The Lonar Crater: The Best Preserved Impact Crater in the Basaltic Terrain

Abstract

The Lonar Crater, created by an impact of a bolide or a meteor about 570 thousand years ago in central part of the Deccan Volcanic Province, is one of the very few hypervelocity impact craters in the world carved out from the basaltic target rocks and the only crater in lava flow sequence of a Continental Flood Basalt Province. With its average diameter of 1.8 km, the crater is a simple, bowl-shaped and remarkably circular depression within a flat country dotted with sporadic conical hills. It has nearly 150 m depth and a rim that is raised nearly 20 m above the surrounding country. The evidence of it being of the impact origin is available in the form of its relatively unaltered morphology, identification of the subsurface breccias beneath the sediments in the crater, presence of shocked minerals, glasses and ejected melt breccias. Although the crater is located on the drainage divide of two moderatesized rivers, namely Purna and Penganga; there is no evidence to suggest that the impact has resulted in the disruption, truncation or reorganization of the drainage network locally or regionally.

Numerical simulation of meteorite impact on basaltic lavas at Lonar Crater, India

“…Being a well preserved impact crater on Earth entirely formed in basalt, the Lonar Crater is a proxy to study similar craters on terrestrial planets and planetoids, and of interest to existing and upcoming missions like 'Chandrayaan'. The geology of the crater and the ejecta blanket has been well studied [3,[17][18][19]along with products of shock metamorphism like impact glasses within the suevite breccia [20][21][22]. The discovery of maskelynite in the moderately shocked basalt and glassy objects in the ejecta clasts of the Lonar crater [23] was an important criterion for establishing the meteoritic impact origin of this crater.…”