四川省西昌市黄水塘地区岩浆活动特征及构造意义

发布时间：2018-11-03 15:33

【摘要】：黄水塘地区区域构造复杂,前人在该区域进行了大量的研究工作,对攀西裂谷的成因及构造期次的推演有详细叙述。然而,对于攀西裂谷的形成及消亡时代仍存在较大争议。笔者试图将黄水塘地区从复杂构造史中剥离出来,重点阐述该区域内构造地质形迹,对该时期的火山岩,沉积岩,变质岩进行详细解析,恢复该区域各期次构造演化特征。本文依托于国家地质调查局下属项目,通过对岩石学、岩石地球化学、地质年龄的研究,并收集前人的有关资料及成果,以咱里组、苏雄组,峨眉山玄武岩组及同时代中元古代—三叠纪基性—酸性火山岩、超基性—酸性侵入岩为研究对象,通过对该区岩浆岩期次梳理,综合厘定研究区岩浆岩序列及构造岩浆演化,划分吕梁-晋宁、澄江、华力西-印支3个构造-岩浆旋回。古元古代火山岩赋存于咱里岩组中,分布上受区域构造影响均位于安宁河断裂带西侧,主要分布于德昌县铁炉乡财地梁子一带,在南华纪和三叠纪花岗岩中呈残留体零星分散产出,岩石较为单一,主要为中粗粒斜长角闪岩。南华纪喷出岩主要赋存于苏雄组。主要分布于安宁河断裂带以东螺髻山中部。岩石类型相对较单一。安宁河断裂带西侧南华纪花岗岩体中见少量苏雄组蚀变玄武岩分布。同期侵入岩分布于安宁河西岸,岩性类型较复杂,包括石英闪长岩、花岗闪长岩、二长花岗岩等。二叠纪基性岩分布于安宁河以西,沿安宁河断裂带西侧呈零星小侵入体侵位于南华纪花岗岩体中,被三叠纪花岗岩侵吞破坏。综合分析表明吕梁-晋宁期基性火山岩,以咱里岩组斜长角闪岩为研究对象,是在区域性汇聚构造体制下的局部拉张环境下,由亏损地幔部分熔融形成的弱碱性—拉斑玄武岩浆喷发的产物。是洋陆碰撞岛弧型火山作用构造环境的产物。澄江期花岗岩主要应是Rodinia超大陆裂解阶段,幔源岩浆底侵/侵入导致地壳早存岛弧岩浆岩重熔或残留俯冲板片部分熔融形成的花岗质岩浆上侵分异而成。二叠纪基性岩岩石地球化学特征与峨眉山玄武岩大同小异,属大陆板内环境产物,同产出花岗岩形成时代为三叠纪,是峨眉地幔柱活动幔源岩浆演化晚期的产物。
[Abstract]:The regional structure of the Huangshuitang area is complicated and the predecessors have done a lot of research work in this area. The origin of the Panxi rift and the derivation of the tectonic period are described in detail. However, there are still some controversies about the formation and extinction of Panxi rift. The author attempts to separate the Huangshuitang area from the complicated structural history, and to expound the tectonic geological features in the area, analyze the volcanic rocks, sedimentary rocks and metamorphic rocks in this period in detail, and restore the tectonic evolution characteristics of each stage in the area. This paper is based on a project under the National Geological Survey, through the study of petrology, geochemistry, geological age, and the collection of relevant information and achievements of the predecessors, to the Zanli formation, the Suxiong formation, Emeishan basalt formation and Mesoproterozoic Triassic basic-acid volcanic rocks and ultrabasic-acid intrusive rocks are studied. The magmatic sequence and tectonic magma evolution in the study area are comprehensively determined by sorting out the magmatic stages in the study area. Lv Liang-Jinning, Chengjiang, Huaxi-Indosinian 3 tectonic-magmatic cycle. Paleoproterozoic volcanic rocks occurred in Zanliyan formation. The distribution of volcanic rocks is located on the west side of the Anning River fault zone, mainly in the area of Cailiangzi, Tielou Township, Dechang County. In the South China and Triassic granites, the residual bodies are scattered and scattered, and the rocks are relatively single, mainly composed of medium-coarse amphibolite. The South China exhalation rocks mainly occurred in Suxiong formation. Mainly distributed in the middle of Luoji Mountain east of the Anning River fault zone. The rock type is relatively single. A small amount of altered basalts of Suxiong formation are found in the South China granitic body on the west side of the Anning River fault zone. The intrusive rocks are distributed in the west bank of Anning River, and their lithologic types are complicated, including quartz diorite, granodiorite, monzogranite, etc. The Permian basic rocks distributed to the west of Anning River, and the west side of the Anning River fault zone was intruded into the South China granitic body, which was misappropriated and destroyed by Triassic granite. The comprehensive analysis shows that the basic volcanic rocks of Lv Liang and Jinning period, taking the amphibolite of Zanliyan formation as the research object, are in the local extensional environment under the regional convergent tectonic system. The product of magmatic eruption of weak alkalinity-lacquer Black Tortoise formed by partial melting of depleted mantle. It is the product of the tectonic environment of oceanic collision island arc volcanism. The Chengjiang granites are mainly composed of Rodinia supercontinent pyrolysis stage, and the granitic magma transgression and differentiation of mantle derived magma underthrust / intrusions lead to the remelting of island arc magmatic rocks or partial melting of residual subduction plates in the crust. The petrogeochemical characteristics of Permian basic rocks are similar to those of Emeishan basalt and belong to the products of continental intraplate environment. The syntectogenic granites were formed in Triassic and were the products of the late evolution of mantle magma derived from the Emei mantle plume.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P588.11

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