Annual Report 2011-2012 - Birbal Sahni Institute of Palaeobotany

EBIRBAL SAHNI INSTITUT
Annual Report 2011-2012
1946
OF PALAEOBOTANY
Participated in the excavation and collected
botanical remains and samples for palynological and
phytolith analyses from the Harappan archaeological sites
Khirsara and Kotada-Badli in Kachchh district, Gujarat.
A.K. Pokharia & Ruby Ghosh
Maceration of samples already collected from
Kumhar Tal near an archaeological site (Ahirua
Rajarampur in District Kannauj, UP) of Ganga valley for
pollen and phytoliths are in progress.
Ruby Ghosh (w.e.f. 29.07.2011)
Project 11.2: Studies on phytodiversity and ethnobotany of Bilaspur in Chhattisgarh State and
Anuppur in Madhya Pradesh State
Different localities of vegetation and tribal rich areas
of Achanakmar, Amarkantak and Bilaspur have been
surveyed and collected about 500 plant specimens. All
plant specimens are identified as 197 species belonging
Isotope and Geochemistry Group
to 169 genera and 77 families. Ethnobotanical survey is
also conducted in different Baiga dominant areas and
documented 400 medicinal plant species used for
treatment of various diseases.
D.C. Saini
Project 12.1:
Tectonoclimatic signatures in Ladakh and Lahul sectors of Tethyan Himalaya during
Quaternary period: A multi-proxy approach using mineral magnetic, geochemical and
geochronological parameters
The geomorphological landscape of young fold
mountain belt can change drastically even within short
time scales of few thousand of years. The existence of a
185 km valley lake during the Late Quaternary (~20 ka
BP) in the Ladakh Himalayas, occupying the present day
Tangtse and Shyok river valleys, covering an area of 1150
sq km is one such example. This lake was the western
extension of the present day Pangong Tso lake. The area
lies in the active zones of Karakorum Fault (KKF) and
Shyok Suture (SS) in NW Trans Himalaya. A slip rate
along KKF with the help of stream offset is calculated as
2.6 mm/year. In spite being washed away by the combined
effects of active tectonics and intense erosion, the buff
colored clay-silt-sand lacustrine facies is well-preserved
at few places and is also exposed almost continuously on
both banks of the rivers indicative of the existence and
extent of this lost lake.
Indus river valley basin situated in NW Indian
Himalaya is tectonically unstable, exhibits a complex
topography, landscape relief and varied Quaternary
sedimentation. A 365 km transact along the valley in
Ladakh (Trans Himalayas) has been conducted, which
reveals the existence of major palaeolakes that sustained
between ~ 17,000-14,000 yrs BP and 10,000-1500 yrs
BP. Of the two lakes one was formed post LGM times
around 17,000 yrs BP and breached out prior to Older
Dryas period indicating of warmer and congenial rainfall
and melt water supply between these two globally marked
cold episodes. Other lake was formed after the Younger
Dryas and existed till ~1,000 yrs BP indicative of the
Holocene warming responsible for its sustenance. These
lacustrine sediments and the climate and tectonic activity
that may have taken place during this age bracket are
studied in details. The major geomorphic landforms are
alluvial fans, debris cones, unsorted pedestals, fluviolacustrine
deposits, scree, talus cone, etc. Ubiquitous mass
movements and catastrophic land sliding, due to tectonic
activity and abnormally high precipitation has transported
the material from steep slopes to valley bottoms and was
responsible of forming lakes (preserved as thick piles of
fine sediment), while the outburst floods redistributed the
sediment down valley.
The water and channel sand samples have been
collected from 60 and 32 locations respectively, which
includes samples from the entire stretch of Indus, Shyok,
Nubra, Tangtse and Zanskar rivers and few first order
streams and hot springs. The physical parameters such
as temperature, pH, conductivity, dissolved solids, etc are
measured in the field itself. The major cation and anions
are analyzed at the Environmental Division of CIMFR,
Dhanbad. Some trace metals in water samples and all
major and trace elements of the sediment samples are
measured at School of Environmental Sciences, JNU, New
Delhi. The preliminary results show that Indus water is
getting their ionic load largely from the silicate rocks;
however all other smaller rivers show a mix of
contribution from silicate and carbonate sources.
Anupam Sharma & Binita Phartiyal
www.bsip.res.in
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