Browsing by Author "Abdul Qayoom Paul"

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A glaciotectonic landform in the Shyok valley, Trans-Himalayan Karakoram Range, India
(Cambridge University Press, 2024) Abdul Qayoom Paul; Harish Bahuguna; Parveen Kumar
This study reports and discusses the first case of glaciotectonic landforms in the Shyok valley of the Trans-Himalayan Karakoram Range, Ladakh, where a large decomposed granite megablock (8.2 km2) along with underlying diamicton is thrust over the unconsolidated Quaternary glaciofluvial sediments along a fault gouge zone near the village of Khalsar.The absence of deformation signatures below the fault gouge indicates that the brittle fault acted as a décollement surface under frozen conditions along which the glaciotectonic megablock was translated.The other deformation features include slickensides, ductile shear, thrust propagation fold noses, clastic dykes and rafts of granite and slate within the diamicton sediments.These features indicate a subglacial glaciotectonic nappe origin of the landform.The presence of juxtaposed brittle to ductile deformation fabric, clastic dykes and the superimposition of deformed decomposed granite and diamicton over the undisturbed fluvial sediments indicates a permafrost glacial margin and proglacial environment under sufficient subglacial hydrodynamic conditions for the entrapment and transportation of the glaciotectonic megablock.The deformation fabric consistently shows a southeast orientation, indicating an advancing glacier motion from northwest to southeast.The Siachen Glacier which formerly flowed down the Nubra valley is the most likely cause of the Khalsar glaciotectonic landform. © The Author(s), 2024.
Geochemistry of recent sediments of the Kurheri basin, Son River, Madhya Pradesh, Central India: implications for source area weathering, sediment provenance, maturity, and sorting
(Springer Science and Business Media Deutschland GmbH, 2023) Abdul Qayoom Paul; Shamim A. Dar; B.P. Singh; Hemant Kumar; Mansoor Ahmad
The geochemical signatures of recent stream sediments in the study area revealed an old recycled sedimentary source and weak to moderate chemical weathering. The sediments exhibit a positive correlation of large ion lithophile elements (Ba, Sr, and Rb), transition trace elements (Co, Cr, Cu, Ni, Sc, and V), and REE with Al2O3 and associated immobile oxides, indicating affinity with phyllosilicate sedimentary rocks of Semri Group of Vindhyan basin. The La–Th–Sc and Th–Sc–Zr/10 ternary plots show mixed sediment sources of clays, silts, and sands. Positive correlations of LREE with Th, Zr, Al2O3, and TiO2 and negative correlations with Y and P2O5 suggests the cumulative influence of Ti-bearing minerals and clay minerals. The high Zr/Sc ratio (mean 30.8), strong LREE/HREE enrichment (mean 8.1), prominent negative Eu anomalies (mean 0.57) and flat HREE suggest input from the recycled sedimentary source. The mean chemical index of alteration (69.17), plagioclase index of alteration (74.94), chemical index of weathering (93.08), and ACNK indicate weak to moderate weathering with the presence of minor K-feldspar mixed in illite dominated mud. This is also supported by a high Rb/Sr ratio (mean 1.09) and K/Rb ratio (0.018). A higher K/Al than Na/Al ratio points to higher illite content. The presence of illite, minor feldspar, and less SiO2/Al2O3 ratio (mean 4.98) suggests low textural and compositional maturity, attributed to the mixing of sediments by significant physical weathering. The positive correlation between Th/Sc (mean 0.6) and Zr/Sc (30.8) indicates less fractionation, low to moderate hydraulic sorting, and sufficient sediment recycling in Kurheri sediments. © 2023, Geologische Vereinigung e.V. (GV).