Geochemistry of Cenozoic coals from Sarawak Basin, Malaysia: implications for paleoclimate, depositional conditions, and controls on petroleum potential  

作　　者：Lanre Asiwaju Khairul Azlan Mustapha Wan Hasiah Abdullah Say Gee Sia Mohammed Hail Hakimi 

机构地区：[1]Department of Geology,Faculty of Science,University of Malaya,50603 Kuala Lumpur,Malaysia [2]Geological Society of Malaysia,C/O Department of Geology,University of Malaya,50603 Kuala Lumpur,Malaysia [3]Department of Mineral and Geoscience,Malaysia,80000 Johor Bahru,Malaysia [4]Geology Department,Faculty of Applied Science,Taiz University,6803,Taiz,Yemen

出　　处：《International Journal of Coal Science & Technology》2024年第4期104-141,共38页国际煤炭科学技术学报(英文)

基　　金：Lanre Asiwaju received a scholarship for doctorate study from the Nigerian Government through the Petroleum Technology Development Fund(PTDF).

摘　　要：Forty Tertiary coals from Mukah-Balingian and Merit-Pila coalfields of the Sarawak Basin,Malaysia were investigated using bulk and molecular geochemical techniques such as proximate analysis,gas chromatography-mass spectrometry,elemental analyser,isotope ratio mass spectrometry,and inductively coupled plasma mass spectrometry to reconstruct their paleovegetation,paleoclimate,and environments of deposition.In addition,principal component analysis(PCA)of selected geochemical parameters was carried out to determine the controlling influences on the petroleum potential of the humic coals.s13C values and the abundance of terpenoids imply the predominant contribution of angiosperms to the paleoflora.Bimetal proxies(Sr/Ba,Sr/Cu,and C-value),andδD values are generally suggestive of a warm and humid climate during the accumulation of the paleopeats.However,n-alkane proxies(P_(wax),P_(aq),n-C_(23)/n-C_(29),etc.)and polycyclic aromatic hydrocarbons(PAHs)distribution suggest that Balingian coals accumulated under relatively drier and strongly seasonal palcoclimate in the Late Pliocene.When compared with published global average abundances,the investigated coals are mostly depleted in major oxides and trace elements,suggesting peat accumulation in freshwater-influenced environments.Nonetheless,higher(>0.5 wt%)total sulfur content in some Mukah-Balingian coals suggests some degree of epigenetic marine influence.Fur-thermore,the low to moderately-high ash contents of the Sarawak Basin coals indicate the presence of ombrotrophic and rheotrophic peat deposits.PCA result of selected geochemical proxies suggests that source input,paleoflora,and marine incursions are not major controlling influences on the petroleum potential.However,climatic,and depositional conditions appear to slightly influence the petroleum potential of the studied humic coals.

关 键 词：Humic coal Sarawak Basin PALEOCLIMATE Paleoflora-Depositional environment Petroleum potential 

分 类 号：P61[天文地球—矿床学]