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Sharma, Kewal K.
- Uranium Distribution in Siwalik Vertebrates using Fission Track Technique
Authors
1 Wadia Institute of Himalayan Geology, 15, Municipal Road, Dehradun 248001, IN
2 Department of Physics, Kurukshetra University, Kurukshetra 132 119, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 22, No 2 (1981), Pagination: 92-97Abstract
Uranium distribution in Vertebrate Fossils from the Siwaliks of NW-Himalaya has been worked out using Fission Track Method. Uranium is found to be uniformly distributed in collophane and ferruginous material of the bone and a sympathetic relationship between uranium and collophane content has been observed. Percolating waters which leached uranium and phosphorus from the granitic matrix (80 to 90%) of the Siwalik sandstones appear to have brought about diagenesis, uranium mineralization and fossilisation of the organic remains in the Siwalik sediments.
- Fluid Inclusion Studies on Fluorite from Chumathang, Ladakh Himalaya
Authors
1 Wadia Institute of Himalayan Geology, Dehra Dun 248001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 24, No 6 (1983), Pagination: 311-313Abstract
Study indicates low salinity and moderate density for the ore forming fluids responsible for the fluorite. The temperature of homogenisation (120°C to 150°C) in different coloured fluorites indicate that the mineralization is of epithermal type.Full Text
- Granites of Himalayas, Karakorum and Hindu Kush
Authors
1 Wadia Institute of Himalayan Geology, Dehra Dun-248 001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 26, No 10 (1985), Pagination: 764-765Abstract
No Abstract.Full Text
- Granitoid Rocks of Wangtu Gneissic Complex, Himachal Pradesh: An Example of In situ Fractional Crystallisation and Volatile Action
Authors
1 Wadia Institute of Himalayan Geology, General Mahadeo Singh Road, Dehradun-248001, IN
2 National Geophysical Research Institute, Hyderabad-500 007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 1 (1995), Pagination: 5-14Abstract
The Wangtu Gneissic Complex (WGC) of Himachal Himalaya represents the basement rocks which remained more or less in its original realm. The unique feature of this complex is that the various phases of deformed and undeformed granitoids are exposed in the area. The complex has a peripheral zone of augen gneisses and core of non-foliated granitoids comprising of Coarse Porphyritic Granites (CPG) and Fine Grained Granites (FGG).
In the field the FGG rocks have sharp intrusive contacts with CPG rocks. At places they are entrapped or have protrusions into CPG rocks. Compositionally they represent syenogranites. They are peraluminous to meta-aluminous with Sr initial ratio of 0.705. The major and trace elements of these rocks show unimodal distribution pattern on different variation diagrams. They along with rare earth elements show marked fractionation trends, with a significant negative Eu anomaly. The rocks more or less define an isochron, representing Rb-Sr age of 1895±64 Ma.
The petrochemical studies favour a fractionated rather than multiple intrusions of magma. The studies suggest that fractional crystallisation of parental magma gave rise to early formed CPG rocks and the residual melts resulted in the crystallisation of FGG rocks. The last formed granitoids, the FGG rocks are interpreted as the final residue which crystallised rapidly after build-up and loss of fluids and volatiles which migrated to higher levels to form pegmatite phase in the aureol zone. The Rb-Sr systematics in the present case indicate that the granite have primary crystallisation melts derived from the deep crustal levels around 1895±64 Ma.
Keywords
Granites, Igneous Petrology, Himachal Pradesh.- Petrological and Geochemical Constraints on the Petrogenesis of the Jaspa Granitic Pluton, Lahual Region, NW Himalaya
Authors
1 Wadia Institute of Himalayan Geology, 33, General Mahadeo Singh Road, Dehradun-248 001
2 Wadia Institute of Himalayan Geology, 33, General Mahadeo Singh Road, Dehradun-248 001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 45, No 6 (1995), Pagination: 629-642Abstract
Several granitic plutons were emplaced in the Lesser and Higher Himalayas of India during early Paleozoic. Jaspa pluton of Lahual region is one such pluton, where the granitoids are intrusive into the low-grade Haimantas made up of phyllitic and quartzitic rocks. The petrochemical studies of the Jaspa granitoids show two successive phases of intrusion. The early phase is dominated by Biotite-Muscovite Granite (BMG) of Ordovician age. Compositionally these rocks are similar to the biotite-granites of Shingo-La of Higher Himalayan range, which are around 50 km to the north of the BMG rocks. The younger phase is represented by tourmaline bearing leucogranites (TLG), which occur as minor phase generally along the marginal parts of the BMG rocks.
The BMG rocks in comparison to TLG rocks have relatively high concentrations of CaO, MgO, TiO2, Fe2O3(T), Nb, Zr, Sr, Pb and Th and low concentrations of SiO2, Na2O, P2O5, Rb,Ga and U. They distinctly plot as two geochemical populations on different variation diagrams. The BMG rocks are characterised by enriched REE concentrations and show fractionating bends, while the TLG rocks have low REE concentrations and show less fractionated trends and depleted HREE pattern. The field, petrographic and geochemical studies suggest that the two phases of Jaspa pluton, the BMG and the TLG rocks were generated from the partial melting of the continental crust in which two chemically different source types were involved.
Keywords
Petrology, Geochemistry, Himalaya, Lahual.- Geochemistry and Rb-Sr Chronology of Upper Jurassic A-type Granite, Tangmarg region, Kashmir Himalaya
Authors
1 Wadia Institute of Himalayan Geology, 33 General Mahadeo Singh Road, Dehra Dun - 248001, IN
2 National Geophysical Research Institute, Hyderabad - 500 007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 3 (1995), Pagination: 225-233Abstract
The present paper deals with petrochemistry and geochronology of granite pluton that intrudes the Agglomerate Slate-Panjal Trap sequence in Tangmarg region of Baramulla district, Kashmir Himalaya. This granite body henceforth called 'Tangmarg Granite' contains biotite, amphibole and rare pyroxene as mafic minerals and shows higher abundances of Zr, Nb, Ga, Y and REE, and lower AI, Mg and Ca contents. The geochemical signatures suggest the granite to be chemically distiIict from most of the orogenic granites (M-, I- and S-types) and points to their Anorogenic nature.The six point whole rock Rb-Sr isochron of the Tangmarg granite gives an age of 161 ± 5 Ma, with Sr ratio of 0.714. The small size of the pluton points to limited melt generated from a partial fusion 'event' of short duration. Such a melt is attributed to pressure release due to reactivation of the faults that were formed during Permo-Triassicrifting event.