The continental margin of Northeast China and its adjacent areas is composed of two tectonic belts. The inner belt is a collage made up of fragments resulting from breakup of an old land with the north part related to...The continental margin of Northeast China and its adjacent areas is composed of two tectonic belts. The inner belt is a collage made up of fragments resulting from breakup of an old land with the north part related to the evolution of the Palaeo-Asian Ocean and the south part to the evolution of the Palaeo - Pacific Ocean. The outer belt is a Mesozoic terrane, which is a melange made up of fragments of the Late Palaeozoic to Early Mesozoic oceanic crust and the Late M esozoic trench accumulations.There existed another ocean-the Palaeo - Pacific Ocean during the period from the closing of the Palaeo-Asian Ocean to the opening of the modern Pacific Ocean or from the Devonian to Jurassic, and the ocean-floor spreading of the Palaeo - Pacific Ocean led to the formation of the above-mentioned tectonic belts. The development of the strike-slip fault system after the Late Jurassic and the formation of an epicontinental volcano -plutonic rock belt in the Late Cretaceous to Early Tertiary are attributed to the interaction between the modern Pacific plate and the Eurasian plate.展开更多
Manganoan skarns consist of special Mn (Ca, Mg, Fe, Al) silicate metasomatic minerals and are usually associated with Pb-Zn(Ag) mineralization. They occur chiefly along the lithologic contacts or faults and fractures ...Manganoan skarns consist of special Mn (Ca, Mg, Fe, Al) silicate metasomatic minerals and are usually associated with Pb-Zn(Ag) mineralization. They occur chiefly along the lithologic contacts or faults and fractures of carbonate wall rocks distal from the intrusive contact zone, and are combined with Fe, Cu, W, Sn and Cu-bearing calcic or magnesian skarns occurring in the contact zones to constitute certain metasomatic zoning. Manganoan skarns are formed later than calcic or magnesian skarns. Their rock-forming temperatures are lower than those of calcic or magnesian skarns. The mineral assemblages of manganoan skarns occurring in different carbonate rocks (limestone or dolomite) are notably different.展开更多
From an angle of integrative analysis on historical-dynamic geotectonics, the formation mechanism of the Eastern Asia continental-margin and historical background of the evolution-movement of the crustobody are discus...From an angle of integrative analysis on historical-dynamic geotectonics, the formation mechanism of the Eastern Asia continental-margin and historical background of the evolution-movement of the crustobody are discussed. The pull-breaking-extending and thinning of the continental margin crustobody in the region result in the formation of the continental-margin extensional belt.Finally, the theoretical and practical significance of the study is pointed out.展开更多
基金A Project supported by the National Natural Science Foundation of China (Nos.9487001,49173131)
文摘The continental margin of Northeast China and its adjacent areas is composed of two tectonic belts. The inner belt is a collage made up of fragments resulting from breakup of an old land with the north part related to the evolution of the Palaeo-Asian Ocean and the south part to the evolution of the Palaeo - Pacific Ocean. The outer belt is a Mesozoic terrane, which is a melange made up of fragments of the Late Palaeozoic to Early Mesozoic oceanic crust and the Late M esozoic trench accumulations.There existed another ocean-the Palaeo - Pacific Ocean during the period from the closing of the Palaeo-Asian Ocean to the opening of the modern Pacific Ocean or from the Devonian to Jurassic, and the ocean-floor spreading of the Palaeo - Pacific Ocean led to the formation of the above-mentioned tectonic belts. The development of the strike-slip fault system after the Late Jurassic and the formation of an epicontinental volcano -plutonic rock belt in the Late Cretaceous to Early Tertiary are attributed to the interaction between the modern Pacific plate and the Eurasian plate.
基金the National Natural Scicnce Foundation of China grant 40073016.
文摘Manganoan skarns consist of special Mn (Ca, Mg, Fe, Al) silicate metasomatic minerals and are usually associated with Pb-Zn(Ag) mineralization. They occur chiefly along the lithologic contacts or faults and fractures of carbonate wall rocks distal from the intrusive contact zone, and are combined with Fe, Cu, W, Sn and Cu-bearing calcic or magnesian skarns occurring in the contact zones to constitute certain metasomatic zoning. Manganoan skarns are formed later than calcic or magnesian skarns. Their rock-forming temperatures are lower than those of calcic or magnesian skarns. The mineral assemblages of manganoan skarns occurring in different carbonate rocks (limestone or dolomite) are notably different.
文摘From an angle of integrative analysis on historical-dynamic geotectonics, the formation mechanism of the Eastern Asia continental-margin and historical background of the evolution-movement of the crustobody are discussed. The pull-breaking-extending and thinning of the continental margin crustobody in the region result in the formation of the continental-margin extensional belt.Finally, the theoretical and practical significance of the study is pointed out.
