The Langshan Group is an important constituent of the Precambrian metamorphic rocks in the Langshan area.The accurate determination of its metamorphic age is of great scientific significance for the further study of t...The Langshan Group is an important constituent of the Precambrian metamorphic rocks in the Langshan area.The accurate determination of its metamorphic age is of great scientific significance for the further study of the Precambrian geological evolution in the region.Disputes remain regarding the metamorphism and deformation overprinting of the Langshan Group.This paper presents a detailed study comprising a field geological investigation,petrological observations,and zircon U-Pb aging of garnet-bearing mica quartz schists in the BangBang District.The result of detrital zircon U-Pb dating from the metamorphosed volcanic sedimentary rock series and geological investigation of the garnet-bearing mica quartz schists suggest the strata formed in the Neoproterozoic.The results from cathodoluminescence(CL)image analysis and U-Pb dating of zircons indicate a large number of metamorphic zircons exist in the garnet-bearing mica quartz schists.The metamorphic overgrowth rims of zircon from two samples were analyzed by LA-ICP-MS.The ^(206)Pb/^(238)U weighted average age of ca.244 Ma of the zircon metamorphism rims represents the timing of Indosinian greenschist-amphibolite facies metamorphism in the Langshan area,which may be in response to the collision-type orogeny of the North China and Siberian plates in the Late Paleozoic.Acid-intermediate magmatic intrusive activities occurred in the Langshan area,and metamorphic events developed at the same time or at a later stage during the closure of the Paleo-Asian Ocean.展开更多
There is a large Mesoproterozoic rift at the northern margin of North China Craton （NCC）, and one of China＇s most important metallogenic belts, the Langshan-Zhaertai Shan-Bayan Obo mesoproterozoic metallogenic belt...There is a large Mesoproterozoic rift at the northern margin of North China Craton （NCC）, and one of China＇s most important metallogenic belts, the Langshan-Zhaertai Shan-Bayan Obo mesoproterozoic metallogenic belt is just located in this rift. This metallogenic belt contains some large or ultra-large ore deposits, such as the Bayan Obo iron deposits and ultra-large rare earth deposits, and the large Dongshengmiao Cu-Pb-Zn sulphide deposits.展开更多
基金funded by the work program of the National Key Research Program of China(No.2016YFC0600502)。
文摘The Langshan Group is an important constituent of the Precambrian metamorphic rocks in the Langshan area.The accurate determination of its metamorphic age is of great scientific significance for the further study of the Precambrian geological evolution in the region.Disputes remain regarding the metamorphism and deformation overprinting of the Langshan Group.This paper presents a detailed study comprising a field geological investigation,petrological observations,and zircon U-Pb aging of garnet-bearing mica quartz schists in the BangBang District.The result of detrital zircon U-Pb dating from the metamorphosed volcanic sedimentary rock series and geological investigation of the garnet-bearing mica quartz schists suggest the strata formed in the Neoproterozoic.The results from cathodoluminescence(CL)image analysis and U-Pb dating of zircons indicate a large number of metamorphic zircons exist in the garnet-bearing mica quartz schists.The metamorphic overgrowth rims of zircon from two samples were analyzed by LA-ICP-MS.The ^(206)Pb/^(238)U weighted average age of ca.244 Ma of the zircon metamorphism rims represents the timing of Indosinian greenschist-amphibolite facies metamorphism in the Langshan area,which may be in response to the collision-type orogeny of the North China and Siberian plates in the Late Paleozoic.Acid-intermediate magmatic intrusive activities occurred in the Langshan area,and metamorphic events developed at the same time or at a later stage during the closure of the Paleo-Asian Ocean.
基金the project of "Properties and Metallogenic Specialization of Meso-Neopreterozoic Multiphases Rift in NCC",funded by the National Basic Research Program of China(grant No.2012CB416604)
文摘There is a large Mesoproterozoic rift at the northern margin of North China Craton （NCC）, and one of China＇s most important metallogenic belts, the Langshan-Zhaertai Shan-Bayan Obo mesoproterozoic metallogenic belt is just located in this rift. This metallogenic belt contains some large or ultra-large ore deposits, such as the Bayan Obo iron deposits and ultra-large rare earth deposits, and the large Dongshengmiao Cu-Pb-Zn sulphide deposits.
