Geological Survey of India, the efforts have not been translated into any action on the ground in terms of developing it as a geopark. In this contribution, we provide geological and geomorphological characteristics of this structure, and in conjunction with the other wide-ranging aspects, propose recognition of this well-preserved “meteorite impact structure” as a “geoheritage site/geopark.””