Petrography, Palynology, and Organic Geochemistry of Neogene Paralic Coal, Mukah,Sarawak, Malaysia: Implications For Paleomires, and Peat-Forming Conditions [post]

Nor Syazwani Zainal Abidin, Khairul Azlan Mustapha, Wan Hasiah Abdullah, Zainey Konjing
2021 unpublished
The eight coal seams of Neogene paralic coals from Mukah coalfield, Sarawak, Malaysia, were investigated using petrographical, palynological, and organic geochemical analyses to describe coal-forming vegetation, conditions during peat development and precursor mires, and their associations in a sequence-stratigraphic context. The petrographic data of the coals implies the existence of oxygen-deficient and water-saturated conditions in the precursor mires. The condition of low mire oxidation was
more » ... followed by biomass loss from the mires. The Mukah coals are suggested to be deposited in freshwater peat swamps, and the rich preservation of angiosperm pollens indicates that the organic matter in dense and lowland forest vegetation was mostly terrigenous. The overwhelming presence of Casuarina and Calamus types, suggesting the paleomires were closely linked to Kerapah/Kerangas peat forest and marginally bordered by rattan and supported by the biomarker data. Rheotrophic–ombrotrophic mires were temporarily formed because of water table fluctuations, which strongly depend on ever-wet climate changes and syn-depositional tectonic during the Neogene, resulting in balanced to high peat accumulation and preservation. A maximum thickness of 35m of peat deposits that formed between 10,000 and 175,000 years ago is suggested. The coals are proposed to be influenced by transgressive to initial highstand cycles within the paralic setting.
doi:10.21203/rs.3.rs-952318/v1 fatcat:ottqltkeqnhu5aulpcrhvob45a