Advances in Magmatic Ni–Cu–(PGE) Sulphide Deposits and Their Constraints on Neoproterozoic Tectonic Settings of China

Abstract

Magmatic Ni–Cu–(PGE) sulphide deposits are the primary global sources of nickel, copper and platinum group elements (PGE). The study of these deposits is critical for mineral exploration and holds important economic implications. This paper reviews recent advances in understanding magmatic Ni–Cu–(PGE) sulphide deposits and their related magmatism. Findings reveal that these deposits have an uneven global distribution and a wide range of classifications. The Proterozoic era represents the main period of mineralisation, and the mineralisation setting is closely related to continental rifts, mantle plumes and collision orogenic belts. An ongoing debate exists between the ‘magma conduit’ and ‘deep-multiple magma chamber segregation’ models, which differ in mineralisation location, magma intrusion mechanisms and the role of external sulphur addition. The primary mechanisms of sulphide segregation include rapid cooling, crystal differentiation and crustal contamination. Furthermore, this paper examines the spatial–temporal distribution and mineralisation dynamic settings of Neoproterozoic magmatic Ni–Cu–(PGE) sulphide deposits in China and their relationship to the convergence and breakup of the Rodinia supercontinent. These Neoproterozoic deposits are located along the margins of the Yangtze, North China and Tarim blocks. They formed in five different stages, 1000–960, 900–850, 830–800, 760–740 and 650–620 Ma, corresponding to the following tectonic settings, respectively: (1) a back-arc extensional setting before the convergence of the Yangtze and Cathaysia blocks; (2) a post-orogenic extensional setting following the convergence between the Yangtze and North China blocks; (3) a rift setting related to the first Neoproterozoic mantle plume event (830–795 Ma) within the Yangtze Block or North China Block; (4) a rift setting related to the second Neoproterozoic mantle plume event (780–745 Ma) within the Tarim Block and (5) an intraplate rift setting within the Yangtze Block. The evolving mineralisation dynamic settings of these deposits indicate that their mineralisation is directly related to large-scale mafic–ultramafic magmatism during the Neoproterozoic and the convergence and breakup of the Rodinia supercontinent.