Geochemical and Chronological Characteristics of Early Silurian Granitic Rocks from the Upper-middle Reaches of Tataleng River in Qinghai
-
摘要: 青海塔塔棱河中上游地区花岗岩类主要岩石类型为斑状二长花岗岩、二长花岗岩、花岗斑岩和斑状正长花岗岩，其次为正长花岗岩、环斑花岗岩、花岗闪长斑岩和石英闪长岩。岩石地球化学研究表明，该区花岗岩具有过铝质（A/CNK值为1.10~1.26）、高钾（K2O>Na2O）特征，属于钙碱性系列（σ为1.22~2.22），具S型花岗岩特征。LA-MC-ICP-MS锆石U-Pb测定结果，显示该区花岗岩年龄为（440.4±1.4） Ma。构造环境判别形成于后碰撞构造环境。综合分析后认为，早志留世花岗岩应当是陆陆汇聚时，南祁连陆块发生俯冲，与全吉地块发生碰撞，南祁连地块遭受挤压导致陆壳部分熔融而形成的产物。Abstract: The granitic rocks from the Upper-middle Reaches of Tataleng River in Qinghai are mainly porphyritic monzonitic granite, monzonitic granite, granitic porphyry and porphyritic syengranite, which are syengranite, rapakiwi granite, granodiorite porphyry and quartz diorite. Geochemical study of these granitic rocks indicate that they are characterized by peraluminous (A/CNK=1.10~1.26) and high-K (K2O > Na2O), belonging to calc-alkaline series (σ=1.22~2.22) and S-type granite. LA-MC-ICP-MS zircon U-Pb results show that their ages are 440.4+1.4Ma. Tectonie setting discrimination diagram suggests that these granitic rocks were formed in post-collision tectonic environment. The comprenensive analysis indicates that the Early Silurian granite was formed by the partial melting of continental crust that caused by the extrusion of South Qilian block, when the South Qilian block was subducted and collided with the Quanji block in the continent-continent convergence stage.
-
Keywords:
- North Qaidam /
- Early Silurian /
- granite /
- geochemistry
-
-
张雪亭,杨生德,杨站君,等.青海省板块构造研究:1:100万青海省大地构造图说明书[M].北京:地质出版社,2007,15-130. ZHANG Xueting,YANG Shengde,YANG Zhanjun,et al. Study on plate tectonics in Qinghai:1:1 million description of the tectonic map of Qinghai Province[M]. BeiJing:Geological Publishing House,2007,15-130.
肖庆辉,邓晋福,马大铨,等. 花岗岩研究思维与方法[M]. 北京:地质出版社,2002,8. XIAO Qinghui,DENG Jinfu,MA Daquan,et al. Thinking and method of granite research[M]. BeiJing:Geological Publishing House,2002,8.
马鸿文.花岗岩成因类型的判别分析[J].岩石学报,1992,8(4):342-343. MA Hongwen. Discriminant analysis of the genetic types of granite[J]. Journal of Petrology,1992,8(4):342-343.
申文环,王云斌,成信东,等.柴北缘塔塔楞地区环斑花岗岩体的地质特征及其意义[A].西安:陕西科学技术出版社,2006,574-577. SHEN Wenhuan,WANG Yunbin,CHENG Xindong,et al. Geological characteristics and significance of the ring spot granite in the Tata Leng area of the northern of Chaidamu[A].Xi'an:Shaanxi Science and Technology Press,2006:574-577.
陈岳龙,杨忠芳,赵志丹,等.同位素地质年代学与地球化学[M].北京:地质出版社,2005,76-93. CHEN Yuelong,YANG Zhongfang,ZHAO Zhidan,et al. Isotopic geochronology and geochemistry[M].BeiJing:Geological Publishing House,2005,76-93.
袁桂邦,王惠初,李惠明,等.柴北缘绿梁山地区辉长岩的锆石U-Pb年龄[J].地质调查与研究,2002,25(01):36-40. YUAN Guibang,WANG Huichu,LI Huiming,et al. Zircon U-Pb age of the gabbro in the Lvliangshan mountain area of the northern of the Chaidamu[J]. Geological Survey and Research, 2002,25(01):36-40.
史仁灯,杨经绥,吴才来,等.柴达木北缘超高压变质带中岛弧拉斑玄武岩锆石U-Pb年龄[J].地质学报,2004,(1):52-64. SHI Rendeng,YANGjinsui,WU Cailai,et al. Zircon U-Pb ages of island arc La basalts in the ultrahigh pressure metamorphic belt of Chaidamu northern[J]. Journal of Geology,2004,(1):52-64.
吴才来,杨经绥.祁连南缘嗷唠山俯冲型钙碱性的I型花岗岩SHRMP锆石年龄及其地质意义[J].岩石学报,2001,17(02):215-221. WU Cailai,YANG Jingsui. The south of Qilian Aoao mountain subduction type calc alkaline I type granite zircon SHRMP age and its geological significance[J].Journal of petrology, 2001,17(02):215-221.
杨经绥,张建新,孟繁聪,等.中国西部柴北缘-阿尔金的超高压变质榴辉岩及其原岩性质探讨[J] 地学前缘,2003,10(03):291-314. YANG Jingsui,ZHANG Jianxin,MEN Fancong,et al. Ultrahigh pressure metamorphic eclogite and its original rock properties in the northern Chaidamu-Aerjin of Western China[J] Earth Science Frontiers, 2003,10(03):291-314.
卢欣祥,孙延贵,张雪亭,等.柴达木盆地北缘塔塔楞环斑花岗岩SHRIMP的年龄[J].地质学报,2007,81(05):626-634. LU Xinxiang,SUN Yangui,ZHANG Xueting,et al. Age of SHRIMP in the northern of the Chaidamu Basin[J].Journal of Geology,2007,81(05):626-634.
夏林圻,夏祖春,徐学义,等.北祁连山构造-火山岩浆演化动力学[J].西北地质科学,1995,16(1):1-28. XIA Lingxin,XIA Zuchun,XU Xueyi,et al. Tectono volcanic magma evolution dynamics in North Qilian Mountains[J]. Northwest Geological Science, 1995,16(1):1-28.
冯益民,吴汉.北祁连山及其邻区古生代以来的大地构造演化初探[J]. 西北地质科学,1992,13(2):61-74. FEN Yimin, WU Han. A preliminary study on the tectonic evolution of the northern Qilian Mountains and its adjacent areas since the Palaeozoic[J]. Northwest Geological Science, 1992,13(2):61-74.
计量
- 文章访问数: 2334
- HTML全文浏览量: 0
- PDF下载量: 2004
下载:
