Characteristic landforms and geomorphic features associated with impact structures: Observations at the Dhala structure, north‐central India

Geomorphological study of some of the just more than 200 known terrestrial impact structures has demonstrated that despite extensive degradation, important geomorphological keys, such as drainage pattern, topographic signatures, erosional landforms, and depositional features, can still be assessed. They can provide possible indicators to assist in the recognition of further impact structures, especially on Precambrian shields and cratonic landmasses. This study documents the surface features and landforms of the Paleoproterozoic, about 11 km diameter Dhala impact structure in India. The Dhala structure has an estimated age that is constrained stratigraphically between 1.7 and 2.5 Ga. This structure is deeply eroded, and barely has a morphological resemblance to other known terrestrial or extraterrestrial impact structures. We have analyzed the operative surface‐forming processes for the Dhala area. We demand to continue the in‐depth study of all terrestrial impact structures, especially the pre‐Paleozoic ones, so that geomorphological criteria can be rigorously constrained and applied in conjunction with a priori remote sensing and field data to support the identification of new structures prior to their ultimate confirmation using diagnostic evidence of shock metamorphism. Evolution of various geomorphological features within and around the Dhala structure shows the combined effect of impact cratering followed by alluvial, eolian and glacial activities since its formation. However, the structure retains some characteristic morphological similarities to other confirmed terrestrial and extra‐terrestrial impact craters despite extensive degradation. Therefore, important geomorphological keys based on topographic signatures, erosional landforms, depositional features and drainage pattern can be developed as possible indicators to locate hitherto unknown impact structures, especially in Precambrian shields and cratonic landmasses.