Quartz grain surface micro textures of 12 samples collected from the beach were examined under scanning electron microscopy to understand the role of coastal processes on their transportation and deposition. The study area has been divided into three sectors on the basis of drainage, geomorphology and nature of the beach and shelf topography. Surface textures of the northern sector display an array of mechanical features like conchoidal fracture, V marks and impact pits, indicating the dominance of mechanical processes. However, silica precipitation in the form of globules indicates an added influence of chemical processes in the Northern sector. The presence of chemical features in northern sector, where energy level is high, corroborates the addition of quartz grains from paleo-sediments, from the nearby Tertiary and Cretaceous formations. Central sector quartz grains display the signatures of chemical and mechanical processes. The presence of step like furrows in southern sector is an indicator of fluvial low energy conditions, and supplements the role of littoral currents in depositing the quartz grains along the coastal region.

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Mangroves and associated plant species were surveyed in 56 estuaries from Pulicat Lake (13º 25' 955" N; 080º 19' 284" E) to Manakkudy Estuary (08º 05' 254" N; 077º 29' 049" E) along 1076 km of coastline in Tamil Nadu, during 2012-2014. The study area was divided into five groups: West coast of Tamil Nadu, Gulf of Mannar, Palk Bay, South and North Coromandel coasts. A total of 16 mangrove species, belonging to nine families and 11 genera, were recorded along with 23 mangrove associates belonging to 17 families and 21 genera. The mangrove species, Avicennia marina and associate species, Pongamia pinnata, Ipomoea pes-caprae and Calotropis gigantea were found to be prevalent along the North Coromandel coast. The mangrove species, Bruguiera gymnorrhiza was only recorded in the Ariyankuppam and Thengaithittu estuaries while Avicennia alba was only found in the Palayakayal Estuary in the Gulf of Mannar. Two mangrove associates Acrostrichum aureum and Fimbristylis ferruginea were reported in the Manakkudy estuary. The mangroves along the North Coromandel Coast were represented more number of mangrove species. Avicennia marina was the dominant species almost all collect sites. Few mangrove plants only available in some species of mangroves in particular study areas, further investigation about mangroves plnats diversity or continue monitoring is necessary. Field studies are wanted for unexplored minor estuaries and hence the present work was undertaken. The aim of the study to identify the more number of rare mangrove species by survey more number of collection sites.

Heavy mineral studies of the nearshore placer deposits of the Konkan Coast reveal a dominant assemblage comprised of garnet and kyanite along with other accessory minerals like epidote, olivine and rutile. The heavy mineral assemblage of the study region shows a characteristic suite of 17 types of heavy minerals. Their abundance shows hardly any drastic variation in the four bays studied. Overwhelming presence of minerals like garnet and kyanite in the studied four bays points to the source as metamorphic rocks. The presence of etched garnets, overgrown zircons and etched kyanites corroborate the recycling of paleo-sediments into the bay. Characterization of opaques under the microscope also corroborates the influence of a metamorphic source, rather than the adjoining basaltic rocks. However, the absence of metamorphic rocks in the hinterland suggests the possibility of deposition of sediments predominantly from offshore. Factor analysis results also corroborate the overwhelming influence of metamorphic rocks in the present study region rather than the abutting basalts.

Characterisation of opaques, comprising of ilmenites and magnetites, separated from the sediment samples off Konkan coast, has been attempted. On the basis of dominance of intergrowth of the exsolved or replaced phases, magnetites of Vijayudurg and Wada vetye are grouped together while the magnetites of Ambolgarh and Rajapur are showing similar characteristics. Ilmenites display intergrowths with hematite and rutile. In Ambolgarh and Rajapur, ilmenites of exsolved and replacement phases are abundant with alterations along the borders. On the basis of intergrown lamellae width, the source rock for the ilmenites is attributed to the distant metamorphic rocks The presence of altered ilmenites testify a higher percentage of TiO 2 in Ambolgarh and Rajapur. A higher amount of FeO (35.79 %-36.25 %) in Wada Vetye and Vijaydurg is ascribed to higher percentage of ilmenite-hematite phase in the exsolved ilmenites. REE pattern of ilmenites, magnetites and non-magnetics show an enrichment of LREE over HREE. Ilmenite, magnetite and non-magnetics show a negative Eu anomaly which is ascribed to the individual or combination of the following conditions: 1) Melt effect, 2) Crystallo-Chemical effect, and 3) Competing mineral effect. A higher enrichment of TiO 2 in the ilmenites reflects the possibility of establishing downstream industries as well as the suitability for converting ilmenites into synthetic rutile.