Holocene paleoenvironmental changes in the marginal marine basin of Great Rann of Kachchh, western India: Insights from sedimentological and mineral magnetic studies on a ∼60 m long core

Holocene evolution of the Banni Plain at the north‐east margin of the Arabian Sea: Constraints from a ca 50 m long sediment core

“…The estuarine sediments show a high sedimentation rate (Figure 2), which conforms to the rapidly rising sea level (Figure 10). The central part of the GRK Basin further north also witnessed high sedimentation rates, but within a subtidal environment during this time (Kumar et al, 2021), which correlates well with data from the Berada core. This phase is recorded in the study area as estuarine conditions, which may have been established due to rising sea level choking off the fluvial sediments that had earlier flowed into the basin, before sea transgression stopped the flow of the river and established estuarine conditions (Chowksey et al, 2011;Maurya et al, 2013).…”

“…The occurrence of micro-fossils, complete and broken shell fragments at ca 39 m indicates deposition during marine flooding (Khonde, 2014). Abundant organic F I G U R E 1 0 Schematic correlation along line A-B (shown in Figure 1B) of depositional environments of Berada core (present study) and Dhordo core (Kumar et al, 2021). Note that the depositional environments inferred in the southern margin (Berada core) and in the central part (Dhordo core) of the GRK Basin complement each other.…”

“…The sedimentation rate in both cores during this phase is similar and ranges between 1.7 cm year −1 and 0.64 cm year −1 . The establishment of supra-tidal conditions, attributed to regressive conditions throughout the basin during the F I G U R E 9 Accumulation curves of Berada core (present study) and Dhordo core (Kumar et al, 2021) with inferred sedimentary units, and comparison with reconstructed sea-level curves and data from other regions during the Holocene. Sea-level data from other regions.…”

“…Accumulation curves based on age-depth plots of two cores, Berada core (this study) and Dhordo core (Kumar et al, 2021) are shown in Figure 9. The accumulation curve provides an inter and intra age-depth relationship indicating the rate and period at which the sedimentary environments (facies) such as fluvial, sub-tidal and intertidal occurred/co-occurred and passed through one core to another in an area.…”

“…Presently, the central and northern half of the GRK Basin comprise a vast supra‐tidal flat, while the southern half forming the Banni Plain is free of marine influence owing to its slightly higher elevation (Maurya et al, 2013; Padmalal et al, 2019). Kumar et al (2021) demonstrated that in the central, deeper part of the GRK Basin, to the north of the Banni Plain, shallow marine conditions prevailed throughout the Holocene. However, the Banni Plain, which is closer to the rocky uplands in the south, is expected to show transitional conditions.…”