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Plug-shaped ichnofossils Conichnus conicus, Conostichus broadheadi and C. stouti are found in the intercalated micritic sandstone and sandy allochemic limestone shale sequence of Bagh Group, Narmada district, Gujarat. These ichnospecies occur at two stratigraphic levels and shows distinct morphological features interpreted as resting/dwelling structures of sea anemone. The occurrence of these ichnospecies along with oyster fossils genera like Bosostrea and Indostrea indicate shallow marine environment.

Chorar Island exposes ∼109 m thick middle Jurassic (Bathonian-Callovian) succession in the eastern most part of the Kachchh Basin, Patan District, Gujarat and is divided into two, Khadir and Gadhada formations. It mainly comprises of mixed siliciclastic-carbonate sediments and limestones; the shales dominate the lower part of the succession while the top of the succession is marked by ferruginous sandstone which also forms the vast, prominent peripheral zone of the Chorar dome. The field and laboratory analysis of the succession reveals nine lithofacies which includes ferruginous sandstone, cross bedded white sandstone, micritic sandstone, allochemic sandstone, sandy micrite, mudstone, sandy allochemic limestone, coralline limestone and shale. The mix siliciclastic-carbonate sediments and ferruginous facies are fossiliferous in nature and display sedimentary structures, like ripple marks, cross- and planar-lamination with biogenic sedimentary structures. Coralline limestone facies comprise of large size (>1m diameter) corals, which are diagenetically modified severely and have lost its original internal structures. The sediment characteristics and associated bioclasts indicates low to moderate wave and current energy in shoreface-offshore subsequently changing to wave dominated shoreface during the deposition of the middle Jurassic sediments of the Chorar Island.

The evolution of the Narmada, Saurashtra, and Kachchh basins in the western margin of the Indian Craton is associated with the Middle Jurassic segmentation of Gondwana. The Narmada Basin was evolved during the Early Cretaceous and preserved a thick clastic and non-clastic sequence of the Bagh Group. The succession lies unconformably on the Precambrian rocks, and a complete sequence is exposed in the Western Lower Narmada Valley (WLNV). Until now, it has been described using various informal lithostratigraphic units emphasizing local lithic characters, which have no relevance with the stratotypes and do not fit into the concept of the International Subcommission on Stratigraphic Classification (ISSC). In the present study, the Bagh Group succession is mapped across the Lower Narmada Valley (LNV) and correlated between sections. The units in WLNV were revised and redefined assigning the stratotypes as per the ISSC. The amended lithostratigraphy of the Bagh Group comprises five formations, viz. Songir, Vajepur, Bilthana, Nodular Limestone, and Uchad. The Uchad Formation is a newly recognized youngest unit and is subdivided into the Narmada sandstone and the Men Nadi Limestone members. The lithological and palaeontological evidences indicate that the Bagh Group succession of the WLNV developed in a fluvio-marine environment during the Berriasian? (Neocomian) to Coniacian age. The Cretaceous succession of the WLNV is also compared with the pervasive Tethyan basins, including the Eastern Desert (Egypt), Saurashtra-Kachchh (India), Mahajanga (Madagascar), and Carnarvon (Australia). The Albian-Coniacian lithostratigraphy of the Narmada Basin is comparable to the Eastern Desert, although located at different palaeolatitudes, which suggest similar eustatic and tectonic conditions. It also shows a similar sedimentation pattern compared with the adjoining Saurashtra Basin during the Cenomanian-Coniacian. However, it differs from the Kachchh, Mahajanga, and Carnarvon basins, which can be attributed to different palaeolatitudes, as well as the development of rift-related events. The deposition of the Bagh Group in WLNV terminated with the separation of the Indian Plate from Madagascar and the outpouring of flood basalts during the Coniacian.

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