Geochronological and Geochemical Study on Liujiaping Granite in the Border Area between Sichuan and Shaanxi Province and Its Tectonic Significance
-
摘要: 对川陕交界地区刘家坪花岗岩岩体进行了系统的锆石U-Pb年代学和地球化学研究，重点讨论了岩体的成因及其构造意义。测试结果显示，刘家坪花岗岩加权平均年龄值为825.9±7.8 Ma，属新元古代中期；岩石低K富Na，显示硅过饱和，w（SiO2）%平均为75.32，并伴有过Al质特征；稀土元素丰度较低，∑REE为（182.13~243.76）×10-6，平均为197.29×10-6，显示LREE富集、HREE相对亏损的特征，稀土元素球粒陨石配分模式图表现为右倾“海鸥”型，并且具有明显的Eu负异常（δEu平均为0.57）；微量元素中Nb/Ta、Rb/Sr的结果及Mg#值综合显示岩浆来源主要为下地壳物质的部分熔融。岩石具有A型花岗岩特征，形成于碰撞期后的伸展构造背景，据此推测碧口地块与扬子地块在825 Ma之前曾发生碰撞造山作用。两者的拼合模式为从北东到南西的剪刀式拼合。Abstract: The Liujiaping granite intrusion is located in Sichuan-Shaanxi border area. The study of the zircon U-Pb geochronology and the geochemistry of the granite aim at discussing its formation and tectonic significance. The results show that the crystallization age of the granite is 825.9±7.8 Ma, which belongs to the mid-Neoproterozoic. The geochemistry analysis shows that the intrusion is low in potassium and rich in sodium and silica (with the average SiO2 being 75.32%), with peraluminous characteristics. The abundance of the ∑REE varies in the range of (182.13-243.76)×10-6, with 197.29×10-6 on average, which shows an enrichment of the LREE and a depletion of the HREE. Chondrite-normalized REE patterns are of the right sea-gull oblique type with the δEu being 0.57, showing a significant negative Eu anomaly. The results of the Nb/Ta, Rb/Sr and Mg# show that the magmatic rocks of this region originated from the partial melting of the lower crust. With the characteristics of A type granites, the rock formed in the post-collision extensional tectonic setting, which indicates a collision had occurred between the Eastern Bikou terrane and the Yangtze block before 825Ma. The jointing mode of the two blocks is scissors joint from northeast to southwest.
-
Keywords:
- Sichuan-Shaanxi border area /
- geochemistry /
- Neoproterozoic /
- A-type granite rock /
- scissors joint
-
-
张国伟, 张本仁, 袁学诚, 等. 秦岭造山带与大陆动力学 [M]. 北京: 科学出版社, 2001: 1-85. Zhang G W, Zhang B B, Yuan X C, et al. The Qinling Orogenic Belt and The Continental Dynamics [M]. Science Press, Beijing,2001: 1-85.
张国伟, 张宗清, 董云鹏. 秦岭造山带主要构造岩石地层单元的构造性质及其大地构造意义 [J]. 岩石学报, 1995, 11(2): 101-104. Zhang G W, Zhang Z Q, Dong Y P. Nature of Main Tectono-Lithostratigraphic Units of the Qinling Orogen: Implications for the Tectonic Evolution [J]. Acta Petrologica Sinica, 1995, 11(2): 101-104.
张国伟, 孟庆任, 于在平. 秦岭造山带的造山过程及其动力学特征 [J]. 中国科学(D辑:地球科学), 1996, 26(03): 193-200. Zhang G W, Meng Q R, Yu Z P. Orogenesis and Dynamics of the Qinling Orogen [J]. Science in China: Series D, 1996, 26(03): 193-200.
裴先治, 张国伟, 赖绍聪, 等. 西秦岭南缘勉略构造带主要地质特征 [J]. 地质通报, 2002, 21(8/9): 486-494. Pei X Z, Zhang G W, Lai S C, et al. Main geological features of the Mianlue tectonic belt on the southern margin of the West Qinling [J]. Geological Bullentin of China, 2002, 21(8/9): 486-494.
李三忠, 张国伟, 李亚林, 等. 秦岭造山带勉略缝合带构造变形与造山过程 [J]. 地质学报, 2002, 76(4): 469-483. Li S Z, Zhang G W, Li Y L, et al. Deformation and Orogeny of the Mian-Lue Suture Zone in the Qinling Orogenic Belt [J]. Acta Geologica Sinica, 2002, 76(4): 469-483.
李佐臣. 扬子地块西北缘后龙门山造山带(北段)物质组成、构造特征及其形成演化 [D]. 长安大学, 2009. Li Z C. Composition, Structural Characteristics and Evolution of Back-Longmenshan Orogen(NorthSection)in the Northwest Margin of Yangtze Block [D]. Chang'an University, Xi'an 2009.
张磊, 吕新彪, 刘阁, 等. 兴蒙造山带东段大陆弧后型花岗岩特征与成因 [J]. 中国地质, 2013, (3): 869-884. Zhang L, Lü X B, Liu G, et al. Characteristics and genesis of continental back-arc A-type granites in the eastern segment of the Inner Mongolia-Da Hinggan Mountains orogenic belt [J]. Geology in China, 2013, (3): 869-884.
柳小明, 高山, 第五春容, 等. 单颗粒锆石的20 μm小斑束原位微区LA-ICP-MS U-Pb年龄和微量元素的同时测定 [J]. 科学通报, 2007,52(2):228-235. Liu X M, Gao S, Di-Wu C R, et al. The simultaneous differmination of the situ micro zone LA-ICP-MS U-Pb age of 20 μm small beam in the single zircon and the trace elements [J]. Chinese Science Bulletin, 2007,52(2):228-235.
干国樑. 矿物-熔体间元素分配系数资料及主要变化规律 [J]. 岩石矿物学杂志, 1993, 12(2): 144-181. Gan G L. Mineral-melt element partition coefficients: data and major variation regularities [J]. Acta Petrologica Et Mineralogica, 1993, 12(2): 144-181.
张旗, 王焰, 李承东, 等. 花岗岩的Sr-Yb分类及其地质意义 [J]. 岩石学报. 2006, 22(9): 2249-2269. Zhang Q, Wang Y, Li C D, et al. Granite classification on the basis of Sr and Yb contents and its implications [J]. Acta Petrologica Sinica, 2006, 22(9): 2249-2269.
赵凤清, 赵文平, 左义成. 陕南汉中地区新元古代岩浆岩U-Pb年代学 [J]. 地质通报, 2006, 25(03): 383-388. Zhao F Q, Zhao W P, Zuo Y C. U-Pb Geochronology of Neoproterozoic Magmatic Rocks in Hanzhong, Southern Shaanxi, China [J]. Geological Bullentin of China, 2006, 25(03): 383-388.
肖龙, Rapp R P, 许继锋. 深部过程对埃达克质岩石成分的制约 [J]. 岩石学报, 2004, 20(2): 219-228. Xiao L, Rapp PR, Xu J F. The role of deep process control on variation of compositions of adakitic rocks [J]. Acta Petrologica Sinica, 2004, 20(2): 219-228.
李春昱, 王荃, 刘雪亚. 中国的内生矿床与板块构造 [J]. 地质学报. 1981, (3): 1-7. Li C Y, Wang Q, Liu X Y. The metallogeny and plate-tectonics of China [J]. Acta Geologica Science, 1981, (3): 1-7.
张国伟, 董云鹏, 姚安平, 等. 秦岭造山带基本组成与结构及其构造演化 [J]. 陕西地质, 1997, 15(2): 1-14. Zhang G W, Dong Y P, Yao A P, et al. The crustal compositions, structures and tectonic evolution of the Qinling Orogenic Belt [J]. Geology of Shaanxi, 1997, 15(2): 1-14.
赵祥生, 马少龙, 邹湘华, 等. 秦巴地区碧口群的时代、层序、火山作用及含矿性研究 [J]. 西北地质科学, 1990, 29: 1-128. Zhao X S, Ma S L, Zou X H, et al. The study of the age, sequence, volcanism and mineralization of Bikou Group in Qinling-Daba Shan [J]. Northwestern Geoscience, 1990, 29: 1-128.
陶维屏, 高锡芬, 孙祁, 等. 中国非金属矿床成矿系列-矿床含矿建造成矿系列形成模式 [M]. 北京: 地质出版社: 1994: 75-90. Tao W P, Gao X F, Sun Q, et al. The minerogenetic series of nonmetallic mineral deposits of China-The formation model of the metallogenic series of the ore formation in the deposit [M]. Geological Publishing House, Beijing, 1994: 75-90.
王尚文. 中国石油地质 [M]. 北京: 石油工业出版社, 1983: 111-154. Wang S W. The petroleum geology of China [M]. Petroleum Industry Press, Beijing, 1983: 111-154.
申安斌. 陕西省莫霍面特征 [J]. 陕西地质, 1997, 15(2): 58-63. Shen A B. The characteristic of Mohole in Shaanxi Province [J]. Geology of Shaanxi, 1997, 15(2): 58-63.
刘铁庚, 叶霖. 碧口群形成的地质构造环境探讨 [J]. 矿物学报, 1999, 19(4): 446-452. Liu T G, Ye L. Geotectonic environment of formation of the Bikou Group as viewed from their geochemical characters [J]. Acta Mineralogica Sinica, 1999, 19(4): 446-452.
张宏飞, 肖龙, 张利, 等. 扬子陆块西北缘碧口块体印支期花岗岩类地球化学和Pb-Sr-Nd同位素组成: 限制岩石成因及其动力学背景 [J]. 中国科学D辑, 2007, 37(4): 460-470. Zhang H F, Xiao L, Zhang L, et al. Geochemical and Pb-Sr-Nd Isotope Composition of Indo-Chinese Granite of Bikou Group, North-West Margin of Yangrze Block: Constraints for lithogenesis and Geodynamics [J]. Science in China: Series D, 2007, 37(4): 460-470.
陶洪祥, 陈祥荣, 冯鸿儒, 等. 略论扬子古陆核北缘西段元古代岛弧火山岩的生成和演化 [J]. 西安地质学院学报, 1982b, 4(2): 20-28. Tao H X, Chen X R, Feng H R, et al. The brief discussion on the formation and the evolution of the Proterozoic island arc volcanic rock in the west of the northern margin of the Yangtze Craton [J]. Journal of Xi'an Geological Institute, 1982b, 4(2): 20-28.
陶洪祥. 扬子古陆核北缘西段元古代侵入岩岩石组合的划分及其地质意义 [J]. 长安大学学报(地球科学版), 1983, (2):24-34. Tao H X. The classification of the rock combination of the Proterozoic intrusive rock and its geological significance in the west of the northern margin of the Yangtze Craton [J]. Journal of Chang'an University Earth Science Edition(Earth Science Edition), 1983, (2):24-34.
夏祖春, 夏林折, 徐学义, 等. 碧口群火山岩性质及形成环境 [J]. 地质论评, 1999, 45(增刊):681-688. Xia Z C, Xia L Q, Xu X Y, et al. The nature and formation environment of volcanic rock series of the Bikou Group [J]. Geological Review, 1999, 45(sup.): 681-688.
夏林圻, 夏祖春, 李向民, 等. 华南新元古代中期裂谷火山岩系: Rodinia超大陆裂谷化-裂解的地质纪录 [J]. 西北地质, 2009, 42(1): 1-33. Xia L Q, Xia Z C, Li X M, et al. Mid-Neoproterozoic Rift-related Volcanic Rocks in South China: Geological Records of Rifting and Break-up of the Supercontinent Rodinia [J]. Northwestern Geology, 2009, 42(1): 1-33.
闫全人, Andrew D H, 王宗起, 等. 扬子板块北缘碧口群火山岩的地球化学特征及其构造环境 [J]. 岩石矿物学杂志, 2004, 23(1): 1-11. Yan Q R, Andrew D. H, Wang Z Q, et al. Geochemistry and tectonic setting of the Bikou volcanic terrane on the northern margin of the Yangtze plate [J]. Acta Petrologica Et Mineralogica, 2004, 23(1): 1-11.
董广法, 王富国, 刘继顺. 勉略宁地区东沟坝组火山岩的成因浅析 [J]. 大地构造与成矿学, 1998, 22(2): 163-169. Dong G F, Wang F G, Liu J S, et al. Tectonic environment analysis of volcanic rocks from the Dnggouba Group of the mianluening region [J]. Geotectonica et Metallogenia, 1998, 22(2): 163-169.
丁振举, 姚书振, 周宗桂, 等. 碧口地体中元古代构造属性 [J]. 大地构造学与成矿学, 1998, 22(3): 219-226. Ding Z J, Yao S Z, Zhou Z G, et al. Tectonic attribute of the mid-proterozoic Bikou Terrane [J]. Geotectonica et Metallogenia, 1998, 22(3): 219-226.
匡耀求, 张本仁, 欧阳建平. 扬子克拉通北西缘碧口群的解体与地层划分 [J]. 地球科学-中国地质大学学报, 1999, 24(3): 251-255. Kuang Y Q, Zhang B R, Ouyang J P, et al. Decomposition and Stratigraphic subdivision of Bikon Group in northwestern margin of Yangze Craton [J]. Earth Science-Journal of China University of Geosciences, 1999, 24(3): 251-255.
夏林圻, 夏祖春, 徐学义, 等. 碧口群火山岩岩石成因研究 [J]. 地学前缘, 2007, 14(3): 84-101. Xia L Q, Xia Z C, Xu X Y, et al. Petrogenesis of the Bikou Group volcanic rocks [J]. Earth Science Frontiers, 2007, 14(3): 84-101.
李永飞. 扬子板块北缘碧口火山岩系岩石地球化学研究 [D]. 西北大学硕士学位论文, 2006. Li Y F. The geochemical study of the Bikou volcanic rock series in the Northern Yangtze plate [D]. Master's degree thesis of Northwestern University, Xi'an, 2006.
李永飞, 赖绍聪, 秦江锋, 等. 碧口火山岩系地球化学特征及Sr-Nd-Pb同位素组成一晋宁期扬子北缘裂解的证据 [J]. 中国科学D辑(增刊), 2007, 37: 295-306. Li Y F, Lai S C, Qin J F, et al. Geochemistry and Sr-Nd-Pb isotopic composition of Bikou Group volcanic rocks: Evidence of North Yangtze splitting[J]. Science in China Series D(supplement), 2007, 37: 295-306.
赖绍聪, 李永飞, 秦江锋. 碧口群西段董家河蛇绿岩地球化学及LA-ICP-MS锆石U-Pb定年 [J]. 中国科学D辑(增刊), 2007, 37: 262-270. Lai S C, Li Y F, Qin J F. The geochemistry and zircon LA-ICP-MS U-Pb dating of the Dong Jia-he ophiolite in the west of the Bikou group [J]. Science in China Series D(supplement), 2007, 37: 262-270.
秦克令, 金浩甲, 赵东宏. 碧口古岛弧带构造演化与成矿 [J]. 河南地质, 1994, 12(4): 304-317. Qin K L, Jin H J, Zhao D H. Tectonic evolution and mineralization in Bikou ancient island arc belt [J]. Henan Geology, 1994, 12(4): 304-317.
Brown G C. Calc-alkaline intrusive rocks: Their diversity, evolution and relation to volcanic arcs [M] // Thorpe R S. Andesites-Orogenic andesites and Related Rocks [M]. John Wiley and Sons, New York,1982: 437-464.
Eby G N. Chemical subdivision of the A-type granitoids. Petrogenetic and tectonic implications [J]. Geology. 1992, 20(7): 641.
Pearce J A, Harris N B W, Tindle A G. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks [J]. Journal of Petrology, 1984, 25(4): 956-983.
Xiao L, Zhang H F, Ping Z N, et al. LA-ICP-MS U-Pb zircon geochronology of early Neoproterozoic ma?c-intermediat intrusions from NW margin of the Yangtze Block, SouthChina: Implication for tectonic evolution [J]. Precambrian Research, 2007, (154): 221-235.
Bonin B. A-type granites and related rocks: Evolution of a concept, problems and prospects [J]. Lithos, 2007, 97(1/2): 1-29.
Yuan H L, Gao S, Liu X M et al. Accurate U-Pb age and traceelement determinations of zircon by laser ablation inductively coupled plasma mass spectrometry [J]. Geostandard and Geoanalytical Research, 2004, 28: 353-370.
Middlemost E A K. Naming Materials in the Magma/Igneous Rock System [J]. Earth Science Reviews, 1994, 37(3/4): 215-224.
Maniar P D, Piccoli P M. Tectonic discrimination of granit-oids [J]. Geological Society of American Bulletin, 1989, 101: 635-643.
Boynton W V. Cosmochemistry of the Rare Earth Elements: Meteorite studies. In: Henderson P(ed.). Rare Earth Element Geochemistry[M]. Elsevier, New York:1984, 63-114.
Sun S S, McDonough W F. Chemical and isotopic systematicsof oceanic basalts: Implications for mantle composition and processes [M] // Saunders A D, Norry M J. Magmatism in the Ocean Basins. Geological Society of London, Special Publication, London,1989, 42: 313-345.
Whalen J B, Currie K L and Chappell B W. A-type granites: geochemical characteristics, discrimination and petrogenesis [J]. Contributions to Mineralogy and Petrology, 1987, 95: 407-419.
Taylor S R and Mclennan S M. The geochemical evolution of the continental crust [J]. Reviews of Geophysics, 1995, 33(2): 241-265.
Rudnick R L and Cao S. Composition of the continental crust//Rudnick R L. The crust, treaties on geochemistry [J]. Oxford: Elsevier Pergamon, 2003, 3: 1-64.
计量
- 文章访问数: 2832
- HTML全文浏览量: 0
- PDF下载量: 2565
下载:
