A comparative analysis of the geochemical characteristics of sediments from the Oligocene Zhuhai Formation(32-23.8 Ma),the Miocene Zhujiang Formation(23.8-16.5 Ma),and the Hanjiang Formation(16.5—10.5 Ma) and a compr...A comparative analysis of the geochemical characteristics of sediments from the Oligocene Zhuhai Formation(32-23.8 Ma),the Miocene Zhujiang Formation(23.8-16.5 Ma),and the Hanjiang Formation(16.5—10.5 Ma) and a comprehensive analysis of the geochemical characteristics of rocks surrounding the paleo-Pearl River drainage contribute to understanding the influences of the Tibetan Plateau uplift on provenance evolution of the paleo-Pearl River.The results show that the geochemical characteristics of sediments from the Oligocene Zhuhai Formation are very different from the geochemical characteristics of sediments from the Miocene Zhujiang and Hanjiang Formations.The ∑ rare earth elements(REE) of mudstone is relatively high in the Zhuhai Formation,204.07-293.88 ppm(average 240.46 ppm),and low in the Zhujiang and Hanjiang Formations,181.32-236.73 ppm(average 203.83 ppm) and 166.84-236.65 ppm(average199.04 ppm),respectively.The chemical index of alteration(CIA) for these samples has a similar trend to the∑ REE:the CIA of the Zhuhai Formation is relatively high and the CIA of the Zhujiang and Hanjiang Formations is relatively low.The uplift of the Tibetan Plateau is crucial to the westward expansion of the paleo-Pearl River drainage.展开更多
Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal t...Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells.展开更多
基金supported by the National Major Scientific and Technological Special Project during the Twelfth Fiveyear Plan Period(Grant No.2011ZX05023-002)
文摘A comparative analysis of the geochemical characteristics of sediments from the Oligocene Zhuhai Formation(32-23.8 Ma),the Miocene Zhujiang Formation(23.8-16.5 Ma),and the Hanjiang Formation(16.5—10.5 Ma) and a comprehensive analysis of the geochemical characteristics of rocks surrounding the paleo-Pearl River drainage contribute to understanding the influences of the Tibetan Plateau uplift on provenance evolution of the paleo-Pearl River.The results show that the geochemical characteristics of sediments from the Oligocene Zhuhai Formation are very different from the geochemical characteristics of sediments from the Miocene Zhujiang and Hanjiang Formations.The ∑ rare earth elements(REE) of mudstone is relatively high in the Zhuhai Formation,204.07-293.88 ppm(average 240.46 ppm),and low in the Zhujiang and Hanjiang Formations,181.32-236.73 ppm(average 203.83 ppm) and 166.84-236.65 ppm(average199.04 ppm),respectively.The chemical index of alteration(CIA) for these samples has a similar trend to the∑ REE:the CIA of the Zhuhai Formation is relatively high and the CIA of the Zhujiang and Hanjiang Formations is relatively low.The uplift of the Tibetan Plateau is crucial to the westward expansion of the paleo-Pearl River drainage.
基金Supported by the China National Science and Technology Major Project(2016ZX05004-004)
文摘Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells.
