Contribution of terrestrial material in West Sulawesi based on geochemical and biostratigraphy analysis Y. Sutadiwiria, D. Syavitri, Yeftamikha
1Geology Department, Faculty of Earth Technology and Energy, Trisakti University,
Jalan Kyai Tapa No. 1, Jakarta 11440, Indonesia
Abstract
The LYS and KYS exploration well were drilled in the north and south of the Bdg Block, onshore West Sulawesi. Geochemical analysis, such as vitrinite reflectance, gas chromatography, and gas chromatography/mass spectrometry, was conducted on cutting samples of LYS and KYS wells. The existing biostratigraphic analysis shows that LYS samples are in the marine environment (outer neritic-upper bathyal) with age of Late Miocene-Pleistocene, while KYS well samples are also in the marine environment (inner neritic-batial) with age of Middle Eocene-Early Pliocene.
There are few terrestrial material found, such as oleanana, bikadinana, taraxastana, and gamaserana that indicates only a small amount of terrestrial material that was carried and moved to the marine environment. The high oleanana to C30hopana ratio (oleanana/C30hopana) in both wells showed the contribution of higher plants. There are variations in the value of the oleanana/C30hopana ratio in KYS well samples at Neogene age which is caused by the abundance of angiosperm plants during the Neogene period (Middle Miocene-Late Miocene). The ternary diagram shows abundance of sterana (C27, C28, and C29) with marine organic material input, followed by contributions from terrestrial material, and deposited in the marine environment
Keywords: West Sulawesi, geochemical, oleanana, Neogene, angiosperm
