Geochemistry of Lenglongling Ophiolite, North Qilian, and Its Tectonic Implications
-
摘要: 在北祁连造山带冷龙岭地区新发现一条蛇绿岩带,该蛇绿岩从下向上由地幔橄榄岩、辉长辉绿岩、玄武岩、硅质岩组成.岩石地球化学特征表明,玄武岩可分类高Ti和低Ti两类,其中高Ti玄武岩具有LREE富集的稀土配分型式,富集K、Rb、Ba、Th、Nb、Ta等不相容元素,呈现隆起型(驼峰式)分布型式,显示了典型的洋岛火山岩地球化学特征,为板内岩浆作用的产物.低Ti玄武岩具有LREE亏损,类似N-MORB的稀土配分模式,同时又具有相对于N-MORB富集的大离子亲石元素,亏损Nb、Ta等高场强元素的岛弧火山岩的地球化学特征,代表了弧后盆地环境岩石组合.蛇绿岩岩石组合和岩石地球化学特征显示该蛇绿岩套形成于弧后盆地环境,是早奥陶世北祁连洋的残留.Abstract: This paper reports a new ophiolite belt found in the Lenlongling area of north Qilian. From bottom to top, the rock belt is composed of mantle peridotites, gabbros, basalts and silicon rocks. Lithogeochemical characteristics indicate that the basalt can be divided into two groups according to its content of Ti. The high-Ti basalt show LREE enrichment patterns in chondrite-normalized REE diagram, and also display enrichment of incompatible elements such as K, Rb, Ba, Th, Nb, Ta in an uplift(hump) tendency when normalized to N-MORB. With typical geochemical characteristics of OIB, the rock may be formed in an intra-plate magma environment. In contrast, the low-Ti basalt has geochemical characteristics of island arc volcanic rock, showing deficiency of LREE similar to N-MORB, enrichment of the LILE and depletion of HFSE including Nb, Ta etc., which represent the back-arc basin setting. The rock assemblage and lithogeochemistry suggest that the Lenglongling ophiolite belt is formed in the back-arc basin and is the residual of the north Qilian ocean in Early Ordovician.
-
Keywords:
- ophiolite /
- geochemistry /
- back-arc basin /
- OIB /
- Lenlongling
-
-
陈雨, 周德进, 王二七, 等. 北祁连肃南县大岔大坂蛇绿岩中玻安岩系岩石的发现及其地球化学特征[J].岩石学报, 1995. 11(增刊): 147-153. CHEN Y, ZHOU D J, WANG E Q,et al. Geochemical Characteristics of Boninite Series Rocks Found in Dachadaban Ophiolite (DDO) Sunan County,North Qilian Mountain[J]. Acat Petrologica Sinica, 1995, 11(S1): 147-153.
甘肃省地质矿产局. 甘肃省区域地质志 [M]. 北京: 地质出版社, 1989: 692. Gansu Bureau of Geology and Mineral Resource (GBGMR), Regional geology of Gansu Province [M]. Beijing:Geological Publishing House, 1989:692.
冯益民,吴汉泉. 北祁连山及其邻区古生代以来大地构造演化初探[J]. 西北地质科学,1992,13(2):61-74. FENG YM, WU HQ. Tectonic Evolution ofNorth Qilian Mountains And Its Neighbourhood Since Paleozoic [J]. Northwest Geoscience, 1992, 13(2):61-74.
冯益民, 吴汉泉. 祁连山及其邻区大地构造基本特征-兼论早古生代海相火山岩的成因环境[J].西北地质科学,1995,16(1): 92-103. FENG YM, WU HQ. Basic characteristics of tectonics in the Qilian mountains and its neighbourings -on genetic environments of early Paleozoic marine volcanics [J]. Northwest Geoscience, 1995, 16(1):92-103.
冯益民, 何世平. 祁连山大地构造与造山作用[M]. 北京: 地质出版社, 1996:232. FENG YM, HE SP. Qilian Mountains tectonic and orogeny [M]. Beijing:Geologic press, 1996:232.
李文渊,赵东宏,宋忠宝,等. 北祁连山塞浦路斯型铜矿特征及勘查方法-以雪泉铜(锌)矿床为例[M].西安:陕西科学技术出版社,2005,105. LI WY, ZHAO DH, SONG BZ, et al. The characters of Cyprus type copper deposits of north Qilian Mountains and its exploration method: a case of Xuequan Copper (zinc) deposit [M]. Xi'an:Shaanxi Science and techtology press, 2005: 105.
孟繁聪, 张建新, 郭春满, 等. 大岔大坂 MOR 型和 SSZ 型蛇绿岩对北祁连洋演化的制约[J]. 岩石矿物学杂志, 2010, 29(5): 453-466. MENG Fancong, ZHANG Jianxin, GUO Chunman, et al. Constraints on the evolution of the North Qilian ocean basin:MOR-type and SSZ-type ophiolites from Dachadaban[J]. Acta Petrologica Et Mineralogica, 2010, 29(5): 453-466.
史仁灯, 杨经绥, 吴才来, 等.北祁连玉石沟蛇绿岩形成于晚震旦世的 SHRIMP 年龄证据[J]. 地质学报, 2004, 78(5): 649-657. SHI Rendeng,YANG Jingsui,WU Cailai,et al.First SHRIMP dating for the formation of the Late Sinian Yushigou ophiolite,North Qilian Mountains [J].Acta Geologica Sinica,2004,78(5): 649-657.
宋述光, 张立飞, Niu Yao ling, 等.北祁连山榴辉岩锆石 SHRIMP定年及其构造意义[J]. 科学通报, 2004, 49(6): 592-595. SONG Shuguang,ZHANG Lifei,NIU Yaoling,et al. Zircon U-Pb SHRIMP ages of eclogites in the North Qilian Mountains and their tectonic implications[J].Chinese Science Bulletin, 2004, 49(6):592-595.
王荃, 刘雪亚. 我国西部祁连山区的古海洋地壳及其大地构造意义.[J] 地质科学, 1976, (1): 42-55. WANG Quan,LIU Xueya.Paleo-oceanic crust of the Chilienshan region westChina and its tectonic significance[J].Scientia Geologica Sinica,1976,(1):42-55.
吴汉泉. 东秦岭和北祁连山的蓝片岩[J]. 地质学报, 1980, 54(3): 159-207. WU Hanquan.The glaucophane-schist of eastern Qinling and northernQilian Mountains in China[J].Acta Geologica Sinica,1980,54(3):195-207.
吴汉泉. 北祁连山高压变质带的岩石学及矿物学[J]. 中国地质科学院西安地质矿产研究所所刊, 1982,4(7): 4-21. WU Hanquan.Petrology and mineralogy of high-pressure metamorphic zones in the northernQilian Mountains,China[J].Bull.Xi'an Inst.Geol.Min.Res.,CAGS,1982,4(7):4-21.
夏林圻,夏祖春. 祁连山及邻区火山作用及成矿[M]. 北京:地质出版社,1998:215. XIA LQ, XIA ZC. Volcanism and mineralization in Qilian Mountains and its adjacent area [M]. Beijing:Geologic Press,1998:215.
肖序常, 陈国铭, 朱志直. 祁连山古蛇绿岩的地质构造意义[J]. 地质学报, 1978, 54(1): 287-295. XIAO Xuchang,CHEN Guoming, ZHU Zhizhi. A Preliminary study on the tectonics of ancient ophiolites in theQilian Mountain,Northwest China[J].Acta Geologica Sinica, 1978, 54(1):287-295
相振群, 陆松年, 李怀坤, 等. 北祁连熬油沟辉长岩的锆石SHRIMP U-Pb年龄及地质意义[J]. 地质通报, 2007.26(12): 1686-1691. XIANG Zhenqun,LU Songnian,LI Huaikun,et al. SHRIMP U-Pb zircon age of gabbro in Aoyougou in the western segment of the North Qilian Mountains,China and its geological implications[J].Geological Bulletin of China, 2007, 26(12):1686-1691.
许志琴, 徐惠芬, 张建新, 等. 北祁连走廊南山加里东俯冲杂岩增生地体及其动力学[J]. 地质学报, 1994. 68(1): 1-14. XU Zhiqin,XU Huifen,ZHANG Jianxin,et al. The Zoulangnanshan Calidonian subductive complex in the northern Qilian Moutains and its dynamics[J].Acta Geologica Sinica, 1994, 68(1):1-14.
张建新, 许志琴, 陈文, 等. 北祁连中段俯冲-增生杂岩/火山弧的时代探讨[J]. 岩石矿物学杂志, 1997.16(2): 111-118. ZHANG Jianxin,XU Zhiqin,CHEN Wen,et al. A Tentative discussion on the subduction-accretionary complex/volcanic arcs in the middle sector ofNorth Qilian Mountain[J].Acta Petrologica et Mineralogica, 1997, 16(2):111-118
张旗,肖序常.中国蛇绿岩研究概述[J].岩石学报,1995,11(增刊):1-9. ZHANG Q, XIAO XC. A Comment on Study of Ophiolites in China[J]. Acat Petrologica Sinica, 1995, 11(S1):1-9.
张旗. 蛇绿岩与地球动力学研究[M].北京:地质出版社,1996:231. ZHANG Q. Study of Ophiolite and geodynamics[M]. Beijing:Geologic Press, 1996, 231.
张旗,孙晓猛,周德进,等.北祁连蛇绿岩的特征,形成环境及其构造意义[J]. 地球科学进展, 1997,12(4):366-393. ZHANG Q, SUN XM, ZHOU DJ,et al. The characteristics of north Qilian ophiolites, forming settings and their tectonic significance [J]. Advance in Erath Sciences, 1997, 12(4): 366-393.
张招崇, 毛景文, 杨建民, 等.北祁连熬油沟蛇绿岩岩石成因的地球化学证据[J]. 地质学报, 1998, 72(1): 42-51. ZHANG Zhaochong,MAO Jingwen,YANG Jianming,et al. Geochemical evidences on the petrogenesis of the Aoyougou ophiolite in north Qilian Mountains[J].Acta Geologica Sinica, 1998, 72(1):42-51.
赵东宏,杨合群,宋忠宝,等.甘肃北祁连山错沟-寺大隆铜锌成矿带区域地质背景及找矿方向[J].地质与资源, 2003, 12(4): 215-220. ZHAO DH, YANG HQ, SONG ZB,et al. Regional geology and prospecting direction of cuogou- sidalong coper(zinc) metallogenic belt in Gansu province[J]. Geology and Resources, 2003, 12(4):215-220.
左国朝,刘义科,张崇.北祁连造山带中—西段陆壳残块群的构造—地层特征[J].地质科学, 2002, 37(3): 302-312. ZUO GC, LIU YK, ZHANG C. Tectono-stratigraphic characteristics of continent crustal reninants in central-western sector of the north Qilian orogen[J]. Chinese Journal of Geology, 2002, 37(3): 302-312.
张旗,王岳明,钱青, 等. 甘肃景泰县老虎山地区蛇绿岩及其上覆岩系中枕状熔岩的地球化学特征[J]. 岩石学报, 1997, 13(1):92-99. ZHANG Q, WANG YM, QIAN Q, et al. Geochemical Characteristicts of Pillow Lavas in Ophiolite and It's Overlying Rock Sequence in the Laohushan Area from Jingtai County,Gansu Province[J]. Acat Petrologica Sinica, 1997, 13(1):92-99.
曾建元, 杨怀仁, 杨宏仪, 等. 北祁连东草河蛇绿岩: 一个早古生代的洋壳残片[J]. 科学通报, 2007, 52(7): 825-835. WU HQ, FENG YM, SONG SG. Metamorphi sm and deformation of bluescist belt and their tectonic imolications, North Qilian Mountains, China[ J]. J. Metamorphic Geol., 1993,11: 523-536.
XU JF, CASTILLO PR, CHEN FR, et al. Geochemistry of late Paleozoic mafic igneous rocks from the Kuerti area, Xinjiang, northwest China: Implications for back arc mantle evolution[J]. Chemical Geology, 2002,193(1-2): 137-154.
CADEG J P, KOBAYASHI K, LALLEMAND S, et al. Deep scientific dives in theJapan and Kurile Trenches. Earth Planet[J]. Sci. Letters, 1987, 83: 313-328.
IRVINE T N and BARAGER W R A. A guide to the chemical classification of the common volcanic rocks[J]. Canadian Journal of Earth Sciences, 1971, 8: 523-548.
MOLNAR and TAPPONNIER. Cenozoic tectonics of Asia: Effects of a continental collision[J]. Science, 1975,(189):419-426.
PEARCE T H, GORMAN, B E, and BIRKETT, T C, The relationship betwee major element chemistry and tectonic environment of basic and intermediate volcanic rocks[J].Earth Planet. Sci. Lett., 1977,(36):121-132.
PEARCE J A and NORRY M J. Petrogenetic Implications of Ti, Zr, Y, and Nb Variations in Volcanic Rocks[J]. Contributions to Mineralogy and Petrology, 1979, 69: 33-47.
PICKETT E A, ROBERTSON A H F. Formation of the Late Palaeozic-Early Mesozoic Karakaya Complex and related ophiolites in NW Turkey by Palaeotethyn subduction-accretion[J]. J. Geol. Soc. London,1996, 153: 995-1009.
计量
- 文章访问数: 2606
- HTML全文浏览量: 0
- PDF下载量: 3225
下载:
