Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

K. Ayyasami ¹, M. N. Gururaja ¹

Affiliations
1 Geological Survey of India, IN

Abstract

A recent search for plant fossils from the East Coast Gondwana sediments of Tamil Nadu has revealed a number of new occurrences. They include Taeniopteris cf. lata, Sphenopteris sp., from the Terani beds from Terani, Tiruchirapally district and Pterophyllum sp., Ptilophyllum acutifolium, Cladophlebis indica, Gingkoites cf. rajmahalensis, Actinopteris sp., from the Sivaganga formations of Ramnad district.

The age of the East Coast Gondwana is reviewed in the light of the recent K-Ar dating of the Rajmahal traps assigning an Aptian age to the lower part of the Rajmahal traps. There is no contradiction in the ages assignable to the coastal Gondwana on the basis of plant and animal fossils.

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M. N. Gururaja ¹, B. R. Jagannatha Rao ¹, B. Bhaskara Rao ¹

Affiliations
1 No. 5-5-449, Mukkaram, Jahi Road, Hyderabad-500001, IN

Abstract

An interesting assemblage of microbiota consisting of filamentous, coccoid and asteroid forms in a stromatolitic black chert sample from Cumbum Formation of Upper Cuddapah sequence, near Zangamarajupalle, Andhra Pradesh is recorded. The microbiota associated with the columnar stromatolite, is dominated by filamentous forms over the coccoids. All the morphotypes reported here from Cumbum Formation are known from the Gunflint chert of Canada dated to be about 1900 to 2000 m years.

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G. Lakshminarayana ¹, M. N. Gururaja ¹, N. Kutumba Rao ¹

Affiliations
1 Geological Survey ofIndia, Chandra Vihar, Hyderabad 500001, IN

Abstract

Variegated clay-clast-bearing sandstones and purple claystones containing upper Gondwana plant fossils viz. Cladophlebis cf. denticulata, Ptilophyllum sp., Pterophyllum sp., Elatocladus conferta and Elatocladus cf. plana are recorded for the first time near Chintalapudi from the upper part of the 'Chintalapudi Sandstone' hitherto believed to be of lower Gondwana age. The present study has established that the newly identified upper Gondwana rock units belong to the Kota Formation overlying the 'Chintalapudi Sandstone' (= Karnthi Formation) with an unconformable contact.

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V. Venkatachalapathy ¹, M. N. Gururaja ²

Affiliations
1 Department of Geology, University of Mysore, Mysore, IN
2 5-5-549, Mukkuramzahi Road Hyderabad, IN

Abstract

The paper records the occurrence of the red alga Aethesolithon from the Neogene limestone of LittIe Andaman Island in the Bay of Bengal. Two species of the genus are described. The new find is significant, for it is the first of its kind from Andaman area and is suggestive of its common occurrence between Andaman and Pacific regions in Miocene.

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