本文選題：東昆侖西段　切入點：阿克蘇河　出處：《中國地質大學(北京)》2017年碩士論文

【摘要】：研究區(qū)位于新疆且末縣阿克蘇河地區(qū),大地構造位置上處于東昆中斷裂帶西段,昆北(祁漫塔格)弧后盆地與昆南增生楔雜巖接壤處,本文依托東昆侖西段祁漫塔格地區(qū)古生代構造變形特征及動力學機制研究項目,對阿克蘇河巖體的巖石學、年代學及地球化學特征進行研究,并討論其構造意義:1.通過野外地質和巖石學研究,系統(tǒng)的厘定了阿克蘇河巖體的巖石類型及空間分布方式。認為阿克蘇河巖體由北至南依次為糜棱巖化中細粒英云閃長巖、糜棱巖化中細�；◢忛W長巖、花崗閃長斑巖、細中粒含二云二長花崗巖和細中粒含白云母二長花崗巖。2.基于侵位關系及鋯石U-Pb測年數(shù)據(jù)結果可知,阿克蘇河巖體形成于晚泥盆世-早石炭世時期,由老至新依次為糜棱巖化中細粒英云閃長巖(355±5.0Ma)、糜棱巖化中細粒花崗閃長巖(354±4.3Ma)、花崗閃長斑巖(362±2.3Ma)、細中粒含二云二長花崗巖(339.7±3.9Ma)和細中粒含白云母二長花崗巖(331±5.0Ma)。3.阿克蘇河巖體地球化學特征揭示,該巖體屬于強過鋁質、高鉀鈣堿性S型花崗巖:富鋁、硅和堿(SiO_2:69.2%-77.77%、Al_2O_3:12.00%-14.78%),全堿含量、Na_2O及K_2O相對富集分別為:4.27%-7.98%、2.95%-4.39%、1.70%-4.23%,貧鐵(0.73%-3.78%)、鎂(0.11%-1.37%)、鈣(0.87%-1.16%)、鈦(0.03%-0.51%)、磷(0.02%-0.16%)等。分異程度相對較高(DI:74.49-95.64),CaO、Al_2O_3、TFeO、MgO、P_2O_5、TiO_2與SiO_2呈負相關;稀土總量∑REE:77.78-161.68×10~(-6),輕稀土相對富集(LREE/HREE:2.71-11.19、(La/Yb)N:1.99-14.26),輕重稀土元素分餾明顯,銪負異常(δEu:0.05-0.75)顯著;Rb、Th、U、Zr、Hf元素相對富集,P、Ti、Ta、Nb相對虧損;鋯飽和溫度為TZr:705-835℃、鋯石Ti溫度為T:524-756℃、成巖環(huán)境壓力較低;Nb/Ta、CaO/Na_2O、Zr/Hf及各源區(qū)判別圖解均具有陸殼特征。反映巖體大致分為兩期,且隨著巖性、年齡、含硅量、銪虧損等因素的變化,巖漿表現(xiàn)出良好的分異演化趨勢。4.本文認為研究區(qū)是在早泥盆世-早石炭世由于古特提斯洋殼俯沖作用形成的活動大陸邊緣弧。
[Abstract]:The study area is located in Aksu River area, Qiemai County, Xinjiang. The geotectonic position is located in the west section of the middle fault zone of East Kunming, and the back arc basin in the north of Kunming (Qimantage) is bordered by the accretive wedge complex in the south of Kunming. In this paper, the petrology, chronology and geochemistry of the Aksu River rock body are studied on the basis of the Paleozoic tectonic deformation characteristics and the dynamic mechanism of the Qimantag area in the western part of East Kunlun. Through field geological and petrological studies, the rock types and spatial distribution patterns of the Aksu River rock body are systematically determined. It is considered that the Aksu River rock body is mylonized in order of fine quartz diorite from north to south. Mylonized medium granodiorite, granodiorite, fine-grained Eryun monzogranite and fine-grained Muscovite monzogranite. 2. Based on emplacement relationship and zircon U-Pb dating data, it can be seen that, The Aksu River rock body was formed during the late Devonian to early Carboniferous. The order from old to new is mylonitization with medium fine quartz diorite (355 鹵5.0 Ma), mylonization with fine granodiorite (354 鹵4.3 Ma), granodiorite with porphyry (362 鹵2.3 Ma), fine granodiorite with Eryun monzogranite (339.7 鹵3.9 Maa) and fine-grained Muscovite diorite with 331 鹵5.0 Mai. 3Acke River. Geochemical characteristics of rock mass reveal, The rock body belongs to strong peraluminous, high-potassium calc-alkaline S-type granite: aluminum-rich, silicon and alkali SiO269.2- 77.7777 and Al2O312.00-14.78. the total alkali content is: Na2O and K2O are relatively enriched in: 4.27-7.982.95-4.3923C, 0.73-3.78m, 0.11-1.37m, 0.11-1.37m, 0.87-1.16kg, 0.03- 0.51N, 0.02- 0.16C, respectively. The differentiation degree is relatively high and the difference is relatively high. The relationship between the two groups is 74.495.CaOAl2O3-CaOMgO2O5O _ 2O _ 5O _ 2O _ 5O _ 2O _ 5 and SiO_2 _ 2O _ 5O _ 2O _ 5, etc. The relative degree of differentiation is 74.495.CaOO _ 2O _ 3O _ 2O _ 5O _ 2O _ 5O _ 2 SiO_2 _ 2 and so _ 2 _ 2 _ _ _. The total amount of rare earth is 鈭，

本文編號：1674893