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
Bhartiya, S. P.
- Geomorphic History and Lithostratigraphy of a part of Eastern Gangetic Plain, Uttar Pradesh
Authors
1 Geological Survey of India, Jaipur 302001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 37, No 6 (1991), Pagination: 569-576Abstract
The Quaternary deposits of the area are classified into three lithounits, viz., Varanasi Older Alluvium, Chhoti Sarju Older Flood Plain Deposits and Chhoti Sarju Recent Flood Plain Deposits. The facies organisation of the Varanasi Older Alluvium (+300 m thick), indicates a braided to meandering river environment for the lower sandy facies and meandering river to local lacustrine conditions for the upper silt clay facies. Presence of a regionally persistent shell-bearing silty-clay horizon (at a depth of about 1 m to 2 m below ground level) indicates commencement of lacustrine conditions towards the waning phase of sedimentation of Varanasi Older Alluvium. The Chhoti Sarju Older Flood Plain Deposits rest over the eroded surface of Varanasi Older Alluvium. This deposit is about 10 m thick with fining upwards sandy facies deposited in a meandering river regime. The Chhoti Sarju Recent Flood Plain Deposits are confined within a very narrow zone (approx. 250 m wide) in the bed portion and flood plain of the river. In this regime, the sedimentation is still going on in the form of point bars, channel bars and side bars. At places, lacustrine conditions (oxbow lakes) are also present.
The Quaternary history of the area indicates at least two prominent episodes of base-level (sea-level) rise during the Late Pleistocene-Holocene period.
Keywords
Quaternary, Eastern Gangetic Plain, Geomorphology, Uttar Pradesh.
- Lithostratigraphy and Alluviation History of Quaternary Deposits of Southern Part Of Gangetic Plain, Uttar Pradesh
Authors
1 Geological Survey of India, Lucknow - 226020, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 4 (1995), Pagination: 393-399Abstract
The Quaternary sediments of a southern part of the Gangetic Plain in parts of Allahabad, Banda, Fatehpur, Hamirpur, Pratapgarh and Raebareli districts of Uttar Pradesh have been classified into the Banda Older Alluvium (BOA), the Varanasi Older Alluvium (YOA) and the Newer Alluvium, each representing different eycles of sedimentation in basins of different configuration during different periods. The Banda Older Alluvium resting over the Bundelkhand Gneissic Complex or the Vindhyan Supergroup, represents the first cycle of Quaternary sedimentation which has been sub-divided into the basal Variegated clays and an upper Chitrakoot Formation. These sediments had their provenance in the Peninsular terrain. The Varanasi Older Alluvium constituting the second cycle of sedimentation comprises polycyclic sequence of sand, silt and clay with or without calcrete bands. Its sediments di ffers in mineralogical assemblage from that of Banda Older Alluvium and have been derived from Extra Peninsular region. The Newer Alluvium, the third cycle of sedimentation, has been sub-divided into Terrace Alluvium and Recent Alluvium confined within the palaeobanks of the rivers.The evidences in favour of neotectonic movements recorded in the area are displacement of beds, deformational structures in Newer Alluvium, unusual straightening and abrupt changes in the river courses and sudden widening of flood plains or entrenchment of the rivers. An attempt has been made to work out the alluviation history of the Quaternary sediments of the area on the basis of available palaeontological data and some close lithological similarities.