Our research programs are
primarily two-fold. One aspect is on the geology of active continental
margins, analyzing stratigraphic sequences to investigate how fundamental
tectonic processes operate where lithospheric plates converge and
collide. The other aspect deals with contaminant groundwater in alluvial
aquifers of Quaternary deltas, and the biogeochemical processes involved in
elevated levels of various contaminants, particularly arsenic in the
aquifers. In addition to purely academic questions about how the earth
works, these research endeavors have important practical long-term
applications for (1) our understanding and ultimate mitigation of geologic
hazards in these regions characterized by devastating earthquakes, land
subsidence, flooding, and (2) assessing natural mineral and energy resources
that are typically concentrated along modern and ancient convergent
continental margins, including an enormous, resource-laden delta.
Our group studies stratigraphic
sequences deposited at modern and ancient collision zones, focusing on
aspects of sedimentary sequences that are sensitive to tectonic settings and
processes. These aspects include such varied geologic features as
lithofacies architecture, detrital mineralogy, patterns of subsidence and
uplift, and deformational styles; this type of research, in order to make an
impact, demands interdisciplinary approaches and a broad base of experience
and expertise. Because the controlling factors can be observed in modern
systems, this work provides valuable constraints both for geoscientists who
work on older geologic terranes and for our understanding of the part of our
environment that provides most of our natural resources. Work in subsurface
lithofacies analysis includes the first reconstruction of a paleo-drainage
system from the huge Himalayan-Indo-Burman orogenic belt and clastic wedge.
Sandstone petrology work, including heavy-mineral analyses and mineral
chemistry, has initiated considerable debates on provenance and early
orogenesis in the eastern Himalayas.
Our group collects groundwater from tube wells penetrated
into various depths in arsenic-effected
alluvial aquifers of Bangladesh in order to record
many a variety of geochemical parameters.
Bioremediation experiments using sulfate-reducing bacteria are underway and
are being constantly monitored. Fresh core samples are collected from 500-
foot deep wells and a series of mineralogical tests are underway to
establish mutual interactions between groundwater and mineral phases that
release arsenic in groundwater. Problematic arsenic concentrations seem to
be confined to inland Quaternary deltas and recent floodplains that drain
from the Himalayas and the Indo-Burman ranges.