西藏泽当地区晚白垩世埃达克岩的发现及其成矿意义

赵珍; 胡道功; 陆露; 吴珍汉

西藏泽当地区晚白垩世埃达克岩的发现及其成矿意义

1.
中国地质科学院地质力学研究所, 北京 100081
2.
中国地质科学院, 北京 100037

基金项目:

中国地质调查局项目编号：1212011120185

详细信息

作者简介:
赵珍(1987-), 女, 硕士研究生, 构造地质学专业。E-mail:zhaozhen03@126.com

中图分类号: P584
计量
- 文章访问数: 153
- HTML全文浏览量: 124
- PDF下载量: 7
- 被引次数: 0
出版历程
- 收稿日期: 2012-09-23
- 刊出日期: 2013-06-01

DISCOVERY AND METALLOGENIC SIGNIFICANCE OF THE LATE CRETACOUS ADAKITES FROM ZETANG, TIBET

1.
Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China
2.
Chinese Academy of Geological Sciences, Beijing 100037, China

摘要

摘要: 埃达克岩对造山带深部构造和热体制具有指示意义，与Cu、Au等成矿关系密切。冈底斯成矿带东段南缘泽当地区桑布加拉矽卡岩型铜矿成矿母岩花岗闪长岩的主量元素测量结果显示高SiO₂（>56%）、高Al₂O₃（>15%）、低MgO（ < 3%），Na₂O含量≥ 3.5%，K₂O含量>2%，Na₂O/K₂O为1.03~1.43，平均1.22；稀土元素和微量元素测量结果显示高Sr（>400×10^-6），低Yb（ < 1.9×10^-6）、低Y（ < 15×10^-6），高Sr/Y（86.88~132.22，>20）、高La/Yb（>10），LREE富集，HREE亏损，无负Eu异常，为埃达克岩地球化学特征。结合地质特征分析认为其是由俯冲洋壳板片部分熔融后与地幔橄榄岩发生相互作用形成的O型埃达克岩，说明冈底斯南缘存在O型埃达克岩成矿。
- 冈底斯成矿带 /
- 矽卡岩铜矿 /
- 埃达克岩 /
- 晚白垩世
Abstract: Adakites have an indicative significance to deep-seated structures of orogenic belt and thermal regime, and a closely relationship with the minralization of Cu and Au. The metallogenic mother rock of Sangbujiala skarn copper deposit, in Zetang, southern margin of the East Gangdise metallogenic belt is Late Cretaceous granodiorite. The major elements are characterized by higher SiO₂ (>56%), Al₂O₃ (>15%), Na₂O (≥ 3.5%) and K₂O (>2%), lower MgO ( < 3%). Na₂O/K₂O is 1.03~1.43, with an average of 1.22. The analyzing results of race earth and trace elements show higher Sr (>400×10^-6), lower Yb ( < 1.9×10^-6) and Y ( < 15×10^-6), higher Sr/Y (86.88~132.22, >20) and La/Yb (>10), enriched in LREE and depleted in HREE, and no negative anomalies of Eu, similar to those of adakite. By geochemical and geological characteristics, it was may be formed in partial melting of subduction oceanic plate of the O-type adakites, which interacted with mantle peridotite, showing that the southern margin of Gangdise has O-type adakites mineralization.
- Gangdise metallogenic belt /
- skarn copper deposit /
- adakite /
- Late Cretaceous

HTML全文

图 1 泽当地区地质略图

（据1:250000泽当幅改编）

Figure 1. Simplified geological map of Zetang

下载: 全尺寸图片幻灯片

图 2 石TAS图解

Figure 2. TAS classification of the granitoid rocks

下载: 全尺寸图片幻灯片

图 3 K₂O-SiO₂图解

Figure 3. K₂O-SiO₂ diagram

下载: 全尺寸图片幻灯片

图 4 稀土元素配分曲线

Figure 4. REE distribution patterns

下载: 全尺寸图片幻灯片

图 5 微量元素蛛网图

Figure 5. Trace element spider diagrams

下载: 全尺寸图片幻灯片

图 6 埃达克岩Sr/Y-Y和（La/Yb）_N-Yb_N图解

Figure 6. Sr/Y vs. Y diagram and(La/Yb)_N vs. Yb_N diagram for the adakite

下载: 全尺寸图片幻灯片

图 7 埃达克成因判别图

Figure 7. Discrimination diagrams of the adakites sources

下载: 全尺寸图片幻灯片

表 1 样品主量元素和微量元素分析结果

Table 1. Major elements and trace elements of the samples

参考文献(32)

[1]	曲晓明, 侯增谦, 李佑国, 等.冈底斯碰撞造山带中发现含矿埃达克岩[J].矿床地质, 2002, 21(增刊):215~218. http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ2002S1062.htm QU Xiao-ming, HOU Zeng-qian, LI You-guo, et al. Ore-bearing adakites found in the Gangdese collision-orogenic belt[J]. Mineral Deposits, 2002, 21(Supp.):215~218. http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ2002S1062.htm
[2]	曲晓明, 侯增谦, 李振清, 等.冈底斯铜矿带含矿斑岩的⁴⁰Ar/³⁹Ar年龄及地质意义[J].地质学报, 2003, 77(2):245~252. QU Xiao-ming, HOU Zeng-qian, LI Zhen-qing, et al. ⁴⁰Ar/³⁹Ar ages of the ore-bearing porphyries of the Gangdese porphyry copper belt and their geological significances[J]. Acta Geologica Sinica, 2003, 77(2):245~252.
[3]	侯增谦, 莫宣学, 高永丰, 等.埃达克岩:斑岩铜矿的一种可能的重要含矿母岩——以西藏和智利斑岩铜矿为例[J].矿床地质, 2003, 22(1):1~12. http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ200301000.htm HOU Zeng-qian, MO Xuan-xue, GAO Yong-feng, et al. Adakite:A possible host rock for porphyry copper deposits:Case studies of porphyry copper belts in Tibetan Plateau and in northern Chile[J]. Mineral Deposits, 2003, 22(1):1~12. http://www.cnki.com.cn/Article/CJFDTOTAL-KCDZ200301000.htm
[4]	姚鹏, 李金高, 王全海, 等.西藏冈底斯南缘火山-岩浆弧带中桑日群adakite的发现及其意义[J].岩石学报, 2006, 22(3):612~620. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200603010.htm YAO Peng, LIJin-gao, WANG Quan-hai, et al. Discovery and geological significance of the adakite in Gangdise island arc belt, Xizang (Tbibet)[J]. Acta Petrologica Sinica, 2006, 22(3):612~620. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200603010.htm
[5]	康志强, 许继峰, 陈建林, 等.藏南白垩纪桑日群麻木下组埃达克岩的地球化学特征及其成因[J].地球化学, 2009, 38(4):334~344. http://www.cnki.com.cn/Article/CJFDTOTAL-DQHX200904004.htm KANG Zhi-qiang, XU Ji-feng, CHEN Jian-lin, et al. Geochemistry and origin of Cretaceous adakites in Mamuxia Formation Sangri Group, South Tibet[J]. Geochimica, 2009, 38(4):334~344. http://www.cnki.com.cn/Article/CJFDTOTAL-DQHX200904004.htm
[6]	韦栋梁, 夏斌, 周国庆, 等.西藏泽当英云闪长岩的地球化学和Sr-Nd同位素特征:特提斯洋内俯冲的新证据[J].中国科学:D辑, 2007, 37(4):442~450. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK200704001.htm WEI Dong-liang, XIA Bin, ZHOU Guo-qing, et al. Geochemistry and Sr-Nd isotope characteristics of tonalities in Zetang, Tibet:New evidence for intra-Tethyan subduction[J]. Science in China:Series D, 2007, 37(4):442~450. http://www.cnki.com.cn/Article/CJFDTOTAL-JDXK200704001.htm
[7]	杨经绥, 许志琴, 耿全如, 等.中国境内可能存在一条新的高压/超高压(?)变质带——青藏高原拉萨地体中发现榴辉岩带[J].地质学报, 2006, 80(12):3~12. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200612000.htm YANG Jing-sui, XU Zhi-qin, GENG Quan-ru, et al. A possible new HP/UHP (?) Metamorphic Belt in China:Discovery of Eclogite in the Lasha Terrane, Tibet[J]. Acta Geologica Sinica, 2006, 80(12):3~12. http://www.cnki.com.cn/Article/CJFDTOTAL-DZXE200612000.htm
[8]	潘桂棠, 莫宣学, 侯增谦, 等.冈底斯造山带的时空结构及演化[J].岩石学报, 2006, 22(3):521~533. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200603001.htm PAN Gui-tang, MO Xuan-xue, HOU Zeng-qian, et al. Spatial-temporal framework of the Gangdese orogenic belt and its evolution[J]. Acta Petrologica Sinica, 2006, 22(3):521~533. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200603001.htm
[9]	李光明, 冯孝良, 黄志英.西藏冈底斯构造带中段多岛弧盆系及其演化[J].沉积与特提斯地质, 2000, 20(4):38~46. http://www.cnki.com.cn/Article/CJFDTOTAL-TTSD200004003.htm LI Guang-ming, FENG Xiao-liang, HUANG Zhi-ying. The multiple island arc-basin systems and their evolution in the Gangdise tectonic belt, Xizang[J]. Sedimentary Geology and Tethyan Geology, 2000, 20(4):38~46. http://www.cnki.com.cn/Article/CJFDTOTAL-TTSD200004003.htm
[10]	侯增谦, 莫宣学, 杨志明, 等.青藏高原碰撞造山带成矿作用:构造背景、时空分布和主要类型[J].中国地质, 2006, 33(2):348~359. http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200602013.htm HOU Zeng-qian, MO Xuan-xue, YANG Zhi-ming, et al. Metallogenses in the collisional orogen of the Qinghai-Tibet Plateau:Tectonic setting, tempo-spatial distribution and ore deposit types[J]. Geology in China, 2006, 33(2):348~359. http://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200602013.htm
[11]	西藏自治区地质矿产局.西藏自治区区域地质志[M].北京:地质出版社, 1994:1~350. Bureau of Geology and Mineral Resources of the Tibet Autonomous Region. Regional Geology of the Tibet Autonomous Region[M]. Beijing:Geological Publishing House, 1994:1~350.
[12]	赵珍, 胡道功, 吴珍汉, 等.西藏冈底斯东段南缘桑布加拉辉钼矿Re-Os定年及地质意义[J].地质力学学报, 2012, 18(2):178~186. http://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20120208&journal_id=dzlxxb ZHAO Zhen, HUDao-gong, WU Zhen-han, et al. Molybdenite Re-Os Isotopic Dating of Sangbujiala Copper Deopsit in the southern margin of the Gangdese eastern section, Tibet and its geological implications[J]. Journal of Geomechanics, 2012, 18(2):178~186. http://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20120208&journal_id=dzlxxb
[13]	梁华英, 魏启荣, 许继峰, 等.西藏冈底斯矿带南缘矽卡岩型铜矿床含矿岩体锆石U-Pb年龄及意义[J].岩石学报, 2010, 26(6):1692~1698. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201006006.htm LIANG Hua-ying, WEI Qi-rong, XU Ji-feng, et al. Study on zircon LA-ICP-MS U-Pb age of skarn Cu mineralization related intrusion in the southern margin of the Gangdese ore belt, Tibet and its geological implication[J]. Acta Petrologica Sinica, 2010, 26(6):1692~1698. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201006006.htm
[14]	Defant M J, Drummond M S. Derivation of some modern arc magmas by melting of young subduction lithosphere[J]. Nature, 1990, 347:662~665. doi: 10.1038/347662a0
[15]	Martin H. Adakitic magmas:Modern analogues of Archean granitoids[J]. Lithos, 1999, 46(3):411~429. doi: 10.1016/S0024-4937(98)00076-0
[16]	Martin H, Smithies R H, Rapp R, et al. An overview of adakite, tonalite trondhjemite granodiorite (TTG) and sanukitoid:Relationships and some implications for crustal evolution[J]. Lithos, 2005, 79(1-2):1~24. doi: 10.1016/j.lithos.2004.04.048
[17]	张旗, 钱青, 王二七, 等.燕山中晚期的"中国东部高原":埃达克岩的启示[J].地质科学, 2001, 36(2):248~255. http://www.cnki.com.cn/Article/CJFDTOTAL-DZKX200102015.htm ZHANG Qi, QIAN Qing, WANGEr-qi, et al. An East China plateau in Mid-Late Yanshanian period:Implication from adakites[J]. Chinese Journal of geology, 2001, 36(2):248~255. http://www.cnki.com.cn/Article/CJFDTOTAL-DZKX200102015.htm
[18]	Atherton M P, Petford N. Generation of sodium-rich magmas from newly underplated basaltic crust[J]. Nature, 1993, 362:144~146. doi: 10.1038/362144a0
[19]	Muir R J, Weaver S D, Bradshaw J D, et al. Geochemistry of the Cretaceous separation point batholith, New Zealand:Granitoid magmas formed by melting of mafic lithosphere[J]. Journal of the Geological Society, 1995, 152(4):689~701. doi: 10.1144/gsjgs.152.4.0689
[20]	Petford N, Atherton M P. Na-rich partial melts from newlyunderplated basaltic crust:The Cordillera Blanca batholith[J]. Journal of Petrology, 1996, 37(6):1491~1521. doi: 10.1093/petrology/37.6.1491
[21]	Wang Q, Xu J F, Jian P, et al. Petrogenesis of adakitic porphyriesin an extensional tectonic setting, Dexing, South China:implicationsfor the genesis of porphyry copper mineralization[J]. Journal of Petrology, 2006, 47(1):119~144.
[22]	Gao S, Rudnick R L, Yuan H L, et al. Recycling lower continental crust in the North China craton[J]. Nature, 2005, 432(7019):892~897.
[23]	Harrison T M, Copeland P, Kid W F, et al. Raising Tibet[J]. Science, 1992, 255(5052):1663~1670. doi: 10.1126/science.255.5052.1663
[24]	Yin A, Harrison T M. Geologic evolution of the Himalayan-Tibetan orogen[J]. Annual Review of Earth and Planetary Sciences, 2000, 28:211~280. doi: 10.1146/annurev.earth.28.1.211
[25]	England P, Houseman G. Extension during continental convergence with application to the Tibetan plateau[J]. Journal of Geophysical Research:Solid Earth and Planets, 1989, 94(B12):17561~17579. doi: 10.1029/JB094iB12p17561
[26]	Rapp R P, Shimizu N, Norman M D, et al. Reaction between slab-derived melts and peridotite in the mantle wedge:Experimental constraints at 3.8GPa[J]. Chemical Geology, 1999, 160:335~356. doi: 10.1016/S0009-2541(99)00106-0
[27]	Kay R W. Aleutian magnesiumandesites:Meltsfromsubducted Pacificoceaniccrust[J]. Journal of Volcanology and Geothermal Research, 1978, 4:117~132. doi: 10.1016/0377-0273(78)90032-X
[28]	Rapp R P, Watson E B, Miller C F. Partial melting of amphibolites/eclogite and the origin of Archean trondhjemites and tonalities[J]. Precambrian Research, 1991, 51:1~25. doi: 10.1016/0301-9268(91)90092-O
[29]	Rapp R P, Watson E B. Dehydration melting of metabasalt at 8~32 kbar:Implications for continental growth and crust-mantle recycling[J]. Journal of Petrology, 1995, 36(4):891~931. doi: 10.1093/petrology/36.4.891
[30]	Sen C, Dunn T. Dehydration melting of a basaltic composition amphiobolite at 1.5 and 2.0 GPa:Implications for the origin of adakites[J]. Contributions to Mineralogy and Petrology, 1994, 117(4):394~409. doi: 10.1007/BF00307273
[31]	Thieblemont D, Stein G, Lescuyer J L. Gisements epothetmaux et porphyriques:la connexion adakite[J]. Earth Planet.Sci, 1997, 325:103~109.
[32]	杜光伟, 程力军, 赵咸明.西藏冈底斯东段地球化学特征及其找矿意义[J].西藏地质, 2001, 19(1):73~79. http://cdmd.cnki.com.cn/Article/CDMD-11415-2006065143.htm DU Guang-wei, CHENG Li-jun, ZHAO Xian-ming. Geochemical features of the East Gangdise, Tibet and their prospecting significance[J]. Tibet Geology, 2001, 19(1):73~79. http://cdmd.cnki.com.cn/Article/CDMD-11415-2006065143.htm