A5037578407- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Geology and Paleoclimatology Research
- Semiconductor materials and devices
- Geochemistry and Geologic Mapping
- High-pressure geophysics and materials
- Radio Frequency Integrated Circuit Design
- Semiconductor materials and interfaces
- Semiconductor Quantum Structures and Devices
- Microwave Engineering and Waveguides
- Paleontology and Stratigraphy of Fossils
- Advancements in Semiconductor Devices and Circuit Design
- Solid-state spectroscopy and crystallography
- Groundwater and Isotope Geochemistry
- Geological formations and processes
- Clay minerals and soil interactions
- Superconducting and THz Device Technology
- Silicon Nanostructures and Photoluminescence
- Pleistocene-Era Hominins and Archaeology
- Geochemistry and Elemental Analysis
- Chalcogenide Semiconductor Thin Films
- Crystal Structures and Properties
- Archaeology and ancient environmental studies
- GaN-based semiconductor devices and materials
- Geological and Geophysical Studies
Indian Institute of Technology Bombay
2015-2024
G.S. Science, Arts And Commerce College
2019
Indian Institute of Technology Indore
1972-2013
Physical Research Laboratory
1993-2005
Carleton University
2001
University of Ottawa
2001
University of Lucknow
1970-1999
Signal Systems Corporation (United States)
1994
Viasat (United States)
1993-1994
Satellite Healthcare (United States)
1990
Bolide impact and flood volcanism compete as leading candidates for the cause of terminal-Cretaceous mass extinctions. High-precision 40Ar/39Ar data indicate that these two mechanisms may be genetically related, neither can considered in isolation. The existing Deccan Traps magmatic system underwent a state shift approximately coincident with Chicxulub extinctions, after which ~70% Traps' total volume was extruded more massive episodic eruptions. Initiation this new regime occurred within...
Late Cretaceous records of environmental change suggest that Deccan Traps (DT) volcanism contributed to the Cretaceous-Paleogene boundary (KPB) ecosystem crisis. However, testing this hypothesis requires identification KPB in DT. We constrain location with high-precision argon-40/argon-39 data be coincident changes magmatic plumbing system. also found DT did not erupt three discrete large pulses and >90% volume erupted <1 million years, ~75% emplaced post-KPB. climate coincide temporally...
Abstract The Deccan Volcanic Province (DVP) is significant for its eruption close to Cretaceous–Paleogene (K-Pg) boundary. Chemostratigraphy established in western parts the foundation of postulated long distance correlations across province and consequential models eruptive history. A critical review diagnostic parameters used characterize stratigraphic units shows them be probabilistic rather than deterministic therefore, they are ambiguous. We compile previously overlooked mapping into...
This study presents geochemical characteristics of glauconites in estuarine deposits within the Maastrichtian Lameta Formation central India. Resting conformably over Bagh Group, consists ∼4–5 m thick arenaceous, argillaceous and calcareous green sandstones underlying Deccan Traps. The sandstone is friable, medium- to coarse-grained, well-sorted thoroughly cross-stratified, contains marine fossils. Detailed petrography, spectroscopy mineral chemistry indicates unique chemical composition...
A review of the existing knowledge on Deccan Volcanic Province India shows that it has a significant geographic bias towards western parts, while rest province is not as well constrained.Emerging data its structure, geochronology and volcanology in last decade suggests many concepts models this large Continental Flood Basalt are open to revisions or replacement.The explicit relation between volcanism Reunion hotspot makes unique laboratory for studying magmatic evolution over active...
Two late Cretaceous mafic dykes with an ENE strike that is orthogonal to the west coast of India and located nearly 200 km inland around Huliyardurga, Karnataka state, yield 40 Ar‐ 39 Ar plateau ages 90.0±1.0 87.5±0.9 Ma. These Fe‐Ti‐enriched tholeiites are essentially co‐eval at least four other igneous suites widely scattered in southern India, namely; south north Kerala dykes, Agali‐Anaikatti central Kerala‐Tamil Nadu lavas St Mary islands off India. The also compositionally very similar...
We present 40 Ar‐ 39 Ar ages of 60.4±0.6 Ma and 61.8±0.6 (2σ) for Deccan Trap trachytes from Manori Saki Naka, Bombay, situated in the tectonized Panvel flexure zone along western Indian rifted continental margin. These provide clear evidence that (i) these are Palaeocene age therefore substantially younger than lower part main flood basalt sequence exposed Western Ghats, which precedes K‐T Boundary (ii) formation west coast must have been subsequent to ∼60 Ma. Considering early alkaline...
The channel mobility of the InP metal-insulator-semiconductor field-effect transistor (MISFET’s) was enhanced by incorporating a phosphorus-rich interfacial oxide between SiO2 gate dielectric and substrate. This grown using an indirect, plasma-enhanced chemical vapor deposition process followed same technique. structures, formed aluminum on SiO2, did not exhibit any hysteresis in its capacitance-voltage characteristic. An interface state density as low 8×1010 cm−2 eV−1 achieved for such MIS...
The electrical properties of m.i.s. structures based on indium phosphide and organic films deposited using the Langmuir-Blodgett technique have been investigated. A strongly inverted low-frequency C/V response occurs at approximately 30 Hz both melt-grown InP single crystals epitaxial layers this material prepared vapour-phase technique. Interface state distributions evaluated from admittance data quasistatic conductance techniques. For an n-type InP-epitaxial-wafer/cadmium-stearate...
Abstract A detailed investigation of a glauconite bed within the Late Cretaceous Bryozoan Limestone Formation Bagh Group in central India, as well study existing records, reveals existence ‘glauconitic sea’ along margins Palaeo-Tethys Ocean during Epoch. The authigenic green mineral formed abundantly on shallow seafloors unlike its modern, deep-sea counterpart. We present an integrated petrographical, geochemical and mineralogical transgressive deposits to highlight unique geochemistry with...
The debate between the impact scenario and hypothesis of Deccan volcanism leading to Cretaceous/Tertiary (K/T) extinctions is far from settled. We add a new dimension this by introducing an overlooked aspect volcanism, emplacement eruption associated carbonatite‐alkaline complexes, which are capable rapidly injecting catastrophic amounts CO 2 SO into atmosphere. 40 Ar‐ 39 Ar dating one several coeval late‐Deccan alkaline pulses has revealed that took place at K/T boundary. A conservative...