ORIGINAL PAPER Diagenetic evolution vis-a-vis reservoir characteristics of Dhosa sandstones, Ler dome, Kachchh, western India Asma A. Ghaznavi 1 & Mohammad Masroor Alam 2 & Zuhi Khan 1 & A. H. M. Ahmad 1 Received: 11 August 2016 /Accepted: 11 July 2018 # Saudi Society for Geosciences 2018 Abstract The detrital mineralogy as well as diagenetic characters of the Dhosa Sandstone Member of Chari Formation exposed at the Lerdome, south of Bhuj was studied. In order to assess the potential of the Dhosa Sandstone as a reservoir, it is substantial to understand the diagenetic processes that are controlled largely by post-depositional cementation and compaction in addition to framework composition and original depositional textures. The petrologic analysis of 33 thin sections was carried out to discern primary composition and diagenetic features including primary and secondary porosity patterns. Monocrystalline quartz dom- inates the detrital mineralogy followed by polycrystalline quartz. Among the polycrystalline variety recrystallized metamorphic quartz surpasses stretched metamorphic quartz in terms of abundance. Feldspars comprise microcline and plagioclase where the former is dominant over the latter. Orthoclase too comprises a very small percentage. Mica, chert, rock fragments, and heavies form the remaining detrital constituent in descending order of their constituent percentage. The diagenetic precipitates are mainly carbonate (8.30%) and iron (7.80%) followed by clay (0.66%) and silica (0.88%) that are minor constituent of the total cementing material. The main paragenetic events identified are early cementation, mechanical compaction, late cementation, dissolution, and authigenesis of clays. The overall reservoir quality seems to be controlled by compaction and authigenic carbonate cemen- tation. The minus cement porosity average 29.4%. The porosity loss due to compaction is 21.92% and by cementation is 29.71%. The loss of original porosity was due to early cementation followed by moderate mechanical compaction during shallow burial. Preservation of available miniscule primary porosity was ascribed to dissolution of carbonates and quartz overgrowth which resisted chemical compaction during deep burial. The studied sandstones may have low reservoir quality owing to existing porosity of less than 9%. More carbonate dissolution and its transformation in dolomite in sub-surface condition and macro- fracture porosity may result in enhanced secondary porosity and good diagenetic traps. Keywords Diagenesis . Porosity . Mechanical compaction . Cementation . Clays . Reservoir Introduction The Kachchh basin holds a unique stature in India for its geological diversity. The multiplicity of geologic facets is ev- ident in the wide range of sedimentary facies and diverse fossil biota. The pericratonic basin had a long history of sedimenta- tion during Mesozoic and Cenozoic times. The Directorate General of Hydrocarbons, Government of India (GOI) recog- nizes the basin as a category II type, i.e., with known accumu- lation of hydrocarbons (Directorate General of Hydrocarbons (DGH) 2012). The study of siliciclastic sedimentary rocks is an important component in revealing the tectonic evolution of ba- sin and provenance which can be linked to source-reservoir-cap rock trinity and its spatial evolution (Singh and Singh 1994; Ahmad et al. 2017; Khan et al. 2018; Quasim et al. 2018). Diagenesis plays a key role not only in generating the hy- drocarbons but also in preserving them. The physicochemical and biochemical and physical processes occurring at low tem- perature and pressure at the surface and near-surface environ- ment are very much controlled by depositional environment, rate of deposition, and basin subsidence. The migration of fluids, chemical potential of the system, and inherent fluids within the basin are key factors of diagenesis (Giles 1997). * Asma A. Ghaznavi ghaznavi.asma@gmail.com 1 Department of Geology, Aligarh Muslim University, Aligarh, UP 202002, India 2 Department of Civil Engineering, ZH College of Engineering and Technology, Aligarh Muslim University, Aligarh, UP 202002, India Arabian Journal of Geosciences (2018) 11:387 https://doi.org/10.1007/s12517-018-3731-z