Structure and Lineaments of the Northwestern Part of Bangladesh and Evolution of the Barind Tract

The Barind Tract is a relatively elevated (about 11-48 m amsl) triangular wedge of landmass. It is one of the many Pleistocene terraces present in northwestern Bangladesh. The geomorphic evolution of this tract is a matter of unresolved debate since long. The present paper is an attempt to delineate the evolution of this tract with help of stratigraphical and structural interpretation of the area. The study imply that the major principal stress and minor principal stress for lineaments and basement controlled faults in the Hunting’s map and lineaments delineated in the present study were applied in the same direction respectively, which indicates that the basement controlled faults played an important role for the morphological evolution of the Barind Tract. Regionally the Barind Tract is outlined by N-S trending Malda-Kishanganj fault in the west, NW-SE trending Karatoya fault in the northeast and Ganges (Padma) fault in the south. Not only the Barind Tract but all the features of the Bengal Basin and its surroundings like, Rajmahal Volcanics, Gangetic Foredeep, Shillong Plateau, Madhupur Tract, Tippera Surface, Sylhet Trough and Gangetic Deltaic Plain are outlined by well-defined faults. Basement surface of the northwestern part of Bangladesh is also criss-crossed by a series of faults. A large number of horst and graben like structures occur within the basement of the area. The sedimentary succession and their thickness in the Bogra Shelf and Platform areas also exhibit remarkable dissimilarities. Some sedimentary groups and formations present in the Bogra Shelf area which are completely missing in platform area. These indicate that all these are related to fault and definitely have some direct influence to build up the present morphological configuration of the Barind Tract. It is, therefore, for future planning and sustainable development of the area, the information revealed from this study might be considered.