Southern Granulite Terrane (SGT) of India preserves extensive high-grade granulite facies rocks of Archaean and Proterozoic age. The SGT is divided into number of blocks by several suture/shear zone. Structural investigations on the basement gneisses and younger mafic/ultramafic dikes have been carried out within the Salem block which is part of Northern Granulite Block (NGB), north of the Cauvery Suture Zone (CSZ). The present work emphasizes various scale fold styles and other structural patterns of the area, which includes regionally metamorphosed high-grade rocks as basement for the multiple ultramafic intrusions to the north of Cauvery Suture Zone (CSZ) which highlights the finite strain geometry, complex deformation pattern and high-grade metamorphism. Structural map of the study area is prepared showing two generations of folding, namely F1 whose axial trend is NE-SW, subparallel with general trend of gneissic foliation and are tight isoclinal folds while F2 which are open folds with axial trend NW-SE.E-W structural cross section across the foliation planes, characterizes antiformal and synformal fold patterns of the basement due to varying dip directions which also reflects type-3 interference pattern of folding. Mesoscopic scale shear zones of dextral kinematics in response to E-W collision during Paleo-Meso Archean time, delta type porphyroclasts, S-C fabrics with the dextral movement of CSZ system, Riedel shear, thrust imbricates implying duplex structures, rotation of mafic boudins along shear zones are the most prominent ductile structural features of this area. Brittle structures like different sets of cross cutting joints and faults indicate younger deformation as well. Petrography of major lithologies has classified them into amphibolite gneiss, migmatite gneiss, charnockites, granulites and mylonites as basement rocks to the younger pyroxenite intrusions. Typical textures like, perthite, granulose, reaction rims, sieve textures and microstructures like S-C fabrics, kink bands, rotated porphyroclasts, etc are observed within the basement rocks. Coarse grained textures with fractured porphyroclasts of garnets indicating the water interactions and retrogradations within the granulite facies rocks. Reaction rims observed in charnockites and granulites are indicative of retrogression during shearing. The coarse grained cummulate nature of pyroxenites neither represent deformation nor metamorphism. Keywords: Southern Granulite Terrane, Salem, Structural Analysis, Mafic/Ultramafics, Dikes, Petrography

The ecology of lakes is largely dependent on rivers. However, because research has frequently concentrated on rivers and lakes independently, the interconnectivity between them is poorly defined. During the present study, hydrochemical investigation of surface water from the Vembanad Lake and its primary inflows, Periyar, Muvattupuzha, Manimala, Meenachil, Pamba and Achenkovil were carried out. This study describes the quality and suitability of lake and river water for consumption and irrigation purposes. It also aids in determining the influence of six rivers over the Vembanad lake water quality. Total 80 samples were collected during pre-monsoon and post monsoon seasons. Various physico-chemical parameters such as Temperature, Turbidity, Total Dissolved Solids (TDS), Conductivity, pH, Alkalinity, Total Hardness, Calcium, Magnesium, Sodium, Potassium, Chloride, Bicarbonate and Sulphate were analysed. The chemical classification using Piper trilinear diagram reveals that sodium is the predominant cation in both seasons. The Water Quality Index value of the Vembanad Lake is found to be higher in the pre-monsoon season compared to the postmonsoon. Sodium hazard (Sodium Adsorption Ratio- SAR), Residual Sodium Carbonates (RSC), Sodium Percentage (Na%), Magnesium Hazard (MH), Kelly's Ratio (KR) and Permeability Index (PI) are the parameters used to identify the irrigation water quality. Based on the irrigation water quality parameters it can be concluded that water from southern portion of the lake and six inflows are suitable for irrigation purpose. The U.S. Salinity diagram indicates that the northern portion of the lake occupies the high sodium hazard zone. The water quality of the southern portion of the Vembanad Lake is chiefly controlled by its primary freshwater in flows and the northern portion by the saline water from the Arabian Sea. Keywords: Hydrogeochemistry, Water Quality, Sodium Adsorption Ratio,Vembanad Lake Kerala

In the present work quantitative strain analysis of Nongbri and Laitsopliah conglomerates of the Mesoproterozoic Shillong basin of the Shillong plateau is carried out considering the stretched pebble as strain markers. Six different techniques for intrapebble, interpebble and bulk rock strain estimation are applied, results are compared systematically and all suggest broadly flattening type of deformation (0<k< 1) for Laitsopliah conglomerate pointing to S- tectonites and constrictional type (1<k <∞) of deformation for Nongbri conglomerate pointing to L-tectonites. Keywords: Strain, Conglomerate, Pebbles, Shillong Plateau

The present study aims to examine the significance of multivariate statistics in studying morphometric behaviour and its relationship in 13 sub- watersheds of Santanavardhani Watershed, Tamil Nadu. Geographic Information System (GIS) based drainage morphometric analysis has been carried out to decipher the geomorphic behaviour of watershed. Different parameters of Linear, Areal and Relief aspects are considered and quantify with the help of Survey of India (SOI) topographic maps and Shuttle Radar Topographic Mission (SRTM) based Digital Elevation Model (DEM) in GIS platform. Correlation Analysis is carried out for twelve morphometric parameters to measure the linear relationship between the variables using Pearson Product Moment Correlation (PPMC) method. Most of the variables show a strong correlation and represent similar geomorphic characteristics. The correlated data was further used to group the variables into different components using Factor Analysis (FA) and it gives 3 different components like Factor of steepness, Factor of magnitude and Factor of geometry. Hierarchical Clustering method (Ward's method) is implemented to group different sub-watersheds based on its geomorphic behaviour. Cluster-1 consists of sub-watersheds S1, S2, S13, S4, S11, S5, S9, S10 shows homogeneous nature and Cluster-2 and Cluster-3 comprises S6, S12, S3 and S7, S8, respectively show heterogeneity of the sub-watersheds. Keywords: Quantitative Drainage Morphometric Analysis, Correlation Analysis, Factor Analysis, Cluster Analysis, GIS

This paper focuses on a granulometric study conducted to investigate the sedimentary characteristics of channel sediments in the upper, middle, and lower reaches of the Kolar River Sub-basin. The study's primary objective is to gain a detailed understanding of sediment transport by seamlessly integrating field surveys and laboratory analyses. The study investigates grain size distribution and the deposition environment in the Kolar River Sub-basin. From sediment data, statistical measures were prepared and utilized to construct bivariate diagrams and examine the inter-relationship of various parameters. The results indicate that the upper reach exhibits poor sediment sorting, while the middle and lower reaches show more moderate sorting. Skewness values indicate dominance of coarser sediments in the upper reach, finer grain sizes in the middle reach, and a mixed distribution in the lower reach. Kurtosis values suggest concentrated distributions in specific areas of the upper and middle reaches, while the lower reach displays a broader distribution. The CM plot analysis reveals distinct sediment transport types in each reach, reflecting the energy level of water transport and sediment load. This study provides valuable insights into spatial variations in sediment dynamics, contributing to a comprehensive understanding of the overall sedimentary regime of the river. With this understanding, effective river basin management techniques, such as vegetative stabilization, check dam construction and prevention of excessive deposition can be implemented to ensure the sustainable management of the Kolar River Sub-basin. Keywords: Granulometry, Stream Sediments, Depositional Environment, Sustainable Management, Kolar River Sub-Basin, Central India

A thorough taxonomic study was carried out for the first time using high-resolution microscopy from Neogene sections of western Kachchh, India. In the present study, 25 species of benthic foraminifera belonging to 3 classes viz. Globothalamea, Tubothalamea, Nodosariata and 4 orders Rotaliida, Textulariida, Miliolida and Polytmorphinida have been identified from limestone and silty-claystone of Murachbann section belonging to lower Miocene. This taxonomic study provides the distribution of benthic foraminifera species from Murachbann section. The attempt is made to interpret depositional palaeoenvironment based on this distribution of the studied foraminifera. Keywords: Morphology, Taxonomy, Benthic Foraminifera, Limestone, Palaeoenvironment, Chhasra Formation

This paper presents the results of Eocene molluscan fauna and benthic foraminifera from the Upper Disang Formation of Indo-Myanmar Ranges (IMR) and discussed here the biostratigraphic zone and depositional environment. These fauna and foraminifera are composed of Bivalvia viz. Noetia magnifica, Pitar (Calpitaria) carteri, Corbula (Bicorbula) rakhiensis, Gastropoda viz. Turritella sp., Turbinella premekranica, Lyria samanaensis and foraminifera Nummulites sp. On the basis of molluscan fauna Noetia magnifica, the biostratigraphic zone (Zone-I) is established and assigned middle-late Eocene age to Upper Disang Formation of IMR, Nagaland. The presence of invertebrate fossils and benthic foraminifers indicate a warm tropical-subtropical climate and shallow marine (neritic) depositional environment during the sedimentation of the Upper Disang Formation. Keywords: IMR, Inner Paleogene Fold Belt, Molluscan Fauna, Nummulites, Phesama, Upper Disang Formation

The seabed is surely one of the last mining frontiers on earth remaining for mankind, to extract economic mineral deposits. It is hence imperative that India with its Obvious Geological Potential (OGP) area on the land surface amounting to 0.57 million km, for which baseline geoscience data has been generated and mineral exploration activities are ongoing, needs to be supplemented with mineral wealth on our sea beds, within our Territorial Waters (TW) and Exclusive Economic Zone (EEZ). Studies by the Geological Survey of India (GSI) and other agencies for mineralized horizons in the terrestrial OGP areas have been a continuous process. The baseline geoscience and mineral exploration data are published regularly by GSI and Indian Bureau of Mines (IBM) and made available to respective stakeholders. India has a 2.02 million km area under its TW and EEZ. Our East and West Coasts of the Peninsular India are endowed with phosphate, manganese nodules, lime mud and monazite sands with rare earth elements (REE) and thorium that have been surveyed by the Marine and Coastal Survey Division (MCSD) of the GSI with their research vessels to establish the potentiality. According to the data available, 1,53,996 million tons of lime mud within the EEZ off Gujarat and Maharashtra coasts, 745 million tons of construction grade sand, off Kerala coast, 79 million tons of heavy mineral placers in the inner-shelf and mid-shelf, off Odisha, Andhra Pradesh, Kerala, Tamil Nadu and Maharashtra, phosphorite in the Eastern and Western continental margins, polymetallic ferromanganese nodules and crusts in Andaman Sea and Lakshadweep Sea have been reported. The CSIR- National Institute of Oceanography has been embarking on research for seabed mineral deposits. The Offshore Areas Mineral (Development and Regulation) Amendment Bill, 2023, passed by Lok Sabha on 01.08.2023, has amendments to the Offshore Areas Mineral (Development and Regulation) Act, 2002, OAMDR Act (Ministry of Mines, Govt. of India, 2002). It envisages major initiatives to allow auction of mineral blocks 45° X 45° (latitude and longitude) in respect of any mineral or prescribed group of associated minerals, under one or more operating rights (taken together). The Act has a provision for setting up of a non-lapsable Offshore Areas Mineral Trust to maintain a fund under the Public Account of India. This fund will be financed by a yet to be determined, additional levy on the production of offshore minerals that will be used for exploration, research, disaster relief and for mitigation of adverse impacts of seabed mining. We have the National Exploration Trust and the District Mineral Foundation Trust funds, to which royalties are paid by stakeholders for onshore mining.

Petrographic and heavy mineral compositions of the Oligocene Barail sandstones exposed in and around Longsa village of Wokha District, Nagaland, have been utilized for provenance interpretation. Grey and yellow coloured sandstones of the study area are comprised of angular to sub-rounded monocrystalline, non-undulatory quartz and the various lithic fragments. The overall composition of sandstones (Q-90.10%, F-1.70 %, RF-8.18%) matches with those of sublith-arenites category. The heavy mineral assemblage of the studied Barail sandstones is represented by euhedral/rounded to sub-rounded grains of zircon, tourmaline, rutile, kyanite, sillimanite, andalusite, titanite, staurolite and iron oxide. The studied sandstone composition suggests that the Barail sediments were derived from mixed provenance. Heavy mineral analysis also corroborates the above. Keywords: Petrography, Heavy Minerals, Provenance, Barail Group, Nagaland

The study investigated the role of hydrogeochemical parameters that act as indicators of environmental pollution in industrial areas of Periyar River, Kerala India. A total of 20 water/sediment samples collected along the industrial stretch of Eloor-Vypin area during the premonsoon season of the year 2020. Among the hydrochemical parameters, extent of pollution was imparted by the assessment of nutrients and heavy metals concentration. The micro nutrients such as silicate (640-3440μg/L), ammonia (4.42-894.2μg/L), phosphate (28.65-132.41μg/L), nitrite (3.12-30.14μg/L), and nitrate (50.13-851.97μg/L) were found to have higher enrichment at locations near the industrial areas of the study. The identified heavy metals, Zn, Mn, Pb, Cr, Cd, and Th having concentrations ranging from 1.0-152.4, 1.2-49.2, 1.2-31.7, 3.0-26.2, 1.1-13.3, 0.1-3.2μg/L, respectively. Various pollution indices suggest that the sediments having low to moderate level heavy metal contamination. The conditions may be worsen in the future if the industrial activities are continued in an unregulated manner. Keywords: Industrial Pollution; Heavy Metals; WQI; Hydrochemical Studies; Contamination Factor