吉林古陆成岩背景及边缘金构造-成矿系统

吉林克拉通广泛出露的粗粒黑云长英片麻岩是以英云闪长岩为主的TTG深成侵入体 ,原始岩浆来自幔源物质的部分熔融作用 ,同源岩浆不同演化阶段形成多种岩石类型 (Gnbd、GnblⅠ、GnblⅡ ) ,后经变质构成统一古陆。古陆隆升 ,边缘滑脱和裂解并接受元古宙地层沉积。层间滑动和韧性剪切达上地幔 ,使部分太古宙黑云长英片麻岩被卷进地层 ,幔源物质加入成矿。这使人们打破原层控金矿的认识 ,将整个古陆边缘金矿床统归于构造 -成矿系统 ,依构造动力学特征的不同划分为三类 :离散型陆缘构造 -成矿系统 ,以中型金矿和Fe、Al、P、B为主 ;会聚型陆缘构造 -成矿系统 ,以金矿化和Ni、Cr为主 ;走滑型陆缘构造 -成矿系统 ,以大型金矿和Cu、Pb、Zn为主 ,该系统有助于全面认识构造特征和矿床分布规律 ,为区域成矿预测和勘查提供科学依据。

PALEOCONTINENTAL DIAGENETIC SETTING IN JILIN AND GOLD TECTONO-METALLOGENIC SYSTEM ON PALEOCONTINENTAL MARGIN

There are lots of coarse biotite felsic gneisses in the Jilin craton. Primitive magmas of these rocks were derived from partial melting of mantle materials and are made of TTG plutonic rocks with prevailing tonalities. Different evolution stages resulted in diverse petrologic types during the same magmatic process. The rocks constitute a unified paleocontinent after metamorphism. Then the paleocontinent uplifted. The paleocontinental margin slided and splitted and relieved Proterozoic group strata deposition. When delamination sliding and ductile shearing reached the upper mantle, parts of these rocks got into the strata. Mantle materials were involved in metallization. All gold deposits on the paleocontinental margin are put into the tectono\|metallogenic system. Three types are classified in terms of the tectono\|dynamic features. 1. The divergent tectono\|metallogenic system or the paleocontinental margin is associated with medium gold deposits and Fe, Al, P, B deposits. 2. The convergent tectono\|metallogenic system on the paleocontinental margin is associated with gold mineralization and Ni, Cr deposits. 3. The strike\|slipped tectono\|metallogenic system on the paleocontinental margin is associated with large gold deposits and Cu, Pb, Zn deposits. The systems help one to know structure characters and ore deposit distribution as a whole and provide scientific basis for regional metallogenic prognosis and exploration.positsand