1994-95 - Birbal Sahni Institute of Palaeobotany

1994-95
Himachal Pradesh were dated. The age range covered by these profiles span entire Late
Quaternary Period. The pollen analytical investigations in the sediment profile of Sithikhar
swamp, Spiti Valley, Himachal Pradesh indicate cold-arid climatB before 1,900 yrs but later
the climate became colder as evidenced by decline in the frequencies of most plant taxa in
younger sediments. The samples from Takche, Spiti Valley were found to be palynologically
barren.
Charcoal samples (6) relating to archaeobotanical studies from the Harappan site
in Dholavira, Kutch, Gujarat were dated. The calibrated C-14 ages of the samples lead to
the inference that the Harappan Civilization was flourishing in this locality for a much
longer period (2,660 to 1,950 B.C.) than at other sites excavated so far.
For a collaborative programme (with the Geology Depattment, Kumaon University)
on neotectonic studies in Himalayas, sediment samples from Pithoragarh were dated.
The ages of two samples differ widely 30,000 yrs in one case and 2,000 yrs in the other.
Dating of systematically eolleeted profile samples is in progress. Samples of peat from
Nilgiris were dated for a collaboration programme with the Indian Institute of Science,
Bangalore in continuation of earlier studies on palaeoelimate of southern India.
The C-14 dating of shell and kankar samples (8) in Gangetic alluvium was continued
for understanding the development of alluvial deposits and climate changes in Holocene
in the Indo-Gangetie Plain.
Five peat samples from West Bengal were dated on payment for Centre for Study of
Man and Environment, Caleutta to reconstlUct palaeoclimate and environment and their
changes during the Quaternat·y of lower Bengal delta in a precise geochronological framework.
Six sample~ of coral, sediment and wood were dated for Jadavpur University on
payment for studies relating to past sea level and palaeoclimate. One charcoal sample was
dated for Lumbini Development Trust, His Majesty's Government, Nepal from a site in
Lord Buddha's birth place, Lumbini in Nepal.
Five samples ofbmnt wood, sediment and ehat·eoal were dated as palt of a programme
relating to the investigations by NGRI of 1993 eaIth quake in Latoor, MahaI·ashtra.
G. Rajagopalan
For the reconstruetion of past trophic conditions around Didwana Lake, Rajasthan
on the basis of elemental analysis, phospholUS eoncentrations (authigenic phospholUs passes
to the sediments primarily through biotic cycling) at different depths of trial trench were
measured. This is in addition to the measurements of elemental, organic and mineral eontents
carried out earlier in these sediments, which covers a time span of 8, 100 yrs BP. Five
samples were analysed for measuring authigenic phospholUs concentrations using Spectrophotometer.
We concentrations range from 7,880-1,8250 ppm . Conclusions derived are
in agreement with those on the basis of other elemental, organic and mineral content data.
G. Rajagopalan & B. SekaI·
Programme 8.3 Potassium-Argon dating of sedimentary and igneous
rocks
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