欢迎访问现代地质！

现代地质 ›› 2016, Vol. 30 ›› Issue (3): 514-527.

• 地球化学 • 上一篇    下一篇

赣江流域(南昌段)水系沉积物物源示踪研究：来自锆石U-Pb同位素证据的约束

李小聪1,2，王安东1,2，万建军1,2，李全忠3，林乐夫1,2   

  1. (1. 东华理工大学核资源与环境省部共建国家重点实验室培育基地，江西 南昌 330013；2. 东华理工大学 地球科学学院，江西 南昌 330013；3. 合肥工业大学 资源与环境工程学院，安徽 合肥 230009)
  • 出版日期:2016-06-14 发布日期:2016-06-15
  • 通讯作者: 王安东，男，博士，讲师，1985年出生，地球化学专业，主要从事同位素地质学、地球化学及地热学的相关研究工作。Email：adw008@mail.ustc.edu.cn。
  • 作者简介:李小聪，男，硕士研究生，1990年出生，地质资源与地质工程专业，主要从事同位素地球化学、地球化学研究工作。Email: 297247787@qq.com。
  • 基金资助:

    江西省教育厅科研项目(GJJ14476)；东华理工大学核资源与环境实验室自主基金项目(Z201403)；国家自然科学基金项目(41303041)；东华理工大学博士启动基金项目(DHBK2013101)。

Tracing the Stream Sediment of the Ganjiang River(Nanchang Section)：Constraint from the Detrital Zircon U-Pb Isotope Evidence

LI Xiaocong1,2, WANG Andong1,2, WAN Jianjun1,2, LI Quanzhong3, LIN Lefu1,2   

  1. (1. State Key Laboratory Breeding Base of Nuclear Resources and Environment, East China Institute of Technology, Nanchang,  Jiangxi 330013, China; 2. College of Earth Sciences, East China Institute of Technology, Nanchang, Jiangxi330013, China; 3. School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China)
  • Online:2016-06-14 Published:2016-06-15

PDF (PC)

13036

摘要：

赣江为长江八大支流之一，是江西省第一大河流，为研究赣江水系沉积物的物质来源，利用LA-ICP-MS分析技术，对赣江河流(南昌段)沉积物碎屑锆石进行了U-Pb年龄研究。对3个河砂样品中的140颗碎屑锆石进行了测试，获得有效测试点123个。测试结果表明：锆石UPb年龄主要有7个年龄段，分别是134~197 Ma、221~290 Ma、386~484 Ma、520~625 Ma、727~895 Ma、980~1 110 Ma、2 502~2 861 Ma。所表现出来的主要年龄区间分别与已知的构造-岩浆热事件时间相对应(燕山运动、印支－海西运动、加里东运动、晋宁运动、吕梁运动)。大多数锆石颗粒具有明显的岩浆结晶环带且Th/U>0.4，表明这些锆石多为岩浆成因。通过对赣江流域及周边各个地区的年代学对比研究揭示：年龄段为134~197 Ma的锆石大部分来自赣中南—闽西—粤北地区；221~290 Ma的印支期锆石主要来自赣南地区，而海西期的锆石来自赣中、九岭地区；386~484 Ma的锆石主要来自赣中南地区，少量来自赣西北；520~625  Ma的锆石可初步判断来自赣南地区；727~895 Ma的锆石主要来自赣北江南造山带附近的九岭地区；980~1 110 Ma和2 502~2 861 Ma的锆石主要来自华夏地块腹地的赣南—粤北地区。因此，赣江水系沉积物碎屑锆石U-Pb年龄可以有效地限定赣江流域的主要物质来源。

关键词: 水系沉积物, 碎屑锆石, U-Pb年龄, 物源分析, 赣江流域

Abstract:

The Ganjiang River is the biggest river in Jiangxi Province, which is also one of eight major tributaries of the Yangtze River. In order to investigate the material source of stream sediment in the Ganjiang River, the U-Pb age of detrital zircons from the Ganjiang River (Nanchang Section) were carried out by the LA-ICP-MS analysis technique. One hundred and twenty three spots are effective among the 140 analytical spots. The data suggest that zircons are mainly composed of 7 age stages, including 134-197 Ma, 221-290 Ma, 386-484 Ma, 520-625 Ma, 727-895 Ma, 980-1,110 Ma and 2,502-2,861 Ma, respectively, corresponding to the known tectonic-magmatic thermal events, i.e., Yanshanian Movement, Indosinian-Hercynian Movement, Caledonian Movement, Jinning Movement, Lüliang Movement. The Th/U ratios of most zircons with distinct magmatic zoning are more than 0.4, indicating that they are of magmatic origin. The result reveals that the zircons of 134-197 Ma mainly come from Southern and Central Jiangxi, Western Fujian and Northern Guangdong area. The Indosinian zircons of 221-290 Ma mainly stem from Southern Jiangxi and Hercynian zircons from Central Jiangxi and Jiuling area. The zircons of 386-484 Ma mainly come from Southern and Central Jiangxi and some are from Northwestern Jiangxi Province. The zircons of 520-625 Ma could be judged that they come from Southern Jiangxi. The zircons of 727-895 Ma are mainly from Jiuling area. The zircons of 980-1,100 Ma and 2,502-2,861 Ma mainly come from Southern Jiangxi and Northern Guangdong in Cathaysia Block. Therefore, the main material resource of the Ganjiang River could be effectively constrained by the U-Pb age of the detrital zircon from stream sediment.

Key words: stream sediment, detrital zircon, U-Pb chronology, provenance analysis, the Ganjiang River

中图分类号: 

京ICP备08011785号-7
版权所有 ©《现代地质》编辑部
地址：北京市海淀区学院路29号　邮编：100083
电话：010-82322463　 Email：xddz@cugb.edu.cn
技术支持：北京玛格泰克科技发展有限公司