(1. 中南大學(xué) 有色金屬成礦預(yù)測教育部重點(diǎn)實(shí)驗(yàn)室,長沙 410083;
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院,長沙 410083)
摘 要: 金川銅鎳硫化物礦床位于華北板塊西南緣的龍首山隆起帶內(nèi),斷裂系統(tǒng)是其主要的控礦因素,在多次構(gòu)造運(yùn)動中,形成了縱橫交錯的斷裂,其運(yùn)動也有多期性,根據(jù)目前斷裂性質(zhì),分為4組,分別為:北西向壓性斷裂,北西向容納金川巖體的斷裂,北東東向扭性斷裂和北東向張性斷裂。其中前兩組在巖體侵入前已經(jīng)存在,為金川巖體提供了成礦通道和成礦空間,而后期被改造;后兩組為成礦后斷裂,改造了礦床的原始形態(tài)。通過微量元素和前人年代學(xué)研究,認(rèn)為其主要形成于中元古代大陸拉張環(huán)境下的龍首山裂谷張開初期。成礦前區(qū)域處于古陸核邊緣的擠壓環(huán)境,成礦期為被動大陸邊緣的拉張裂谷環(huán)境,成礦后變?yōu)榛顒哟箨戇吘壍臄D壓環(huán)境。通過恢復(fù)其原始產(chǎn)狀發(fā)現(xiàn)容礦斷裂成右列式的雁列形態(tài)展布,根據(jù)后期改造的特點(diǎn),推測在Ⅲ礦區(qū)與F1斷層間、Ⅳ礦區(qū)的東南部的第四系覆蓋層下,是找礦的有利靶區(qū)。
關(guān)鍵字: 金川銅鎳硫化物礦床;礦體原始形態(tài);斷裂系統(tǒng);礦體改造;成礦預(yù)測
(1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China)
Abstract:The Jinchuan Cu-Ni (PGE) sulfide deposit is located in the Longshou Mountain, southwestern margin of North China plate. The fault system is the main ore-controlling factor. During numbers of periodic tectonic movements, the criss-cross faults formed. According to the fault properties, these faults can be divided into four categories as: Northwestern compression fault, Northwestern fault which accommodates the Jinchuan intrusion, Northeastern sheer fault, and Northeastern tension fault. The former two groups formed before intrusive bodies are emplaced. These faults provide Jinchuan intrusion with metallogenic conduction and space, which were transformed at the later stage. The latter two groups belong to post-metallogenic faults, and transform the original form of deposit. Through the study of trace elements and geochronology, it could be found out that the deposit formed in the primer period of Longshou Valley’s fissuration at an atmosphere of Mesoproterozoic continental tentional zone. This area has experienced various kinds of environment, which are as follows: the crushing environment of craton in pre-ore stage, the extensional rift environment of passive continental margin in ore stage, and the crushing environment of active continental margin in post-ore stage. By restoring the original form, it shows that the ore-controlling faults crack into en-echelon. According to the properties of the late-reformation, it is estimated that there exist several favorable areas for ore-prospecting, including the region between mining area III and F1, and the district under the Quaternary strata, which is in SE of IV mining area.
Key words: Jinchuan Cu-Ni (PGE) sulfide deposit; orebody original form; fault system; orebody transformation; metallogenic prognosis


