The formation age of the kimberlite zone in Poli area of Mengyin, Shandong Province: Zircon U-Pb dating data of diabase
-
摘要:
金伯利岩是化学成分、矿物组成和结构多变的混杂岩,极易发生蚀变,因此对金伯利岩全岩及各种矿物进行测年的方法很难确定金伯利岩的侵位年龄,且数据结果差别很大。通过分析蒙阴坡里金伯利岩带与辉绿岩的侵入关系,以及辉绿岩锆石U-Pb测年,结合辉绿岩与上覆灰岩的接触关系及金刚石砂矿储集层与已知金刚石原生矿的关系,确定辉绿岩脉的侵位时代为中生代燕山晚期,证实坡里金伯利岩带形成时代为中生代燕山晚期而非加里东期。
Abstract:Kimberlite is a kind of melange with changeable chemical composition, mineral composition and structure and tends to be altered. Therefore, it is difficult to determine the emplacement age of kimberlite by dating kimberlite whole rock and all kinds of minerals, and the data obtained are very different. In this paper, the intrusive relationship between kimberlite zone and diabase in Poli of Mengyin was analyzed. Through dating the zircon U-Pb in diabase and studying the contact relationship between diabase and overlying limestone as well as the relationship between diamond sand reservoir and known diamond protoores, the emplacement age of diabase vein was determined to be the Late Yanshanian period of Mesozoic. Therefore, it is proved that the Poli kimberlite belt was formed in Late Yanshanian rather than in Caledonian period.
-
Key words:
- kimberlite belt /
- formation period /
- Mesozoic /
- Poli area
-
-
图 1 坡里金伯利岩带分布[13]
Figure 1.
表 1 测试条件
Table 1. Summary of test conditions
技术指标 参数 激光电压/kV 23~29 激光能量/J·cm2) 10.2 载气流速(ml·min-1) 745 剥蚀次数/次 500 激光频率/Hz 9 束斑直径/μm 30/20 激光能量透过率/% 75 截取透镜(V) 140 雾化器(l/min) 0.760 U(cps) > 3×105 Th/U ≈1.0 表 2 蒙阴坡里辉绿岩锆石U-Th-Pb测年分析结果
Table 2. The results of the zircon U-Th-Pb dating analysis of the diabase in Poli of Mengyin
样号 Pb Th U 207Pb/206Pb 207Pb/235U 206Pb/238U 208Pb/232Th 207Pb/206Pb 207Pb/235U 206Pb/238U 208Pb/232Th 谐和度 10-6 10-6 10-6 比值 1 σ 比值 1 σ 比值 1 σ 比值 1 σ 年龄/Ma 1 σ 年龄/Ma 1 σ 年龄/Ma 1 σ 年龄/Ma 1 σ 1 76.079 38.057 83.811 0.226 0.012 16.467 0.728 0.519 0.009 0.579 0.0393 3021 81 2904 42 2696 39 9238 503 92% 2 53.504 28.869 90.2661 0.163 0.004 10.896 0.282 0.484 0.0078 0.179 0.0079 2483 42 2514 24 2547 34 3332 136 98% 3 194.438 194.369 387.736 0.168 0.004 9.221 0.327 0.394 0.0114 0.122 0.0044 2543 37 2360 33 2142 53 2332 79 90% 4 268.238 309.890 531.286 0.163 0.017 8.227 0.408 0.363 0.0089 0.267 0.0429 2487 176 2256 45 1998 42 4791 685 87% 5 204.267 193.460 540.218 0.160 0.003 7.109 0.161 0.320 0.0058 0.108 0.0033 2461 35 2125 20 1791 28 2072 60 82% 6 167.254 183.344 517.917 0.174 0.003 6.323 0.135 0.262 0.0032 0.079 0.0022 2594 32 2022 19 1502 16 1536 41 70% 7 222.876 591.128 653.885 0.147 0.003 5.482 0.125 0.268 0.0034 0.058 0.0016 2314 35 1898 20 1532 17 1118 30 78% 8 442.952 1002.751 960.304 0.344 0.015 10.632 0.396 0.225 0.0047 0.189 0.0070 3670 69 2492 35 1308 25 3496 119 37% 10 74.758 146.663 280.781 0.091 0.002 2.892 0.081 0.231 0.0042 0.067 0.0020 1439 46 1380 21 1337 22 1303 39 96% 11 79.646 79.047 112.431 0.136 0.008 9.196 0.250 0.498 0.0072 0.212 0.0131 2176 98 2358 25 2604 31 3888 219 90% 12 363.162 154.543 279.508 0.377 0.009 32.198 0.927 0.614 0.0099 0.849 0.0286 3820 37 3556 28 3087 39 12420 312 85% 14 237.477 1733.793 2191.428 0.154 0.005 1.780 0.066 0.083 0.0022 0.028 0.0016 2395 52 1038 24 515 13 549 27 32% 9 1.853 68.147 81.843 0.058 0.011 0.131 0.019 0.018 0.0009 0.005 0.0005 522 411 125 18 117 6 106 9 92% 13 7.779 225.29 325.240 0.051 0.003 0.129 0.007 0.019 0.0004 0.007 0.0003 256 142 123 6 121 3 132 6 98% 表 3 测年结果
Table 3. Summary of dating results
岩性 方法 年龄/Ma 测试单位 测年时间 斑状富金云母金伯利岩 企岩K-Ar 371.8 屮科院地球化学研究所 1968年 斑状富金云母金伯利岩 企岩K-Ar 233.8 成都地质学院 1988年 富金云母金伯利岩 企岩K-Ar 379 地矿部宜昌地研所 1988年 斑状富金云母金伯利岩 Sm-Nd法 479±32 地矿部宜昌地研所 1988年 斑状金伯利岩 锆石U-Pb 1452.8 地矿部宜昌地研所 1989年 -
[1] 孔庆友, 张天祯, 于学峰, 等.山东矿床[M].济南:山东科学技术出版社, 2006:473-474.
[2] 尹作为, 路凤香, 陈美华, 等.山东蒙阴金刚石的形成时代及地质环境[J].地学前缘, 2005, 12(4):614-621. doi: 10.3321/j.issn:1005-2321.2005.04.034
[3] 张宏福, 杨岳衡.华北板块东部含金刚石金伯利岩的侵位年龄和Sr-Nd-Hf同位素地球化学特征[J].岩石学报, 2007, 23(2):285-290. http://www.cnki.com.cn/Article/CJFDTotal-YSXB200702010.htm
[4] 王照波, 王庆军.华北板块东缘金刚石成矿区域地质背景分析与成矿预测[J].山东国土资源, 2014, 30(10):8-14. doi: 10.3969/j.issn.1672-6979.2014.10.004
[5] 吕青, 葛跃进.对金伯利岩测年方法和测年样品的探讨[J].山东国土资源, 2016, 32(10):12-16. doi: 10.3969/j.issn.1672-6979.2016.10.003
[6] Li Q L, Li X H, Liu Y, et al. Precise U-Pb and Th-Pb age determination of kimberlitic perovskites by secondary ion mass spectrometry[J]. Chemical Geology, 2010, 269:396-405. doi: 10.1016/j.chemgeo.2009.10.014
[7] Yang Y H, Wu F Y, Wilde S A, et al. In situ perovskite Sr-Nd isotopic constraints on the petrogenesis of the Ordovician Mengyin kimberlites in the North China Craton[J]. Chemical Geology, 2009, 264:24-42. doi: 10.1016/j.chemgeo.2009.02.011
[8] 王瑛, 凌文黎, 路凤香, 等.山东省蒙阴金伯利岩侵位年代研究新成果[J].地质科技情报, 1997, 16(3):8-12.
[9] 罗声宣, 任喜荣, 朱源, 等.山东金刚石地质[M].济南:山东科技出版社, 1999:87-88.
[10] 杨斌, 马祥县, 唐璐璐, 等.山东省蒙阴地区金刚石原生矿形成时代的讨论[J].山东国土资源, 2015, 31(4):19-22. doi: 10.3969/j.issn.1672-6979.2015.04.004
[11] 周登诗, 王伟德, 杨道荣, 等.钻石之路[M].北京:地质出版社, 2015:46-48.
[12] 张增齐, 张成基, 王世进, 等.山东省地层侵入岩构造单元划分对比意见[J].山东国土资源, 2014, 30(3):6-9. http://d.old.wanfangdata.com.cn/Periodical/sddz201403001
[13] 宋瑞祥.中国金刚石矿床专论[M].北京:地质出版社, 2013:177-179.
[14] 王照波, 吕青, 葛跃进, 等.论"牛岚构造体系"特征及其对蒙阴金伯利岩带的控制[J].山东国土资源, 2013, 29(10):1-5. doi: 10.3969/j.issn.1672-6979.2013.10.001
[15] 杨斌, 孙秀珠, 罗文强, 等.三论蒙阴地区金刚石原生矿的形成时代[J].山东国土资源, 2016, 32(9):14-16. doi: 10.3969/j.issn.1672-6979.2016.09.004
[16] Liu S, Hu RZ, Zhao J H, et al. K-Ar geochronology of Mesozoic mafic dikes in Shandong Province, Eastern China:Implications for crustal extension[J]. Acta Geol. Sinica, 2005, 78(6):1207-1213. https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1755-6724.2004.tb00777.x
[17] 杨超, 唐菊兴, 郑文宝, 等.藏南扎西康锌多金属矿床辉绿岩锆石U-Pb年代学、岩石地球化学特征研究[J].有色金属, 2014, 66(5):30-37. http://d.old.wanfangdata.com.cn/Periodical/ysjs-ks201405008
[18] 陈岳龙, 罗照华, 赵俊香, 等.从锆石SHRIMP年龄及地球化学特征讨论四川冕宁康定杂岩的成因[J].中国科学, 2004, 34(8):687-697. http://www.cnki.com.cn/Article/CJFDTotal-JDXK200408000.htm
[19] Jackson K A, Horoi M, Chaudhuri I, et al.Unraveling the shape transformation in silicon clusters[J]. Physical Reviev Letters, 2004, 93(1):1-4. http://d.old.wanfangdata.com.cn/NSTLQK/10.1103-PhysRevLett.93.013401/
[20] Anderson T.Correction of common Pb in U-Pb analvses that do not report 204Pb[J]. Chemical Geology, 2002, 192:59-79. doi: 10.1016/S0009-2541(02)00195-X
[21] Ludwig K R. User's Manual for isoplot 3.00[J]. Berkelcy Geochronology Center Special Publication, 2003, 4:315-320.
[22] 侯贵廷, 刘玉琳, 李江海, 等.关于基性岩墙群的U-Pb SHRIMP地质年代学的探讨——以鲁西莱芜辉绿岩岩墙为例[J].岩石矿物学杂志, 2005, 24(3):179-185. doi: 10.3969/j.issn.1000-6524.2005.03.003
[23] 路凤香, 赵磊, 邓晋福, 等.华北地台金伯利岩岩浆活动时代讨论[J].岩石学报, 1995, (4):365-374. doi: 10.3321/j.issn:1000-0569.1995.04.009
[24] 侯贵廷, 李江海, 金爱文, 等.鲁西前寒武纪基性岩墙[J].地质学报, 2005, 79(2):190-199. doi: 10.3321/j.issn:0001-5717.2005.02.006
[25] 王世进, 万喻生, 张成基, 等.鲁西地区早前寒武纪地质研究新进展[J].山东国土资源, 2008, 24(1):10-20. doi: 10.3969/j.issn.1672-6979.2008.01.005
[26] 甘延景, 张荣隋, 金爱文.鲁西地区中元古代四堡期辉绿岩基本特征——以蒙阴野店及费县高家围子地区为例[J].山东地质, 2002, 18(2):20-23. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=sddz200202009
[27] 赵秀芳.鲁西白彦砾岩中金刚石特征及来源探讨[J].山东国土资源, 2016, 32(4):27-31. doi: 10.3969/j.issn.1672-6979.2016.04.006
① 朱源, 毛志海.山东金伯利岩同位素地质学研究.山东省地矿局第七地质队. 1989: 35-36.
-