Granulometric and facies analysis of Middle–Upper Jurassic rocks of Ler Dome, Kachchh, western India: an attempt to reconstruct the depositional environment

Abstract

Grain size analysis is an important sedimentological tool used to unravel hydrodynamic conditions, mode of transportation and deposition of detrital sediments. For the present study, detailed grain size analysis was carried out in order to decipher the palaeodepositional environment of Middle–Upper Jurassic rocks of the Ler Dome (Kachchh, western India), which is further reinforced by facies analysis. Microtextures were identified as grooves, straight steps and V-shaped pits, curved steps and solution pits suggesting the predominance of chemical solution activity. Grain size statistical parameters (Graphic and Moment parameters) were used to document depositional processes, sedimentation mechanisms and conditions of hydrodynamic energy, as well as to discriminate between various depositional environments. The grain size parameters show that most of the sandstones are medium- to coarse-grained, moderately to well sorted, strongly fine skewed to fine skewed and mesokurtic to platykurtic in nature. The abundance of medium- to coarse-grained sandstones indicates fluctuating energy levels of the deposition medium and sediment type of the source area. The bivariate plots show that the samples are mostly grouped, except for some samples that show a scattered trend, which is either due to a mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function analysis is predominantly indicative of turbidity current deposits under shallow-marine conditions. The C-M plots indicate that the sediments formed mainly by rolling to bottom suspension and rolling condition in a beach subenvironment. Log probability curves show that the mixing between the suspension and saltation populations is related to variable energy conditions.

Role of cementation and compaction in controlling the reservoir quality of the Middle to Late Jurassic Sandstones, Jara dome, Kachchh Basin, western India

“…Several workers (Ahmad & Bhat, 2006; Ahmad, Noufal, Alam, & Tavheed, 2014; Chaudhuri, Banerjee, & Chauhan, 2020; Chaudhuri, Banerjee, & Le Pera, 2018; Ghaznavi, Ahmad, Alam, & Quasim, 2018; Ghaznavi, Khan, Quasim, & Ahmad, 2018; Ghaznavi, Quasim, Ahmad, & Ghosh, 2019; Khan, Ahmad, Alam, & Quasim, 2016; Khan, Quasim, Ahmad, & Alam, 2017; Srivastava & Singh, 2019; Srivastava, Singh, & Patra, 2018) have made significant contributions towards understanding of the regional geology, sedimentology, tectonic evolution, and tectono‐provenance of the Kachchh Basin. However, significant work regarding the diagenetic evolution and its effects on reservoir quality of Ridge and Athleta Sandstone members (Chari Formation) of the Jara dome, Kachchh Basin is still pending.…”

QFL and Litho Facies: Predicting Reservoir Quality of the Middle Miocene Deep-Water Facies at Kutei and North Makassar Basins

“…The detailed description of these litho facies characterized by upper medium-to lower coarse-grained sublitharenite sandstones that have cross-bedding structures, overall blocky to upwards fining succession, but relatively massive textures (non-laminated), moderately to well sorting, subangular to subrounded grains, none to traces porefilling cements/ overgrowth of quartz (<1.5%), carbonate (<10% siderite), and clay materials (<5% of kaolinite). Ghaznavi et al, 2019). The coarse-grained sediments suggest a range of moderate to high energy depositions (Boggs, 2009;in Ghaznavi et al, 2019), while the well-sorted and subrounded grains are devoid of matrix, also indicating a high-energy beach subenvironment (Ghaznavi et al, 2019).…”

Depositional mechanism of Fort Member Sandstone (Early-Late Bathonian), Jaisalmer Formation, Western Rajasthan: insights from granulometric analysis

“…To demarcate different depositional environments, the combination of several textural parameters in the form of bivariant plots has been used (Friedman, 1979). The basis behind these plots is the assumption that statistical parameters reliably reflect variations in the fluid flow mechanism of sediment transportation and deposition (Sutherland & Lee, 1994).…”