Abstract:Alkali magmatism exerts a distinctive influence on mineralization processes in metal ore- concentrated areas. However, deep exploration and mineral prediction in the study area face challenges due to the complex interplay of volcanic- intrusive rock sequences, metal mineralization, and superimposing magmatic- tectonic systems. This study focuses on two key regions in eastern Yunnan, China: the Dongchuan Fe- Cu- Au ore concentrated area (Proterozoic marginal rifted basin) and the Gejiu Sn- Cu- W- Cs- Rb polymetal ore concentrated area (Triassic back- arc rifted basin). By applying innovative tectonic lithofacies mapping techniques, we investigated the volcanic- intrusive rock sequences related to alkali magmatic activity, rifted basin evolution, rock associations, and superimposed magmatic- intrusive systems. This approach aims to elucidate the superimposed mineralization of IOCG, Cu- Co- rutile, and Sn- Cu- W- Cs- Rb polymetallic deposits in the region. Our investigation has yielded several noteworthy findings. Firstly, Neoarchean alkali rocks in the Dongchuan Fe- Cu- Au ore- concentrated area are composed of calcite albitite (2520±14 Ma) and Fe- rich alkalipicrite (2529±77 Ma). The Neoarchean- Paleoproterozoic Xiaoliukou Formation Complex (>2. 50 Ga), particularly its upper part exhibiting homotopy in different lithofacies (2. 50 to 1. 80 Ga), serves as the new host strata for Cu- Co- rutile- REE mineralizations. These strata have been reworked by Mesoproterozoic volcanic- intrusive rocks in the Dongchuan Fe- Cu- Au ore- concentrated area. Secondly, during the Mesoproterozoic stage of volcanic rifting basins, alkaline rocks, including Fe- Na- rich alkali basic rocks, Fe- K- rich trachyte, and Fe- rich alkali diabase- gabbros, formed as part of the first member of the Yinmin Formation. Xikuangshan- type Fe- Cu deposits, or IOCG deposits, are hosted in the second to third members of the Mesoproterozoic Yinmin Formation. Additionally, Fe- K- rich trachyte in the footwall of the Fe- Cu orebody hosts monazite- type REE mineralization. The IOCG system and rutile superimposing mineralization are formed in alkaline Ti- Fe- rich gabbros (1097 to 1047 Ma), alkaline Ti- Fe- rich diorites, and alkaline monzoporphyry, all of which formed during the Greenville Orogeny in eastern Yunnan. Thirdly, Triassic alkalipicrite and tephrite, with primary enrichment of Sn- Cu- Zn- Li- Rb- Cs, were produced in the Triassic arc- back rifted basin in the Gejiu area of eastern Yunnan Province, China. These rocks were subsequently superimposed by leucogranite intrusion, which played a pivotal role in the formation of Sn- Cu- W- Cs- Rb- bearing phlogopite- type skarn. Finally, alkali rocks with initial metal enrichment in the early stage of the rifted basin evolution were superimposed by later- stage alkaline intrusive rocks with metal mineralization. This process represents the primary mechanism for metal mineralization in the rifted basin in eastern Yunnan. Breccia- pipes formed by magmatic hydrothermal fluids in the alkaline magmatic- intrusive tectonic system control the hypernormal enrichment of Cu- Co- rutile- REE mineralization. Conversely,leucogranite intruded into alkalipicrite and tephrite with Sn- Cu- W- Cs- Rb primary enrichment is responsible for the hypernormal enrichment of Sn- Cu- W- Cs- Rb- bearing phlogopite- type skarn.