International E-publication: Publish Projects, Dissertation, Theses, Books, Souvenir, Conference Proceeding with ISBN.  International E-Bulletin: Information/News regarding: Academics and Research

Mineralogical composition and spatial variation of suspended sediments in a 2nd order channel of the Brahmaputra River in Majuli, Assam, India

    ,

Author Affiliations

  • 1Department of Geological Sciences, Gauhati University, Guwahati, Assam, India
  • 2Department of Geological Sciences, Gauhati University, Guwahati, Assam, India

Int. Res. J. Environment Sci., Volume 6, Issue (11), Pages 16-22, November,22 (2017)

Abstract

The Brahmaputra River flows across Assam in a braided pattern with large discharge and heavy sediment load. The present study investigates the post-monsoon mineralogical variations in the suspended load in a 2nd order channel of the Brahmaputra River in Majuli, Assam. The channel flows along the southern bank of Majuli. Representative suspended sediment samples were collected from different locations and depths along the 2nd order channel, which were subsequently subjected to laboratory analysis for the determination of amount of suspended load as well as their mineralogical content. The suspended load varies from 0.337 gm/l to 1.77 gm/l. X-ray Diffraction analysis of the sediments indicate the presence of quartz, chlorite, chamosite, strontianite, sanidine, orthoclase, tourmaline, albite, oligoclase, augite, hornblende, biotite, muscovite, enstatite, epidote calcite, dolomite, hematite, goethite, gypsum, garnet, apatite, tourmaline, zircon, silimanite, kyanite, rutile, zoisite, clinozoisite and glauconite. The clay minerals varieties found are illite, montmorillonite and chlorite. A decrease in the amount of suspended load is observed from upstream towards the downstream part of the channel due to drop in stream power and change in flow direction of the 2nd order channel in its downstream portion. No clear segregation of minerals is observed along the course of the river channel.

References

  1. Campodonico V.A., García M.G. and Pasquini A.I. (2016)., The geochemical signature of suspended sediments in the Parana River basin: Implications for provenance, weathering and sedimentary recycling., Catena, 143, 201-214.
  2. Acharya Anu (2011)., Experimental study and numerical simulation of flow and sediment transport around a series of spur dikes., Dissertation thesis. The University Of Arizona UMI Number: 3454308, 192.
  3. Mahanta C., Zaman A.M., Newaz S.M.S., Rahman S.M.M., Mazumdar T.K., Choudhury R., Borah P.J. and Saikia L. (2014)., Physical Assessment of the Brahmaputra River Ecosystems for Life: A Bangladesh-India Initiative, Dialogue for Sustainable Management of Trans Boundary Water Regimes in South Asia., Ch- 2, IUCN 2014, 90.
  4. Immerzeel W. (2008)., Historical trends and future predictions of climate variability in the Brahmaputra basin., International Journal of Climatology, 28(2), 243-254.
  5. Datta B. and Sing V.P. (2004)., Hydrology., The Brahmaputra Basin Water Resources, Singh V.P., Sharma N., Shekhar C. and Ojha P., Kluwer Academic Publishers, Netherlands, 139-195.
  6. Coleman J.M. (1969)., Brahmaputra river channel processes and sedimentation., Sedimentary Geology, 3(2), 129-239.
  7. Lahiri S.K. and Sinha R. (2014)., Morphotectonic evolution of the Majuli Island in the Brahmaputra valley of Assam, India inferred from geomorphic and geophysical analysis., Geomorphology, 227, 101-111.
  8. Lindholm Roy C. (1987)., A Practical Approach to Sedimentology., Allen and Unwin, Inc, USA., 276.
  9. Carroll D. (1970)., Clay Minerals: A guide to their x-ray identification., Geol. Society of America, Boulder, Colorado. Spl., 126, 80.