Annual Report 2011-2012 - Birbal Sahni Institute of Palaeobotany

EBIRBAL SAHNI INSTITUT
1946
OF PALAEOBOTANY
Annual Report 2011-2012
footprint and fight global warming. It is a crucial element
in the balance of oxygen and carbon dioxide in the
atmosphere.
S.K. Basumatary, Kanupriya Gupta, S.K. Bera
[& S.K. Acharya & Sneha Bera (BCKB, W. Bengal) &
M. Ahmad (Goalpara College, Assam)]
Prepared manuscript based on Isotope analysis
(d 13 C and d 18 O) of tree-ring of Abies pindrow collected
from forest near to Dokriani Bamak glacier, Uttarakhand.
A. Bhattacharyya & S.K. Shah [& R. Ramesh
(PRL, Ahmedabad)]
Past climate and vegetation history have been
analyzed from two profiles collected from Nonkremp close
to Shillong, Meghalaya based on pollen data.
A. Bhattacharyya, S.K. Shah & Sandhya Misra [&
Pawel Prokop Polish Academy of Sciences, Poland)
Studied the tree line dynamics of Himalayan silver
fir (Abies spectabilis D. Don) based on its tree-ring data
and age stand distribution at Langtang National Park,
Central Nepal. The study shows that the average tree
density of the species in the study area (total 48 plots of
20 m x 20 m) was 236 no/ha while that for sapling and
seedling in the study area was 255 and 350 no/ha,
respectively. The stand character and age distribution of
the species showed a high level of recruitment in the recent
decades, with decreased in average age along with
increased altitude. Tree-growth climate relationship
showed negative response with temperature of March-
May. Upward advancement of tree line is expected in
the coming recent decades though not necessarily uniform
through the line.
S.K. Shah [& R. Bhuju, Nepal Academy of S&T, Nepal)]
Two Pleistocene-Holocene sedimentary profiles
from Darjeeling Sub-Himalaya have been studied for
palaeoclimatic reconstructions using pollen and phytolith
proxies.
Ruby Ghosh [& Subir Bera,
University of Calcutta, Kolkata)]
The ongoing collaborative work in Spiti Valley is
to study for their sedimentary architecture and
chronological parameters. Lithofacies analyses of relict
sedimentary sequences located in the rain shadow zone
of Tethyan Himalaya shows six different lithofacies. The
six different lithofacies identified can be grouped into three
lithofacies associations: i) glacial outwash, ii) sedimentation
in channel and accreting bars under braided conditions,
and iii) formation of lakes due to channel blockage by
landslide activity. Abnormal Monsoon Years at 14-8 ka
and 50-30 ka are responsible for the phases of channel
damming and lake formation in the valley. A research
paper is under review.
Anupam Sharma & Binita Phartiyal [& Pradeep Srivastava
& Yogesh Ray (WIHG, Dehradun)]
The Spiti river basin in the NW Indian Himalaya
(31–33°E:77–79°S), is tectonically unstable, exhibiting a
complex topography, landscape relief and varied
Quaternary sedimentation. The major geomorphic
landforms are fill terraces, strath terraces, alluvial fans,
debris cone, fluvio-lacustrine deposits, scree and talus
cone are present throughout the valleys. The dynamics
of landscape evolution of the region are currently not well
understood. An attempt is made by using the
geomorphometry approach to access the areas in terms
of its neotectonic instability as this basin feeds the river
Sutlej. The Spiti and the Parachu basin of the Sutlej valley
are mapped and assessed in the valley to elucidate the
spatio-temporal scale dependencies of surface have been
in news several times in the last decade causing flooding
downstream, due to the outburst of glacial lakes and the
temporary lakes formed during the land sliding even by
the processes active in the region.
The Spiti river (constituting of Spiti and Parachu
basins) is examined using and geomorphic field methods
(Spiti basin), and OSL chronologies by Phartiyal et al.,
(2009) are used. During the Quaternary a ubiquitous mass
movements and catastrophic land sliding transported
material from steep slopes to valley bottoms is seen which
was responsible of forming lakes (preserved as thick piles
of fine sediment), while the outburst floods redistributed
sediment down valley along with affecting life and property
downstream. The morphometric approach such as Basin
Asymmetry (AF), Topographic Symmetric Factor (T),
Stream length Gradient Index (GI) Hydauralic Sinuosity
Index (HSI), Topographic sinuosity Index (TSI) and
Standard Sinuosity Index (SSI) have helped in
understanding tectonic and climatic perturbation. Our
observations point towards a tectonically active region
with enormous piles of loose, unconsolidated sediment
cover which could be disastrous during the slight shift of
the climatic and tectonic forces operating in this area.
Binita Phartiyal [& G.C. Kothyari (ISR, Gandhinagar)]
In order to determine the mid Holocene climatic
fluctuations, multi-proxy study involving palynology,
phytolith, clay mineralogy, geochemistry and magnetic
susceptibility are carried out on Wadhavana lake sediments
of main land Gujarat area. The 2.3 m sediment profile of
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