吉中-延边地区燕山期岩浆作用与矿床成矿系列研究

A study of magmatism and ore deposit series of Yanshanian magmatism in the central Jilin-Yanbian area

运用矿床的成矿系列理论,以构造岩浆演化为基础,对吉中-延边成矿带与燕山期岩浆作用有关的矿床成矿规律进行了分析总结。研究表明,受古太平洋板块俯冲方向、速度的制约,吉中-延边地区燕山期构造岩浆活动复杂,总体上可分为5次成岩成矿事件:①晚三叠世初基性超基性岩侵入,形成红旗岭铜镍矿床等岩浆型矿床;②晚三叠世-早侏罗世初,吉中地区高钾钙碱性岩浆活动,形成兰家金矿床等岩浆热液型矿床,延边地区中低钾钙碱性-高钾钙碱性岩浆活动,形成前山金矿床等火山-潜火山岩型矿床;③早侏罗世末-中侏罗世初,富铝酸性岩浆活动,形成大黑山钼矿床等斑岩型钼矿床;④中侏罗世末-晚侏罗世初,研究区以抬升剥蚀为主,成岩成矿作用较弱;⑤晚侏罗世末-早白垩世,吉中地区高钾钙碱性岩浆活动,形成二道甸子金矿床等岩浆热液型矿床,延边地区中低钾钙碱性-高钾钙碱性岩浆活动,形成小西南岔金铜矿床等火山-斑岩型矿床。在建立吉中-延边地区与燕山期岩浆作用有关的矿床成矿系列的基础上,进一步划分为6个矿床成矿亚系列,各亚系列在时间、空间上既有联系,又有区别,显示了成矿作用的复杂性。

The metallogenic regularity of the central Jilin-Yanbian metallogenic belt related to Yanshanian magmatism were analyzed and summarized based on the study of tectonic-magmatic evolution and ore deposit metallogenic series theory. The study shows that due to the subduction direction and velocity of the ancient Pacific plate, the complex Yanshanian tectonic-magmatic activity in the central Jilin-Yanbian area can be divided into five diagenetic and mineralizing events:(1) the late Triassic intrusion of mafic-ultramafic rocks that led to the formation of magmatic deposits such as Hongqiling copper-nickel deposit;(2) the late Triassic to early Jurassic high-potassium calcium-alkali magmatic activity in the Jizhong area and the formation of magmatic hydrothermal deposits such as the Lanjia Gold deposit, and the low potassium calcium alkali-high potassium calcium alkali magmatic activities in Yanbian resulting in the formation of volcanic-subvolcanic rock type deposits such as Qianshan gold deposit;(3) the early Jurassic to the middle Jurassic aluminum-rich acidic magma activity and the formation of porphyry molybdenum deposits such as Daheishan molybdenum deposit;(4) the middle Jurassic to late Jurassic was marked by uplift and erosion in the research area resulting in weak diagenesis and mineralization;(5) the late Jurassic to the early Cretaceous high-potassium calcium-alkali magmatic activity in the Jizhong area, and the formation of magmatic hydrothermal deposits such as the Erdaodianzi gold deposit;low-potassium calcium-alkali and high-potassium-calcium-alkali magmatic activity in the Yanbian leading to formation of volcano-porphyry deposits such as the Xiaoxinancha gold-copper deposit. Based on the establishment of the ore-forming series of magmatic processes during the Yanshanian period in the Jizhong-Yanbian area, they are further divided into 6 metallogenic subseries. Despite geospatial and temporal differenes, the subseries are related indicating the complexity of the mineralization process.