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PESD_GSU_20200717_0523_(ongoing): Paleogeography of the Neogene
foreland basin of Eastern Himalaya and its relationship with
contemporaneous sediments of Mizoram

PESD_GSU_20200717_0523_(ongoing)
1. Title of the Project:

Paleogeography of the Neogene foreland basin of Eastern Himalaya and its relationship with
contemporaneous sediments of Mizoram

2. Name of Proposing Scientists:
Tapan Chakraborty
3. Brief objectives and justification:
The evolution of a foreland basin is controlled by continuous interaction of allogenic
processes like tectonics and climate as well as autogenic sedimentary processes. Careful
analysis of basin-fill strata should reveal the sedimentary processes active during deposition
and the tectonic-climatic controls on its deposition. Over the last decades several workers
attempted to reconstruct the Neogene evolution of the axial Paleo-Brahmaputra River in this
basin. was reconstructed by several workers based mainly on the analysis of the detrital
minerals. Other underlying considerations of these works were that the contemporaneous
succession of the Bengal Basin and Eastern Himalayan Foreland Basin (EHFB) were
deposited in an exclusively continental fluvial environment. However, these studies lack the
basic data on the fluvial origin of these strata. As a result the reconstructed paleogeographic
models differ amongst the workers, often ambiguous and inconsistent with the on-ground
observations. Recent findings of wave-/storm- and tidal signatures and occurrence of marine
trace fossils at several horizons of the Neogene sediments raise questions against the decades’
old theory of continental paleogeographic evolution of the EHFB. The main goal of this study
is analyzing the sedimentary, petrographic data in the context of the depositional environment
followed by understanding Himalayan tectonism (particularly advancing Himalayan
deformation front and uplift of the Shillong Plateau), regional climatic changes and
geomorphic evolution of the foreland basin flanking the rapidly exhuming eastern syntaxis.

The sediments of the Bengal Basin and the accretionary deposits of the Chittagong-Tripura-
Mizoram-Nagaland fold belt shows close connection with the EHFB based on their
depositional age, existence of similar kind of palynomorphs and Himalayan-Transhimalayan
source material. The project was aimed to study the Neogene sediments around Aizawl to
understand the connection with the EHFB through the evolution of the paleo-Brahmaputra
and coupling it with upheaval of the Shillong Plateau and Indo-Myanmar Range. The
traditional view of the existence of two distinctive entities of the Bengal Basin and the EHFB
is already being questioned on the basis of new data.

4. Name of Others Scientists associated with their affiliation:
From the Institute:
1. Professor Soumendranath Sarkar, Retired Professor, Indian Statistical Institute 2. Arijit
Debnath, SRF, GSU, Indian Statistical Institute
From Other Institutions:

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