(1. 中南大學(xué)有色金屬成礦預(yù)測教育部重點實驗室，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；
3. 湖南省有色地質(zhì)勘查局，長沙 410016)
摘 要: 對合江口礦的礦床地質(zhì)特征，特別是巖相學(xué)和礦相學(xué)特征進行系統(tǒng)研究，并對該礦床中的輝鉬礦進行Re-Os同位素測年，獲得印支期(225±3.6Ma)成巖成礦作用的地質(zhì)和年代學(xué)證據(jù)；結(jié)合以往的成巖成礦時代資料，認為錫田地區(qū)存在多期成礦事件，并討論成礦動力學(xué)演化特征。結(jié)果表明：合江口礦床的第Ⅰ期成礦事件發(fā)生在印支期，成礦物質(zhì)來源為殼幔混合源，發(fā)生于擠壓大地構(gòu)造背景中，礦化較弱；第Ⅱ期為燕山早期，在拉張的構(gòu)造背景下，幔源物質(zhì)大規(guī)模參與成礦，是本區(qū)的主成礦期；第Ⅲ期為燕山晚期，是與花崗斑巖脈侵入相關(guān)的斑巖-矽卡巖型礦體的成礦期，該期形成的礦體為錫田礦田內(nèi)新發(fā)現(xiàn)類型，也是下一步的找礦方向之一。
關(guān)鍵字: 錫鎢礦床；多期成礦作用；Re-Os同位素；合江口；錫田；欽杭帶
（1. Key Laboratory of Metalloginic Prediction of Non-ferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
3. Hunan Nonferrous Geological Exploration Bureau, Changsha 410016, China）
Abstract:Thegeology and mineralogy of the Hejiangkou deposit and conducted Re-Os isotopic dating on molybdenite from the Hejiangkou deposit were systematically studied. The dating results provided new evidence for the mineralization that occurred during the Indosinian (225±3.6Ma). By combining the rock-forming ages and mineralization ages obtained by both previous researches, the Xitian area experienced multi-periods mineralizations. Moreover, the metallogenetic tectonic settings of different mineralizations were also discussed. The results show that period I is the Indosinian mineralization period that involves mixing between both crust-derived and mantle-derived ore-forming materials. The period of mineralization took place under the compressional tectonic regime and featured by the weak mineralization. Period Ⅱis the early Yanshanian mineralization that represents the main mineralization period of the area and is related to a large influx of mantle-derived materials under an extensional regime. PeriodⅢ is the late Yanshanian porphyry-skarn type mineralization that is related to the emplacement of granite-porphyry veins and is a recently discovered type in the Xitian orefield. The porphyry-skarn type mineralization also becomes the target of the future ore-prospecting.
Key words: Sn-W deposit; multi-periods mineralization; Re-Os isotope; Hejiangkou; Xitian; Qinzhou-Hangzhou suture
