Palynology of Late Oligocene to Pliocene succession in Temana Field of Balingian Province, offshore Sarawak

Palynological records in Late Cenozoic succession from two Temana wells were reviewed and investigated for palynomorph assemblages, biostratigraphic correlation and age dating, as well as for paleoenvironment and paleoclimate interpretation. The data indicates abundant and diverse pollen and spores deposited in marginal marine with tidal influence setting. Three main palynomorph assemblages were identified from the Temana wells: (1) Zone-1 (dated as Late Oligocene), characterized by abundant Florschuetzia trilobata and dominant montane and seasonal elements such as Picea, Tsuga and Pinus, (2) Zone-2 (Early to Middle Miocene), dominated by Kerapah Casuarina-type pollen and characterized by increasing abundance of Rhizophoraceae mangrove pollen. Zone-2 can be further differentiated into Subzone-2a and Subzone-2b based on later appearance of Florschuetzia levipoli, and (3) Zone-3 (Late Miocene to Pliocene) occurring above a major angular unconformity is marked by a high percentage of the rainforest pollen Rubiaceae and a minor increase in seasonal elements. The interpreted paleoclimate inferred from temporal variations in hinterland-derived pollen shows cyclical pattern from seasonally dry climate in the Oligocene to warm and ever-wet climate, marked by the growth of Kerapah peat swamp during Early to Middle Miocene, and finally a prolong humid climate characterized by rainforest vegetation with minor intermittent seasonality since Late Miocene/Pliocene.