PALYNOLOGY AND PALYNOFACIES OF THE PERMIAN STRATA IN THE KOTHAGUDEM SUB BASIN, ANDHRA PRADESH, SOUTHERN INDIA

摘要

Quantitative and qualitative palynological investigations of 448 m deep borecore A/333, 5B Incline from Kothagudem sub-basin have revealed two distinct palynological assemblages. Palynoassemblage-I (425.50 to 448 m) is characterized by the dominance of non-striate bisaccates mainly, Scheuringipollenites spp. (43-57%; S. barakarensis, S. maximus, S. tentulus) and Ibisporites spp. (7-15%; I. diplosaccus, I. jhingutdahiensis). Striate bisaccates viz., Striatopodocarpites spp. (10-18%; S. brevis, S.decorus, S. diffuses) and Faunipollenites spp. (5-25%; F bharadwajii, F. goraiensis, F varius) are sub-dominant. Palynoassemblage-II (202 - 240 m) is characterized by the dominance of striate bisaccates mainly, Striatopodocarpites spp. (7-38%; S. decorus, S. diffuses, S. brevis, S. ovalis), Faunipollenites spp. (14-38%; E varius, E bharadwajii, Fgoraiensis) alongwith good percentage of Striasulcites spp. (15-33%; S. tectus, S. ovatus). Stratigraphically significant taxa indicating Late Permian (Raniganj) affinity recorded in the assemblage in rare percentage includes Chordasporites australiensis, Densoisporites sp., Guttulapollenits, hannonicus, Hamiapollenites insolatus, Klausipollenites schaubergeri, Lunatisporites spp. (L. paliensis, L. pellucidus), Osmundacidites sp., Striomonosaccites ovatus, Strotersporites communis and Weylandites obscures. By palynocomposition Artinskian and Guadalupian age has been assigned to Palynoassemblage-I and Palynoassemblage-II respectively. By the stratigraphic division of the palynofacies associations, three intervals were documented in fluviatile sequence. Interval 1 (I1) is distinguished by the dominance of palynomorphs with a moderate water level, low energy and depleted oxygen conditions; interval 2 (I2) is characterized by high water level alongwith the pre-eminence of amorphous and degraded terrestrial and interval 3 (I3) predominated by charcoal is illustrated by the lowest water level in the paleomire with highly oxidizing conditions.