The Bengal Foredeep is one of the world's largest exogeosynclines.Chapter 4. Study Area, Stratigraphic evolution and geochemistry of the Neogene Surma Group, Surma Basin, Sylhet, Bangladesh; Oulu University Library It runs parallel to the hinge zone of the Sub-Himalayan Foredeep. It is about 450 kilometers wide in southern Bangladesh, narrowing towards the northeast. Folded belts of the Burmese Alpide mobile belt mark its eastern boundary. It can be divided into further sub-zones: (1) the Faridpur Trough; (2) the Barisal High; (3) the Hatiya Trough; (4) the Sylhet Trough; and (5) the Madhupur High.Eldridge M. Moores, Rhodes Whitmore Fairbridge; Eldridge M. Moores, Rhodes Whitmore Fairbridge; Encyclopedia of European and Asian Regional Geology; page 67; Champion & Hall
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