Geochronology and geochemistry of the granodiorite intrusion in Yangkang area of Qinghai Province and its geological significance
FANG Yong-Kun1,2,3,4(), Cao Cheng-Gang1,2,3,4, DONG Jun-Lin5, LI Ling-Gui5
1. Qinghai Environmental Geological Exploration Bureau, Xining 810000, China 2. No.906 Engineering Survey and Design Institute of Qinghai Province, Xining 810000, China 3. Key Laboratory of Environmental Geology Qinghai Province,Xining 810000, China 4. Qinghai Engineering Research Center of Geoenvironment Pritection and Geohazard prevention,Xining 810000, China 5. No.5 Geological and Mineral Survey Institute of Qinghai Province, Xining 810000, China
The formation age and petrogenesis of the Yangkang granites in the Qilian block remain controversial. In this study, LA-ICP-MS zircon U-Pb dating and whole-rock geochemical analysis were conducted to constrain the petrogenetic and tectonic processes during the formation of the granites. The results show that U-Pb age of granodiorite in Yangkang pluton is 444±1.2Ma, (MSWD=1.14), indicating that it was formed in the early Late Ordovician and that the rocks belong to weak peraluminous-strong peraluminous I-type granite.The rocks are enriched with large ion lithophile elements (K,Ba, Rb) and Light Rare Earth Elements (LREEs) and Th, but depleted in the high field strength elements (e.g., Ta-Nb). The above results show that Yangkang granites were derived from partial melting of continental crust. Combined with the regional data, the authors suggest that the Yangkang granites were probably formed in an active continental margin during Late Ordovician.
方永坤, 曹成刚, 董峻麟, 李领贵. 青海省天峻县阳康地区花岗岩岩体锆石U-Pb年代学及地球化学特征研究[J]. 物探与化探, 2021, 45(6): 1367-1377.
FANG Yong-Kun, Cao Cheng-Gang, DONG Jun-Lin, LI Ling-Gui. Geochronology and geochemistry of the granodiorite intrusion in Yangkang area of Qinghai Province and its geological significance. Geophysical and Geochemical Exploration, 2021, 45(6): 1367-1377.
Liu Z W, Wang C L, Shi X H. Granitoids characteristics and tectonic setting of Danghenanshan area in South Qilian Mountains[J]. Geoscience, 2006, 20(4):545-554.
Xia L Q, Xia Z C, Peng L G, et al. Determination of magmatic nature of ordovician island arc volcanic series in the Shihuigou area in the Northern Qilian Mountains[J]. Acta Petrologica et Mineralogica, 1991, 10(1):1-10.
Zuo G C, Zhang S L, Cheng J S, et al. Division of ophiolite zones and their tectonic significance in Qilian area[C]// Symposium on Ophiolites and Geodynamics, 1996:129-134.
Qiu J X, Zhang Z F. Experiment, composition and tectonic opening closing of early palaeozoic marine volcanic rocks from northern Qinling mountains, China[J]. Earth Science:Journal of China University of Geosciences, 1997, 22(3):233-239.
Hou Q Y, Zhang H F, Zhang B R, et al. Characteristics and tectonic affinity of Lajishan paleo-mantle in Qilian orogenic belt:A geochemical study of basalts[J]. Earth Science:Journal of China Universilty of Geosciences, 2005, 30(1):61-70.
Wang E Q, Zhang Q. The Lajishan fault belt in Qinghai province: A multi-staged upliftingstructural window[J]. Scientia Geologica Sinica, 2000, 35(4):493-500.
Yan Z, Wang Z Q, Li J L, et al. Tectonic settingsand accretionary orogenesis of the West QinlingTerrane, northeastern margin of the Tibet Plateau[J]. Acta Petrologica Sinica, 2012, 28(6):1808-1828.
[9]
Song S G, Wang M J, Wang C, et al. Magmatism during continental collision, subduction, exhumation and mountain collapse in collisional orogenic belts and continental net growth: A perspective[J]. Science China:Earth Sciences, 2015, 58(8):1284-1304.
doi: 10.1007/s11430-015-5102-x
Xia L Q, Li X M, Yu J Y, et al. Mid-late Neoproterozoic to early Paleozoic volcanism and tectonic evolution of the Qilian Mountain[J]. Geology in China, 2016, 43(4):1087-1138.
[11]
Kang H, Chen Y L, Li D P, et al. Zircon U-Pb ages and Hf isotopic compositions of fluvial sediments from the Huangshui, Beichuan, and Xichuan rivers, Northwest China:Constraints on the formation and evolution history of the Central Qilian Block[J]. Geochemical Journal, 2018, 52:37-57.
doi: 10.2343/geochemj.2.0495
[12]
Kang H, Chen Y L, Li D P, et al. Detrital zircon record of rivers’ sediments in the North Qilian orogenic belt: Implications of the tectonic evolution of the northeastern Tibetan Plateau[J]. Geological Journal, 2019, 54(4):2208-2228.
doi: 10.1002/gj.v54.4
[13]
Kang H, Chen Y L, Li D P. The nature and history of the South Qilian orogenic belt:Constraints from compositions of rivers’ sediments and their detrital zircon U-Pb geochronology, Lu-Hf isotopic compositions[J]. Geological Journal, 2020, 55(1):712-727.
doi: 10.1002/gj.v55.1
Li Z, Chen Y L, Liu C Z, et al. Formation and evolution history on the Northern Qilian orogen:The evidences from compositions of rivers,sediments and their zircon U-Pb ages,Hf isotopic compositions[J]. Acta Geologiva Sinica, 2016, 90(2):267-282.
Xiao X C, Chen G M, Zhu Z Z. A preliminary study on the tectonics of ancient ophiolites in the Qilian mountain, Northwest China[J]. Acta Geologiva Sinica, 1978(4):282-296.
Xu Z Q, Xu H F, Zhang J X, et al. The Zhoulangnanshan caledonian subductive complex in the Northern Qilian mountains and its dynamics[J]. Acta Geologiva Sinica,, 1994, 68(1):1-15.
Zhang J X, Xu Z Q, Xu H F, et al. Structure and dynamics of caledonian subduction accretion wedge in North Qilian[J]. Geological Science, 1998, 33(3):290-299.
Wu C L, Xu X Y, Gao Q M, et al. Early Palaezoic grranitoid magmatism and tectonic evolution in North Qilian, NW China[J]. Acta Petrologica Sinica, 2010, 26(4);1027-1044.
Chen J L, Xu X Y, Zeng Z X, et al. Geochemical characters and LA-ICPMS zircon U-Pb dating constraints on the petrogenesis and tectonic setting of the Shichuan intrusion, east segment of the Central Qilian, NW China[J]. Acta Petrologica Sinica, 2008, 24(4):841-854.
Yong Y, Xiao W J, Yuan C, et al. Geochronology and geochemistry of Paleozoic granitic plutons Prom the eastern central and their tectonic implications[J]. Acta Petrologica Sinica, 2008, 24(4):855-866.
LI J F, Zhang Z C, Han B F. Geochro-nology and geochemistry of early Paleozoic from Subei and Shibaocheng areas, the western segment of central Qilian and their geological implications[J]. Acta Petrologica Sinica, 2010, 26(8):2431-2444.
Guo J J, Zhao F Q, LI H K, et al. New chronological evidence of the age of Huangyuan group in the eastern segment of Mid-Qilian massif and its geological significance[J]. Regional Geology of China, 2000, 19(1):26-31.
Yu J Y, LI X M, Ma Z P, et al. Zircon U-Pb dating of the Yishichun mafic-ultramafic complex from Southern Qilian and its geological significance[J]. Geological Journal of China Universities, 2012, 18(1):158-163.
Zhang Z W, Li W Y, Gao Y B, et al. Ni-Cu mineralization conditions of Hualong basic-ultrabasic rocks belt in Qinghai Province and Iits prospecting potentiality[J]. Northwestern Geology, 2012, 45(1):140-148.
Guo Z P, Li W Y, Zhang Z W, et al. Petrogenisis of Lumanshan granites in Hualong area of southern Qilian Mountain: Constraints from geochemistry, zircon U-Pb geochronology and Hf isotope[J]. Geology in China, 2015, 42(4):864-880.
Zhou Z Q, Cao X D, Zhao J T, et al. Early palaeozoic stratigraphy and sedimentary-tectonic evolution in Eastern Qilian mountains,China[J]. Northwest Geoscience, 1996, 17(1):1-58.
Lin T R, Peng S C, Zhou Z Q, et al. Cambrian polymerid trilobites from the nidanshan and liudaogou groups, Hualong, Northestern Qinghai, China[J]. Acta Palacontologica Sinica, 2013, 52(4):424-458.
Lin T R, Peng S C, Zhou Z Q. Cambrian agnostoid trilobites from the nidanshan and liudaogou groups, Hualong, Northeastern Qinghai, China[J]. Acta Palacontologica Sinica, 2015, 54(2):184-206.
[31]
Yuan H L, Gao S, Liu X M, et al. Accurate U-Pb age and trace element deternunations of zircon by laser ablation-inductively coupled plasma-mass spectrometry[J]. Geostandards and Geoanalytical Research, 2004, 28(3):353-370.
doi: 10.1111/ggr.2004.28.issue-3
[32]
Liu Y, Hu Z C, Gao S, et al. In situ analysis of major and trace elements oI anhydrous minerals by IA-ICP-MS without applying an internal standard[J]. Chemical Geology, 2008, 257(1):34-43.
doi: 10.1016/j.chemgeo.2008.08.004
[33]
Taylor S R, Mclennan S M. The gcochcmical evolution of the continental crust[J]. Reviews of Geophysics, 1995, 33(2):241-265.
doi: 10.1029/95RG00262
[34]
鄢明才, 迟清华. 应用地球化学元素丰度数据手册[M]. 北京: 地质出版社, 2007.
[34]
Yan M C, Chi Q H. Handbook of applied geochemical element abundance data[M]. Beijing: Geological Publishing House, 2007.
[35]
刘英俊, 曹励明. 元素地球化学导论[M]. 北京: 地质出版社, 1993.
[35]
Liu Y J, Cao L M. Introduction to element geochemistry[M]. Beijing: Geological Publishing House, 1993.
[36]
Rudnick R L, Gao S. Composition of the continental crust[J]. Treatise on Geochemistry:Second Edition, 2014, 4:1-51.
Li J F, Zhang Z C, Han B F. Geochronology and geochemistry of early Paleozoic granitic plutons from Subei and Shibaocheng areas, the western segment of central Qilian and their geological implications[J]. Acta Petrologica Sinica, 2010, 26(8):2431-2444.
Yong Y, Xiao W J, Yuan C, et al. LA-ICP-MS zircon U-Pb ages of granitic plutons from the eastern sector of the central Qilian and their geologic implication[J]. Xinjiang Geological, 2008, 26(1):62-70.
Gao Y B, Li W Y, Zhang Z W, et al. Re-Os isotopic analysis of the Yulonggou Cu-Ni sulfide deposit in the South Qilian Mountain[J]. Acta Geoscientica Sinica, 2012, 33(6):899-906.
Jia Q Z, Yang Z T, Xiao C Y. The metallogenic regularity and metallogenic prediction of copper,gold and tungsten deposits in Qilian mountain[M]. Beijing: Geological Publishing House, 2007.
Mao J W. The copper, gold, iron and tungsten poly-metallic metallogenic series of ore deposits and prospecting evaluation in orthwestern Qilian mountain[M]. Beijing: Geological Publishing House, 2003.
Wei L M, Yang Y Z, Zhng H, et al. Petrogcncsis of Yanzhiba granite in South Qinling:Constraints from zircon U-Pb ages,geochemistry and Sr-Nd-Pb isotope[J]. Journal of Earth Sciences and Environment, 2016, 38(4):527-546.
[44]
Altherr R, Holia, Hegner E, et al. High-potassium,calc-alkaline I-type plutonism in the European Variscides:North Vosges(France) and northern Schwarzwald (Germany)[J]. Lithos, 2000, 50(1):51-73.
doi: 10.1016/S0024-4937(99)00052-3
[45]
Wu F Y, Jann B M, Wilde S A, et al. Highly fractionated I-type granites in NE China(I):Geochronology and petrogenesis[J]. Lithos, 2003, 66(3/4):241-273.
doi: 10.1016/S0024-4937(02)00222-0
[46]
Li X H, Li Z X, Li W X, et al. Initiation of the indosinian urogcny in South China:Evidence for a Per-main magmatic arc on Hainan Isiand[J]. The Journal of Geology, 2006, 114(3):341-353.
doi: 10.1086/501222
[47]
Li X H, Li Z X, Li W X, et al. U-Pb zircon, geochemical and Sr-Nd-Hf isotopic constraints on age and origin of Jurassic I- and A-type granites from central Guangdong, SE China: A major igneous event in response to foundering of a subducted flat-slab[J]. Lithos, 2007: 18(9):186-204.
[48]
Chappell B W. Aluminium saturation in I- and S-type granites and the characterization of fractionated haplogranites[J]. Lithos, 1999, 46(3):535-551.
doi: 10.1016/S0024-4937(98)00086-3
[49]
Whalen J B, Currie K L, Chappell B W. A-type granites:Geochemical characteristics,discrimination and petrogencsis[J]. Contributions to Mineralogy and Petrology, 1987, 95(4):407-419.
doi: 10.1007/BF00402202
Xiao Q H, Deng J F, Qiu R Z, et al. A preliminary study of the relationship between granitoids and the growth of continental crust: A case study of the formation of key orogen granitoids in China[J]. Geology in China, 2009, 36(3):594-621.
[51]
陆凤香, 桑隆康. 岩石学[M]. 北京: 地质出版社, 2002:373-380.
[51]
Lu F X, Sang L K. Petrology[M]. Beijing: Geological Publishing House, 2002:373-380.
Zhu X H, Chen D L, Liu L, et al. Geochronology,geochemistry and significance of the early Paleozoic back-arc type ophiolite in Lvliangshan area,North Qaidam[J]. Acta Petrologica Sinica, 2014, 30(3):822-834.
Yang W R, Deng Q L, Wu X L. The basic characteristics and tectonic attributes of the Lajishan orogenic belt in South Qilian[J]. Acta Geologiva Sinica, 2002, 76(1):106.
Huang Z B, Zheng J P, Li B H, et al. Age and geochemistry of the early Paleozoic back-arc type ophiolite in Dadaoerji area, South Qilian, China[J]. Geotectonica et Metallogenia, 2016, 40(4):826-838.
[56]
Song S G, Niu Y L, Zhang L R, et al. Tectonic evolution of early Paleozoic HP metamorphic rocks in the north Qilian mountains,NW China: New perspectives[J]. Journal of Asian Earth Sciences, 2009, 35:334-353.
doi: 10.1016/j.jseaes.2008.11.005
[57]
Song S G, Niu Y L, Su L, et al. Tectonics of the north Qilian orogen, NW China[J]Gondwana Research, 2013, 23(4):1378-1401.
doi: 10.1016/j.gr.2012.02.004