The beginning of intraplate (diwa type) activization must be attributed to Early Proterozoic, When thick continental earthcrust and thermodynamic conditions close to the present had estahlished.Precambrian activizatio...The beginning of intraplate (diwa type) activization must be attributed to Early Proterozoic, When thick continental earthcrust and thermodynamic conditions close to the present had estahlished.Precambrian activization (protodiwa) induced hypogene structural recaworking, deepseated laults and troughs development, gabbro-granite and subalkaline magtnatizm, zone metamorphism, magmatogenic and hydrothermal ore production,whicll proceeded regularly, that allows their timing.Protodiwa metallogeny contrasts with the previous Precambrian due to relatively increased petrogenic and ore elements differentiation. Elements of various geochemical origins and noncharacteristic of Early Precambrian are found.ore deposition appears determined by gabbro-diorite-granite, gabbroumonzonite-syenite-granite, gabbro-anorthosite-rapakivi granite differentiated magmatic series. Elements mode is controlled both by fractional crystallization and the alliance with fluid phase.Throughout Late Proterozoic diwa geodynamics remained uniform, the most intensive on the fringe of Early Proterozoic folded belts. This allows us suggest the post-collisional subduction activating mantle and lower litosphere, and mantle diapirs formation the motive forces of protodiwa activization.展开更多
Since the late Hercynian episode the crust in Hainan has entered the post-platform activation or the diwa stage in which it has undergone a process from compressive (collision) orogeny and up1ifting during the late He...Since the late Hercynian episode the crust in Hainan has entered the post-platform activation or the diwa stage in which it has undergone a process from compressive (collision) orogeny and up1ifting during the late Hercynian-Indosinian movements to block-faulting type mountain- and basin-making during the Yanshanian-Himalayan movements. It has been shown through researches of igneous rocks that a post-platform orogenic belt being of a greatly thickened continental crust was once formed in the Hainan area during the late Hercynian-lndosinian cyc1e. The taphrogeny starting in the late Yanshanian episode was a product at the stage of late orogenic extension under conditions of the mountain root with a thickness of about 60 km retained. At 1ast, the lower lithospheric delamination and the crustal de-rooting of the orogen caused Hainan and its neighboring areas to transform from the continenta1 type crustobody to the continental-margin-spreading type crustobody.展开更多
文摘The beginning of intraplate (diwa type) activization must be attributed to Early Proterozoic, When thick continental earthcrust and thermodynamic conditions close to the present had estahlished.Precambrian activization (protodiwa) induced hypogene structural recaworking, deepseated laults and troughs development, gabbro-granite and subalkaline magtnatizm, zone metamorphism, magmatogenic and hydrothermal ore production,whicll proceeded regularly, that allows their timing.Protodiwa metallogeny contrasts with the previous Precambrian due to relatively increased petrogenic and ore elements differentiation. Elements of various geochemical origins and noncharacteristic of Early Precambrian are found.ore deposition appears determined by gabbro-diorite-granite, gabbroumonzonite-syenite-granite, gabbro-anorthosite-rapakivi granite differentiated magmatic series. Elements mode is controlled both by fractional crystallization and the alliance with fluid phase.Throughout Late Proterozoic diwa geodynamics remained uniform, the most intensive on the fringe of Early Proterozoic folded belts. This allows us suggest the post-collisional subduction activating mantle and lower litosphere, and mantle diapirs formation the motive forces of protodiwa activization.
文摘Since the late Hercynian episode the crust in Hainan has entered the post-platform activation or the diwa stage in which it has undergone a process from compressive (collision) orogeny and up1ifting during the late Hercynian-Indosinian movements to block-faulting type mountain- and basin-making during the Yanshanian-Himalayan movements. It has been shown through researches of igneous rocks that a post-platform orogenic belt being of a greatly thickened continental crust was once formed in the Hainan area during the late Hercynian-lndosinian cyc1e. The taphrogeny starting in the late Yanshanian episode was a product at the stage of late orogenic extension under conditions of the mountain root with a thickness of about 60 km retained. At 1ast, the lower lithospheric delamination and the crustal de-rooting of the orogen caused Hainan and its neighboring areas to transform from the continenta1 type crustobody to the continental-margin-spreading type crustobody.
