Reconstruction of the upper gondwana palaeoclimates based on palynostratigraphy, palynofacies and sedimentology of the Jurassic sequences in the Tabbowa Basin, Sri Lanka

Abstract

The palynological study of the Tabbowa sediments from Sri Lanka reveals predominant Jurassic gymnospermous pollen assemblage (Araucariacites australis, A. cooksonii, A. fissus and Callialasporites dampieri with spore Murospora florida) belongs to the Callovian-Kimmeridgian age. The collective palynoflora can be correlated to the Classopollis–Araucariacites–Shanbeipollenites assemblage zone of Africa and the Murospora florida zone of the Indian subcontinent and Australia, showing close phytogeographic relationships from the middle to late Jurassic periods. Palynofacies and sedimentological investigations inferred oxic-dysoxic conditions that prevailed when the sediments and organic matter deposited in shallow brackish water conditions in a fluvio-deltaic environment.