【作者】 张志；

【导师】 胡祥昭；

【作者基本信息】 中南大学 ， 构造地质学， 2010， 硕士

【摘要】 海南省儋州市南江铅锌多金属矿区位于海南岛中北部,处于岭南褶皱系五指山褶皱带北缘,王五-文教深大断裂带的南侧。本文结合生产实际,通过区域成矿地质背景、矿区地质特征和物化探工作的研究,首次全面系统地论述了矿区铅锌矿和褐铁矿矿体地质特征,明确了矿床成因和成矿规律,提出了本区成矿模式,总结了找矿标志并对矿区找矿远景区和资源量进行预测。研究发现,矿区出露地层为志留系下统空列村组(S1k)和石炭系下统南好组(Cn-q)及第四系(Q)；矿区褶皱构造不发育,为一单斜地层；断裂和节理较发育,共发育有7条断裂,走向北北东向、北西向及近东西向；矿区南部和西北角可见海西-印支期黑云母二长花岗岩侵入,脉岩发育。矿区发育有铅锌矿和褐铁矿体,铅锌矿呈透镜状、脉状产出；新发现褐铁矿(化)体由四个矿段组成,分别标为Ⅰ号矿段、Ⅱ号矿段、Ⅲ号矿段、Ⅳ号矿段,矿(化)体走向北北东向,倾向南东,倾角40°-70°,断续长达800m,地表出露宽度10-100m左右,呈脉状、透镜状产出,规模较大,矿体品位很高质量较好。根据物化探异常分析,圈出物探异常极化率异常带一处,视电阻率低阻带两处,化探异常发现三处较明显,物化探异常与地质工作成果相同。研究认为,矿区成矿物质来源主要为地层沉积和岩浆热液来源,铅锌和褐铁矿主要受地层、断裂和岩浆岩控制。铅锌矿赋矿围岩为志留系空列村组(S1K)结晶灰岩,F6断层控制了南江铅锌矿的产出,呈北东向为矿液运移提供通道,后期发育了一系列缝隙,组成容矿构造。褐铁矿(化)体产于石炭系下统南好组上段(C1n—2)地层中,区内三组NNE向断裂控制了矿体的产出并为矿液运移提供通道。蓝洋岩体富碱、富钾、钙碱性,岩体分异指数高,分异程度完好,为铅锌矿和褐铁矿成矿提供热液流体和物质来源。根据矿床地质特征,结合物化探异常分析结果,认为铅锌矿为碳酸盐岩与花岗岩接触带附近成矿物质沿裂隙向上侵入成矿,为一中小型浅成交代热液矿床,成矿时期为海西-印支期；褐铁矿成矿时期为海西-印支期到中生代后,为中低温热液交代充填一风化淋滤型矿床。更多还原

【Abstract】 Nanjiang lead-zinc polymetallic deposit in Danzhou city Hainan province is located in north-central Hainan Island, in department of Lingnan fold belt north edge of Wuzhishan and in the south of Wang wu to Wenjiao deep faults. Combined with actual production, through investigating regional geological background, mining area geological features, and geophysical and geochemical works, we discuss the lead and limonite ore geological features comprehensively and systematically for the first time, demonstrate the ore genesis and metallogenetic rules, propose mineralization model in this area, summarize ore-hunting indicators and forecast the mining and resource prospecting area in this article.The follwing facts have been discovered after careful study:Kong liecun formation(S1k) strata in lower Silurian, Nanhao Formation(Cn—q) strata in lower Carboniferous and Quaternary were exposed in the mining area;the fold structure was not developeded and there is only one monoclinic stratum in the mining area; fractures and joints were developed, and there are seven fractures with strick direction of NNE, NW and EW in the mining area;Hercynian-Indosinian biotite monzogranite was appeared in the south and northwest of the mining area and vein rocks was found here.Lead-zinc ore and limonite body were developed in the mining area. lead-zinc ore was discovered with their occurrence being vein state and lens, and limonite body is composed by four ore blocks which was labeled by ore blockⅠ,ore blockⅡ, ore blockⅢand ore blockⅣ, respectively. The orebody with strick direction of NNE, tilt direction of SE and dip 40(degrees)-70(degrees) extend 800 meter sapproximately.The orebody with their occurrence being vein state and lens was exposed at the surface of the earth and its width is about 10-100 meters.According to analysis of geophysical and geochemical anomalies, one place with abnormal polarization geophysical anomaly, two places with low apparent resistivity geochemical anomaly and three places with geochemical anomaly were found.The above geophysical and geochemical anomalies are identical with the geological works. It is believed by investigating that ore-forming material sources in the mining area are mainly from the stratum and magmatic hydrothermal sources, and lead-zinc and limonite are mainly controled by the strata, fracture and magmatic. The wall rocks of lead-zinc is crystalline limestone which is hosted in Kong Lie Cun Formation strata(S1K) in Silurian. Nanjiang lead-zinc deposit is controlled by F6 fault and the channels for ore solution migration is provided by the NE-trending faults(F6 fault). A series of cracks were developed after the fault formed and the ore-hosting structures are composed by them. Limonite deposit is hosted in the Nanhao Formation (C1n—2) strata in lower carboniferous, and the orebody is controlled by the NNE-trending faults and the channels for ore solution migration is provided by these faults. The Lanyang rock mass is alkali-rich, K-rich, calc-alkaline, and it has high differentiation index and good degree of differentiation, and hydrothermal fluids and materials sources for lead-zinc ore and limonite mineralization are provided by it. According to geological characteristics, combined with geophysical and geochemical anomalies, we speculate preliminarily that lead-zinc deposit is a middle and small hypabyssal metasomatic hydrothermal deposits, which mineralization period is Hercynian Indosinian; The mineralization period of limonite ore is from the Hercynian-Indosinian to the Mesozoic and it is a middle-low temperature hydrothermal type related tometasomstic filling-weathering and leaching deposit.更多还原