Palynological investigation of the Gondwana outcrop from Vemavaram with remarks on the age of the bed

Abstract

The present paper deals with the dispersed spores-pollen recovered from Vemavaram shale (Jurassic) in the east coast Gondwanas, Andhra Pradesh, India. The palynological assemblage comprises 21 genera and 43 species, out of which two genera, viz. Ramanujamiaspora and Singhiapollis are new. The assemblage is dominated by gymnospermous pollen grains mosUy represented by Callialasporites, Sillghiapollis, Podocarpidites, Laricoidites and Araucariacites. The trilete spores are not common and mostly represented by Cyathidites and Ramanujamiaspora. The monolde and monocolpate pollen grains are rare. The trisaccate pollen grains are also meagrely represented by Podosporites. Operculate pollen grains are also rare and represented by Classopollis and Granuloperculatipollis. The present palynological assemblage has also been compared with the other known Jurassic assemblages of India. Palynological evidence indicates an Upper Jurassic age for the Vemavaram shales.

Palynology of the Athgarh formation, near Cuttack, Orissa

“…In the paucity of the pteridophytic spores, the Athgarh mioflora is strikingly similar to the one described from the Vemavaram beds (Kar & Sah, 1970;histogram III in Bharadwaj, 1969). In both miofloras the dominant genera are Araucariacites and Callialasporites.…”

“…The J urassic-Lower Cretaceous miofloras are known from the Rajmahal Hills (Sah & Jain, 1965), Madhya Pradesh (Bharadwaj et al 1972;Maheshwari, 1973Maheshwari, , 1974, Andhra Pradesh (Kar & Sah, 1970), Gujarat (Venkatachala & Kar, 1970), Rajasthan (Srivastava, 1966;Banerjee, 1972;Lukose, 1972) and the Cauvery Basin (Venkatachala et al, 1972), and others.…”

“…are so far not known from the Vemavaram beds. Kar and Sah (1970) palynologically date the Vemavaram beds as Upper Jurassic, but on the basis of faunistic evidences, afforded by the ammonites and fish remains, the beds at Vemavaram do not seem to be older than Upper Neocomian. Considering the dissimilarity of the Athgarh and Vemavaram megafloras, the overall similarity in the generic frequency count of the two miofloras is inexplicable.…”

Palynostratigraphy of coal deposits in Jabalpur stage, Upper Gondwana, India

“…Lathi Formation resembles very much the Variegated Shales of the Salt Range which has an abundance of Classopollis complex (50%) and the younger beds in Leigh Creek Coal Measures of Australia (Playford & Dettmann, 1965). Ramanujam (1957), Kar and Sah (1970) and Bharadwaj (1969) and *Granuloperculatipollis etc. The asterisk marked genera have not been found in the assemblages of the Jabalpur Stage.…”

“…Fossil spores and pollen grains have been described by Srivastava (1963Srivastava ( , 1966 from the Lathi Formation in the Jaisalmer area of W. Rajasthan. Ramanujam (1957), Bharadwaj (1969) and Kar and Sah (1970) have studied the mioflora from Vemavaram on the East Coast of India. Rao (1943) and Vishnu-Mittre (1954) have studied the miospore contents from the Nipania Chert, Rajmahal Hills, Bihar.…”