赛什塘地区铜多金属矿构造控矿特征和成矿规律

发布时间：2018-01-27 03:29

本文关键词： 赛什塘地区铜多金属矿床成矿规律锆石 U-Pb 同位素测年　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：赛什塘地区位于东昆仑和西秦岭接合部位,地处青海省兴海县,鄂拉山的东南部,隶属鄂拉山多金属矿带的赛什塘-日龙沟亚矿带。由于地处高寒地区,加之地质构造复杂等因素,制约了对该区矿床成因类型和控矿因素的认识,目前找矿工作遇到了“瓶颈”。因此,选择赛什塘和铜峪沟两个铜多金属矿开展成矿规律及矿床成因的研究,为下一步找矿方向提供理论依据。在前人研究基础上,通过野外调研和室内综合分析,依据岩浆成矿学理论,从构造特征、岩浆性质、成矿期次等分析入手,对赛什塘地区铜多金属矿进行成矿规律研究。取得了如下成果和认识:1.研究区位于东昆仑与西秦岭造山带的接合部位,属于秦祁昆造山系的一部分,由东昆仑和西秦岭两大构造单元组成,受鄂拉山构造带影响,区内广泛分布有火山岩,产于二叠纪和三叠纪地层中。夹在海相沉积地层中的火山沉积建造是主要的赋矿层位,矿体主要产于火山喷发的间歇期-火山碎屑沉积岩的夹层中;研究区内的侵入岩主要分为四期,与成矿作用密切的是第二期侵入的中酸性侵入体;该区成矿背景属于板内裂谷构造环境。2.研究区内有两期成矿作用。早期为火山沉积成矿,矿体主要产于海相火山沉积建造中,早期成矿时代为晚三叠世早期,与鄂拉山组时代相当,成矿主要为Cu、Pb、Zn、Sn;晚期成矿与中酸性岩体侵入作用有关,晚期成矿时代为晚三叠世中期,晚期成矿主要为Cu、Pb、Zn、Sn、Mo。综合分析认为,赛什塘地区矿床成因类型为早期火山沉积型叠加晚期矽卡岩-斑岩型铜多金属矿。3.研究区内,由于早期成矿矿体多赋存于晚三叠世的海相火山沉积地层中,因此沿各矿床中主要含矿层位继续追索是找矿突破口之一;晚期成矿与三叠纪晚期的石英闪长岩和花岗闪长岩侵入体有关,因此应对研究区内出露的中酸性侵入岩体重点勘查;对1:50万遥感影像图中的环形构造区进行了重点勘探,环形构造指示可能有火山机构的存在,并且火山机构与成矿密切相关。
[Abstract]:The Sesitang area is located at the junction of East Kunlun and West Qinling, located in Xinghai County, Qinghai Province, in the southeast of Ora Mountain, belonging to the Sesitang-Rilonggou sub-ore belt of the Ela Mountain polymetallic ore belt. It is located in the alpine area. In addition, the complex geological structure and other factors restrict the understanding of the genetic types and ore-controlling factors of the ore deposits in this area, so the prospecting work has encountered a "bottleneck" at present. Two copper polymetallic ore deposits, Sesitang and Tongyugou, are selected to study the metallogenic regularity and genesis of the deposit, which provides the theoretical basis for the next prospecting direction. On the basis of previous studies, field investigation and indoor comprehensive analysis are carried out. Based on the theory of magmatic metallogeny, the structural characteristics, magmatic properties and secondary metallogenic stages are analyzed. The metallogenic regularity of copper polymetallic deposits in Sesitang area has been studied. The following results and understandings have been obtained. 1. The study area is located at the junction of East Kunlun and West Qinling orogenic belts and is part of the Qi-Kun orogenic system. It is composed of two tectonic units, East Kunlun and West Qinling, and is widely distributed in the area under the influence of the Ora Mountain tectonic belt. The volcanic sedimentary formation intercalated in marine sedimentary strata is the main ore-bearing bed, and the orebody mainly occurs in the intercalation of volcanic eruption-volcanic clastic sedimentary rocks. The intrusive rocks in the study area are mainly divided into four stages, and the intermediate-acid intrusions in the second stage are closely related to mineralization. The metallogenic background of this area belongs to the intraplate rift tectonic environment. 2. There are two stages of mineralization in the study area. In the early period, volcanic deposits were formed, and the orebodies mainly occurred in marine volcanic sedimentary formations. The early metallogenic age is the early late Triassic, which is similar to that of the Orashan formation. The late mineralization is related to the intrusion of intermediate-acid rock mass, the late metallogenic age is the middle stage of the late Triassic, and the late mineralization is mainly the Cu PbPbZZZZZN SnMo.The comprehensive analysis shows that the metallogenic age of the late stage is the middle of the late Triassic. The genesis type of Sesitang deposit is the early volcanic sedimentary type superimposed late skarn porphyry copper polymetallic ore. 3. In the study area, the early metallogenic bodies mostly occurred in the marine volcanic sedimentary strata of the late Triassic. Therefore, the continuous tracing along the main ore-bearing strata in each ore deposit is one of the breakthrough points for prospecting. The late mineralization is related to the quartz diorite and granodiorite intrusions in the late Triassic. An important exploration of the ring tectonic area in the 1:50 remote sensing image is carried out. The ring structure indicates that there may be a volcanic mechanism, and the volcanic mechanism is closely related to the mineralization.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.2

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