A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Singh, I. B.
- Point Bar Complex of an Exhumed Channel in Upland Interfluve of the Ganga Plain, India
Authors
1 Department of Geology, Lucknow University, Lucknow - 226007, IN
2 Department of Geology, Kumaun University, Nainital - 263 002, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 51, No 3 (1998), Pagination: 315-322Abstract
Facies architecture and evolutionary history of a point bar complex of exhumed channel on the upland interfluve surface of the Ganga Plain is presented. The point bar complex is made up of four distinctive sequences, each characterized by a specific lithofacies association and grain size, where successive sequence shows decrease in grain size and reduced channel width denoting reduction in the discharge of the channel. The top of each sequence represents a hiatus surface marked by dense bioturbation. The flow in the exhumed channel was towards south and southwest. At the end of the deposition of third sequence neotectonic activity caused uplift, tilting of the surface and disruption of the river channel. A facies model of such deposits is proposed.Keywords
Point Bar Complex, Fluvial, Ganga Plain, Palaeocurrent, Indo-Gangetic Alluvium.- On the Stratigraphy and Sedimentation of the Vindhyan Sediments in the Chitrakut Area, Banda District (U.P.)-Satna District (M.P.)
Authors
1 Geology Departrnent, Lucknow University, Lucknow-226007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 19, No 8 (1978), Pagination: 359-367Abstract
The lower Vindhyan sediments of Chitrakut area (Chitrakut Formation-Semri Group of Son Valley) are deposits of a tidal swept shallow sea, mainly in tidal flats under extremely stable conditions. They represent a special case of condensation horizons (condensed deposit) under conditions of exceptionally low rates of deposition and negligible sinking of the basin. The stromatolite assemblage suggests lower Riphean age and can be correlated to the Kajrahat limestone of Son Valley area. A marked depositional hiatus is established at the base of Kaimur at Sangrampur hill. Variation in the facies and absence of time plane index-horizons makes the correlation in the Chitrakut area very difficult. It is too early to suggest a generalized lithostratigraphy for the Chitrakut Formation.- Depositional Pattern in Upland Surfaces of Central Gangetic Plain Near Lucknow
Authors
1 Department of Geology, Lucknow University, Lucknow - 226007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 5 (1995), Pagination: 545-555Abstract
Several meter thick muddy sequences make up the topmost part of upland surfaces in Central Gangetic Plain. Excavations in the river-valley terrace (T1-surface) of Gomti River show about 4 m thick fine-grained deposits, which are underlain by a meter thick sand body: The sand of such sand bodies is coarser-grained than the present-day Gomti River sand. The sequence is essentially a silty very fine sand, highly mottled due to extensive bioturbation. These muddy successions are deposited by sheet floods of monsoon rains and not linked to flood plain of present-day active river. The high plateau surface (T2-surface) shows locally a few meter thick channel fill sequences, produced by small channels which have been abandoned. The muddy sediments of upland surfaces show high degree of variability.Keywords
Fluvial Morphology, Sedimentology, Gomti Alluvial Valley, Quaternary Deposits, Gangetic Plain, Uttar Pradesh.- Neotectonic Control on Drainage System in Gangetic Plain, Uttar Pradesh
Authors
1 Department of Geology, Lucknow University, Lucknow-226 007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 47, No 5 (1996), Pagination: 599-609Abstract
Study of remotely sensed data and SOl topographical maps with some field observations has helped in the identification of lineaments controlling the drainages, using various indications like displacement of Siwalik hills, skewness of fan surfaces, preferential alignment of river channel, knick points, distorted meanders, abrupt change in river courses, escarpments and asymmetrical terraces. The northern part of the Gangetic plain, the Piedmont zone shows two major lineaments, i.e. NNE-SSW and NW-SE, developed as conjugate strike slip features, with some evidences of gravity component. The NW-SE direction of the conjugate system is very prominent in Central Alluvial Plain and has controlled the major drainages. These lineaments have caused abrupt change in flow directions of many streams; and in parts, have behaved as gravity fault with NE blocks as downthrown side. The drainage in the Marginal Alluvial Plain (southern part) is essentially controlled by the reactivated basement lineaments of predominantly SW-NE direction. The drainage of northern and central part of Gangetic plain is controlled by newly developed lineaments formed due to compressional stresses of the Himalaya while drainage in southern part is controlled by reactivated basement lineaments.Keywords
Neotectonics, Drainage, Lineaments, Gangetic Plain, Uttar Pradesh.- Markov Chain Analysis of the Shallow Marine lBhuj Sandstone of Early Cretaceous Age, Kachchh Basin, India
Authors
1 Department of Geology, Lucknow University, Lucknow - 226 007, IN
2 Uttar Pradesh, Khanij Bhawan, 2 Way Road, Lucknow - 226001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 48, No 5 (1996), Pagination: 567-578Abstract
Cyclic characteristics of lithofacies of the shallow marine Bhuj Sandstone were studied statistically, using embedded Markov chain analysis and the concept of entropy. Data came from thirteen measured sections. The upward transmissions from one sedimentary lithofacies to another are plotted on a 5×5 matrix and a transition tree is constructed. Results strongly suggest that the Bhuj Sandstone was influenced by a Markovian mechanism and accumulating in well-defined depositional environments; the vertical distribution of lithofacies was controlled by a number of natural processes. The preferential upward transition path of lithologic and depositional envitonment changes are as follows: Carbonaceous siltstone/shale (A) (Coastallagoon) → Coarse-grained cross bedded Sandstone (8) (Estuarine channel) → interbedded sandstone siltstone (C) (Tidal flat-tidal channel) → silty sandstone (D) (Sandflat - shoal) → Bioturbated sandstone (E) (Shelf Sheet sand) → Carbonaceous siltstone/shale (A) (Coastal lagoon).This sequence is an asymmetrical cycle. It can be identified into a progradational event (lithofacies A-D) and a transgressive event (lithofacies E). The statistical results concur with the sedimentological evidence for depositional environments.
Entropy plots of the E(pre) and E(post) values of each lithological state correspond to the type A-4 category (Hattori, 1976), signifying lower and upper truncated asymmetrical cycles. The values of E (system) fall just on the boundary of the area allocated for the neritic environment. The area occupied by the Bhuj Sandstone evidently represents the domain of deposits of a coastal complex of estuary, lagoon and tidal flat environments, deposits for which Hattori had no data base.
Keywords
Sedimentology, Bhuj Sandstone, Markov Analysis, Kachchh Basin, Gujarat.- Signatures of Palaeofloods in Sandbar-Levee Deposits, Ganga Plain, India
Authors
1 Department of Geology, Banaras Hindu University, Varanasi - 221 005, IN
2 Department of Geology, Lucknow University, Lucknow - 226007, IN