Biostratigraphic analysis of Tanjung-1 and Tapi-1 wells in Malaysia-Thailand joint development area (JDA) Of North Malay basin based on foraminifera and palynology / Fatin Nur Adilah Md Idris

Fatin Nur Adilah , Md Idris (2023) Biostratigraphic analysis of Tanjung-1 and Tapi-1 wells in Malaysia-Thailand joint development area (JDA) Of North Malay basin based on foraminifera and palynology / Fatin Nur Adilah Md Idris. Masters thesis, Universiti Malaya.

	PDF (The Candidate's Agreement) Restricted to Repository staff only Download (290Kb)
	PDF (Thesis M.A (Restricted due to data confidentiality) Restricted to Repository staff only Download (3483Kb)

Abstract

The JDA is a tertiary basin located to the north of North Malay Basin. It consists of thick rift successions with lacustrine deposits, followed by a sag phase of mainly paralic and shallow marine sediments during the Miocene. This study analyzed selected wells which are Tanjung-1 and Tapi-1, located 36.6km apart. The analyzed depth of Tanjung-1's ranged from 3050-740 meter of measured depth (mMD), and Tapi-1's ranged from 2800-740mMD. Tanjung-1 had 48 taxa of palynomorphs, whereas Tapi-1 contained 72. The palynomorphs have been grouped into mangrove taxa, hinterland pollen ‘sum’, spore, algae, and dinocysts. A total of 13 foraminifera taxa including the agglutinated, calcareous hyaline, and calcareous porcelaneous groups identified from both wells. Species composition in the wells, supported by environmental parameters such as particle size analysis, organic matter, and calcium carbonate content in the sediments, suggested the paleodepositional environment ranged from fluviolacustrine, fluviomarine, marginal marine, and inner neritic. Notice that the inner shelf in Tanjung-1 is dominated by Asterorotalia pulchella and the accessory species is Pseudorotalia schroeteriana. Whereas Tapi-1, is dominated by Pseudorotalia schroeteriana but Asterorotalia pulchella is absent. For delta front species, Bigenerina sp. and Reophax sp. are found throughout Tapi-1.While, in Tanjung-1, Bigenerina sp. and Miliammina sp. abundantly in Serravallian to Tortonian and Cavarotalia annectens survive from Tortonian to Messinian. Hence, the age of the succession is determined based on the quantitative palynological data that follow PR zones which have been the standard reference for the chronostratigraphic of Malay Basin. Therefore, a spatial correlation has been made referring to their distribution pattern supported by gamma ray log. The T-R event was observed that led to the formation of delta and inner shelf bioprovinces. During Aquitanian, Tapi-1 recorded a high abundance of benthic foraminifera whereas Tanjung-1 recorded the least specimens of Rhizophora and benthic foraminifera. Myrtaceae acme zone in Tanjung-1 and the abundance of Myrtaceae in Tapi-1 during Burdigalian supported the occurrence of a regression major event. The transgression during Langhian resulted in the formation of Florschuetzia linage zone in both wells. Meanwhile, the PR 10UC, PR 11, and PR 12LC went missing because the northern flank of the Malay Basin lifted up or tilted, leading to a difference in distribution later. Regression in Serravallian is indicated by the abundance of hinterland pollen dominated by Ilex type in Tanjung-1, and Florschuetzia trilobata acme in Tapi-1. Reactivation of Malay Basin axial shear zone in the Middle to Late Miocene, caused the shallow marine sag basin to form. Meanwhile, the temporal distribution of the species present is governed by glacio-eustatic sea -level fluctuations that contribute to sediment accumulation. Glacial periods with low sea levels become cooler and drier, marked by montane forests with frost-tolerant conifers, typically of Podocarpus, Picea, and Pinus. Interglacial periods with high sea levels become wetter and warmer highlighted by rainforest, peat swamp, and back mangrove swamp taxa. With that, a depositional model of the Tanjung-1 and Tapi-1 wells is generated together with reconstructing the gross depositional environment model of JDA in North Malay Basin.

Actions (For repository staff only : Login required)