Singh P.K.,Banaras Hindu University |
Rajak P.K.,Banaras Hindu University |
Singh M.P.,Banaras Hindu University |
Naik A.S.,Banaras Hindu University |
And 3 more authors.
Journal of the Geological Society of India | Year: 2015
The present paper contains the result of investigation carried out on selected trace elements in the less studied lignite deposits of Rajasthan, Western India. The study has been made on two new lignite deposits–Barsingsar and Gurha. The former has elevated ash content (mean 20.8%) than the latter one (mean 5.1%) and both of them have high volatile matter (mean 43.7% and 49.9% respectively). The lignite samples have been studied for selected elements like Fe, Ca, Mg, Mn, K, Na, Cu, Co, Ni, Cr, Zn, Pb, Cd and As. The elements like Cd, Co, Ni, Pb and Cu occur in high concentration when compared to the Clarke values for brown coal. Ca and Mg relate positively with organic matter in Barsingsar lignite indicating their organic source while K, Cu, Co, Pb and Cd indicate their inorganic origin. Ca might have come in contact with the organic matter during humification and would have become a part of humate. The elements like Cu, Co, Ni, Cr, Cd and Pb showing strong affinity with inertinite could have got associated with the mineral matter present in the fusinite and funginite macerals. In Gurha lignites Pb and Co have shown their affinity with inorganic matter which could have been drawn from sulphides and clay minerals. © 2015, Geological Society of India.
Eller G.K.,Princeton University |
Bhowmick P.K.,KDMIPE |
Upadhyay H.,KDMIPE |
Dave A.,KDMIPE |
And 3 more authors.
Journal of the Geological Society of India | Year: 2011
A scientific challenge is to assess the role of Deccan volcanism in the Cretaceous-Tertiary boundary (KTB) mass extinction. Here we report on the stratigraphy and biologic effects of Deccan volcanism in eleven deep wells from the Krishna-Godavari (K-G) Basin, Andhra Pradesh, India. In these wells, two phases of Deccan volcanism record the world's largest and longest lava mega-flows interbedded in marine sediments in the K-G Basin about 1500 km from the main Deccan volcanic province. The main phase-2 eruptions (∼80% of total Deccan Traps) began in C29r and ended at or near the KTB, an interval that spans planktic foraminiferal zones CF1-CF2 and most of the nannofossil Micula prinsii zone, and is correlative with the rapid global warming and subsequent cooling near the end of the Maastrichtian. The mass extinction began in phase-2 preceding the first of four mega-flows. Planktic foraminifera suffered a 50% drop in species richness. Survivors suffered another 50% drop after the first mega-flow, leaving just 7 to 8 survivor species. No recovery occurred between the next three mega-flows and the mass extinction was complete with the last phase-2 megaflow at the KTB. The mass extinction was likely the consequence of rapid and massive volcanic CO 2 and SO 2 gas emissions, leading to high continental weathering rates, global warming, cooling, acid rains, ocean acidification and a carbon crisis in the marine environment. Deccan volcanism phase-3 began in the early Danian near the C29R/C29n boundary correlative with the planktic foraminiferal zone P1a/P1b boundary and accounts for ∼14% of the total volume of Deccan eruptions, including four of Earth's longest and largest mega-flows. No major faunal changes are observed in the intertrappeans of zone P1b, which suggests that environmental conditions remained tolerable, volcanic eruptions were less intense and/or separated by longer time intervals thus preventing runaway effects. Alternatively, early Danian assemblages evolved in adaptation to high-stress conditions in the aftermath of the mass extinction and therefore survived phase-3 volcanism. Full marine biotic recovery did not occur until after Deccan phase-3. These data suggest that the catastrophic effects of phase-2 Deccan volcanism upon the Cretaceous planktic foraminifera were a function of both the rapid and massive volcanic eruptions and the highly specialized faunal assemblages prone to extinction in a changing environment. Data from the K-G Basin indicates that Deccan phase-2 alone could have caused the KTB mass extinction and that impacts may have had secondary effects. © GEOL. SOC. INDIA.
Keller G.,Princeton University |
Adatte T.,Geological and Paleontological Institute |
Bhowmick P.K.,KDMIPE |
Upadhyay H.,KDMIPE |
And 3 more authors.
Earth and Planetary Science Letters | Year: 2012
In C29r below the Cretaceous-Tertiary boundary (KTB) massive Deccan Trap eruptions in India covered an area the size of France or Texas and produced the world's largest and longest lava megaflows 1500. km across India through the Krishna-Godavari (K-G) Basin into the Bay of Bengal. Investigation of ten deep wells from the K-G Basin revealed four lava megaflows separated by sand, silt and shale with the last megaflow ending at or near the KTB. The biologic response in India was swift and devastating. During Deccan eruptions prior to the first megaflow, planktic foraminifera suffered 50% species extinctions. Survivors suffered another 50% extinctions after the first megaflow leaving just 7-8 species. No recovery occurred between the next three megaflows and the mass extinction was complete with the last mega-flow at or near the KTB. The last phase of Deccan volcanism occurred in the early Danian C29n with deposition of another four megaflows accompanied by delayed biotic recovery of marine plankton. Correlative with these intense volcanic phases, climate changed from humid/tropical to arid conditions and returned to normal tropical humidity after the last phase of volcanism. The global climatic and biotic effects attributable to Deccan volcanism have yet to be fully investigated. However, preliminary studies from India to Texas reveal extreme climate changes associated with high-stress environmental conditions among planktic foraminifera leading to blooms of the disaster opportunist Guembelitria cretacea during the late Maastrichtian. © 2012 Elsevier B.V.
Mehrotra N.C.,University of Lucknow |
Journal of the Geological Society of India | Year: 2010
This paper presents an updated account of palynostratigraphic, source rock evaluation and palaeoenvironment data on Western Offshore and Krishna Godavari (K-G) Basins. Forty three dinoflagellate biohorizons have been identified in the Tertiary subsurface of Mumbai Offshore, facilitating a high resolution correlation of Oil bearing horizons. In K-G Basin integrated palynostratigraphic data and the composite general lithologies for the Mesozoic and Cenozoic have been presented in a tabular form; Eighty two dinoflagellate biohorizons have been identified. A very fine dinoflagellate based stratigraphic resolution has been achieved at most levels making it useful in geological modelling for hydrocarbon exploration in both Western Offshore and K-G Basin. Useful information on matured organic matter facies distribution in Panna Formation (Western Offshore) and Cretaceous of K-G Basin has been summarized. Recently, potential source rock facies have been identified in Panna Formation in Western Offshore. Limitations of present studies and future areas of focus have been outlined. © GEOL. SOC.
Kapoor S.,IOGPT |
Jain A.,KDMIPE |
Proceedings of the Annual Offshore Technology Conference | Year: 2011
Globally, the oil majors are establishing their future environmental and social responsibility benchmarks as restructuring to their newer outlook. These concerns call for better control of emissions & releases from their operations and finally handling of decommissioning of oil / gas installations etc. The national oil company ONGC, currently produces about 0.12 million m 3per day of water from its various on land & offshore oil assets. Oil field waters contain highly toxic organic and inorganic substances, which have deleterious effect on local flora and fauna. The various conventional methods currently in vogue are less satisfactory as being less environment friendly, less cost effective and more energy demanding. The petroleum industry has made enormous strides in improving its environmental operations. A technique coined as electroflotation has been developed for the separation of hydrocarbons from oil field waters. A regulated low direct current is passed through identified electrodes to treat the effluent resulting in separation of oil. The designed tiny bubbles of hydrogen & oxygen (∼ 50 micron) through strategic electrode stacking produced during electrolysis of water accelerate its migration to surface. The oil droplets coalesce at the surface to form an oily layer, which is skimmed off. Various parameters governing the process were optimized on bench scale followed by its validation at pilot level. A total of nearly 200 m 3 effluent for over 250 hours was treated through this technique in an oil field of Indian Western on land oil province. Nearly 200 chemical assays of inlet and outlet water were estimated for total oil content. The oil content of treated effluents was less than 10 PPM that met the laid standards. The system has additional advantage, due to bubbling out of oxygen during process, which improves the BOD & COD of the treated effluent. The technique holds wider potential for its application in treating oily water produced during field operations and is also accredited with patent # 209854 & SPE update -21 Nov 2007 (Facilities (PFC), Production (PO), Central Asia). This innovative technology is ready to open new doors for its application to treat oily effluents in both upstream & downstream segments of oil sector & ready for commercialization. Acouple of global techno-economic enquries have also generated business interest. Copyright 2008, Society of Petroleum Engineers.