甘肃马鬃山地区梧桐井片麻岩年代学的研究
Geochemical Characteristics and Tectonic Implications of Wutongjin Granitic Gneisses in the Mazongshan Area, Gansu Province
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摘要: 甘肃北山梧桐井片麻岩体主要为花岗片麻岩,岩石化学成分特点为准铝质(Al2O3为11.45%～16.07%),富硅(SiO2为61.03%～75.28%),偏碱(Na2O+K2O为6.74%～8.24%),TFeO/MgO值高,而CaO含量低(0.13%～5.33%);富含REE(ΣREE=102.17×10-6～372.17×10-6),Y、Nb等高场强元素(HFSE).这些特点与I型和S型花岗质岩石有明显的区别,是一种典型的A2型花岗岩.梧桐井片麻岩体U-Pb等时线年龄为558Ma,表明北山地区在新元古代末处于造山后拉张裂解环境.Abstract: The Wutongjin granitic gneisses is exposed in the Beishan area, Gansu Province. The Wutongjin granitic gneisses arem etalum in ous(Al2O3=11.45%～16.07%) and characterized by high SiO2 (61.03%～75.28%),Na2O+K2O (6.74%～8.24%) and TFeO/MgO radios, and high REE(102.17×10-6～372.17×10-6), Y, Nb, and low CaO (0.13%～5.53%)contents. The characteristics are obviously different from those observed from I-and S-type granites, but quite similar to A2 type granites. The Wutongjin granitic gneisses has given a U-Pb isochron age of 558 Ma. Therefore, it is suggested that a crustal rifting eventmight have started in the Beishan a readuring Neoproterozoic.
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Key words:
- granitic gneiss /
- geochemical characteristics /
- Mazongshan area
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龚全胜,刘明强,梁明宏.北山造山带大地构造相及构造演化[J].西北地质,2003,36(1):11-17.
左国朝,何国琦.北山板块构造及成矿规律[M].北京:北京大学出版社,1990:1-209.
赵茹石,周振环,毛金海.甘肃省板块构造单元划分及其构造演化[J].中国区域地质,1994,13(1):28-36.
黄增保,金霞.甘肃红石山蛇绿岩地球化学特征及构造环境[J].地质科学,2006,41(4):601-611.
左国朝,李茂松.甘蒙北山地区早古生代岩石圈形成与演化[M].兰州:甘肃科学技术出版社,1996:1-91.
龚全胜,梁明宏,刘明强,等.北山造山带若干基础地质问题讨论[J].中国区域地质,1998,(增刊):80-87.
魏志军,黄增保,金霞,等.甘肃红石山地区蛇绿混杂岩地质特征[J].西北地质,2004,37(2):13-17.
王德滋,赵广涛,邱检生.中国东部晚中生代A型花岗岩的构造制约[J].高校地质学报,1995,1(2):13-21.
陈培荣,章邦桐.A型花岗岩类研究综述[J].国外花岗岩类地质与矿产,1994,(4):9-11.
洪大卫,王式洸,韩宝福,靳满元.碱性花岗岩的构造环境分类及其鉴别标志[J].中国科学(D集),1995,25(4):418-426.
许保良,阎国翰,张臣,等.A型花岗岩的岩石亚类及其物质来源[J].地学前缘,1998,5(3):113-125.
齐瑞荣,黄增保,金霞.甘肃北山大石山A型花岗岩体的地球化学特征及构造意义[J].岩石矿物学杂志,2006,25(2):91-96.
GONG Quansheng,LIU Mingqiang,LIANG Minghong,et al.The tectonic facies and crust evolution of Beishan orogenic belt,Gansu[J].Northwestern Geology.2003,36(1):11-17(in Chinese).
ZUO Guochao,HE Guoqi.Plate Tectonics and Metallogenic Regularities in Beishan Region[M].Peking University Publishing House,Beijing,1990:1-209.
ZHAO Rushi,ZHOU ZhengHuan,MAO Jinhai.The plate tectonics and tectonic evolution of Gansu province[J].Regional Geology of China.1994,13(1):28-36.
HUANG Zenbao,JIN Xia.Geochemistry Features and Tectonic Setting of the Hongshishan Ophiolite,in Gansu Province[J].Science Geology Sinica 2006,41(4):601-611.
ZUO Guochao,LI Maosong.Formation and evolution of the early Paleozoic lithosphere in the Beishan area Gansu-Inner Mongolia,China[M].Gansu Science and Technology Press,Lanzhou,1996:1-91.
WEI Zhijun,HUANG Zengbao,JIN Xia,et al.Geological characteristics of ophiolite magmatitic complex of Hongshishan region,Gansu[J].Northwestern Geology,2004,37(2):13-18(in Chinese).
Eby G N.Chemical subdivision of the A-type granitoids:Petrogenesis and tectonic implications[J].Geology,1992,20:641-644.
Loiselle M C and Wones D R.Characteristics and origin of anorogenic granites[J].Geol.Soc.Am.Abstr.Programs,1979,11:468.
WANG Dezi,ZHAO Guangtao,QIU Jianshen.The tectonic constraint on the later Mesozoic A-type granitoids,in eastern China[J].Geology Journal of China Universities,1995,1(2):13-21(in Chinese with English abstract).
CHEN Peirong,ZHANG Bangtong.Summarize of studying on A-type granites[J].Overseas Granitoid Geology and Minerals,1994,(4):9-11.
HONG Dawei,WANG Shiguang,HAN Baofu,et al.Discrmination marks for tectonic setting of alkaline granite[J].Science in China(D),1995,25(4):418-426(in Chinese).
XU Baoliang,YAN Guohan,ZHANG Chen,et al.Petrologic subdivision and source material of A-type granites[J].Earth Science Frontiers,1998,5(3):113-125(in Chinese).
Eby G N.The A-type granitoids:A review of their occurrence and chemical characteristics and speculations on their petrogenesis[J].Lothos,1990,26:115-134.
QI Ruirong,HUANG Zenbao,JIN Xia.Geochemical Characteristics and Tectonic Implication of Dashishan A-type Granitic Intrusives in the Beishan area,Gansu Province[J].Acta Petrologica Minneralogica,2006,25(2):91-96.
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