黑龙江嘉荫连珠山金矿床成岩成矿年代学及其地质意义  

Petrogenic and metallogenic geochronology and its geological implications of Lianzhushan gold deposit,Jiayin,Heilongjiang Province

作　　者：任亮[1] 孙景贵[1] 唐臣 门兰静[3] 李怡欣 崔培龙[1] 

机构地区：[1]吉林大学地球科学学院,长春130061 [2]黑龙江省地质调查研究总院,哈尔滨150036 [3]长春工程学院,长春130021 [4]山东黄金资源开发有限公司,济南250100

出　　处：《岩石学报》2015年第8期2435-2449,共15页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(41390444;41172072);黑龙江省地质调查研究总院项目联合资助

摘　　要：连珠山矿床位于小兴安岭北麓,是一个产于花岗岩内部断裂体系的蚀变岩型金矿床。为了限定其成矿时代与成矿地质背景,本文对其赋矿围岩黑云母二长花岗岩和石英闪长岩进行了岩石地球化学、锆石U-Pb和绢云母40Ar/39Ar年代学的系统研究。定年结果表明黑云母二长花岗岩形成时代为中三叠世（243.7±1.3Ma,MSWD=0.77,n=12）,岩浆上侵过程中受到早古生代（474~438Ma）和中二叠世（267~261Ma）的岩浆混染,而石英闪长岩形成于晚三叠世（215.3±1.3Ma,MSWD=0.35,n=17）;黄铁绢英岩化矿石中的绢云母40Ar/39Ar坪年龄为194.2±2.0Ma,指示为早侏罗世成矿;元素地球化学特征显示连珠山侵入岩为准铝质-弱过铝质、高钾钙碱性岩石系列,具有I型花岗岩的地球化学属性;轻稀土元素富集,相对亏损重稀土元素,且具有弱的负Eu异常;富集大离子亲石元素（LILE）,亏损高场强元素（HFSE）。结合小兴安岭-张广才岭地区已有年代学资料和区域构造演化特征,认为其成矿地质背景为兴蒙造山晚期与古太平洋板块俯冲转换期,或成矿发生在兴蒙造山期后的伸展阶段。Located in the northern Lesser Xing＇an Range,the Lianzhushan deposit is an altered rock type gold deposit,host in the inner fractured zone of granite. To constrain its formation age and metallogenic geological setting,this paper carried out geochemistry research,LA-ICP-MS zircon U-Pb,and sericite40 Ar /39 Ar dating on biotite monzogranite,and quartz diorite. The analytic results show that biotite monzogranite formed in the Middle Triassic（ 243. 7 ± 1. 3Ma,MSWD = 0. 77,n = 12）,which had been contaminated by the Early Palaeozoic（ 474 ~ 438Ma） and the Middle Permian（ 267 ~ 261Ma） magma during magmatic ascending; the quartz diorite formed in the Late Triassic（ 215. 3 ± 1. 3Ma,MSWD = 0. 35,n = 17）; the sericites from pyritization phyllic altered ores have plateau age of40 Ar /39 Ar at 194. 2 ± 2. 0Ma,indicating that mineralization occurred in the Early Jurassic. Element geochemical characteristics show the Lianzhushan intrusive belong to metaluminous to weakly prealuminous,high potassium calc alkaline series,and have the geochemical characteristics of I-type granite,which enriched in light rare earth element（ LREE） and large ion lithophile element（ LILE） and relatively depleted in heavy rare earth element（ HREE） and high field strength element（ HFSE） with weak Eu anomalies. Combining the previous geochronology and regional evolution features of Lesser Xing＇an Range-Zhangguangcai Range,the metallogenesis took place in a transition setting from late period of Xingmeng orogen to the subduction of Paleo-pacific oceanic plate,or the mineralization occurred in the extensional stage of the Xingmeng orogen.

关 键 词：成岩成矿时代 地球化学特征 成岩成矿背景 连珠山金矿床 黑龙江 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]