4 results on '"Ranjit G. Khangar"'
Search Results
2. Slumping as a record of regional tectonics and palaeoslope changes in the Satpura Basin, central India
- Author
-
Ranjit G. Khangar, Anand T. Babhare, Merajuddin Khan, and Nilasree Raychowdhury
- Subjects
QE1-996.5 ,Geochemistry ,soft-sediment deformation structures ,Geology ,Structural basin ,Soft-sediment deformation structures ,refolding ,talchir formation ,Tectonics ,fold analysis ,slump folds ,General Earth and Planetary Sciences ,Slumping - Abstract
Soft-sediment deformation structures play an important role in interpreting regional tectonics and basin evolution during slumping events. The Satpura Basin is interpreted as pull-apart with a monoclinal northerly palaeoslope throughout its evolution. The basin formed as a result of sinistral strike-slip faulting, induced by the ENE–WSW-trending Son-Narmada South fault in the north and the Tapti North fault in the south. We have analysed the slump folds within the basalmost Talchir Formation and related these to regional tectonics and palaeoslope changes in the Satpura Basin. The glaciofluvial strata of the Talchir Formation, exposed in the southern part of the Satpura Basin, record intricacies of folds created during slumping. Several fold styles can be distinguished, within alternations of competent sandstone and incompetent shale layers, some of which indicate buckling. Upright folds, resulting from pure shear, underwent rotation of their axial planes and fold axes during simple shear-dominated progressive deformation when the slump moved downslope. The soft-sediment deformation structures that we have studied show refolding patterns that closely resemble comparable folds known from lithified rocks. These layers with refolded structures are overlain by unde-formed sediments, which proves that they are the product of a single ongoing slumping process, rather than of successive deformation events. Our analysis of their fold axes and axial planes, together with fold vergences and thrust directions within the slumps, suggests a mean slumping direction towards the southwest. Analyses of slump folds and their relationship with regional tectonics have allowed us to reinterpret basin evolution history. The southwesterly trending palaeoslope of the basin suggest that the slope of the basin was not uniform throughout its evolution. At the opening, the oblique slip fault, which trended NE–SW, generated due to movement along the ENE–WSW basin bounding faults, was more active and triggered slumping event within the Talchir deposits in the basin. With progressive overlapping of the basin-bounding faults, the Satpura Basin gradually tilted towards the north.
- Published
- 2021
3. Dickinsonia discovered in India and late Ediacaran biogeography
- Author
-
Sharad Master, Ranjit G. Khangar, Merajuddin Khan, Gregory J. Retallack, and Neffra A. Matthews
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,biology ,Coastal plain ,Biogeography ,Geology ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Plate tectonics ,Paleontology ,Cave ,Group (stratigraphy) ,True polar wander ,Dickinsonia ,Mesolithic ,0105 earth and related environmental sciences - Abstract
The discovery of Dickinsonia in India allows assessment of biogeographic provinces and plate tectonic reconstructions for the late Ediacaran. The fossils were found in the roof of Auditorium Cave at Bhimbetka Rock Shelters, a UNESCO World Heritage Site for Paleolithic and Mesolithic cave art, near Bhopal, Madhya Pradesh. The fossils are identical with Dickinsonia tenuis from the Ediacara Member of the Rawnsley Quartzite in South Australia, and like them also show deformation due to lateral impingement, arcuate pieces missing, and alignment. They are within the late Ediacaran, Maihar Sandstone of the Bhander Group, in red sandstones formed in coastal plain paleoenvironments, including eolian, tsunamite, and intertidal bedforms. This new occurrence confirms assembly of Gondwanaland by 550 Ma, but not reconstructions adjusted for true polar wander. Cloudina and other small shelly marine fossils were low latitude, but vendobionts such as Dickinsonia were at temperate to subtropical latitudes.
- Published
- 2021
- Full Text
- View/download PDF
4. Organo-petrographic and pore facets of Permian shale beds of Jharia Basin with implications to shale gas reservoir
- Author
-
Sujeet Kumar, Atul Kumar Varma, Durgesh Kumar, Vinod Atmaram Mendhe, Alka Damodhar Kamble, Harpal Singh, Mollika Bannerjee, Ranjit G. Khangar, and Subhashree Mishra
- Subjects
020209 energy ,Maceral ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Diagenesis ,Inertinite ,Source rock ,Liptinite ,Facies ,0202 electrical engineering, electronic engineering, information engineering ,General Earth and Planetary Sciences ,Petrology ,Vitrinite ,Oil shale ,Geology ,0105 earth and related environmental sciences - Abstract
The shale deposits of Damodar Valley have received great attention since preliminary studies indicate their potential for shale gas. However, fundamental information allied to shale gas reservoir characteristics are still rare in India, as exploration is in the primary stage. In this study, Barakar shale beds of eastern part of Jharia Basin are evaluated for gas reservoir characteristics. It is evident that Barakar shales are carbonaceous, silty, contains sub-angular flecks of quartz and mica, irregular hair-line fractures and showing lithological variations along the bedding planes, signifying terrestrial-fluviatile deposits under reducing environment. The values of TOC varies from 1.21 wt.% to 17.32 wt.%, indicating good source rock potentiality. The vitrinite, liptinite, inertinite and mineral matter ranging from 0.28 vol.% to 12.98 vol.%, 0.17 vol.% to 3.23 vol.%, 0.23 vol.% to 9.05 vol.%, and 74.74 vol.% to 99.10 vol.%, respectively. The ternary facies plot of maceral composition substantiated that Barakar shales are vitrinite rich and placed in the thermal-dry gas prone region. The low values of the surface area determined following different methods point towards low methane storage capacity, this is because of diagenesis and alterations of potash feldspar responsible for pore blocking effect. The pore size distribution signifying the micro to mesoporous nature, while Type II sorption curve with the H2 type of hysteresis pattern, specifies the heterogeneity in pore structure mainly combined-slit and bottle neck pores.
- Published
- 2017
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.