The Unique Geoheritage of the Kachchh (Kutch) Basin, Western India, and its Conservation

Abstract

The Kachchh Basin is a peri-cratonic rift basin in the Gujarat state of Western India which exposes a vast range of geological features which are of great importance for basic and applied research by geoscientists. The fossil-rich stratigraphy of the Kachchh Basin represents the past 200 million years of geological history from the Jurassic Period to the present day, including through the Neogene Period. Both Mesozoic and Cenozoic sequences are highly fossiliferous with a variety of mega, macro, and micro-fossils, including invertebrate, plant, trace, and vertebrate fossils. Crucially, the Kachchh Rift Basin demonstrates a uniquely well exposed, syn to post-rift tectono-sedimentary sequence formed from the Late Triassic to the Early Cretaceous during the break up of Eastern Gondwanaland. The basin is bounded by reactivated primary faults forming tilted horsts and half-grabens. Tilted-up edges of the uplifted fault blocks are represented by uplifted hilly ranges, whereas the intervening subsiding blocks are the geomorphological expression of the low-lying Rann and Banni plains (mudflats, marshes, and grassland). This activity was followed by an inversion cycle initiated in Late Early Cretaceous following the aborting of the rift and is active in the present neotectonic cycle. Thick Deccan Trap lava flows and basic intrusive bodies indicate associated deeper crustal and mantle processes associated with this rift basin evolution. Easily accessed, well-exposed continuous sedimentary sequences with scanty vegetation provide a unique window of opportunity to looking into the geological past of this unique landscape which has preserved the evidence of the evolution of life both in near shore, coastal, and terrestrial environment, as well as a rare opportunity to understand a history of syn/post-rift-fill sedimentation, volcanism, and tectono-geomorphical evolution. More recently the terrain has become a hotspot amongst the planetary scientists as it provides a terrestrial analogue for Lunar and Martian landscapes. These and many other features justify why the unique geological heritage of the Kachchh Basin should be conserved for posterity not only for geoscientists from all over the world but also for local communities and visitors who could learn from its 200 million year history. We therefore propose that the landscapes of the Kachchh Basin should be conserved as a National Geopark in India to achieve such ambitions, and we believe that in this, they have an immense potential to achieve many of the UN’s Sustainable Development Goals. It is proposed to create 9 geo-stations (for administration) and 75 geosites grouped under these stations within the proposed Kachchh Geopark.