辽东林家三道沟-小佟家堡子地区金（银）矿成矿特征及成因

以林家三道沟、小佟家堡子金（银）矿床为例，系统总结了区内金（银）矿床的成矿条件及地质特征，对矿床的相关岩体、围岩及矿石进行了流体包裹体、稳定同位素测试分析。结果表明：矿床赋存于古元古界辽河群大石桥亚群杨树沟岩组第6岩段碎屑岩-碳酸盐岩建造和盖县亚群汤家沟岩组碎屑岩建造中；主要容矿岩石为硅化大理岩、变粒岩、片岩；近矿围岩蚀变主要为硅化、绢云母化、黄铁矿化和碳酸盐化；自然金的粒度以显微不可见金为主；均一温度（100～200 ℃）、成矿流体盐度（w（NaCl）（1.91 % ～9.73%）均较低；矿石石英中成矿流体δD值为-48.0‰～-93.0‰，δ¹⁸O_H2O计算值为-8.63‰～+1.31‰，表明成矿流体主要来自于地热水和原生地层水；矿石硫同位素δ³⁴S值平均为+8.61‰，赋矿围岩、岩体δ³⁴S为＋0.50‰～＋7.6‰，表明矿石中硫主要来自古元古代地层和印支晚期岩体；金（银）矿石中²⁰⁶Pb/²⁰⁴Pb为17.664～19.186 7,²⁰⁷Pb/²⁰⁴Pb为15.044～15.883,²⁰⁸Pb/²⁰⁴Pb为37.693～38.784，铅源具有壳幔混合源特点。矿床成因类型为沉积变质-岩浆热液叠加型。

Metallogenetic Characteristics and Genesis of the Gold(Silver)Mineralization in Linjiasandaogou-Xiaotongjiapuzi Area, Eastern Liaoning Province

Taking the Linjiasandaogou and Xiaotongjiapuzi gold(silver) deposits as examples,authors systematically summarize the metallogenetic conditions and geological characteristics of gold(silver) mineralization in the region.Fluid inclusions and stable isotope composition in the intrusion related to the deposit,wall rocks and ores are also analyzed.The results show that gold deposits in this area mainly occur in the clastic-carbonatite formation of the 6th rock segment in the Yangjiagou Formation of the Dashiqiao Sub-Group,and the Tangjiagou Formation clastic of Gaixian Sub-Group.Ore-hosting rocks mainly include silicated marble,leptynite and schist.Types of wall-rock alteration include silication,sericitization,pyritization and carbonatization.Such gold minerals as native gold mostly occur as microscopic and invisible gold minerals.Both homogenization temperature(100-200℃) and salinity(w(NaCl)=1.91%-9.73%) of mineralizing fluids are low.The δD values of ore-forming fluids in the quartz from the ore change from-48.0‰ to-93.0‰,and the calculated values of δ18OH2O from-8.63‰ to +1.31‰,which shows that the mineralizing fluid was derived from the geothermal water and connate water.The mean value of sulfur isotope(δ34S) in the ore is +8.61‰,and those of ore-hosting rocks and metallogenetic intrusion vary from-8.63‰ to +1.31‰,which indicating that most of the sulfur in minerals are from Paleo-Proterozoic strata and Late Indosinian intrusion;the values of 206Pb/204Pb,207Pb/204Pb and 208Pb/204Pb in gold(silver) ores are 17.664-19.186 7,15.044-15.883 and 37.693-38.748,respectively.The Pb has the mixing source of crustal materials with mantle components.The gold(silver) mineralization in Linjiasandaogou-Xiaotongjiapuzi area can be defined as sedimentary metamorphic magmatic hydrothermal superimposed deposit.