A cluster of lamproite dykes are located 1 km west of Vattikod village at the NW margin of the Cuddapah basin, Eastern Dharwar craton, southern India, during the pursuit for locating primary diamond source rocks by adapting multifarious applications. These exotic rocks are emplaced along WNW-ESE to NW-SE trending fractures in the granitic rocks belonging to the Peninsular Gneissic Complex. Ten out of twelve lamproites occur near Vattikod village and one each is located in the vicinity of Marepalli and Gundrapalli villages respectively. These lamproites, though highly altered, contain microphenocrysts of altered olivine, clinopyroxene, phlogopite, leucite and sanidine and translucent to opaque, amoeboid shaped patches of glass set in a groundmass rich in carbonate, phlogopite, serpentine, and chlorite. This new cluster of lamproites constitutes a part of the recently discovered Ramadugu lamproite field. The Vattikod and Ramadugu lamproites, together with those from Krishna lamproite field and the Cuddapah basin, constitute, a wide spectrum of ultrapotassic magmatism emplaced in and around the Palaeo-Mesoproterozoic Cuddapah basin in southern India.

The Permo-Carboniferous depositional sequence of Lower Gondwana in Sikkim Lesser Himalaya was investigated through an integrated approach of lithological, petrological, and geochemical studies. Lithologically, it is characterized by glacial diamictite at the base and shale-sandstone facies at the top of a sequence which is interpreted as a glaciomarine deposit. Coarser sandstone and massive diamictite composed of quartz, feldspar, muscovite, zircon, and other lithic fragments are observed in thin section. Geochemistry of all studied samples from the Rangit Pebble Slate Formation shows the dominance of silicon dioxide compared to other elemental oxides. The tectonic discrimination diagram positively infers passive margin sedimentation from a felsic-rich provenance. Chemical Index of Alteration was used to depict the weathering trends of all studied samples which reflect paleosedimentation under humid to sub-humid climatic conditions.

The Rangit Gondwana Basin of Sikkim in the lesser Himalaya witnessed a wide span of climate change during the Permo-Carboniferous period. The principal objective of the present study is to document this Permo-Carboniferous climate change in the form of a geochemical signature preserved in the siliciclastic facies of the Rangit Pebble Slate Formation. The stratigraphic sequences of the Rangit Gondwana Basin are categorically well defined and subdivided into upper and lower sequences on the basis of their depositional environment. The lower sequences of the Rangit Gondwana basin are comprised of massive diamictite with large stromatolitic dolomite boulders and dropstone embedded in the coarser sandstone which indicate the cold glaciomarine environment of deposition, whereas upper sequences consist of repeated alternate beds of sandstone, black shale and coal seam with a regular interval depicting the fluvial and deltaic environment of deposition. The enrichment of SiO2, Al2O3, TiO2, MnO, MgO, and K2O indicates that these sediments were mostly derived from felsic rock source areas. Chemical Index of Alteration (CIA) and Index of Compositional Variability (ICV) CaO + Na2O + K2O/Al2O3, and SiO2 vs. (Al2O3 + K2O + Na2O) values suggest that the sediments maturity and paleoclimatic environment deposition of the sediments of lower sequences was cold and semi-humid whereas the deposition of sediments of upper sequences was warm and humid. The A-CN-K ternary plot and CIA vs ICV binary plot also indicate and verify that the source areas were subjected to prolonged intense chemical weathering from low to high grade due to shifting of cold to warm humid paleo-climatic condition.

The present study deals with the systematic description of macro and miofloral analysis of Gangamopteris rajaensis and Glossopteris indica from the carbonaceous shale-coal bearing sequences of the Rajmahal Open Cast Mine, Rajmahal Basin, Jharkhand, India. The floral diversity, age correlation, and the paleoenvironment of the Barakar Formation were well described. Morphological analysis revealed the reticulate venation pattern, anastomosing of veins, and the absence of the midrib in Gangamopteris rajaensis. The recovered megafloral assemblages of Gangamopteris rajaensis and Glossopteris indica suggest a late early Permian (Artiskian-Kungurian) age for the Barakar strata of Rajmahal coal mine and the prevalence of a moderately warm climate during their deposition. Earlier the species was reported from the Barakar Formation of Damodar and Mahanadi Gondwana basins in India. However, this is the first detailed systematic investigation of this species from the Rajmahal Gondwana Basin,

The geochemical (REE & traces elements) characteristics of Permo-Carboniferous sandstone has been taken into account to decipher tectonic setting and provenance of the Rangit Pebble Slate Formation of Sikkim Lesser Himalaya. The chondrite normalized REE pattern with Eu negative anomaly and a bivariate plot (Th/Co-La/Sc) clearly indicates that studied sediments were likely derived from upper crust felsic source. The average elemental ratio of traces elements La/Sc (∼ 3.85), Th/Sc (∼ 2.57), Cr/Th (∼ 6.64), Th/Co (∼ 2.52), La/Co (∼ 3.74), and Eu/Eu* (∼ 0.32) also shows close affinities with Upper Continental Crust. The trivariate plot (La-Th-Sc plot, Th-Sc-Zr/10 plot, & Th-Co-Zr/10 plot) and a bivariate plot (Ti/Zr-La/Sc) plotted on the field of passive tectonic region for the Rangit Pebble Slate Formation sandstone. A binary plot between the ratio of Th/Sc-Zr/Sc and Th/U-Th reflects the enrichment of zircon and weathering trend during sedimentary recycling.