Characteristics of Superposed Folds and Its Tectonic Significance in Saishitang Ore District, Qinghai Province—Tectonic Study on a Superposed Fold Zone
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摘要: 新的资料揭示，青海赛什塘铜矿区是褶皱叠加变形区。为矿山勘探工作提供基础地质支撑，采用露头构造解析基础上的构造综合分析方法，在露头条件欠佳的矿区中下三叠统中首次厘定出4期褶皱组合样式，形成露头和区域尺度上的各类叠加构造。第二期褶皱（F2）叠加在第一期褶皱（F1）之上，主要形成Ramsy（Ramsay et al.，1987）的第三类叠加，表明二者可能是同一构造事件中连续的2阶段变形作用的结果，代表了从分层剪切到横向缩短的地壳变形机制转换过程，其间同时发生了印支期岩浆杂岩的侵入就位，推测是对区域上印支期西秦岭地块与柴达木地块之间从俯冲向碰撞转换的远程效应的响应。褶皱构造对赛什塘铜多金属矿的形成、改造和保存都起了重要作用。Abstract: Recent geological studies have revealed that Qinghai Saishitang copper mining area is a deformation zone with several superimposed folds. To provide basic geological support for mine exploration programs, integrated tectonic analysis method drawn on outcrop structural analysis is adopted in this paper. Middle-Early Triassic rocks in mining area of poor outcrop condition are classified into four phases of fold association styles. All phases of folds are involved to produce various superimposed structures in light of outcrop and regional scale. In most cases, the presence of the Ramsy's Type 3 superposition, which is formed by the overlay of F2 folds on earlier F1 ones, suggesting that the two may be result of two successive deformation phases in one tectonic cycle and representing a crustal deformation mechanism transition from delamination shear to horizontal shortening. The intrusion and emplacement of Indosinian magmatic complex also took place between two deformation phases, which is probably a response to the far field transition from subduction to collision of the west Qinling and Qaidam blocks in the Indosinian tectonic period. The fold structure plays an important role on the formation, reconstruction and preservation of the polymetallic deposit in Saishitang mining area.
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Keywords:
- Saishitang mining area /
- superposed fold /
- structural analysis /
- cleavage /
- indosinian
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芦文泉, 童海奎, 仓索南尖措, 等. 鄂拉山查查香卡地区晚三叠世火山岩产出环境分析 [J]. 西北地质, 2012, 45(1): 48-55. Lu W. Q., Tong H. K., Cang suonanjiancuo, et al. Analysis of environment for late Triassic volcanic rocks in Chachaxingka, Elashan [J]. Northwestern Geology, 2012, 45(1): 48-55 (in Chinese with English abstract).
李永祥, 李善平, 王树林, 等. 青海鄂拉山地区陆相火山岩地球化学特征及构造环境 [J]. 西北地质, 2011, 44(4): 23-32. Li Y. X., Li S. P., Wang S. L., et al. Geochemical characteristics and tectonic environment of the continental facies volcanic rocks in Elashan area, Qinghai province, Northwestern Geology [J]. 2011, 44(4): 23-32 (in Chinese with English abstract).
李福东, 张汉文, 宋治杰, 等. 鄂拉山地区热水成矿模式 [M]. 西安: 西安交通大学出版社, 1993. Li F. D., Zhang H. W., Song Z. J., et al. Thermal water metallogenic model in Ngolashanregion [M]. Xi'an Jiaotong University Press, Xi'an,1993 (in Chinese with English abstract).
柳淮夫, 蒋万银, 钱卫, 等. 青海省兴海县赛什塘铜矿初步勘探地质报告 [R]. 西宁: 青海省地质局第三地质队, 1983. Liu H. F., Jiang W. Y., Qian W., et al. Primary copper geological exploration report in Saishitang of Xinghai County, Qinghai province [R]. Third Geological Team of Geological Bureau of Qinghai Province, Xining,1983.
青海省区调综合地质大队. 中华人民共和国区域地质调查说明书. 1[DK]:50000赛什塘牧场幅(I-47-32-B) [R]. 西宁: 青海省地质矿产局, 1993. Qinghai R. C. G. B. Report of the Geology for the Nanmutang sheet at the scale of 1[DK]:50000 [R]. Qinghai Provincial Bureau of Geology and Mineral Resources, Xining,1993.
孙延贵, 张国伟, 郭安林, 等. 秦-昆三向联结构造及其构造过程的同位素年代学证据 [J]. 中国地质, 2004, 31(4): 372-378. Sun Y. G., Zhang G. W., Guo A. L., et al. Oinling-kunlun triple junction and isotope chronological evidence of its tectonic process [J]. Geology in China, 2004, 31(4): 372-378 (in Chinese with English abstract).
孙延贵. 西秦岭-东昆仑造山带的衔接转换与共和坳拉谷 [D]. 西北大学博士学位论文, 2004. Sun Y G. Gonghe aulaeogen and conjugate and transfer between the west Qinling and east Kunlunorogens [D]. A Dissertation Submitted to Northwestern University for Doctoral Degree, 2004, (in Chinese with English abstract).
宋治杰, 张汉文, 李文明, 等. 青海鄂拉山地区铜多金属矿床的成矿条件及成矿模式 [J]. 西北地质科学, 1995, 16(1): 134-144. Song Z. J., Zhang H. W., Li W. M., et al. Metallogenic conditions and model of copper-multi-metal deposits in Ngolashan region, Qinghai province [J]. Northwest Geoscience, 1995, 16(1): 134-144 (in Chinese with English abstract).
汤加富, 王希明, 刘芳宇, 等. 武功山变质岩区构造变形与地质填图 [M]. 武汉: 中国地质大学出版社, 1991. Tang J. F., Wang X. M., Liu F. Y., et al. Tectonic deformation and geological survey of Wugongshan metamorphic terrane [M]. China University of Geosciences Press, Wuhan, 1991 (in Chinese with English abstract).
吴庭祥, 肖海源, 窦国林, 等. 青海省兴海县赛什塘铜矿一期勘探报告 [R]. 西宁: 青海省地质局第三地质队, 1994. Wu T. X., Xiao H. Y., Dou G. L., et al. The first phase of copper geological exploration report in Saishitang of Xinghai County, Qinghai province [R]. Third Geological Team of Geological Bureau of Qinghai Province, Xining, 1994.
张忠义, 董树文. 大巴山西北缘叠加褶皱研究 [J]. 地质学报, 2009, 83(7): 923-936. Zhang Z. Y., Dong S. W., Superposed buckle folding in the northwest Dabashan, central China [J]. Acta Geologica Sinica, 2009, 83(7): 923-936 (in Chinese with English abstract).
张洪美, 李海平, 冯乔, 等. 柴达木盆地东南缘晚三叠世火山岩地球化学特征及构造环境分析 [J]. 西北地质, 2011, 44(4): 15-22. Zhang H. M., Li H. P., Feng Q., et al. Geochemical characteristics and tectonic environmental analysis of volcanic rocks from late Triassic in Southeastern margin of the Qiadam basin [J]. Northwestern Geology, 2011, 44(4): 15-22 (in Chinese with English abstract).
张智勇, 朱迎堂, 周光第, 等. 中华人民共和国区域地质调查报告. 1[DK]:25万兴海幅(I47 C 001003) [R]. 西宁: 青海省地质调查院, 2001. Zhang Z. Y., Zhu Y. T., Zhou G. D., et al. Report of the Geology for the Nanmutang sheet at the scale of 1[DK]:250000 [R]. Qinghai Provincial Institute of Geological Survey, Xining, 2001.
张智勇, 殷鸿福, 王秉璋, 等. 昆秦接合部海西期苦海-赛什塘分支洋的存在及其证据 [J]. 地球科学-中国地质大学学, 2004, 29(6): 691-696. Zhang Z. Y., Yin H. F., Wang B. Z., et al. Presence and Evidence of Kuhai-Saishitang Branching Ocean in Copulae between Kunlun-Qinl ing Mountains [J]. Earth Science—Journal of China University of Geosciences, 2004, 29(6): 691-696 (in Chinese with English abstract).
张智勇. 昆秦接合部造山带兴海古特提斯小洋盆形成与演化 [D]. 武汉: 中国地质大学, 2008: 1-90. Zhang Z. Y. The formation and evolution of Paleo-Tethys small oceanic of Xinghai in junction part of Kunlun and Qinling orogenic belts [D]. China University of Geosciences, Wuhan, 2008: 1-90 (in Chinese with English abstract).
Bell, A. M. Vergence: an evaluation [J]. Journal of Structural Geology, 1981, (3): 197-202.
Brogi. A. Foliation relationships and structural facing vs. vergence determinations in refolded low-grade metamorphic rocks: an example from the Tuscan Metamorphic ‘Basement' (Northern Apennines, Italy) [J]. Journal of Structural Geology, 2006, 28: 115-128.
Ghosh S. K, Deb S. K, Sengupta S. Hinge migration and hinge replacement [J]. Journal of Structural Geology, 1996, 263: 319-337.
Ghsosh S. K, Mandal N, Khan D, et al. Modes of superposed buckling in single layers controlled by initial tightness of early fold [J]. Journal of Stuctural Geology, 1992, 14(4): 381-394.
Ghsosh S. K, Mandal N, Sengupta S, et al. Superposed buckling in multilayers [J]. Journal of Structural Geology, 1993, 15(1): 95-111.
Guo A. L., Zhang G. W., Sun Y. G., et al. Geochemistry and spatial distribution of Late-Paleozoic mafic volcanic rocks in the surrounding areas of the Gonghe Basin: Implications for Majixueshan triple-junction and east Paleotethyan archipelagic ocean [J]. Science in China (Series D), 2007, 50(Suppl.): 292-304.
Ramsay, J. G., Hube, M. I. The techniques of modern structural geology, Volume 2 folds and fractures [M]. Academic Press, London, 1987.
Soma R., The south-western side of the Calabrian Arc (Peloritani Mountains): Geological, structural and AMS evidence for passive clockwise rotations [J]. Journal of Structure Geology, 2006, 41: 422-439.
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