Sequence Stratigraphy, Architectural Elements and Depositional Evolution of the Northeast Bengal Fan in Offshore Myanmar

On the basis of high-resolution 2D and 3D seismic data as well as some well data, an integrated seismo-stratigraphic study was carried out in offshore northwest Myanmar in order to define and understand the Miocene-Pleistocene sequence stratigraphic framework, deepwater depositional system and reservoir potential of the northeast Bengal fan. Five depositional sequences were recognized in the Miocene– Pleistocene Bengal fan. A typical depositional sequence in outer shelf and upper slope is mainly composed of LST canyons, TST sediments and HST deltas. Whereas a typical depositional sequence in lower slope and basin floor is mainly composed of LST deepwater depositional system, and TST and HST are condensed. The analysis of seismic facies and seismic attributes indicate that deepwater architectural elements of the Miocene– Pleistocene Bengal fan mainly include canyons, slope channel complexes, individual channels, channel-levee complexes, depositional lobes and mass-transport complexes. The investigation of depositional evolution suggests that the northeast Bengal fan experienced rapid progradation during the Miocene-Early Pliocene and gradual retrogradation during the Early Pliocene-Pleistocene.