沱沱河地区多才玛铅锌矿晶屑熔结凝灰岩锆石SHRIMP年龄及岩石地球化学特征
SHRIMP Zircon U-Pb Ages and Its Geological Significance of CrystalIgnimbrite in the Duocaima Pb-Zn Deposit, Tuotuohe Area
-
摘要: 多才玛铅锌矿是近年来沱沱河地区发现的一处超大型铅锌矿床,位于青藏高原东北部的东羌塘地块。恶劣的气候条件以及矿床发现时间晚,造成该地区地质研究程度极低。笔者重点对容矿围岩之一的晶屑熔结凝灰岩进行了SHRIMP锆石U-Pb测年和岩石化学成分分析。研究表明,晶屑熔结凝灰岩中锆石呈自形-半自形,发育典型的岩浆锆石振荡生长环带,Th/U值较高(0.39~0.69),为典型的岩浆锆石。测得晶屑熔结凝灰岩U-Pb加权平均年龄为(254.0±2.9) Ma, MSWD=1.9;谐和年龄值为(254.0±3) Ma,MSWD=1.9,属海西末期。岩石化学成分表现为高硅过铝、贫钙和镁,明显富集Rb、Th、U等大离子亲石元素,强烈亏损P、Ti、Nb、Ta等高场强元素,富集LREE,Nb/Ta值(7.78~8.29)等特征表现为壳源岩浆和弧火山岩特征。综合分析认为,254 Ma±时期本区处于深俯冲消减阶段。
-
关键词:
- 晶屑熔结凝灰岩 /
- 锆石SHRIMP年龄 /
- 地球化学特征 /
- 多才玛
Abstract: The DuocaimaPb-Zn deposit, is a super-large scale Pb-Zn deposit found in Tuotuohe area recently, which is located in the East Qiangtang Block of Northeast Qinghai-Tibet Plateau.Because the adverse weather conditions in this exploration area, the researches on this depositare very low, especially magmatic evolution and tectonic setting. In this paper, the zircon SHRIMP U-Pb age and geochemical compositions of crystal ignimbrites from this deposit have beentested.The zircons of crystal ignimbrite mainly show euhedral and hypidiomorphic texture, with clear ring and high Th/U ratios (0.39~0.69), which belong to the typical magmatic zircons.The dating results show that the 206Pb/238U average weighted age of these crystal ignimbrites is(254.0±2.9) Ma (MSWD=1.9), and their concordant agesare (254.0±2.9) Ma (MSWD=1.9). The geochemical data suggest that these crystal ignimbrites are enriched in large ion lithophile elements (LILE)and LREE, strongly depleted in high field-strength element (HFSE). The trace elements ratios, such as Nb/Ta ratio (7.78-8.29), showthat these crystal ignimbrites belong to arc volcanic rocks, which are derived from the crustalmaterials.Combined with regional geological information, the new geochemical and geochronology datareveal that this research area was experienced the consistent subduction stage in 254Ma±.-
Key words:
- crystal ignimbrite /
- zircon SHRIMP dating /
- geochemical characteristics /
- Duocaima
-
-
许志琴,杨经绥,李海兵.造山的高原一青藏高原的地体拼合、碰撞造山及隆升机制[M].北京:地质出版社,2007.
XU Zhiqin, YANG Jingsui,LI Haibing.Orogenic Plateau-TerraneAmalgamation,collision and Uplift in the Qinghai-Tibet Plateau[M]. Beijing: Geological Publishing House, 2007.
宋玉财,侯增谦,杨天南,等."三江"喜马拉雅期沉积岩容矿贱金属矿床基本特征与成因类型[J].岩石矿物学杂志,2011,30(3):355-380.
SONG Yucai,HOU Zengqian,YANG Tiannan,et al. Sediment-hosted Himalayan base metal deposits in Sanjiangregion:characteristics and genetic types[J].Acta Petrologica et Mineralogical,2011,30(3):355-380.
刘长征,李世金,高永旺,等.三江多才玛超大型铅锌矿床同位素地球化学及矿源研究[J]. 中山大学学报(自然科学版),2015,54(1):136-144.
LIU Changzheng,LI Shijin,GAO Yongwang,et al.Isotopic Geochemistry and origin of the Duocaima Lead-Zinc Deposit in the NorthternSanjiang Area.[J].Acta Scientiarum Naturalium Universitatis Sunyatseni, 2015,54(1):136-144.
侯增谦,宋玉财,李政,等,青藏高原碰撞造山带Pb-Zn-Ag-Cu矿床新类型:成矿基本特征与构造控矿模型[J]. 矿床地质,2008,27(2):123-144.
HOU Zengqian, SONG Yucai, LI Zheng,et al. Thrust-controlled,sediments-hosted Pb-Zn-Ag-Cu deposits in eastern and northern margins of Tibetan orogenicbelt:Geological features and tectonic model[J]. Mineral Deposits, 2008, 27(2):123-144.
刘长征,陈岳龙,许光,等.地球化学块体理论在青海沱沱河地区铅锌资源潜力预测中的应用[J].地学前缘,2011,18(5),271-282.
LIU Changzheng,CHEN Yuelong,XU Guang,et al.The application of geochemical block theory to lead and zinc resources assessment in Tuotuohe area of Qinghai Province[J].Earth Science Frontiers,2011,18(5):271-282.
钱烨.青藏高原沱沱河地区成矿背景及铅锌成矿作用[D].长春:吉林大学,2014.
QIAN Ye.Metallogenic Setting and Metallogenesis of Lead and Zinc in Tuotuo Region, Qinghai-Tibet Plateau[D].Chang chun:Jilin University, 2014.
宋彪,张玉海,万渝生,等.锆石SHRIMP样品靶制作、年龄测定及有关现象讨论[J].地质论评,2002,48(增刊):26-30.
SONG Biao,ZHANG Yuhai,WAN Yusheng,et al. Mount Making and Procedure of the SHRIMP Dating[J]. Geological Review, 2002,48(Supp.):26-30.
曹花花.珲春地区晚海西期辉长岩-闪长岩的形成时代和地球化学[D].长春:吉林大学,2010.
CAO Huahua.Chronology and Geochemistry of Late Hercynian Gabbro and Diorite in HunchunArea[D].Changchun:Jilin University, 2010.
边千韬,沙金庚,郑祥身.西金乌兰晚二叠一早三叠世石英砂岩及其大地构造意义[J].地质科学,1993,28(4):327-335.
BIAN Qiantao,SHA Jingeng,ZHENG Xiangshen. The Late Permian-Early Triassic beach-subfaciesquartzose sandstone in the Xijin Ulan Area and its tectonic significance[J]. Scientia Geological Sinica, 1993,28(4): 327-335.
杨延乾,李碧乐,许庆林,等. 东昆仑埃坑德勒斯特二长花岗岩锆石U-Pb定年及地质意义[J]. 西北地质,2013, 46(1):56-62.
YANG Yanqian, LI Bile, XU Qinglin, et al.Zircon U-Pb Ages and Its Geological Significance of the Monzonitic Granite in the Aikengdelesite,Eastern Kunlun[J]. Northwestern Geology, 2013,46(1):56-62.
李善平,马海州,沈存祥,等. 青藏高原北羌塘盆地结扎乡一带二叠系尕笛考组火山岩的特征及构造环境[J]. 西北地质,2008,41(2):31-40.
LI Shanping, MA Haizhou, SHEN Cunxiang, et al. Geochemical Characteristics and Tectonic of Volcanic Rocks of the Permian GadikaoGormation in the JiezhaArea,NorthernQiangtang,Qinghai-Tibet Plateau[J]. Northwestern Geology, 2008, 41(2):31-40.
朱迎堂,伊海生,王强,等. 青海西金乌兰还东河中二叠世埃达克岩的发现及其意义[J]. 沉积与特提斯地质,2004,24(2):30-34.
ZHU Yingtang, YI Haisheng, WANG Qiang, et al. The discovery and significance of the Middle Permian adakites along the Huandong River north of the Xijir Ulan Lake,Qinghai[J]. Sedimentary Geology And Tethyan Geology, 2004, 24(2):30-34.
伍新和,王成善,伊海生,等.西藏羌塘盆地中生界烃源岩探讨[J].西北地质, 2005, 38 (4): 78-85.
WU Xinhe, WANG Chengshan, YI Haisheng, et al. Discussion on Mesozoic source rock of Qiangtang basin in Tibet[J].Northwestern Geology, 2005, 38 (4): 78-85.
张修政,董永胜,李才,等. 羌塘中部晚三叠世岩浆活动的构造背景及成因机制——以红脊山地区香桃湖花岗岩为例[J]. 岩石学报,2014,30(2):547-564.
ZHANG Xiuzheng,DONG Yongsheng,LI Cai,et al. Tectonic setting and petrogenesis mechanism of Late Triassic magmatism in Central Qiangtang,TibetanPlateau:Take the Xiangtaohu pluton in the Hongjishan region as an example[J]. Acta Petrologica Sinica, 2014, 30(2):547-564.
陈健,李建放,安勇胜,等. 风火山地区西金乌兰湖-金沙江蛇绿构造混杂带的物质组成及发展演化特征[J]. 西北地质,2007,40(3):36-43.
CHEN Jian,LI Jianfang,AN Yongsheng,et al. Xijinwulan Lake-Jinsha River OphioliteMelange Zone and Its Evolution in the Fenghuo Mountain Area[J]. Northwestern Geology,2007,40(3):36-43.
李才.龙木错-双湖-澜沧江板块缝合带与石炭二叠纪冈瓦纳北界[J]. 长春地质学院学报,1987,17(2):155-166.
LI Cai.The Longmucuo-Shuanghu-Lancangjiang Plate Suture and the north boundary of distribution of Gongdwanafaciespermo-carboniferous system in Northern Xizang,China[J].Journal of Changchun College of Geology, 1987, 17(2):155-166.
李才,翟庆国,董永胜,等. 青藏高原羌塘中部榴辉岩的发现及其意义[J]. 科学通报,2006,51(1):70-74.
LI Cai,ZHAI Qingguo,DONG Yongsheng,et al.The discovery of the eclogitein the Central Qiangtang,Qinghai-Tibet Plateauand its significance[J]. Chinese Science Bulletin, 2006, 51(1):70-74.
李才,黄小鹏,牟世勇,等. 藏北羌塘南部走构由茶错地区火山岩定年与康托组时代的厘定[J]. 地质通报,2006,25(1-2):226-228.
LI Cai,HUANG Xiaopeng,MOU Shiyong,et al.Age dating of the Zougouyouchacuo volcanic rocks and age determination of the Kangtog Formation in southern Qiangtang,northernTibet,China.[J]. Geological Bulletin of China, 2006,25(1-2):226-228.
汪啸风,陈孝红. 中国奥陶纪古生物地理与古气候[J]. 地层古生物论文集,1999,(27):1-27.
WANG Xiaofeng, CHEN Xiaohong. Palaeobiogeography and Palaeoclimatology of Ordovician in China[J]. Professional Papers Of Stratigraphy Paleontology And Palaeontology, 1999, (27):1-27.
李勇,王成善,伊海生.西藏金沙江缝合带西段晚三叠世碰撞作用与沉积响应[J].沉积学报,2003,21(2):191-197.
LI Yong,WANG Chengshan,YI Haisheng. The Late Triassic Collision and Sedimentary Responses at Western Segment of JinshajiangSuture,Tibet.[J]. Acta Sedimentologica Sinica, 2003,21(2):191-197.
BLACK L P,KAMO S L,ALLEN C M,et al.TEMORA1:A New Zircon Standard for Phanerozoic U-PbGeochronology[J].Chemical Geology,2003,200(1-2):155-170.
NASDALA L,HOFMEISTER W G,NORBERGN,et,al.Zircon M527:A Homogeneous Natural Reference Material for the Ion Microprobe U-Pb Analysis of Zircon[J].Geoanalytical Research,2008,32(3):247-265.
COMPOSTON W,WILLIAMSIS,MEYER C.U-Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass-resolution ion microprobe. Chinese Journal of Geophysics[J]. 1984,89(supp.):525-534.
HOSKIN P W O,BLACK L P.Metamorphic zircon formation by solidstate recrystallization of protolith igneous zircon[J]. Journal of Metamorphic Geology, 2000,18(4):423-439.
WANG H, MO X.An outline of tectonic evolution of China[J].Episodes,1995,18(1-2):6-16.
MO Xuanxue,LU Fengxiang,SHEN Shangyue,etal.San-jiang Tethyan volcanism and related mineralization[M].Beijing:Geological Publishing House,1993.
ZHONG Dalai.PaleoTrthyanorogenic belt in West Sichuan and West Yunnan[M].Beijing:Science Press,1998.
PAN Guitang,XU Qiang,HOU Zengqian, et al.Archipe-lagicorogenesis,metallogenicsustems and assessment of the mineral resources along the NujiangLancangjiangJinshajinag area in southwestern China[M].Beijing:Geological Publishing House,2003.
ZHANG J X,YANG J S,MENG F C,et al.U-Pb isotopic studies of eclogites and their host gneisses in the Xitieshan area of the North Qaidammountains,westernChina:New evidence for an early Paleozoic HP-UHP metamorphic belt[J]. Journal of Asian Earth Sciences,28(2-3):143-150.
KAPP P,YIN A,GRAIGE,et al.Blueschist-bearing metamorphic core complexes in Qiangtang block reveal deep crustal structure of northern Tibet[J].Geology, 2000,28(1):19-22.
KAPP P,YINA,GRAIG E et al.Tectonic evolution of the Early Mesozoic blueschist-bearing Qiangtangmetermorphicbelt,centralTibet[J].Tectonies, 2003,22(4):1029-1043.
GREEN T H. Significance of Nb/Ta as An Indicator of Geochemical Processes in the Crust-mantle System[J].Chemical Geology, 1995,120(3-4):347-359.
JIANG Y H, LIU Z, JIA R Y, et al. Miocene Potassic Granite-Syenite Association in Western Tibetan Plateau: Implications for Shoshonitic and High Ba-Sr Granite Genesis[J]. Lithos, 2012, 134-135: 146-162.
-
计量
- 文章访问数: 2487
- PDF下载数: 2000
- 施引文献: 0
下载: