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 sp...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.展开更多
基金Lanre Asiwaju received a scholarship for doctorate study from the Nigerian Government through the Petroleum Technology Development Fund(PTDF).
文摘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.
