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YU Tao, XU Jiali, GAO Qiang, FAN Bingliang, XU Changhao. 2020: LA-ICP-MS zircon U-Pb age and geological characteristics of the Early Jurassic potassium porphyritic granites in Kargang area, eastern Tibet. Geological Bulletin of China, 39(5): 621-630.
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In this paper, LA-ICP-MS zircon U-Pb age test was carried out on the potassium porphyritic granites in the Kargang area, which shows that the 206Pb/238U age weighted average value of the rock mass is 178±2 Ma(MSWD=3.7, n=20), suggesting a product of Early Jurassic.The geochemical characteristics of the rocks show that the rocks have alkali-rich potassium(K2O+Na2O=8.02%~8.76%, K2O/Na2O=1.71~2.11), but low aluminum(Al2O3=14.08%~14.73%, A/CNK=1.01~1.04), without pyroxene and with lower corundum molecules.The rocks are generally characterized by rich Rb, Th, K, U and other large ionic pro-stone elements, obvious loss of Ba, Nb, Sr, P, Ti and other elements, and very low values of high field strength elements Zr, Nb, with(Ga/Al)×104 values of 4.48~5.06 and Rb/Sr ratios of 1.84~2.29, which shows the characteristics of high magma differentiation; in addition, the formation of rocks was related to subduction reduction, and its tectonic environment changed gradually from extrusion environment to relative stretching environment, accompanied by the decrease of deep crustal pressure, which led to the upwelling of mantle source magma and the partial melting of the overlying crust.
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刘本培, 冯庆来, 方念乔.滇西南昌宁-孟连带和澜沧江带古特提斯多岛洋构造演化[J].地球科学, 1993, 18(5):529-538. https://www.ixueshu.com/document/946e317b94c48768d0577d3e508ea41a318947a18e7f9386.html
|
|
樊炳良, 王新然, 白涛, 等.藏东卡贡地区晚寒武世错多勤石英闪长岩LA-ICP-MS锆石U-Pb年龄及地质意义[J].地质通报, 2019, 39(4):471-479. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20200406&flag=1
|
|
樊炳良, 张鑫利, 于涛, 等.藏东吉塘复式花岗岩成因——来自锆石U-Pb年龄和地球化学的证据[J].地质通报, 2019, 38(8):1274-1286. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20190803&flag=1
|
|
樊炳良, 白涛, 冯德新, 等.藏东纽多黑云母二长花岗岩锆石U-Pb年龄及成因[J].地质通报, 2018, 37(7):1226-1235. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20180707&flag=1
|
|
Liu Y S, Hu Z C, Gao S, et al.In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J].Chemical Geology, 2008, 257:34-43. doi: 10.1016/j.chemgeo.2008.08.004
|
|
Liu Y S, Gao S, Hu Z C, et al.Continental and oceanic crust recycling-induced melt-peridotite interactions in the Trans-North China Orogen:U-Pb dating, Hf isotopes and trace elements in zircons of mantle xenoliths[J].Journal of Petrology, 2010, 51:537-571. doi: 10.1093/petrology/egp082
|
|
Ludwig K R.User's Manual for isoplot 3.00: A Geochronological Toolkit for Microsoft Excel[M].Berkeley: Berkeley Geochronology Center, Special Publication No.4a.2003.
|
|
吴元保, 郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报, 2007, 8(16):1589-1604. http://d.old.wanfangdata.com.cn/Periodical/kxtb200416002
|
|
Sun S S, McDonough W F.Chemical and isotopic systematics in ocean basalt: Implication for mantle composition and processes[C]//Saunders A D, Norry M J.Magmatism in the Ocean Basins.Geological Society of London Special Publications, 1989, 42: 313-345.
|
|
Chappell B, White A J R.I- and S-type granites in the Lachlan Fold Belt.Transactions of the Royal Society of Edinburgh[J].Earth Sciences, 1992, 83:1-26. http://cn.bing.com/academic/profile?id=6f03caf823d3c86871acbbe1254988a2&encoded=0&v=paper_preview&mkt=zh-cn
|
|
王永文, 颜丹平, 刘红旭, 等.西天山伊犁地块北缘桦木沟高分异I型花岗岩年代学、地球化学及其构造意义[J].现代地质, 2015, 29(3):529-541. doi: 10.3969/j.issn.1000-8527.2015.03.005
|
|
高栋, 吴才来, 郜源红, 等.南阿尔金玉苏普阿勒克塔格花岗岩体锆石U-Pb年代学、地球化学特征及地质意义[J].地球科学, 2019, 44(11):3812-3828. http://d.old.wanfangdata.com.cn/Periodical/dqkx201911019
|
|
Condie K C.High field strength element rations in Archean basalts:a window to evolving sources of mantle plumes[J].Lithos, 2005, 79:491-504. doi: 10.1016/j.lithos.2004.09.014
|
|
Muller D, Groves D I.Potasic igneus rocks and associated gold-copper mineralization[M].Lect Notes Earth Sci., 1994.
|
|
Gorton M P, Schandl E S.From continents to island arcs:a geochemical index of tectonic setting for arc-related and within-plate felsic to intermediate volcanic rocks[J].Canadian Mineralogist, 2000, 38(5):1065-1073. doi: 10.2113/gscanmin.38.5.1065
|
|
西藏自治区地质矿产勘查开发局地热地质大队.1: 5万吉塘镇幅、益庆乡幅、亚雪村幅、察雅县幅区域地质调查报告.2019.
|
|
西藏自治区地质调查院.1: 25万八宿幅区域地质调查报告.2007.
|
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