西秦岭东段秦岭大堡岩体地球化学特征及地质构造意义
Geochemical Character and Tectonic Significance of the Qinling Dabu Granite Body in the Eastern Section of Western Qinling Mountains
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摘要: 通过详细的野外调研，以及岩石学、同位素年龄、地球化学特征研究，将西秦岭东段天水地区原秦岭大堡花岗岩岩基进一步解体为加里东期百花岩体和印支期大堡岩体。百花岩体具I型花岗岩的地球化学特征，形成于岛弧构造环境。大堡岩体岩石化学以高酸度（平均为73.71%）、高碱度（8.50%~9.19%）、低铁镁为特征，次铝-过铝质岩石类型，属钙碱性-偏碱性系列；∑REE=183.27×10-6~267.05×10-6，以轻稀土元素富集、明显的Eu负异常（δEu=0.27~0.63）为特征；（87Sr∕86Sr）0介于0.706 3~0.707 7，氧同位素δ18O介于+9.12%~+9.86‰，属壳源花岗岩类，具S型花岗岩的特征，形成于后碰撞构造环境，与大陆抬升作用有关。Abstract: After carrying out the detailed study on the petrology, isotope age, geochemistry of the Dabu granite batholithin Southeast Tianshui of Western Qinling Mountains, the original Dabugranite batholith has been further divided into Caledonian Baihua granite body and Indosinia Dabugranite body. The Baihua body has the character of I-type granite, which was formed in island-arc tectonic environment. The Dabu body is characterized by high AI2O3(with an average of 73.71%) and K2O+Na2O(8.50%~9.19%) contents, as well as low Fe2O3+FeO and MgO contents, which belong to peraluminous rocks and calc-alkaline-alkaline series. ∑REE values range from 183.27×10-6 to 267.05×10-6, with enriched LREE and obvious negative Eu anomaly (δEu=0.27~0.53). The (87Sr/86Sr)0 values vary from 0.706 3 to 0.707 7, the δ18O values range from +9.12% to +9.86‰, showing the features of crust-derived granite and S-type granite, and suggesting that these granites were formed in post-collision tectonic environment and might be the products of continental uplift during the period of post-orogenics.
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丁仨平,裴先治,李勇,等.西秦岭天水地区李子园群的解体及其构造环境浅析[J].地质通报,2004,23(12):1213-1214.
DING Saping,PEI Xianzhi, LI Yong, et al. Amalysis of The Disintegration and Tectonic Setting of the Liziyuan Group in the Tianshui Area, Western Qinling[J]. Geological Bulletion of China, 2004,23(12):1213-1214.
李永军,张翔,胡晓隆,等.天水地区花岗岩类及其构造演化[J].西北地质,2008,41(1):29-36.
LI Yongjun, ZHANG Xiang, HU Xiaolong, et al. The Granitoid and Its Tectonic Evolution in Tianshui Area[J]. Northwestern Geology,2008,41(1):29-36.
李永军,辜平阳,刘静,等.西秦岭党川花岗岩基的地球化学特征[J].西北地质,2007,40(1):35-41.
LI Yongjun,GU Pingyang, LIU Jing, et al. Geochemistry of the Dangchuan Granitic Batholith in West Qinling[J]. Northwestern Geology,2007,40(1):35-41.
裴先治,丁仨平,胡波,等.西秦岭天水关子镇蛇绿岩的厘定及其地质意义[J].地质通报,2004,23(12):1202-1208.
PEI Xianzhi, DING Saping, HU Bo, et al. Analysis of the Disintegration and Tectonic Setting of the"Liziyuan Group"in the Tianshui Area, Western Qinling[J]. Regional Geology of China, 2004,23(12):1202-1208.
裴先治, 李佐臣,丁仨平,等.西秦岭天水地区岛弧型基性岩浆杂岩的地球化学特征及形成时代[J].中国地质,2005,32(4):529-540.
PEI Xianzhi, LI Zuochen, DING Saping,et al.Geochemical Characteristics and Zircon U-Pb Ages of Island-Arc Basic Igneous Complexes in the Tianshui Area, West Qinling[J]. Geology in China, 2005, 32(4):529-540.
裴先治,刘战庆,丁仨平,等.甘肃天水地区百花岩浆杂岩的锆石LA-ICP-MS U-Pb定年及其地质意义[J].地球科学进展,2007,22(8):818-827.
PEI Xianzhi, LIU Zhanqing, DING Saping, et al. Zircon LA-ICP-MS U-Pb Dating of the Gabbro from the Baihua Igneous Complex in Tianshui Area, Eastern Gansu, and its Geological Significance[J].Advances in Earth Science,2007,22(8):818-827.
温志亮,吴金刚,郭周平,等.天水地区北秦岭造山带花岗岩地球化学及构造环境探讨[J].岩石矿物学杂志,2008,27(6):505-518.
WEN Zhiliang, WU Jingang, GUO Zhouping, et al. Granite Geochemistry and Tectonic Environments of Tianshui Area in NorthQinling Orogenic Belt[J].Acta Petrologica et Mineralogica,2008,27(6):505-518.
张国伟,张本仁,袁学诚.秦岭造山带与大陆动力学[M].北京:科学出版社,2001.
ZHANG Guowei, ZHANG Benren, YUAN Xuecheng. Qinling Orogenic Belt and Continental Dynamayic[M]. Beijing:Science Press, 2001.
张维吉,孟宪恂,胡健民.祁连-北秦岭造山带结合部位构造特征与造山过程[M].西安:西北大学出版社,1994.
ZHANG Weiji, MENG Xianxun, HU Jianmin. Tectonics Featuresand Orogenic Process in the Juncture Area of Qilian and North Qinling Orogenic Belt[M]. Xi'an:Northwest University Press, 1994.
温志亮,杨天喜,张勇. 1:50000元龙幅、党川幅、佘家门幅区域地质调查报告[R].2006.
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