关键词: 壳幔岩浆作用, 区域成矿效应, 包体和包晶, 皖赣沿江地区

Abstract: Numerous Mesozoic meso-epizonal small intrusions, hosting various rock enclaves, are widely distributed in the Jiangxi to Anhui segment of the Yangtze River. Some mineral peritectics occur in both the intrusions and their enclaves, while exsolved phases from melt inclusions are present in various mineral grains of these rocks. Based on comprehensive field investigations and detailed petrographic observations, the intrusions in the study area are classified into eight groups: those associated with postcollisional gold, gold-copper and copper deposits, those related to post-orogenic gold deposits, dispersed element mineralization, copper and iron deposits, and barren intrusions. The rock enclaves within the intrusions are divided into five types: hybrid rocks, mantle-derived xenoliths, cumulates, polycrystalline aggregates, and metamorphic xenoliths. The peritectic minerals in the intrusions and their enclaves are categorized into four types: mantle-derived crystals, megacrysts, cumulus crystals, and polycrystals. The exsolved phases from melt inclusions in various minerals of the intrusions and enclaves are grouped into two categories: oxides and sulfides. Systematic mineralogical and geochemical investigations were conducted on the intrusions, their rock enclaves, and various minerals within them. The results demonstrate that two major episodes of crust-mantle magmatism occurred in the Jiangxi to Anhui segment of the Yangtze River: the Proterozoic and Mesozoic episodes. The Proterozoic crustmantle magmatism was dominated by mantle-derived magma underplating and crust-mantle hybrid magmatism, followed by regional metamorphism. In contrast, the Mesozoic crust-mantle magmatism comprised three distinct phases of mantle-derived magma underplating and crust-mantle hybrid magmatism. These two episodes of crust-mantle magmatism triggered a series of post-collisional to post-orogenic magmatic events, driving the corresponding crust-mantle magma evolution. This evolution is primarily recorded in the variations of intrusion-enclave assemblages, formation ages, physicochemical conditions, mineral associations, and geochemical compositions. With respect to metallogenic effects, the crust-mantle magmatism in the study area exerts a fundamental control on both regional mineralization processes and metallogenic regularity. The regional mineralization processes are governed by four key factors: sources of ore-forming materials, mechanisms of metal acquisition and enrichment, fluid/melt transport pathways and driving forces, and post-mineralization preservation environments and conditions. The regional metallogenic regularity is mainly characterized by the temporal-spatial distribution of ore deposits and the genetic superposition of multiple mineralization events. 

Key words: crust-mantle magmatism, regional metallogenic effect, rock enclaves and peritectic minerals, Jiangxi to Anhui
segment of the Yangtze River