Gas chromatography-mass spectrometry(GC-MS)was used to analyze the pentacyclic triterpenoid distributions,specifically hopane and oleanane fingerprints,in 24 crude oil samples from the Niger Delta depobelts,with the a...Gas chromatography-mass spectrometry(GC-MS)was used to analyze the pentacyclic triterpenoid distributions,specifically hopane and oleanane fingerprints,in 24 crude oil samples from the Niger Delta depobelts,with the aim of defining the petroleum system,filling history,and the age of source rock producing these oils.The results indicate that the Niger Delta oils belong to a single fluvio-deltaic petroleum system,reflecting similar source organic facies and depositional environments.Geochemical parameters,including C29/C30hopane ratios,oleanane index,Ts/Tm,(Ts/(Ts+Tm)),moretane/C30hopane ratios,and C3222S/(22S+22R)ratios,suggest oxic conditions during source rock deposition and thermal maturity of the oils.The presence of terrigenous organic matter and complex filling history are also evident and influenced by multiple phases of sedimentation,and petroleum generation.A comparative plot of geologic time(Paleogene-Neogene age)and oleanane percentage composition show that the crude oils are constrained to the chronostratigraphic ages of their respective depobelts,demonstrating the potential of oleanane-derived parameters for relative dating of hydrocarbon sources,complementing traditional index fossil methods.展开更多
Patterns and rates of deposition,migration and retention of pollutants in man-made strata depend on the depositional history and physical and chemical characteristics of the constituent materials.A sound understanding...Patterns and rates of deposition,migration and retention of pollutants in man-made strata depend on the depositional history and physical and chemical characteristics of the constituent materials.A sound understanding of the spatial and chronological relationships of materials is required for effective evaluation of solid,liquid and gaseous geo-pollution and design and understanding and interpretation of investigations of potentially contaminated land.Description of materials and boundaries requires clear terminology.A proposed terminology has been developed based on experience from a variety of sites in Japan including the experimental infilling of an old quarry.The terminology is commended for further discussion.展开更多
文摘Gas chromatography-mass spectrometry(GC-MS)was used to analyze the pentacyclic triterpenoid distributions,specifically hopane and oleanane fingerprints,in 24 crude oil samples from the Niger Delta depobelts,with the aim of defining the petroleum system,filling history,and the age of source rock producing these oils.The results indicate that the Niger Delta oils belong to a single fluvio-deltaic petroleum system,reflecting similar source organic facies and depositional environments.Geochemical parameters,including C29/C30hopane ratios,oleanane index,Ts/Tm,(Ts/(Ts+Tm)),moretane/C30hopane ratios,and C3222S/(22S+22R)ratios,suggest oxic conditions during source rock deposition and thermal maturity of the oils.The presence of terrigenous organic matter and complex filling history are also evident and influenced by multiple phases of sedimentation,and petroleum generation.A comparative plot of geologic time(Paleogene-Neogene age)and oleanane percentage composition show that the crude oils are constrained to the chronostratigraphic ages of their respective depobelts,demonstrating the potential of oleanane-derived parameters for relative dating of hydrocarbon sources,complementing traditional index fossil methods.
文摘Patterns and rates of deposition,migration and retention of pollutants in man-made strata depend on the depositional history and physical and chemical characteristics of the constituent materials.A sound understanding of the spatial and chronological relationships of materials is required for effective evaluation of solid,liquid and gaseous geo-pollution and design and understanding and interpretation of investigations of potentially contaminated land.Description of materials and boundaries requires clear terminology.A proposed terminology has been developed based on experience from a variety of sites in Japan including the experimental infilling of an old quarry.The terminology is commended for further discussion.
