Tracking temporal palynofloral changes close to Cretaceous-Paleogene boundary in Deccan volcanic associated sediments of eastern part of central Deccan volcanic province

Deccan volcanic sequences （DYS） in the central Deccan volcanic province （CDYP） are designated as Sahyadri Group having -500 m thick lava pile associated with multiple sedimentary beds at different strati-graphic levels. In the eastern part of CDYP between the latitude 19°55-20°25 ′N and the longitudes 78°15-78° 30′E, palynological investigation of the intertrappean sedimentary beds at five stratigraphic levels was carried out. The study was basically aimed for tracking the floral and environmental changes across the Deccan transi-tion. The resulting finds indicate that the intertrappean sediments at the lowest stratigraphic level between the earliest lava flows are characterized by presence of marker Maastrichtian palynomorphs - Gabonisporis vigour- ouxii, Aquilapollenites bengalensis, Azolla cretacea and Farabeipollis associated with triporate and tricolpate pol-len grains, phytoliths of Oryzeae of Poaceae family and peridinoid dinoflagellate cysts. The increasing volcanism deteriorated the existing flora as evident by absence of pollen-spores and presence of only structured biodegraded organic matter, fungal spores, acritarchs and algal （Botryococcus） remains in the sediments of higher-up in the sequence. For chronostratigraphic constraints on the lava flows magnetic polarity of the flows bracketing the in-tertrappean beds was investigated. The results indicated presence of N-R-N-R magnetic polarity in the basal la-va pile that are interpreted as representing the magnetochron C30N to C28R （ Maastrichtian-Paleogene）. The floral change begins with the onset of volcanism in the chron C30N and floral deterioration is observed in C29N with increasing volcanism and it is only in the chron C28 R （ Danian） that some evidence of recovery of flora is recorded. The current study shows that in eastern part of CDYP the post Cretaceous-Paleogene boundary erup-tions represent the main phase of eruptions that triggered deterioration of the flora.

A review of the～1600 Ma sedimentation,volcanism,and tectono-thermal events in the Singhbhum craton,Eastern India

The Palaeoproterozoic-Mesoproterozoic transition （ -1600 Ma） is a significant event in the Earth history as a global thermal perturbation affected the pre-1600 Ma landmasses. Like other cratonic blocks of the world, lithospheric thinning, sedimentation, magmatism, metamorphism and crustal melting/anatexis are associated with this significant geological event in the Singhbhum cratonic province of India. This paper is a review of sedimentological, magmatic and tectono-thermal events in the Singhbhum craton at 1600 Ma. The Palaeo-Mesoproterozoic sedimentation and volcanism in the Singhbhum craton took place in a terrestrial intracontinental rift setting. The available geochronological data are indicative of late Palaeoproterozoic to Neoproterozoic tectono-thermal events in the Chhotanagpur Granite Gneissic Complex （CGGC）, an east-west trending arcuate belt of granite gneisses, migmatites and metasedi- mentary rocks. A detailed multidisciplinary geo-scientific investigation of the Dalma volcanic belt and the area to its north （Chandil Formation） and further north in CGGC will enable us to constrain the extant surface processes and crust-mantle interactions, the collision events between the North and South Indian cratonic blocks, and the position of India in the Columbia supercontinent.