1994-95 - Birbal Sahni Institute of Palaeobotany

BSIP
From amongst the forked Dicroidium, D. odontopteroides has been identified on the
basis of exomorphic and epidermal features. So far, the records were made only upon external
morphology and the specimens were not forked. Presence of D. odontopteroides in
Nidpur bed is of significance because of its wide-spread occurrence all over the
Gondwanaland.
Nearly 500 specimens of Dicroidium leaf in varied forms are being studied in order
to evaluate the fossil population of Dicroidium found in the Indian Peninsula as well as in
other Gondwana regions.
Shyam C. Srivastava
Programme 2.4
Palynostratigraphy of Gondwana Sequence in Son­
Mahanadi Graben
Objecrive To analyse palynoassemblages with a view to interpret floral
changes, boundary transitions and age determination at afiner
level in the intraformational succession olSon Valley cOalfields
To identify Talchir/Athgarh relationship in the Talcher
Coalfield and Athgarh Basin
The palynological studies of samples ofbore-hoJe TCC-19, drilled by Geological
Survey of India near Chendipada, Talcher Coalfield have yielded three distinct
palynoassemblages. The Assemblage I is recorded from the lowermost coal horizon of the
sequence at 170.96 to 177.24 m depth, dominated by the pteridophytic spores -Microbaculispora
together with Brevitriletes and Lacinitriletes. The Assemblage II at 65.60 to 169.22
m depth is dominated by the nonstriate bisaccate Scheuringipollenites and is recorded from
the coal-bearing sediments just below the marker conglomeratic pebbly bed. Assemblage
Ill, recorded at 10.75 to 60.47 m depth in the coal-bearing horizon above the conglomeratic
bed, shows the dominance of striate bisaccate pollen Faunipollenites and Striatopodocarpites.
The Assemblages I and II are comparable with the palynoflora of Early Barakar Stage
while Assemblage 111is comparable to the mioflora of Late Barakar Stage. The occurrence
of acritarchs at 65.60 to 67.21 m and 10.75 to 60.45 m depth indicates presence of high
salinity condition whicb started before the deposition of conglomeratic bed and continued
even after its deposition. The palynofacies analysis of coal samples reveals that low energy,
lacustrine conditions were prevailing during the coal deposition.
The palynological studies of bore-hole TP-8, drilled by MECL in Talcher Promotional
Block, reveal Late Permian assemblage equivalent to Raniganj palynoflora of Damodar
Basin and Is represented by the dominance of Striatopodocarpites and Faunipollenites along
with characteristic palynotaxa, viz., Gondisporites, Navalesporites, Satsangisaccites and
Falcisporites. The taxa Lundbladispora, Play/ordiaspora, Lunatisporites and Goubinispora
at 350 m depth indicate its affiliation with Early Triassic palynoassemblage of Raniganj
Coalfield. The assemblages from younger levels have dominance of Striatopodocarpites
but with increased frequency of Lundbladispora and Lunatisporites at 334.00 m depth and
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