Mahesh Shivanna

A palynostratigraphic study of the Umrer Coalfield of Wardha Basin, Maharashtra State, Central India and its putative correlation with Indian and other Gondwanan areas

The present work details the results of the palynological studies carried out in the Umrer Coalfield of Wardha Basin of Maharashtra State, Central India. The coalfield covers an area of 4 sq. km and is characterized by three coal seams designated as bottom, middle and top seams with partings. Statistical analysis of the palynomorphs from these sediments have revealed the dominance of radial monosaccate pollen grains of the genus Parasaccites and subdominance of non-striate bisaccate genus Scheuringipollenites in association with other typical early Permian taxa viz. Crucisaccites, Callumispora, Caheniasaccites, Brevitriletes, Tiwariasporis and Primuspollenites. This association characterizes the palynoflora of the upper Karharbari Formation of India on the basis of which the Umrer Coalfield has been assigned an early Permian late Sakmarian to early Artinskian age. It is further authenticated by the presence of the species Crucisaccites monoletus significant of the Karharbari Formation. Age deductions have also been made by correlations with similar assemblages from different basins in India and early Permian palynoflora from other Gondwanan continents some of which have been associated with radiometrically dated sediments.

Coníferas pensilvanianas da tafoflora interglacial de Monte Mor, Grupo Itararé, São Paulo, Brasil: as mais antigas da Bacia do Paraná

The pre-glossopterid macroflora from the Volpe Ranch, in Monte Mor (State of São Paulo), was deposited during an interglacial context of the Itararé Group. It is characterized by the Paranocladus-Ginkgophyllum-Brasilodendron Association and is included in the middle-basal part of the Itararé Group outcrop, in the NE of the Paraná Basin. It is similar to the Argentine macrofloristic association Krauselcladus-Asterotheca Phytozone (ex-Interval Zone) and its palynofloristic contents belong to the Crucisaccites monoletus Palynozone (Kasimovian to Gzhelian). The conifers in this assemblage are represented by macro and microfossils and record the first level of occurrence of conifers in the basin. They are documented by leafy branches impressions and compressions of Paranocladus dusenii Florin and Buriadia heterophylla (Feistmantel) Seward and Sahni emend. Singh, and platyspermic seeds of the genus Paranospermum. Cuticular studies allowed to correlate the presence of Paranocladus dusenii with the platyspermic seeds Paranospermum cambuiense Ricardi-Branco and to identify a new species of Paranospermum as well. Previous palynological studies in this level led to the recognition of some pollen grains affinis to the gymnosperms (conifers, ginkgoaleans and pteridospermales) comprising monosaccate and bisaccate forms allocated to the genera Cannanoropollis, Plicatipollenites, Potonieisporites and Caheniasaccites indicating certain diversity of conifers as early as in Pennsylvanian. The association of conifers and Ginkgophyllum represents a mesoxerophytic tree community. The abundance of their fragmented material in the taphofloral assemblage suggests allochthonous origin transported toward a deltaic plain which were associated to a parautochthonous origin material. Their fossiliferous sandy matrix overlying the coal also suggests a higher energy agent of transport.