(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: 通過分析14個礦床礦化點(diǎn)的分布資料，編制錫礦山銻礦田古成礦環(huán)境網(wǎng)絡(luò)示意圖，總結(jié)錫礦山銻礦床的14項(xiàng)基本成礦特點(diǎn)，歸納分析前人對本區(qū)銻礦成因的5種觀點(diǎn)和相關(guān)依據(jù)，提出錫礦山礦田古環(huán)境系統(tǒng)，深-流-障，即深流-環(huán)流-障積成礦系統(tǒng)的新認(rèn)識。湘中晚古生代臺內(nèi)斷陷盆地是成礦環(huán)境系統(tǒng)的重要地質(zhì)基礎(chǔ)，由西向東NE向5條深切基底的斷裂構(gòu)成斷陷盆地的成礦環(huán)境主干，而以冷水江大斷裂及其分支75號斷裂表現(xiàn)尤為突出。錫礦山礦田構(gòu)造展布、蝕變礦化、包體分析、化探異常，表明它們間存在疊合和耦合關(guān)系，并顯示出礦田內(nèi)存在一個由南西向北東，并有多處分支分叉的環(huán)境系統(tǒng)。礦田內(nèi)眾多礦體分布表明NE向主斷裂帶、F75及其3條分支斷裂帶與棋梓橋組、佘田橋組、劉家塘組3個層頂界面處為成礦的有利空間，而以佘田橋組頂界處規(guī)模最大，連續(xù)性最好，組成了完整的障積組合系統(tǒng)。盆地周邊侵入巖體和深部可能的地幔柱，是盆內(nèi)的主要熱源，上升熱礦水與下滲水的長期環(huán)流是盆地內(nèi)成礦作用重要動力機(jī)制，分析并剔除了3種環(huán)流(垂向環(huán)流、雙向環(huán)流、洞穴環(huán)流)的方式和機(jī)制。總結(jié)了鑒別古成礦環(huán)境系統(tǒng)的4大標(biāo)志。針對礦田成礦系統(tǒng)環(huán)流分布特點(diǎn)，提交了馬月山背斜至陳家排的6處有利找礦靶區(qū)。
關(guān)鍵字: 錫礦山礦田；古成礦環(huán)境系統(tǒng)；深邊部找礦
（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:According to the distribution data of 14 mineralization points, the sketch map of the ancient ore-forming environment in Xikuangshan antimony ore-field was drawn, 14 basic mineralization characteristics in this area were summarized, and the previous 5 kinds of viewpoints on genesis as well as its relevant basis were analyzed. Through the above comprehensive analysis, the paleoenvironmental system of the Xikuangshan ore-field, deep-flow-barrier, namely the new understanding of flow-circulation-bafflestone metallogenic system was proposed. The late Paleozoic rift basin, which is inside the platform of central Hunan, is a significant geological basis of the metallogenic environment system. In this mining area, from west to east, there exist 5 NE trending faults, which deeply ingrow into the basement, constitute the backbone of the metallogenic environment. Among these faults, the Lengshuijiang fault and its branch No.75 fault are particularly prominent. In Xikuangshan ore-field, by the analysis of the structural distribution, mineralization and alteration, inclusion and the geochemical anomaly, it can be concluded that there exists a superposition and coupling relationship between them, thus demonstrating that there is a environment system extending from SW to NE with various branches of bifurcation. According to the distribution of the numerous mineral deposits, it can be concluded that the favorable space for mineralization is the top layer interface between the NE-trending main fault zone, F75 as well as its three branches and the three groups of Qiziqiao formation, Shetianqiao formation and Liujiatang formation. In addition, with the largest top boundary and the best continuity, the Shetianqiao formation composes a complete bafflestone combined system. The intrusive rocks around the basin and the deep mantle plume are possibly the main heat source. What’s more, the uprising thermal water and the infiltration water are the important driving force in the basin mineralization mechanism. Through analysis, three kinds of modes and mechanisms i.e., the circulation-vertical circulation, two-way circulation and the cave circulation, were analyzed and removed. Also, four signs for the identification of ancient metallogenic environment system were summed up. According to the distribution characteristics of the metallogenic circulation system, the six areas of favorable prospecting targets from Mayue mountain antiline to Chenjiapai were put forward.
Key words: Xikuangshan ore-field; ancient metallogenic environment system; deep and side prospecting
