本文選題：東昆侖 + 濤歌巖體�。� 參考：《中國(guó)地質(zhì)大學(xué)(北京)》2017年碩士論文

【摘要】：東昆侖拉陵灶火中游濤歌巖體周邊成礦現(xiàn)象豐富,但是致礦侵入體至今不明。本文以濤歌巖體作為研究的出發(fā)點(diǎn),對(duì)濤歌巖體及其周邊的成礦現(xiàn)象進(jìn)行了細(xì)致的研究。獲得了濤歌巖體地質(zhì)特征及其與成礦作用的聯(lián)系,推斷濤歌巖體為中游地區(qū)可能的致礦侵入體之一。對(duì)濤歌巖體及其周邊進(jìn)行了地質(zhì)填圖,發(fā)現(xiàn)濤歌巖體與片麻巖呈侵入接觸關(guān)系,片麻巖的產(chǎn)狀顯示其大致為一個(gè)以濤歌巖體為樞紐的背斜,表明濤歌巖體在構(gòu)造上符合致礦侵入體要求。濤歌巖體本身含金,富集銅,表明濤歌巖體在成礦物質(zhì)來源上符合致礦侵入體要求。對(duì)濤歌巖體進(jìn)行詳細(xì)的礦物學(xué)研究。對(duì)金屬礦物進(jìn)行電子探針分析顯示載金礦物為黃鐵礦和磁鐵礦。陰極發(fā)光研究表明斜長(zhǎng)石普遍存在增生邊。鏡下使用卡鈉復(fù)合雙晶法測(cè)定了斜長(zhǎng)石牌號(hào),發(fā)現(xiàn)斜長(zhǎng)石牌號(hào)分為兩類。對(duì)斜長(zhǎng)石成分進(jìn)行了電子探針分析,發(fā)現(xiàn)斜長(zhǎng)石分為基性斜長(zhǎng)石和中性斜長(zhǎng)石兩類。這些表明巖石經(jīng)歷了兩種不同的結(jié)晶過程。由CSD曲線的樣式和SiO2、角閃石含量可以識(shí)別出兩期流體活動(dòng)。角閃石的方向優(yōu)選顯示中間樣品的定向強(qiáng)度大于邊緣樣品的定向強(qiáng)度,這表明第二期流體活動(dòng)強(qiáng)度大于第一期流體活動(dòng)強(qiáng)度。對(duì)濤歌巖體進(jìn)行了巖石地球化學(xué)分析,顯示濤歌巖體冷卻結(jié)晶過程中SiO2、Na2O、Fe2O3、P2O5、K2O的含量總體升高,而Al2O3、TiO2、CaO的含量總體降低。濤歌巖體稀土元素含量存在明顯重稀土虧損,負(fù)Eu異常,顯示巖石受到嚴(yán)重蝕變改造。Nb、Ta的負(fù)異常顯示中游濤歌巖體應(yīng)該為島弧火山巖,這與區(qū)域內(nèi)中三疊世是島弧碰撞構(gòu)造環(huán)境相吻合。濤歌巖體形成的時(shí)間在225~230Ma,而濤歌巖體下部的被活化的巖漿形成的時(shí)間是245~250Ma。濤歌巖體結(jié)晶溫度存在兩個(gè)區(qū)間:493℃~650℃和752℃~810℃;壓力在2.81Kbar至1.54Kbar,前四個(gè)溫度較低的樣品的平均壓力為2.68 Kbar,后六個(gè)溫度較高的樣品的平均壓力為2.15 Kbar。表明巖體不同部位巖石經(jīng)歷了不同溫壓條件的結(jié)晶過程。濤歌巖體的形成過程是:第一期流體活動(dòng)——巖體結(jié)晶粗化——第二期流體活動(dòng)——巖體結(jié)晶粗化的波動(dòng)過程。并且第二期流體活動(dòng)活動(dòng)的強(qiáng)度大于第一期流體活動(dòng)的強(qiáng)度,在流體活動(dòng)過程中由于下部巖漿的活化,導(dǎo)致下部近固結(jié)巖漿房中的鋯石帶入濤歌巖體。
[Abstract]:The ore-forming phenomena around the TAOGE rock body in the middle reaches of Laling Zaozao in East Kunlun are abundant, but the ore-forming intrusions are still unknown. Taking the TAOGE rock mass as the starting point, this paper makes a detailed study on the ore-forming phenomenon of the TAOGE rock mass and its surroundings. The geological characteristics of the TAOGE rock mass and its relation with mineralization are obtained, and it is inferred that the TAOGE rock body is one of the possible ore-forming intrusions in the middle reaches. The geological mapping of the TAOGE rock body and its surrounding area shows that the TAOGE rock body has an intrusive contact relationship with the gneiss, and the occurrence of the gneiss shows that it is approximately an anticline with the TAOGE rock body as its pivot. It shows that the TAOGE rock body meets the requirements of ore-forming intrusion in structure. The ore-forming source of the TAOGE rock body is in accordance with the requirements of ore-forming intrusive body. A detailed mineralogical study of the TAOGE rock mass is carried out. Electron probe analysis of metallic minerals shows that the gold bearing minerals are pyrite and magnetite. Cathodoluminescence studies show that plagioclase generally exists accretive edges. The plate number of plagioclase was determined by the method of sodium Carbonate and double crystal under the microscope, and it was found that the plate number of plagioclase can be divided into two categories. The composition of plagioclase is analyzed by electron probe. It is found that plagioclase can be divided into basic plagioclase and neutral plagioclase. These indicate that rocks undergo two different crystallization processes. Based on the CSD curve and Sio _ 2, amphibole content can be used to identify the two-stage fluid activity. The directional optimum selection of amphibole shows that the directional strength of the intermediate sample is higher than that of the edge sample, which indicates that the second phase of fluid activity is greater than the first phase. The geochemistry analysis of the TAOGE rock mass shows that the content of SiO2Na2O3Fe2O3Fe2O3P2O5K2O increases and the content of Al2O3TiO2CaO decreases during the cooling and crystallization of the TAOG rock body. The REE content in the Taoge rock body is obviously depleted in heavy rare earth elements and negative EU anomaly, which indicates that the rock is seriously altered. The negative anomaly of NbGTA indicates that the TAOGE rock body in the middle reaches should be island arc volcanic rock. This coincides with the tectonic environment of the island arc collision in the Middle Triassic in the region. The formation time of the TAOGE rock mass is 225 ~ 230 Ma, while the activated magma formation time of the lower part of the TAOGE rock body is 245 ~ 250 Ma. There are two ranges of crystallization temperature: 1: 493 鈩，

本文編號(hào)：2025561