本文關(guān)鍵詞： 構(gòu)造變形 顯微構(gòu)造 構(gòu)造控礦模式 數(shù)值模擬 焦家金礦帶 膠東　出處：《中國地質(zhì)大學(xué)(北京)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：膠東是全球重要的黃金產(chǎn)地,也是中國探明金資源量最多的地區(qū),其中焦家金礦帶已探明金資源量1000噸,其內(nèi)金礦床(體)嚴(yán)格受焦家斷裂帶及其下盤次級(jí)斷裂/裂隙控制,構(gòu)造控礦模式是亟待深入研究的關(guān)鍵問題。為此,論文通過典型剖面構(gòu)造-蝕變-礦化巖相填圖、露頭尺度構(gòu)造解析、載金礦物黃鐵礦微區(qū)原位技術(shù)和3D有限元數(shù)值模擬方法,從區(qū)域→露頭→礦物多尺度系統(tǒng)剖析金礦床(體)分布規(guī)律與不同級(jí)別、序次和型式的控礦構(gòu)造的關(guān)系,以揭示焦家金礦帶構(gòu)造控礦規(guī)律和巨量金活化富集的構(gòu)造控制機(jī)理,構(gòu)建其構(gòu)造控礦模式,為新的勘查部署提供理論依據(jù)。主要取得以下認(rèn)識(shí):(1)焦家斷裂帶空間結(jié)構(gòu)可細(xì)分為斷裂核(主斷裂面、斷層泥、片理化和糜棱巖化帶)、破碎帶(碎裂巖、構(gòu)造熱液脈群、密集節(jié)理和劈理帶)和弱變形帶(稀疏節(jié)理帶)。(2)焦家斷裂帶經(jīng)歷了5期構(gòu)造變形:D1主要表現(xiàn)為成礦前NE向韌性剪切帶;D2為成礦前韌-脆性構(gòu)造活化;D3為成礦期韌-脆性變形(伴隨強(qiáng)烈的水巖反應(yīng)和大規(guī)模金成礦作用);D4為成礦期脆性變形,主要表現(xiàn)為巖/礦石的脆性破裂和熱液脈體(如石英-硫化物脈和方解石脈)的充填;D5為成礦后脆性變形。(3)識(shí)別出四類黃鐵礦,可見金通常發(fā)育于黃鐵礦脆性變形形成的裂隙和晶隙間或破裂-愈合的裂隙內(nèi),以裂隙金為主,兼有包裹體和晶隙金,并發(fā)育納米金粒,可能是黃鐵礦顯微-超顯微變形的位錯(cuò)中不可見金的再活化和再富集而形成。(4)斷裂面擦痕所反映的斷裂運(yùn)動(dòng)學(xué)和動(dòng)力學(xué)特征具有復(fù)雜的二元結(jié)構(gòu),既有正斷層活動(dòng)特征,也有逆斷層活動(dòng)特征,兼有走滑分量。成礦期主體表現(xiàn)為張剪性構(gòu)造控礦樣式(NW向拉張兼有左行走滑分量),是成礦前的主要構(gòu)造形跡在成礦期構(gòu)造應(yīng)力場作用下再活化而形成的�？氐V構(gòu)造應(yīng)力場3D有限元數(shù)值模擬結(jié)果顯示,成礦前主應(yīng)變和剪應(yīng)變的相對(duì)高值區(qū),隨著成礦期構(gòu)造再活化或應(yīng)變能釋放是成礦流體聚集和成礦物質(zhì)沉淀的有利部位。
[Abstract]:Jiaodong is an important gold producing area in the world, and it is also the largest area of proven gold resources in China. The Jiaojia gold belt has been proved to have 1000 tons of gold resources. The gold deposit (body) is strictly controlled by the Jiaojia fault zone and its secondary faults / fissures in the footwall. The structural ore-controlling model is a key problem to be studied in depth. In this paper, through typical section tectonic-alteration mineralized lithofacies mapping, outcrop scale structure analysis, in-situ technique of pyrite microarea and 3D finite element numerical simulation method, the regional analysis is carried out. 鈫扥utcrop. 鈫扵he relationship between the distribution law of gold deposits (bodies) and the ore-controlling structures of different grades, order and pattern is analyzed in order to reveal the structural ore-controlling law of Jiaojia gold deposit belt and the tectonic control mechanism of huge amount of gold activation and enrichment. Construct its tectonic ore-controlling model to provide a theoretical basis for new exploration and deployment. The main knowledge is as follows: 1) the spatial structure of Jiaojia fault zone can be subdivided into fault core (main fault surface, fault gouge). Schistatic and mylonized zones, broken zones (cataclastic rocks, tectonic hydrothermal vein groups). The dense joints and cleavage zones) and the weak deformation zone (sparse joint belt, Jiaojia fault zone) experienced five tectonic deformation stages: 1: D1, mainly showing NE ductile shear zone before mineralization; D2 was activated by pre-metallogenic ductile-brittle structure; D _ 3 is ductile brittle deformation during metallogenic period (accompanied by strong water-rock reaction and large-scale gold mineralization); D _ 4 is a brittle deformation in metallogenic period, which is mainly characterized by brittle fracture of rock / ore and filling of hydrothermal veins (such as quartz-sulfide vein and calcite vein). Four types of pyrite were identified by D5 as post-metallogenic brittle deformation. The visible gold is usually developed in the cracks formed by the brittle deformation of pyrite and the intergranular gap or the fracture and healing fissure, mainly in the fissured gold. There are inclusions and intergranular gold, and nanocrystalline gold particles are developed. It may be that the reactivation and reenrichment of invisible gold in the micro-ultramicro deformation of pyrite formed the fracture kinematics and dynamics characteristics of the fracture surface, which reflect the complex binary structure. Both normal fault activity and reverse fault activity, as well as strike-slip component. The main ore-forming stage is characterized by tension-shearing tectonic control style and left strike-slip component. The result of 3D finite element numerical simulation of the ore-controlling tectonic stress field shows that the relative high value region of the principal strain and shear strain before mineralization is obtained. With the tectonic reactivation or strain energy release during metallogenic period, the ore-forming fluid accumulates and the ore-forming minerals are precipitated.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：P618.51
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本文編號(hào)：1448840