摘要
黑龙江多宝山斑岩铜矿的形成与加里东期的火山岛弧密切相关,并因海西期的岩浆活动进一步富集成超大型铜矿,在燕山运动时遭受改造。燕山期变形可分为两期,早期为陆内造山带发育及坍塌,构造线方向北东东,晚期为北东向断裂左行走滑。在此基础上剖析了铜山断裂的活动方式及对矿体的破坏。作为成矿期后的改造断裂,铜山断裂既切断了地质体、矿体和斑岩型矿化蚀变带,同时又起到了保护下盘矿体免遭剥蚀的重要作用。对铜山矿床成矿条件、特别是热液蚀变与铜山断裂“控矿”构造细节的配套研究表明:铜山矿区南部仍然隐伏着含矿蚀变环带的上盘,有矿体存在,为寻找超大型斑岩铜矿提供了可靠的证据。事实证明:深入研究成矿构造控矿规律是行之有效的矿床预测工作基础,细致研究成矿期后构造运动是在已知矿区寻找新矿体的捷径。
The Duobaoshan porphyry copper deposit was situated in Nenjiang county, NW Heilongjiang, where outcropped the Ordovician calc-alkaline volcanic suite, indicating the copper mine an arc-related porphyry deposit formed in the Caledonian orogeny. The deposit was reformed by the Yanshanian orogeny, and two episodes of deformation could be distinguished： the early one being rejuvenation of the NEE structure in the Hercynian basement, and the second one being neo-genetic NE-striking shear zone in Early Cretaceous. The Tongshan fracture, separating the deposit into two parts, might be a representative of the Yanshanian deformation, whose early activation was normal faulting related to collapse of the Yanshanides, and the later one was thrusting southwards. As a destructive structure of postmineral period, the Tongshan fracture cut off the wall rocks, ore bodies and porphyritic mineralized alteration belts, and protected the ore bodies in the lower wall to avoid from denudation. The study on deep-seated geology and the analyses of hydrothermal alteration confirmed the existence of blind ore body in southern flank of the Tongshan fracture. To sum up, the deepened study on controlling law of metallogenic tectogenesis was a base of the effective prediction of ore deposit, and the detailed study on ore-controlling structure had a practical meaning and effect on exploration of ore deposit.
出处
《地质科学》
CAS
CSCD
北大核心
2007年第1期124-133,共10页
Chinese Journal of Geology(Scientia Geologica Sinica)
关键词
斑岩铜矿
燕山期变形
铜山断裂
断失矿体
黑龙江西北部
Porphyry copper deposit, The Yanshanian deformation, The Tongshan fracture, Faulted and buried ore body,Northwestern Heilongjiang
