_____________________________________________________________________________________________________ *Corresponding author: E-mail: satyakrsonowal@gmail.com; Journal of Geography, Environment and Earth Science International 15(4): 1-9, 2018; Article no.JGEESI.41822 ISSN: 2454-7352 Sedimentary Structures and Lithofacies Found in a Channel Bar of Brahmaputra River in Panikhaiti, Kamrup District, Assam Satyajit Sonowal 1* , Beauty Dutta 1 and Jayanta Jivan Laskar 1 1 Department of Geological Sciences, Gauhati University, Guwahati–781014, Assam, India. Authors’ contributions This work was carried out in collaboration between all authors. Author SS designed the study, performed the statistical analysis, wrote the protocol and first draft of the manuscript. Authors BD and JJL managed the analyses of the study. All authors read and approved the final manuscript. Article Information DOI: 10.9734/JGEESI/2018/41822 Editor(s): (1) Anthony R. Lupo, Professor, Department of Soil, Environmental, and Atmospheric Science, University of Missouri, Columbia, USA. Reviewers: (1) Luis Enrique Ibarra Morales, Sonora State University, Mexico. (2) Timur Chis, Ovidius University, Romania. (3) Etim Uko, Rivers State University, Nigeria. Complete Peer review History: http://www.sciencedomain.org/review-history/24948 Received 23 rd March 2018 Accepted 29 th May 2018 Published 2 nd June 2018 ABSTRACT Accumulation of sediments in river channels often leads to the formation of sediment bars. They form prominent elevated regions during the non-flood period within the river channel, and contain characteristic bedform features and internal stratification. These features reflect the hydrodynamic conditions prevailing during the deposition of the sediments. The present study deals with the recognition and interpretation of various bedform features and lithofacies that had developed in a channel bar of the Brahmaputra River, in Panikhaiti near Guwahati, Kamrup district, Assam. The different bedform features that are identified are small and mega ripples, water level cut marks, mud cracks, worm track and trails and raindrop imprints. Internal stratification was identified in trenches of depth ranging between 1.80 m and 2.25 m. in which eight varieties of lithofacies were identified. These are Trough cross-bedded sand (St), Planar cross-bedded sand (Sp), Horizontally laminated sand (Sh), Climbing ripple lamination (Sr), Convolute bedding (Fc), Flaser bedding (Sf), Massive sand (Sm) and Massive Mud (Fm). The lithofacies associations indicate deposition of sediments under multiple episodes of flood, and characterized by multiple migrations from low flow regime conditions to high flow regime conditions. Original Research Article