Neoproterozoic magmatic Ni–Cu–(PGE) sulfide deposits related to the assembly and breakup of the Rodinia supercontinent in China: An overview

Abstract

The tectonic affinity of Neoproterozoic magmatic Ni–Cu–PGE sulfide deposits and their related mafic–ultramafic intrusions can provide insights into furthering our understanding of the assembly and breakup of the Rodinia supercontinent. A significant number of Chinese Neoproterozoic magmatic Ni–Cu–(PGE) sulfide deposits are located along the margins of three Precambrian continental cratons, namely the North China, Yangtze, and Tarim cratons (NCC, YC, and TC, respectively). These deposits are hosted by six metallogenic belts: (1) the Longshoushan metallogenic belt within the western margin of the NCC, (2) the South Qinling metallogenic belt within the northern margin of the YC, (3) the West Jiangnan metallogenic belt within the southern margin of the YC, (4) the Kangdian metallogenic belt within the western margin of the YC, (5) the Quruqtagh metallogenic belt within the northeastern margin of the TC, and (6) the Yanshan metallogenic belt within the northeastern margin of the NCC.Recent geochronological research indicates that this Ni–Cu–(PGE) mineralization formed during the Neoproterozoic (980–620 Ma, peaking at ∼800 Ma) in four different stages at 980–880, 830–810, 760–740, and 640–620 Ma. Combining these ages with regional geological data yields four different tectonic settings: (1) post-orogenic extensional settings after collisional convergence between the YC and Cathaysia Block or between the YC and NCC associated with Rodinia assembly at 980–880 Ma, (2) a first Neoproterozoic mantle plume event (at 830–795 Ma) within the NCC or YC associated with Rodinia breakup at 830–810 Ma, (3) a second Neoproterozoic mantle plume event (at 780–745 Ma) within the TC associated with Rodinia breakup at 760–740 Ma, and (4) an intraplate rift setting within the YC associated with Rodinia breakup at 640–620 Ma. The regional setting of these deposits in time and space and their relationships to changes in geodynamic setting indicate that the generation of this mineralization was directly associated with large-scale mafic–ultramafic magmatism linked to the assembly and breakup of the Rodinia supercontinent.