Articles written in Journal of Earth System Science
Volume 115 Issue 4 August 2006 pp 395-402
Geomorphic expression of land-sea interaction is preserved in the form of abandoned cliffs, marine terraces, shore platforms and marine notches along the southern Saurashtra coast. These features have been used to ascertain the magnitude of sea level changes during late Quaternary. Notch morphology and associated biological encrustation have been used to estimate the magnitude and duration of palaeo-sea strands. Marine notches and other erosive features occurring between 12 and 15 m above the present Biological Mean Sea Level (BMSL) are attributed to the last interglacial corresponding to the Marine Isotopic Stage 5 (MIS-5). However, 6 to 9 m upliftment of the coastal fringe is attributed to this sea level. The second major high sea strand was identified during the mid-Holocene when the sea rose 2 m above the present level. Notches corresponding to this high sea level are recorded 4 to 5 m above the present BMSL.
Volume 117 Issue 1 February 2008 pp 33-40
The coastline constitutes a very sensitive geomorphic domain constantly subjected to dynamic coastal processes. The study of its ever-changing physiography and stratigraphy provides a wealth of information on its history and evolution, in many cases at decadal and annual scales. The present study was carried out on the Modwa beach complex between Rawal Pir and Modwa, about 10 km east of Mandvi on the northern coast of the Gulf of Kachchh. The Modwa spit is a 7-km long WNW-ESE trending prograding amalgamated beach ridge complex that is about 0.5 km wide at its western end and 1.5 km wide at its eastern end. This Ground-Penetrating Radar (GPR) survey delineated a variety of the radar surfaces and radar facies which reflects not only large scale sedimentary architecture, but depositional facies of the beach ridge complex. These are bounding surfaces separating the radar facies outline beach ridge (br), washover (wo), coastal dune (cd) and swale (sw) depositional environments. The internal sedimentary structures like tangential, parallel, concave and convex upward stratifications could also be visualized from the GPR profiles. The architecture suggests the formation of this complex due to a combined process of eastward littoral drift of locally derived sediments and its onshore deposition by storms and eolian activities.
Volume 123 Issue 1 February 2014 pp 121-133
The present study is an attempt towards understanding the sediment routing system in the semi-arid margin of the Gulf of Kachchh, which is one of the largest macrotidal regimes in the northern Arabian Sea. Investigations based on heavy minerals, clay minerals, mineral magnetic properties and sediment geochemistry indicated that there are three major sources of sediments contributing to the Gulf of Kachchh basin: (1) Indus River, (2) Kachchh mainland coastal rivers and (3) the Saurashtra peninsular coastal rivers. The flanks of northern and southern coast of western Gulf of Kachchh show dominant signatures of Kachchh mainland/Saurashtra peninsular provenance. In contrast, the eastern Gulf of Kachchh coast bearing fine grained sediments shows dominant Indus River Provenance. Although ephemeral in nature, the small coastal rivers of Saurashtra and Kachchh contribute significant amount of sediments to the Gulf of Kachchh coastline because of their ‘dryland’ nature and thus they control the coarse grained sedimentation processes.