The eastern part of the Caucasus orogen,termed the Georgian segment,is mainly underlain by highly deformed Lower-Middle Jurassic shales,sandstones,and volcaniclastic rocks,and cut by numerous intrusive bodies of vario...The eastern part of the Caucasus orogen,termed the Georgian segment,is mainly underlain by highly deformed Lower-Middle Jurassic shales,sandstones,and volcaniclastic rocks,and cut by numerous intrusive bodies of various compositions.All units contain a variety of mineral deposit types and their surrounding zones of hydrothermal alteration.Detailed geological and metallogenic research,after 30 years stagnation,has led to important new information regarding the evolution of this region.Three main stages of magmatic activity are now clearly distinguished.The oldest magmatism comprises early Jurassic events,related to extensional tectonism,with volcanism and subvolcanic plutonism that ranged from rhyolitic,through dacitic and andesitic,and to basaltic.Additional extensional processes(in Bajocian times)were characterized by intrusion of a gabbro and diorite dike system into slightly older late Early Jurassicearly Middle Jurassic formations.The final magmatic event was associated with Middle Jurassic folding and uplift during which multiphase diorite plutons were emplaced.Intense hydrothermal activity related to this latest magmatism was responisble for important polymetallic mineralization including more than 100 historically recognized outcropping occurrences.A detailed study of 11of the more significant of these occurrences has indicated anomalous concentrations of base metals as well as gold,thorium,yttrium,cobalt,cadmium,and bismuth.In addition,several new and potentially significant mineral occurrences were discovered,including two designated here as Gelia and Lechuri.展开更多
The Paleogene geological framework and evolution process in the central anticline zone in the Lufeng 13 sag in Pearl River Mouth Basin is well analyzed through seismic data and drilling data,and control of tectonic ev...The Paleogene geological framework and evolution process in the central anticline zone in the Lufeng 13 sag in Pearl River Mouth Basin is well analyzed through seismic data and drilling data,and control of tectonic evolution on hydrocarbon accumulation is also discussed.The results show that the central anticline zone in the Lufeng 13 sag develops the upper deformation layer and lower deformation layer.The“arched graben system”is developed in the upper deformation layer,and the magmatic diapir structure and flowing deformation of plastic strata is developed in the lower deformation layer.The evolution process of the central anticline zone can be divided into four stages,i.e.fault block uplifting stage,prototype stage,strengthening stage and finalization stage.The geological framework and tectonic evolution of the central anticline zone control Paleogene hydrocarbon accumulation.The Paleogene twolayer geological framework is favorable for development of structural traps and composite traps;the paleostructure highs are the direction of hydrocarbon migration,and the gravitational gliding faults are the main carrier bed for vertical hydrocarbon migration;the tectonic uplift is a key factor for reservoir diagenesis improvement and preservation of primary pores,and also controls distribution of high-quality reservoirs.展开更多
基金Rustaveli National Science Foundation of Georgia for funding the project(#GNSF/ST09-1071-5-150)through which the research work was conducted in the eastern Greater Caucasus.
文摘The eastern part of the Caucasus orogen,termed the Georgian segment,is mainly underlain by highly deformed Lower-Middle Jurassic shales,sandstones,and volcaniclastic rocks,and cut by numerous intrusive bodies of various compositions.All units contain a variety of mineral deposit types and their surrounding zones of hydrothermal alteration.Detailed geological and metallogenic research,after 30 years stagnation,has led to important new information regarding the evolution of this region.Three main stages of magmatic activity are now clearly distinguished.The oldest magmatism comprises early Jurassic events,related to extensional tectonism,with volcanism and subvolcanic plutonism that ranged from rhyolitic,through dacitic and andesitic,and to basaltic.Additional extensional processes(in Bajocian times)were characterized by intrusion of a gabbro and diorite dike system into slightly older late Early Jurassicearly Middle Jurassic formations.The final magmatic event was associated with Middle Jurassic folding and uplift during which multiphase diorite plutons were emplaced.Intense hydrothermal activity related to this latest magmatism was responisble for important polymetallic mineralization including more than 100 historically recognized outcropping occurrences.A detailed study of 11of the more significant of these occurrences has indicated anomalous concentrations of base metals as well as gold,thorium,yttrium,cobalt,cadmium,and bismuth.In addition,several new and potentially significant mineral occurrences were discovered,including two designated here as Gelia and Lechuri.
基金supported by the National Science and Technology Major Project of China(No.2016ZX05024-004)comprehensive scientific research project of CNOOC(China National Offshore Oil Corporation)(YXKY-2015-SZ-02).
文摘The Paleogene geological framework and evolution process in the central anticline zone in the Lufeng 13 sag in Pearl River Mouth Basin is well analyzed through seismic data and drilling data,and control of tectonic evolution on hydrocarbon accumulation is also discussed.The results show that the central anticline zone in the Lufeng 13 sag develops the upper deformation layer and lower deformation layer.The“arched graben system”is developed in the upper deformation layer,and the magmatic diapir structure and flowing deformation of plastic strata is developed in the lower deformation layer.The evolution process of the central anticline zone can be divided into four stages,i.e.fault block uplifting stage,prototype stage,strengthening stage and finalization stage.The geological framework and tectonic evolution of the central anticline zone control Paleogene hydrocarbon accumulation.The Paleogene twolayer geological framework is favorable for development of structural traps and composite traps;the paleostructure highs are the direction of hydrocarbon migration,and the gravitational gliding faults are the main carrier bed for vertical hydrocarbon migration;the tectonic uplift is a key factor for reservoir diagenesis improvement and preservation of primary pores,and also controls distribution of high-quality reservoirs.
