Tectonic Setting and Metallogenic Regualtion of Sedimentary Manganese Deposits of East Kunlun,Qinghai Province
The East Kunlun orogenic belt is located in the northeast of the Qinghai-Tibet Plateau.It experienced the early tectonic evolution of the Proto-Tethys Ocean and formed a series of marine sedimentary manganese deposits.However,there are still different understandings on the specific details of the evolution of the Proto-Tethys Ocean in East Kunlun,such as expansion and subduction,active and passive continental margins,island arc and back-arc basin.There are also controversies regarding the timing of ocean closure during the Middle-Late Ordovician or Early Silurian periods.Based on the geological and geochemical research of sandstone and siliceous rock in marine sedimentary manganese deposits in East Kunlun,it was indicated that Hongshuihe ferromanganese and Langmuri manganese deposits formed in the Mesoproterozoic,as well as Ordovician-Early Silurian Santonggou north manganese deposit,show geochemical characteristics of active continental margin,but Santonggou Ⅵ-Ⅶ manganese ore belt formed in the Neoproterozoic shows the tectonic attribute of passive continental margins.Comprehensive research indicates that the minddle and south Kunlun belts in Proto-Tethys tectonic domain has undergone an evolution processes from Mesoproterozoic active continental margin to Neoproterozoic passive continental margin,and Ordovician-Early Silurian Nachitai Group was formed in the stage of island arc accretion or back-arc basin in the Proto-Tethys Ocean.
NETL
NSTL
万方数据
