【摘要】：謝米斯臺(tái)地區(qū)位于新疆西準(zhǔn)噶爾北緣。本文在前人研究的基礎(chǔ)上,以野外地質(zhì)考察、巖相學(xué)、礦相學(xué)、地球化學(xué)和金屬礦物電子探針?lè)治龅确椒橹?查明謝米斯臺(tái)布拉特地區(qū)自然銅礦化中-基性火山巖的地質(zhì)、地球化學(xué)特征,初步探討其形成時(shí)代、巖石成因和形成構(gòu)造環(huán)境,為探討謝米斯臺(tái)地區(qū)古生代構(gòu)造演化提供新的證據(jù);查明自然銅礦化特征和金屬礦物成分特征,初步探討自然銅成因,找礦前景和找礦標(biāo)志,為區(qū)內(nèi)進(jìn)一步找礦勘查工作提供參考。論文取得以下主要成果:1、通過(guò)野外地質(zhì)考察及項(xiàng)目?jī)?nèi)部獲得的區(qū)內(nèi)酸性火山巖、次火山巖年齡,初步推測(cè)謝米斯臺(tái)地區(qū)自然銅礦化中-基性火山巖形成于晚志留世或晚志留世之前。2、研究區(qū)基性火山巖MgO含量為(4.32%～7.23%),Mg#值為49.59～58.38,FeOT/MgO 比值為 1.57～2.24;中性火山 MgO 含量為(3.84%～6.08%),Mg#為 56.57～62.45,略高于基性火山巖,FeOT/MgO比值為1.32～1.51,略低于基性火山巖。兩者都屬于鈣堿性系列巖石,具有較高的Na2O+K2O和Al2O3值,相對(duì)富鐵貧鎂,富集Ba、Sr和Pb,虧損Nb、Ta和Ti等元素。3、研究區(qū)中-基性火山巖形成于俯沖背景下的大陸邊緣弧環(huán)境,主要經(jīng)歷了單斜輝石的分離結(jié)晶作用、大陸地殼物質(zhì)的混染和俯沖流體的交代。4、研究區(qū)礦化中-基性火山巖蝕變較強(qiáng),蝕變類型多樣,火山熱液脈發(fā)育。自然銅礦化主要發(fā)育于這些蝕變的中-基性火山巖及其中的晚期熱液脈中,礦化與火山熱液熱液作用有關(guān),熱液作用可以分為3個(gè)階段。5、布拉特地區(qū)自然銅礦化中-基性火山巖規(guī)模相對(duì)較小,可以作為品位高、埋藏淺、易采選的小型銅礦床進(jìn)行勘查開(kāi)發(fā),具有一定的經(jīng)濟(jì)和社會(huì)效益。區(qū)內(nèi)自然銅找礦標(biāo)志:a蝕變及脈體標(biāo)志;b顏色呈綠灰色,氣孔杏仁體小;c石英綠簾石團(tuán)塊。
[Abstract]:The Shermisi area is located in the northern margin of Xinjiang West Junggar. On the basis of previous studies, based on field geological investigation, petrography, mineralogy, geochemistry and electron probe analysis of metallic minerals, this paper investigates the geology of the natural copper mineralization of the Meso-basic volcanic rocks in the Shemistibart area. Geochemical characteristics, preliminary study of its forming age, petrogenesis and tectonic setting provide new evidence for the paleozoic tectonic evolution in the Semistii area, and find out the characteristics of natural copper mineralization and metallic mineral composition, and provide new evidence for the discussion of the evolution of Paleozoic structures in the Shemishitai area. The origin of natural copper, the prospecting prospect and the prospecting marks are discussed preliminarily, which provides a reference for further prospecting and exploration in the area. The main achievements of this paper are as follows: 1. The ages of acid volcanic rocks and subvolcanic rocks in the area obtained through field geological investigation and internal project. It is inferred preliminarily that the natural copper mineralization in the Shermisitai area was formed in the middle to basic volcanic rocks during the late Silurian or before the late Silurian. 2. The MgO content of the basic volcanic rocks in the studied area is (4.32 ~ 7.23%), the Mg# value is 49.59 ~ 58.38%, the FeOT / MgO ratio is 1.572.24, and the neutral volcanic MgO is 1.572.24. The content of FeOT/MgO is (3.84 ~ 6.08%), Mg# is 56.57 ~ 62.45, which is slightly higher than that of basic volcanic rock, and the FeOT/MgO ratio is 1.32 ~ 1.51, which is slightly lower than that of basic volcanic rock. Both belong to calc-alkaline series rocks, with high Na2O K _ 2O and Al2O3 values, relatively rich in iron and magnesium, rich in Ba,Sr and Pb, depleted in elements such as Nb,Ta and Ti. 3. The meso-basic volcanic rocks in the study area were formed in the continental margin arc environment in the subduction setting. It mainly experienced the separation and crystallization of clinopyroxene, the mixing of continental crustal materials and the metasomatism of subduction fluids. The natural copper mineralization is mainly developed in these altered meso-basic volcanic rocks and their middle-late hydrothermal veins, and the mineralization is related to the volcanic hydrothermal process. The hydrothermal process can be divided into three stages. 5. The natural copper mineralization in Blatter area is relatively small in scale and can be used as a small copper deposit with high grade, shallow burial and easy to be mined. It has certain economic and social benefits. The natural copper prospecting marks in this area are as follows: a alteration and vein marker; b color green-gray, small stomatal almond body; c quartz green coronite mass.
【學(xué)位授予單位】：西北大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P588.14;P618.41
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本文編號(hào)：2265118