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| Article Name : | | | Study Of Textural Characteristics And Heavy Mineral Assemblage Of Shallow Subsurface Sediments Of A Part Of The Brahmaputra Valley In Assam, India | | Author Name : | | | R. K. Sarmah , J. N. Sarma , R. Hazarika And C. Gogoi | | Publisher : | | | Ashok Yakkaldevi | | Article Series No. : | | | GRT-2642 | | Article URL : | |  | Author Profile View PDF In browser | | Abstract : | | The study area is located on the south bank of the mighty river Brahmaputra in the districts of Tinsukia and Dibrugarh of Assam within the interfluves between the rivers Noa Dihing and Burhi Dihing. Thick deposits of Recent alluvial sediments comprising Older Alluvium, High level Terraces and New Alluvium along with active flood plain deposits are well exposed in natural cut bank sections of the Burhi-Dihing and Noa-Dihing rivers and their tributaries.The alluvium had been drilled for coring up to about 50 m at four sites, viz. Dhola, Dum Duma, ChotaTingrai and Naharkatiya, which are almost equally placed in a north-south direction from the river Brahmaputra towards south close to the foot of the Naga Hills. Grain size distribution of the sediments reveals that the samples are invariably sand with minor amount of clay and silts. Most of the sediments show bimodal size distribution. Cummulative curves indicate combination of different modes of transport and deposition and represent mostly two line segments and a few three line segments. Mean size of the sediments varies from very fine sand to medium sand. Majority of the sediments are moderately sorted and fine skewed. The frequency of leptokurtic and extremely leptokurtic sediments are maximum. Bivariate plots of standard deviation, skewness and kurtosis vs mean size show wide scatter of the valuessuggesting fluctuating energy conditions.. The bivariate plots and the CM plot suggest the fluvial nature of the sediments deposited chiefly in channel sub environment under medium to high energy condition. Ultra stable and unstable heavy mineral assemblage in the sediments points to their derivation mainly from source areas consisting mainly of high grade metamorphic and acid igneous rocks.naltrexone information go vivitrol uk | | Keywords : | | - grain size parameters, C-M pattern, heavy minerals, depositional condition, Recent sediments, Brahmaputra valley, Assam, India.,
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