新疆巩留—特克斯达坂库勒萨依一带花岗岩类研究

【作者】 杨俊泉；

【导师】 李永军；

【作者基本信息】 长安大学 ， 构造地质学， 2006， 硕士

【摘要】 库勒萨依位于新疆伊犁地区巩留-特克斯达坂一带,花岗岩类在这一带呈岩基状分布。前人对研究区花岗岩类的研究是在岩相学的背景下,用相变的理论指导进行的岩石相带的划分,未对本区花岗岩类进行解体,将其作为一个岩体。另外,在岩石地球化学研究方面,只做了一些岩石化学分析,地球化学数据较少,同位素年龄要么没有,要么因为测试方法的不可靠而不具说服力,因而对研究区花岗岩类的成因及构造环境未作深入研究。缺乏对花岗岩类与区内主要岩浆事件的配套研究,对火成岩组合、成因关系、大地构造演化探讨较少。成矿上无大进展,未发现有较好的矿化信息和线索。通过对库勒萨依一带花岗岩类的岩石学特征、岩石化学特征、地球化学特征,及花岗岩类形成的时代及成矿元素背景、成矿条件和与构造的关系等进行系统研究和全面认识,取得了以下新的认识和进展:1.运用岩石谱系单位填图方法和理论,将研究区出露花岗岩类解体为两个序列,即早石炭世库勒萨依序列和早二叠世其那尔萨依序列。二者均侵入于下石炭统大哈拉军山组（C₁d²）中。二者之间呈超动接触,早二叠世其那尔萨依侵入于早石炭世库勒萨依序列中。2.早石炭世库勒萨依序列侵入时代为330～320Ma,主要岩石类型有石英闪长玢岩、花岗闪长斑岩。石英闪长玢岩早于花岗闪长斑岩形成。3.早二叠世其那尔萨依序列侵入时代为292～290Ma,主要岩石类型有花岗闪长岩、二长花岗岩、正长花岗岩。从岩性上说,其侵入次序由老到新依次为花岗闪长岩→二长花岗岩→正长花岗岩,其那尔萨依序列由老到新有从中性向酸性演化的趋势;从粒度上说,细粒的形成时代早于粗粒。4.早石炭世库勒萨依序列为钙碱性花岗岩,形成于火山岛弧环境,与下石炭统大哈拉军山组（C₁d²）的形成环境相对应,属混源成因类型花岗岩;早二叠世其那尔萨依序列为碱性花岗岩,形成于板内环境,与下二叠统乌郎组（P₁w）的形成环境相对应,属壳源成因。5.岩浆可能为成矿作用提供部分成矿物质,最主要是为成矿提供热源,岩浆上涌的通道可能是区域构造发育的部位。更多还原

【Abstract】 Kulesayi is lacated in the mountains between Gongliu and Tekesi in Yili, Sinkiang province. The granitoids in this area appear as a batholith. In the past, people who researched the granitoids in this area categorized the granitoids into several petrographical facies on the base of petrography. Instead of disintegration of the granitoids, they regarded the granitoids as a whole. They did not do deep research in genesis and tectonic setting of the granitoids in this area. For one thing, there is lack of chemistry data and samples of isotopic age. For another thing, the few isotopic data which are tested by the old research methods are incredible. The study about the connection of the granitoids and major magma events is very little, so are assemblage of igneous rocks, genesis and geotectonic evolution. The big progress is not made in ore-forming.According to the investigation of petrological characters, petrochemical characters, geochemical characters, the intrusive time of the granitoids in this area, and the backgrounds of ore-forming and tectonic, some new results are made as follows:1. Using theories of rock lineage, the granitoids in this area are disintegrated into two succession, the Kulesayi succession in the early Carboniferous period and the Qinaersayi succession in the early Permian period. Both invaded into the Dahalajunshan formation in the early Carboniferous period. The relation of the two succession is pulsation, and the Qinaersayi succession invaded of the Kulesayi succession.2. The instrusive time of the Kulesayi succession in the early Carboniferous period is 330～320Ma, and main rock types are the quartz dioritized-porphyrite and the granodioritized-porphyry. The former is earlier than the latter.3. The instrusive time of the Qinaersayi succession in the early Permian period is 292～290Ma, and main rock types are the granodiorite, the adamellite and the syenogranite. In lithology, from old to new, the order is granodiorite→adamellite→syenogranite. In grain size, fine-grained rocks is earlier than coarse grained rocks.4. The Kulesayi succession in the early Carboniferous period, which belongs to the calc-alkalic rock type, are formed in the environment of volcanic arc （VAG） , comparable with the Dahalajunshan formation in the early Carboniferous period（C₁d²） . It belongs to the mixed genesis. The Qinaersayi succession in the early Permian period, which belongs to the alkalic rock type, are formed in the intraplate environment （WPG） , comparable with the Wulang formation in the early Permian period （P₁w） . It belongs to the crustal genesis.5. It is possible for magma to provide some parts of metallogenic materials in ore-forming process, primarily with heat. The access that magma goes through maybe tectonic zones.更多还原