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Tiwari, G. S.
- SEM Surface Microtextures of Quartz Grains from Ganga and Yamuna River Sediments, Allahabad, U.P.
Abstract Views :198 |
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Authors
Affiliations
1 Petrology Division, Geological Survey of India, Lucknow - 226 024, IN
2 Department of Geology, Banaras Hindu University, Varanasi - 221 005, IN
1 Petrology Division, Geological Survey of India, Lucknow - 226 024, IN
2 Department of Geology, Banaras Hindu University, Varanasi - 221 005, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 63, No 5 (2004), Pagination: 515-521Abstract
Quartz grain surface features of recent sediments saniples collected from vertical profiles developed in channel bar, point bar and natural levee deposits around the confluence of the Ganga and Yamuna rivers at Allahabnd, UP, were examined under the Scanning Electron Microscope (SEM). The study reveals the existence of several surface features as a result of mechanical and chemical action on the quartz grains.In channel bar and point bar deposits, mechanicaf features like low relief, v-shaped impact pits of coalescing nature and conchoidal fracture are dominating surface textures, which indicate the high-energy fluviatile depositional environment. Features like surface pits and surface solution are common in quartz grains from natural levee deposits. These surface textures owe their origin to chemical dissolution, which is possible only in low energy conditions associated with the deposition of natural levee and flood plain deposits.
Keywords
SEM-Microtextures, Quartz Grains, Fluvial Sediments, Ganga-Yamuna, U.P.- Variation of Heavy Minerals in Different Lithofacies and Geomorphic Units of the Ganga - Yamuna River near their Confluence at Allahabad, Uttar Pradesh
Abstract Views :204 |
PDF Views:2
Authors
Affiliations
1 Petrology Division, Geological Survey of India, Lucknow - 226 024, IN
1 Petrology Division, Geological Survey of India, Lucknow - 226 024, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 71, No 1 (2008), Pagination: 133-139Abstract
Recent sediments of the Ganga and Yamuna Rivers in three sectors, viz Sector-A , Sector-B and Sector-C were subjected for heavy minerals study to understand their distribution in various facies, and differences and similarities The heavy minerals mciude garnet, hornblende, kyanite, tourmaline, epidote, sillimanite, zircon, chloritoid, apatite and staurolite There exists an mverse relationship between their percentage and gram size Among the heavies, garnet dominates in all the three sectors of study area, followed by hornblende in Sector-A and -B, and epidote in Sector-C with augite and rutile m the Sector-B only Anatase, hypersthene, sphene and corundum are restricted to Yamuna nver sediments Also, brookite is more common m Sector-A Nine lithofacies, namely St, Sp2, Sp1, Sr1, Sr2, S1, Sh, Fl and Fm (8 SandandlMud- sublithofacies) are identified in the area Irrespective of occurrence in any geomorphic unit, Sr1, - Sr2 facies have higher concentration of heavies in coarser fraction while the Sp1 - Sp2 facies have higher concentration of heavies in finer fraction Bed forms have significant control on the distribution of the heavy minerals in a vertical profile, with differences m the source of the sediments of the Ganga and Yamuna Rivers reflected well in the respective heavy mineral assemblage.Keywords
Quaternary sediments, Heavy minerals, Provenance, Ganga and Yamuna rivers, Allahabad, Uttar Pradesh.- Vertical Successions of Channel Bar, Point Bar and Natural Levee Deposits, Ganga and Yamuna River, Allahabad, U.P.
Abstract Views :219 |
PDF Views:2
Authors
Affiliations
1 Petrology Division, Geological Survey of India, Lucknow - 226 024, IN
2 Department of Geology, Banaras Hindu University, Varanasi - 221 005, IN
1 Petrology Division, Geological Survey of India, Lucknow - 226 024, IN
2 Department of Geology, Banaras Hindu University, Varanasi - 221 005, IN