img

Wechat

Adv. Search

Gold Science and Technology ›› 2015, Vol. 23 ›› Issue (5): 20-27.doi: 10.11872/j.issn.1005-2518.2015.05.020

Previous Articles     Next Articles

he Sr,Nd,Pb Isotopic Compositon and its Implication for the Magmatic Source of the Baimashan Rock Mass,Southern Qinling

ZHANG Yonghua1,WANG Jianzhong1,2,QIAN Zhuangzhi2,XU Gang2,JIANG Chao2   

  1. 1.No.5 Gold Geological Party of  CAPF,Xi’an    710100,Shaanxi,China;
    2.Key Laboratory of Western China’s Mineral Resources and Geological Engineering,Ministry of  Education,Chang’an University,Xi’an    710054,Shaanxi,China
  • Received:2015-02-15 Revised:2015-05-12 Online:2015-10-28 Published:2015-12-09

Abstract:

This paper studies Sr,Nd,Pb,isotopic compositions of 7 granitoids from South Qinling,which were all formed about 200 Ma B.P.The results indicate that the granitic rocks including the Baimashan rock mass from the South Qinling are characterized by low radiogenic Pb isotopic composition.Their initial(87Sr/86Sr)t ratios range from 0.70495 to 0.70908,εNd(t) values from -2.40 to -8.55,and Nd isotopic model ages(TDM) from 1.2 Ga to 1.7 Ga.their εNd(t) values gradually decrease from east to west,whereas TDM values gradualy increase.The Baimashan rock mass has much lower (87Sr/86Sr)t (0.70637),lower εNd(t)(-6.75) and much higher TDM(1.53 Ga).This study reveals that the magmatic source of the Baimashan rock mass was derived from the deep continental crust.In the magmatic source,basic magmatic material in the crust similar to the Yaolinghe Group basic volcanic rocks in South Qinling,is the major source for the formation of granitoids with less significant old continental crust material.The Baimashan adakite which is in favor of copper and gold mineralization,may resulted from partial melting of mafic lower crust in the thickened lower crust due to the lithospheric delamination and the asthenospheric upwelling,which can provide some clues to the direct copper-gold prospecting.

Key words: isotopic composition, magmatic source, basic lower crust, Baimashan rock mass, adakite, Southern
Qinling

CLC Number: 

  • P597

[1] 张宏飞,肖龙,张利,等.扬子陆块西北缘碧口块体印支期花岗岩类地球化学和Pb-Sr-Nd同位素组成:限制岩石成因及其动力学背景[J].中国科学(D辑),2007,37(4):360-370.
[2] 张国伟,张本仁,袁学诚,等.秦岭造山带与大陆动力学[M].北京:科学出版社,2001:1-885.
[3] 秦江峰,赖绍聪.秦岭造山带晚三叠世花岗岩成因与深部动力学[M].北京:科学出版社,2011:1-266.
[4] Sun W D,Li S G,Chen Y D,et al.Timing of synorogenic granotoids in the south Qinling,central China:Constraints on the evolution of the Qinling-Dabie orogenic belt[J].Journal of Geology,2002,110(4):457-468.
[5] 李先梓,严阵,卢欣祥,等.秦岭—大别山花岗岩[M].北京:地质出版社,1993:1-218.
[6] 王建中,钱壮志,姜超,等.南秦岭白马山金矿区石英闪长岩地球化学特征及其构造意义[J].黄金科学技术,2014,22(5):30-38.
[7] 田伟,董申保,陈咪咪,等.南秦岭造山印支期花岗岩带的“地幔印记”[J].地学前缘,2009,16(5):119-128.
[8] 王晓霞,王涛,卢欣祥,等.北秦岭老君山和秦岭梁环斑结构花岗岩及构造环境——一种可能的造山带型环斑花岗岩[J].岩石学报,2003,19(4):650-660.
[9] 王晓霞,王涛,Happala I,等.秦岭环斑结构花岗岩中暗色包体的岩浆混合成因及岩石学意义——元素和Nd、Sr同位素地球化学证据[J].岩石学报,2005,21(3):935-946.
[10] 张成立,张国伟,晏云翔,等.南秦岭勉略带北光头山花岗岩体群的成因及其构造意义[J].岩石学报,2005,21(3):711-720.
[11] 张宏飞,靳兰兰,张利,等.西秦岭花岗岩类地球化学和Pb-Sr-Nd同位素组成对基底性质及其构造属性的限制[J].中国科学(D辑),2005,35(10):914-926.
[12] 刘志鹏,李建威.西秦岭金厂石英闪长岩的岩浆混合成因:岩相学和锆石U-Pb年代学证据及其构造意义[J].地质学报,2012,86(7):1077-1090.
[13] 柳世强,王建中,党满宏,等.甘肃白马山金矿床成因初探[J].黄金科学技术,2013,21(4):32-38.
[14] 张智兴,辛存林.甘肃金厂矽卡岩型铜金矿地质特征及成因探讨[J].甘肃冶金,2004,26(2):23-25.
[15] Liew T C,Hofmann A W.Precambrian crustal components,plutonic associations plate environment of the Hercynian Fold Belt of central Europe:Indications from a Nd and Sr isotopicstudy[J].Contribution to Mineral and Petrology,1988,98 (2) :129-138.
[16] 张宏飞,欧阳建平,凌文黎.南秦岭宁陕地区花岗岩Pb、Sr、Nd同位素组成及深部地质信息[J].岩石矿物学杂志,1997,16(1):22-31.
[17] 邵世才,张本仁,李泽九.秦岭造山带东江口花岗岩体群的地球化学研究及其构造环境[J].矿产与地质,1994,25(5):424-429.
[18] 张宏飞,张本仁,赵志丹,等.东秦岭商丹构造带陆壳的俯冲和碰撞:花岗质岩浆源区同位素示踪证据[J].中国科学(D 辑),1996,26(3):231-236.
[19] 张宏飞,张本仁,凌文黎,等.南秦岭新元古代地壳增生事件:花岗质岩石钕同位素示踪[J].地球化学,1997,26(5):16-24.
[20] Huang X,Wu L R.The Study on the Granitoids in  Shanxi Province by Nd-Sr isotopes[M]//Advances in Geosciencea.Beijing:China Ocean Press,1992:211-219.
[21] 张旗,王焰,熊小林,等.埃达克岩和花岗岩:挑战与机遇[M」.北京:中国大地出版社,2008.
[22] 张本仁,骆庭川,高山,等.秦巴岩石圈构造及成矿规律地球化学研究[M].武汉:中国地质大学出版社,1994:1-446.
[23] Zartman R E,Doe B R.Plumbotectonics:The model[J].Tectonophysics,1981,75(1/2):135-162.
[24] 张宗清,张国伟,唐索寒,等.南秦岭变质地层同位素年代学[M].北京:地质出版社,2002:1-256.
[25] 陈衍景,张静,张复新,等.西秦岭地区卡林—类卡林型金矿床及其成矿时间、构造背景[J].地质论评,2004,50(2):134-152.
[26] Defant M J,XU J F,Kepezhinskas P,et al.Adakites:Some variations ona theme[J].Acta Petrologica Sinica,2002,18(2):129-142.
[27] Oyarzun R,Marquez A,Lillo J,et al.Giant versus small porphyry copper deposits of Cenozoic age in northern Chile:Adakitic versus normal calc-alkaline magmatism[J].Mineralium Deposita,2001,36(8):794-798.
[28] Thieblemont D,Stein G,Lescuyer J L.Gisements epithermaux et porphyriques:La connexion adakite[J].Earth and Planetary Science,1997,325(1):103-109.
[29] 曲晓明,江军华,辛洪波,等.西藏冈底斯造山带几乎同时形成的两套埃达克岩为什么一套含矿一套不含矿[J].矿床地质,2010,29(3):381-394.
[30] 罗照华,卢欣祥,陈必河,等.透岩浆流体成矿作用导论[M].北京:地质出版社,2009:1-179.

[1] GUO Yuncheng,LIU Jiajun,MAO Shidong,LI Hu. Paleozoic Terrane Was Found in the Middle Part of the Ganzi-Litang Suture Zone,West Sichuan: Evidences from the Detrital Zircon Geochronology [J]. Gold Science and Technology, 2017, 25(6): 9-20.
[2] JIAO Xueyao,FAN Xiaolong,YU Pinghui,JIANG Guohao,XIONG Wenbo,CHENG Zhiyan,MA Jinlong. He-Ar Isotopic System of Fluid Inclusions in Pyrite from the Changba Lead-Zinc Deposit in Gansu Province [J]. Gold Science and Technology, 2016, 24(4): 47-53.
[3] ZHANG Yan,CHEN Wen,YONG Yong,LIU Xinyu. Application Prospect of(U—Th)/He Dating in Ore Deposit Ge0chr0n0l0gy [J]. J4, 2008, 16(4): 1-3.
[4] Ying Hanlong. THE GEOCHEMISTRY CHARACTERISTICS OF WALLROCK ALTERATION AND ISOTOPES OF THE DAHE GEOCHEMISTRY CHARACTERISTICS OF WALLROCK ALTERATION AND ISOTOPES OF THE DAPING GOLD DEPOSIT [J]. J4, 1998, 6(4): 14-23.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!