|本期目录/Table of Contents|

[1]徐多勋,杨拴海,李瑞保,等.西秦岭西段塔洞花岗闪长岩体年代学、地球化学特征及其地质意义[J].地球科学与环境学报,2015,37(03):22-33.
 XU Duo-xun,YANG Shuan-hai,LI Rui-bao,et al.Geochronological, Geochemical Characteristics and Geological Significance of Tadong Granodiorite Pluton in the Western Section of West Qinling[J].Journal of Earth Sciences and Environment,2015,37(03):22-33.
点击复制

西秦岭西段塔洞花岗闪长岩体年代学、地球化学特征及其地质意义(PDF)
分享到:

《地球科学与环境学报》[ISSN:1672-6561/CN:61-1423/P]

卷:
第37卷
期数:
2015年第03期
页码:
22-33
栏目:
基础地质与矿产地质
出版日期:
2015-05-15

文章信息/Info

Title:
Geochronological, Geochemical Characteristics and Geological Significance of Tadong Granodiorite Pluton in the Western Section of West Qinling
文章编号:
1672-6561(2015)03-0022-12
作者:
徐多勋杨拴海李瑞保王伟锋魏立勇李飞刘满年常亮李国英刘霞
1. 中国人民武警黄金第五支队,陕西 西安 710100; 2. 长安大学 地球科学与资源学院,陕西 西安 710054
Author(s):
XU Duo-xun YANG Shuan-hai LI Rui-bao WANG Wei-feng WEI Li-yong LI Fei LIU Man-nian CHANG Liang LI Guo-ying LIU Xia
1. No.5 Gold Geological Party of Chinese People’s Armed Police Force, Xi’an 710100, Shaanxi, China; 2. School of Earth Science and Resources, Chang’an University, Xi’an 710054, Shaanxi, China
关键词:
地球化学花岗闪长岩埃达克质岩锆石U-Pb年龄岩石成因构造环境后碰撞西秦岭
Keywords:
geochemistry granodiorite adakitic rock zircon U-Pb age petrogenesis tectonic post-collision West Qinling
分类号:
P588;P597
DOI:
-
文献标志码:
A
摘要:
塔洞花岗闪长岩体位于西秦岭造山带西段,主体岩性为灰白色中细粒块状花岗闪长岩,岩体中未见暗色闪长质包体。对该岩体进行LA-ICP-MS锆石U-Pb同位素年代学测试,所选锆石均为具岩浆韵律环带结构的岩浆锆石,锆石w(Th)/w(U)值主体大于0.4,锆石U-Pb加权平均年龄为(219.0±5.3)Ma,代表塔洞花岗闪长岩体的结晶年龄。地球化学特征显示,该岩体具有高SiO2质量分数(66.88%~67.46%)、高Al2O3质量分数(15.39%~16.54%)、富K(质量分数为2.83%~4.12%)、准铝质(A/CNK值介于0.97~1.0之间)的高钾钙碱性花岗岩特征。该岩体轻、重稀土元素分异强烈,Eu异常不明显,球粒陨石标准化稀土元素配分模式为右倾型,原始地幔标准化微量元素蛛网图具明显的富集大离子亲石元素(Cs、Rb、Ba等),亏损重稀土元素与高场强元素(如Nb、Ta等)的特征。该岩体具有与埃达克质花岗岩相似的特征,如高Sr质量分数(主体大于400×10-6)、低Y质量分数((5.49~12.8)×10-6)、低Yb质量分数((0.34~0.91)×10-6)、高w(Sr)/w(Y)值(大于40,多介于50~90之间)。岩石成因研究表明,该岩体为加厚下地壳石榴子石角闪岩(石榴子石体积分数为10%~20%)部分熔融并经历分离结晶作用形成的。综合区域资料认为,西秦岭造山带西段古特提斯洋于印支晚期已经关闭,南北陆块完成同碰撞造山作用,并进入后碰撞构造演化阶段。
Abstract:
Tadong granodiorite pluton, which is located in the western section of West Qinling orogenic belt, is mainly composed of gray-white fine-to-medium grained massive granodiorite without any dioritic enclaves, and several schist xenoliths are found at the margin of the pluton. LA-ICP-MS zircon U-Pb isotope chronology of the pluton was analyzed. The zircons have the characteristics of magmatic oscillatory zoning. The ratios of mass fractions of Th and U are mainly more than 0.4, and the U-Pb weighted average age of zircon is (219.0±5.3)Ma, which represents the crystallization age of Tadong granodiorite pluton. The geochemical characteristics show that the pluton has the characteristics of high-K calc-alkaline granite, including high mass fraction of SiO2 (66.88%-67.46%), high mass fraction of Al2O3 (15.39%-16.54%), K-rich (the mass fraction is 2.83%-4.12%) and metaluminous (the value of A/CNK is 0.97-1.0). Chondrite-normalized REE pattern of the pluton is right-inclined, which displays obvious differentiation of light and heavy rare earth elements and weak Eu anomaly. Primitive mantle-normalized trace element spider diagram of the pluton shows that large ion lithophile elements (Cs, Rb, Ba, etc.) are obviously enriched, heavy rare earth elements and high field strength elements (Nb, Ta, etc.) are depleted. The characteristics of Tadong granodiorite pluton are similar to adakite-like granite, which is typical of high mass fraction of Sr(mainly more than 400×10-6), low mass fraction of Y ((5.49-12.8)×10-6), low mass fraction of Yb ((0.34-0.91)×10-6) and high ratio of mass fractions between Sr and Y (more than 40, mostly 50-90). Petrogenesis results show that Tadong granodiorite pluton may result from the partly melt of garnet amphibolite (volume fraction of garnet is 10%-20%) from the thickening lower crust, following the process of fractionation and crystallization. In general, Paleotethys has closed at the later stage of Indosinian in the western section of West Qinling, and the syn-collision orogenesis between the north and south blocks finishes, following the tectonic evolution stage of post-collision.

参考文献/References:

-

相似文献/References:

[1]高林,陈斌.鲁西地块济南辉长岩岩石学、地球化学和Os-Nd-Sr同位素研究[J].地球科学与环境学报,2013,35(02):19.
 GAO Lin,CHEN Bin.Study on Petrology, Geochemistry and Os-Nd-Sr Isotopes of Jinan Gabbro in Luxi Block[J].Journal of Earth Sciences and Environment,2013,35(03):19.
[2]要梅娟,刘家军,翟德高,等.内蒙古道伦达坝铜多金属矿床微量元素地球化学特征[J].地球科学与环境学报,2013,35(01):24.
 YAO Mei-juan,LIU Jia-jun,ZHAI De-gao,et al.Geochemistry Characteristic of Trace Element in Daolundaba Copper-polymetallic Deposit of Inner Mongolia[J].Journal of Earth Sciences and Environment,2013,35(03):24.
[3]李云峰,李波,周亚楠,等.潜水质量安全评价指标体系的研建:以西安为例[J].地球科学与环境学报,2013,35(01):80.
 LI Yun-feng,LI Bo,ZHOU Ya-nan,et al.Establishment of Index System to Evaluate the Safety of Phreatic Water Quality: Taking Xi’an as an Example[J].Journal of Earth Sciences and Environment,2013,35(03):80.
[4]冯冲,邹华耀,郭彤楼,等.川东北及邻区上二叠统吴家坪组烃源岩评价[J].地球科学与环境学报,2013,35(04):18.
 FENG Chong,ZOU Hua-yao,GUO Tong-lou,et al.Evaluation of Source Rocks in Upper Permian Wujiaping Formation of Northeast Sichuan and Its Adjacent Area[J].Journal of Earth Sciences and Environment,2013,35(03):18.
[5]李艳,张秀颀,逯晓喻,等.松辽盆地上古生界烃源岩特征及有效性分析[J].地球科学与环境学报,2013,35(04):39.
 LI Yan,ZHANG Xiu-qi,LU Xiao-yu,et al.Characteristics and Validity Analysis of Hydrocarbon Source Rocks of Upper Paleozoic in Songliao Basin[J].Journal of Earth Sciences and Environment,2013,35(03):39.
[6]宁培松,龙群,程婷,等.鲁西地块晚中生代中—基性岩地球化学和Sr-Nd-Pb同位素组成特征[J].地球科学与环境学报,2013,35(04):62.
 NING Pei-song,LONG Qun,CHENG Ting,et al.Geochemistry and Sr-Nd-Pb Isotopic Composition of Late Mesozoic Intermediate-basic Rock in Western Shandong Block[J].Journal of Earth Sciences and Environment,2013,35(03):62.
[7]张嘉升,潘爱芳,樊会民,等.陕西柞水地区金盆梁金矿区水系沉积物地球化学特征与找矿方向[J].地球科学与环境学报,2014,36(04):55.
 ZHANG Jia-sheng,PAN Ai-fang,FAN Hui-min,et al.Geochemical Characteristics of Stream Sediment in Jinpenliang Gold Mining Area of ZhashuiArea, Shaanxi and Its Prospecting Direction[J].Journal of Earth Sciences and Environment,2014,36(03):55.
[8]曹军,钟宁宁,邓运华,等.下刚果盆地海相烃源岩地球化学特征、成因及其发育的控制因素[J].地球科学与环境学报,2014,36(04):87.
 CAO Jun,ZHONG Ning-ning,DENG Yun-hua,et al.Geochemical Characteristics, Origin and Factors Controlling Formation of Marine Source Rock in Lower Congo Basin[J].Journal of Earth Sciences and Environment,2014,36(03):87.
[9]姜常义,王子玺,杜玮,等.柴达木地块北缘南北沟岩体地球化学特征及成矿前景[J].地球科学与环境学报,2015,37(01):12.
 JIANG Chang-yi,WANG Zi-xi,DU Wei.Geochemical Characteristics of Nanbeigou Intrusion in the Northern Margin of Qaidam Massif and Its Prospecting Potential[J].Journal of Earth Sciences and Environment,2015,37(03):12.
[10]刘成林,徐韵,马寅生,等.柴达木盆地北部滩间山群碳沥青地球化学特征与成因[J].地球科学与环境学报,2015,37(01):85.
 LIU Cheng-lin,XU Yun,MA Yin-sheng,et al.Geochemical Characteristics and Origin of Anthraxolite of Tanjianshan Group in the Northern of Qaidam Basin[J].Journal of Earth Sciences and Environment,2015,37(03):85.
[11]王鑫,董国臣,董亮琼.东昆仑东段早泥盆世花岗岩成因:来自龙漠卡岩体的证据[J].地球科学与环境学报,2018,40(04):414.
 WANG Xin,DONG Guo-chen,DONG Liang-qiong.Genesis of Early Devonian Granitoid in East Segment of East Kunlun: Evidences from Longmoka Pluton[J].Journal of Earth Sciences and Environment,2018,40(03):414.

备注/Memo

备注/Memo:
收稿日期:2014-11-18
基金项目:中国地质调查局地质大调查项目(1212011220660)
作者简介:徐多勋(1986-),男,陕西定边人,工程师,E-mail:xdxyx@163.com。
更新日期/Last Update: 2015-05-27