Study on genesis, mineralization age and tectonic setting of Dangjiang copper polymetallic deposit in Zhiduo County, Qinghai Province
-
摘要:
当江铜多金属矿床新发现于2014年，地处西南三江成矿带北段、青海省南部治多县多彩铜多金属矿整装勘查区，成矿时代尚未精确限定，矿床成因也未形成统一认识。通过高精度LA-ICP-MS锆石微区原位U-Pb同位素测年，获得与铜矿化、铅锌矿化密切相关的流纹岩锆石206Pb/238U年龄加权平均值为227.5±1.7 Ma，确定矿化发生在晚三叠世。通过与尕龙格玛铜多金属矿的对比研究，以及含矿围岩、蚀变特征、矿石矿物、矿石类型等分析，认为其成矿于巴塘群第二岩组火山岩韵律层中，形成过程与火山喷发作用密切相关，后期构造作用为成矿元素富集起着叠加构造的作用，矿床成因为火山喷流沉积-叠加改造型。综合判断认为，当江铜多金属矿形成于北羌塘地块北部的陆缘裂谷环境，为进一步深入研究西南三江成矿带北段铜多金属矿形成构造环境和扩大找矿提供了新思路。
Abstract:The Dangjiang copper polymetallic deposit, located in the northern section of the " Sanjiang metallogenic belt ", is newly discovered in 2014 in Duocai copper polymetallic deposit integrated exploration area in Zhidoi County, southern Qinghai Province.The mineralization age has not been precisely defined, and unified understanding of the genesis of Dangjiang copper polymetallic deposit has not been formed.LA- ICP-MS zircon U-Pb dating shows that the weighted mean age of rhyolite, which is closely related with copper, lead and zinc mineralization, is 227.5±1.7 Ma, in the Late Triassic.Through the comparative study with Galonggema copper polymetallic ore deposit and the analysis of its ore-bearing wall rock, alteration characteristics, ore minerals and ore types, It is believed that the ore-forming process is closely related with volcanic eruption, and the mineralization is formed in the volcanic rhythmical layer of the second rock formation in Batang Group.It is considered that the deposit is formed as volcanic exhalation sedimentation-superimposition reworking type, and the tectonism plays the role of superposition structure for enrichment of ore-forming elements.Comprehensively, we consider that Dangjiang copper polymetallic deposit is formed in the continental margin rift tectonic setting in the northern part of the north Qiangtang block, which provides a new perspective for further studying the tectonic setting of copper polymetallic deposits in the northern" Sanjiang metallogenic belt " and expanding prospecting.
-
-
图 3 流纹岩锆石阴极发光(CL)图像(a)、锆石U-Pb谐和图(b)及206Pb/238U年龄加权平均值(c) (圆圈为同位素测年激光剥蚀的示意范围，相应编号为测点号，数字为206Pb/238U年龄，单位为Ma)
Figure 3.
表 1 青海省当江铜多金属矿区流纹岩(15DJ-2)LA-ICP-MS单颗粒锆石U-Th-Pb同位素测年结果
Table 1. LA-ICP-MS zircon U-Th-Pb isotopic analyses of rhyolite(15DJ-2) in Dangjiang copper polymetallic mining area, Qinghai Province
样号 同位素含量/10-6 同位素比值 同位素年龄/Ma Th/U 谐和度
/%Th U Pb* 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 208Pb/232Th 1σ 207Pb/206Pb 1σ 207Pb/235U 1σ 206Pb/238U 1σ 208Pb/232Th 1σ 15DJ-2-1 162.05 393.61 18.03 0.0506 0.0012 0.251 0.006 0.036 0.0005 0.0122 0.0006 221.5 52.9 227.3 4.7 227.9 2.9 245.2 12.6 0.41 100 15DJ-2-5 163.25 373.29 17.05 0.0511 0.0015 0.254 0.007 0.0361 0.0005 0.0109 0.0007 245.5 65.5 230 5.8 228.6 3.2 218.8 14.8 0.44 101 15DJ-2-6 59.01 113.38 5.26 0.0508 0.0025 0.253 0.012 0.0362 0.0007 0.0101 0.0011 233.6 111.4 229.4 9.9 229.1 4.2 203.1 22.8 0.52 100 15DJ-2-7 132.23 262.19 11.98 0.0508 0.0015 0.252 0.007 0.036 0.0005 0.0096 0.0006 231.6 65 228.3 5.7 228.1 3.1 192.2 12.7 0.5 100 15DJ-2-8 113.02 275.93 12.48 0.0515 0.0016 0.255 0.008 0.036 0.0005 0.0108 0.0008 264.5 70.9 230.9 6.3 227.7 3.3 217.8 16.9 0.41 101 15DJ-2-9 283.54 615.87 27.88 0.051 0.0008 0.253 0.004 0.036 0.0004 0.0096 0.0004 241.7 36.3 229.4 3.3 228.3 2.6 192.2 7.3 0.46 100 15DJ-2-15 562.36 367 21.75 0.051 0.0026 0.252 0.012 0.0359 0.0007 0.0104 0.0007 239.5 112.9 228.4 10 227.4 4.3 209 14.4 1.53 100 15DJ-2-16 968.21 1298.39 63.8 0.0518 0.001 0.257 0.005 0.036 0.0004 0.01 0.0004 276.2 43.9 232.2 4 228.1 2.7 200.8 7.7 0.75 102 15DJ-2-17 258.81 400.47 19.61 0.0526 0.0012 0.258 0.006 0.0356 0.0005 0.0118 0.0005 309.3 52.4 233.1 4.8 225.8 2.9 236.4 10.9 0.65 103 15DJ-2-20 139.23 273.16 12.81 0.0516 0.0015 0.254 0.007 0.0357 0.0005 0.0115 0.0007 269.6 63.6 229.6 5.7 225.9 3 231 14.1 0.51 102 15DJ-2-22 371.64 254.57 14.6 0.0526 0.0035 0.26 0.016 0.0359 0.0008 0.0097 0.0009 310.7 142.6 234.7 13.2 227.4 5.2 195.9 18.8 1.46 103 15DJ-2-23 269.96 433.45 20.86 0.0524 0.0019 0.258 0.009 0.0358 0.0006 0.0108 0.0008 301.3 79.4 233.1 7.2 226.6 3.4 216.3 16.6 0.62 103 15DJ-2-27 79.3 158.88 7.44 0.0515 0.0025 0.254 0.012 0.0358 0.0007 0.0111 0.0012 264.2 106.3 229.8 9.5 226.7 4 222.3 24.2 0.5 101 15DJ-2-28 42.28 71.39 3.3 0.0509 0.0027 0.252 0.013 0.036 0.0007 0.0083 0.001 236.1 119.5 228.2 10.7 227.7 4.1 166.1 19.6 0.59 100 注：Pb*=0.241×206Pb+0.221×207Pb+0.524×208Pb; 谐和度=(207Pb/235U)/(206Pb/238U)×100 
下载: 导出CSV
-
[1] 尹福光, 徐波, 王冬兵, 等. 西南三江造山带早古生代岩浆事件及其对原特提斯大洋演化的响应[J]. 地质通报, 2021, 40(6): 817-826. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20210601&flag=1
[2] 王冬兵, 王保弟, 唐渊, 等. 西南三江特提斯研究进展与展望[J]. 地质通报, 2021, 20(11): 1799－1813. doi: 10.12097/j.issn.1671-2552.2021.11.002 http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20211102&flag=1
[3] 董庆吉, 肖克炎, 陈建平, 等. 西南"三江"成矿带北段区域成矿断裂信息定量化分析[J]. 地质通报, 2010, 29(10): 1479-1485. doi: 10.3969/j.issn.1671-2552.2010.10.010 http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20101009&flag=1
[4] 陈建平, 郝金华. 青海南部三江北段铜多金属成矿系统演化研究[J]. 西北地质, 2012, 45(1)236-243. doi: 10.3969/j.issn.1009-6248.2012.01.030
[5] 何世平, 时超, 辜平阳, 等. 西南"三江"成矿带北段成矿地质背景及成矿规律[M]. 北京: 科学出版社, 2019.
[6] 时超, 李荣社, 何世平, 等. 沱沱河地区扎拉夏各涌铅锌矿成矿时代及其地质意义: 钾长花岗斑岩年代学和地球化学特征[J]. 地质科学, 2017, 52(4): 1181-1194. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201703010.htm
[7] Hou Z Q, Zaw K, Pan G T, et al. Sanjiang Tethyan metallogenesis in S.W. China: Tectonic setting, metallogenic epochs and deposit type[J]. Ore Geology Reviews, 2007, 31: 48-87. doi: 10.1016/j.oregeorev.2004.12.007
[8] Deng J, Wang Q F, Li G J, et al. Cenozoic tectono-magmatic and metallogenic processes in the Sanjiang region, southwestern China[J]. Earth-Science Reviews, 2014, 138: 268-299. doi: 10.1016/j.earscirev.2014.05.015
[9] 卢世银, 张启龙, 张尧, 等. 青海省治多县当江铜多金属矿地质特征及找矿前景[J]. 甘肃冶金, 2014, 36(2): 61-65. https://www.cnki.com.cn/Article/CJFDTOTAL-GSYE201402020.htm
[10] 马炳春, 缑明亮, 陈秉芳. 青海省治多县当江地区铜矿床地质特征与找矿标志研究[J]. 世界有色金属, 2018, (8): 71-73. https://www.cnki.com.cn/Article/CJFDTOTAL-COLO201815045.htm
[11] 李艳广, 汪双双, 刘民武, 等. 斜锆石LA-ICP-MS U-Pb定年方法及应用[J]. 地质学报, 2015, 89(12): 2400-2418. doi: 10.3969/j.issn.0001-5717.2015.12.015
[12] 袁洪林, 吴福元, 高山, 等. 东北地区新生代侵入体的锆石激光探针U-Pb年龄测定与稀土元素成分分析[J]. 科学通报, 2003, 48(14): 1511-1520. doi: 10.3321/j.issn:0023-074X.2003.14.008
[13] Anderson T. Correction of common lead in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 2002, 192(1/2): 59-79.
[14] Ludwig K R. 3.0-A geochronology cal toolkit for Micro-soft Excel[J]. Berkeley Geochronology Center Special Publication, 2003, (4): 1-70.
[15] 冯志兴, 周吉谦, 杨兵. 青海尕龙格玛矿区火山岩地层对成矿的控制作用[J]. 矿产与地质, 2016, 30(6): 909-916. https://www.cnki.com.cn/Article/CJFDTOTAL-KCYD201606007.htm
[16] 白云山, 牛志军, 段其发, 等. 青海南部治多县扎河一带上三叠统巴塘群火山岩特征及其构造环境[J]. 华南地质与矿产, 2014, 30(4): 319-327. https://www.cnki.com.cn/Article/CJFDTOTAL-HNKC201404003.htm
[17] 唐华, 肖龙, 李欢, 等. 青海省治多县宗可曲地区火山岩特征[J]. 西北地质, 2016, 49(4): 19-31. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDI201604002.htm
[18] 刘银, 李荣社, 计文化, 等. 青海治多地区多彩蛇绿混杂岩带南侧当江荣二叠纪—三叠纪岩浆弧的确定[J]. 地质通报, 2010, 29(12): 1840-1850. http://dzhtb.cgs.cn/gbc/ch/reader/view_abstract.aspx?file_no=20101212&flag=1
[19] 郑宗学, 覃泽礼, 吴远安. 青海治多多彩地区火山岩岩石特征[J]. 西北地质, 2012, 45(1): 63-69. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDI201201012.htm
[20] 吴碧娟, 赖健清, 郑宗学, 等. 尕龙格玛铜锌多金属矿区火山岩特征[J]. 矿产与地质, 2013, 27(4): 283-291. https://www.cnki.com.cn/Article/CJFDTOTAL-KCYD201304004.htm
[21] 冯志兴, 李义邦. 青海尕龙格玛铜多金属矿区侵入岩特征及其控矿作用青海尕龙格玛铜多金属矿区侵入岩特征及其控矿作用[J]. 矿产与地质, 2014, 30(6): 129-142. https://www.cnki.com.cn/Article/CJFDTOTAL-KCYD201402001.htm
[22] 徐佳富, 李青云, 谭俊, 等. 青海治多县多彩铜铅锌矿床蚀变矿化分带性与成因类型[J]. 地质科技情报, 2016, 35(6): 167-176. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ201606024.htm
[23] 侯增谦, 莫宣学, 谭劲, 等. "三江"义敦岛弧带玄武岩喷发序列与裂谷-岛弧转化[J]. 地球学报, 1993, (1): 49-67. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXB199301004.htm
[24] 侯增谦, 杨岳清, 王海平, 等. 三江义敦岛弧碰撞造山过程与成矿系统[M]. 北京: 地质出版社, 2003.
① 青海省地质调查院. 1: 25万治多县区域地质调查报告. 2006.
-
图(4)
表(1)
计量
- 文章访问数: 948
- PDF下载数: 44
- 施引文献: 0