岩石学报  2014, Vol. 30 Issue (9): 2725-2738   PDF    
澜沧江构造带南段变质岩系锆石U-Pb年代学及构造涵义
王丹丹1,2, 李宝龙3, 季建清4 , 刘昱恒5    
1. 中国地质大学能源学院, 北京 100083;
2. 中国地质调查局油气资源调查中心, 北京 100029;
3. 中国地质科学院矿产资源研究所, 成矿作用与资源评价国土资源部重点实验室, 北京 100037;
4. 北京大学地球与空间科学学院, 造山带与地壳演化教育部重点实验室, 北京 100871;
5. 中国地质大学地球科学与资源学院, 北京 100083
摘要:澜沧江构造带南段的古老变质岩系因临沧花岗岩基的大面积出露而呈零星分散状出露,该地区是否存在前寒武纪结晶基底和变质岩系的精确时代以及澜沧江构造带变质岩系的变质时限等问题还不是很清楚。本文以变质岩系为研究对象,挑选出锆石颗粒进行U-Pb SHRIMP定年,获得锆石核部U-Pb年龄是1802Ma、1404Ma、1092Ma、906~961Ma、812Ma和727~623Ma,时代为古元古代、中元古代和新元古代,揭示研究区存在前寒武纪的结晶基底,三叠纪(~230Ma)发育区域性岩浆作用事件,破坏改造了其结晶基底;昌宁-耈街剖面近澜沧江岸边花岗质片麻岩的锆石U-Pb谐和年龄为73.9±1.8Ma(MSWD=1.3,N=6),记录澜沧江构造带变质岩经历了晚白垩世变质事件。综合研究认为澜沧江构造带南段存在区域性前寒武纪结晶基底,构造带中昌宁段之变质岩系的变质时间为晚白垩世(85~74Ma),并一直持续到36Ma,约32Ma之后构造带发生走滑运动,变质事件明显早于走滑运动事件。
关键词变质岩系     锆石U-Pb年代学     前寒武纪结晶基底     晚白垩世     澜沧江构造带南段    
Zircon SHRIMP U-Pb geochronology and it tectonic implication of the metamorphic rocks in southern Lancang River tectonic zone, West Yunnan Province
WANG DanDan1,2, LI BaoLong3, JI JianQing4 , LIU YuHeng5    
1. School of Energy Resources, China University of Geosciences, Beijing 100083, China;
2. Oil and Gas Survey, China Geological Survey, Beijing 100029, China;
3. MLR Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resource, China Academy of Geological Sciences, Beijing 100037, China;
4. MOE Key Laboratory of Orogenic and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China;
5. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
Abstract: The metamorphic rock series located in the southern Lancang River tectonic zone was distributed as sporadic scattered due to large area of the Lincang granite batholiths outcrops. In the study area, several scientific problems are still not very clear such as the Precambrian crystalline basement exists or not, the age of the ancient metamorphic rocks, the metamorphic time of metamorphic rocks in the Lancang River tectonic zone, and so on. In this paper, the metamorphic rocks were taken as the study objects and yielded the U-Pb ages of 1802Ma, 1404Ma, 1092Ma, 1054Ma, 906~961Ma, 812Ma and 727~623Ma using the zircon U-Pb SHRIMP dating method. These ages belong to Early Proterozoic, Mesoproterozoic and Neoproterozoic era and also reveal the existence of Precambrian crystalline basement in the study area, and the Precambrian crystalline basement was destroyed or transformed by a period regional Triassic magmatic event (~230Ma). The granitic gneiss of Changning-Goujie section cross the Lancang River yielded the zircon U-Pb SHRIMP concordia age of 73.9±1.8Ma (MSWD=1.3, N=6), which was the record of Late Cretaceous metamorphic event in the Lancang River tectonic zone. Based on this study and combined with the other research data, it is suggested that the southern Lancang River area had the Precambrian crystalline basement existence and the metamorphic time of the Lancang River tectonic zone began in Late Cretaceous (85~74Ma). This metamorphic event probably continued until 36Ma, and the strike-slip movements started from ~32Ma. So the metamorphic structural event was earlier than the strike-slip geological event in the Lancang River tectonic zone.
Key words: Metamorphic rock series     Zircon U-Pb geochronology     Precambrian Crystalline basement     Late Cretaceous     Southern Lancang River tectonic zone    

1 引言

澜沧江构造带地处欧亚板块与印度板块的结合部位,是古特提斯构造域的重要组成部分,在中国西南“三江”古特提斯构造演化中具有重要的研究意义(赵靖等, 1994ab冯庆来等,2002)。印度板块向欧亚板块之下的俯冲、欧亚岩石圈收缩增厚和沿岩石圈尺度走滑断裂带滑移的陆块侧向挤出等模式(Tapponnier et al., 1986; Dewey et al., 1989; Houseman and England ,1993; Yin and Harrison, 2000)都不可回避的需要考虑澜沧江构造带活动史和变质岩系的变质时限及其剥露机制和过程。同时,研究区内因大面积临沧花岗岩基出露和众多金属矿床,吸引了地质学者对其岩石学、年代学、地球化学、地球动力学和盆山耦合及区域构造对比等方面进行研究(彭头平,2006彭头平等,2006施小斌等, 2006ab杨岳清等,2006刘德利等,2008范蔚茗等,2009李元庆,2009陈珲等,2010杨鑫等,2010李钢柱等, 20112012王硕,2011王保弟等,2011孙会磊,2011米云川等,2012张彩华等,2012孙会磊等,2012王硕等,2012钟维敷等,2012许志琴等,2013张海等,2013)。然而本区的前寒武纪变质岩系的研究相对薄弱,且元古代变质岩系在滇西地区分布广泛特点显著,基本上都呈有规律的N-S或NW-SE向带状展布(图 1a)。澜沧江构造带南段变质岩系自北而南主要由中元古界崇山群、上元古界澜沧群和西盟群以及中元古界大勐龙群变质岩系组成(云南省地质矿产局,1990)。澜沧江构造带南段是否存在前寒武纪结晶基底、基底年龄和分布范围、变质岩系的变质时代和构造演化史及其与走滑运动的关系等关键科学问题还不是很清楚;这些都制约着滇西地区变质岩系的变质时代和剥露机制及时限的相关研究,也影响着对古特提斯构造演化的认识。

图 1 滇西澜沧江构造带地质简图(据谢力华,2000修编) 1 -古元古代陆壳变质地体;2-中、新元古代至寒武纪早期陆壳变质地体;3-古生代复理石与细碧角斑岩建造;4-裂谷;5-地台;6-印支期岛弧;7-中、新生代后碰撞裂陷;8-汇聚边界;9-断层;10-基性火山岩;11-中基性火山岩;12-酸性火山岩;13-基性岩;14-超基性岩;15-花岗岩;16-采样点 Fig. 1 Simplified geological map of the Lancang River zone,West Yunnan(modified after Xie,2000)
1-Paleoproterozoic crust metamorphic terrane; 2-Meso-Neoproterozoic to Early Cambrian crustal metamorphic terrane; 3-Paleozoic flysch and fine keratophyre construction; 4-rift; 5-platform; 6-Indosina arc; 7-Mesozoic-cenozoic rift after collision; 8-convergence boundary; 9-fault; 10-basic volcanic rocks; 11-intermediate-basic volcanic rocks; 12-acidic volcanic rocks; 13-basic rocks; 14-ultrabasic rocks; 15-granite; 16-sample location

本研究选取澜沧江构造带南段作为研究区,通过详细的野外地质考察,采集昌宁-耉街剖面近澜沧江边的崇山群、西盟群和景洪南端的大勐龙群的变质岩作为研究对象,进行锆石U-Pb年代学测试分析,并收集和整理研究区的最新研究成果和锆石SHRIMP U-Pb年代学数据,以期获得古老变质岩群的时代、变质岩系的变质年龄,并探讨其地质意义和区域构造演化。 2 地质背景

澜沧江构造带是“三江”构造带的重要组成部分,位于特提斯-喜马拉雅构造域三江褶皱系中南部,主体部分集中在澜沧江断裂及其附近的呈南北向展布的狭长地带。在区域构造上,其东侧是昌都-思茅地块,西侧是属缅泰马微大陆的保山地块(图 1b)。研究区地处扬子板块西缘的思茅地块和保山地块的结合部位。至少从早二叠世开始,特提斯澜沧江洋盆在扩张的同时,向东俯冲消减,形成了一系列近南北向的构造带(莫宣学等, 19931998朱勤文等,1991朱勤文,1993)。

澜沧江构造带呈北北西向沿澜沧江分布,东界为澜沧江大断裂,西界是崇山断裂与昌宁-孟连古洋盆。其内分布地层主要为一套中元古-古生代的变质岩系,变质岩带中发育有一条延伸达600km以上,平均宽度25km的花岗岩类侵入体带,永平以南的花岗岩体泛称临沧花岗岩基,规模巨大。澜沧江变质岩系具双变质带特点,核部为强变形高级变质岩带,两侧为强变形低级变质带,这种双变质样式与红河-哀牢山变质带极为相似(Leloup and Kienast, 1993; 钟大赉等,1998)。

研究区三叠纪地层最为发育,以澜沧江深断裂为界,其东以浅变质的上古生界及不含或少含火山岩的中生界地层为主,西侧以变质岩及花岗岩基为主。断裂带的南端景洪-大勐龙一线元古界-新生界均有发育。前寒武纪地层主要分布于澜沧江深断裂西侧,从北部碧江向南到凤庆、临沧、勐龙呈狭长带状断续分布。主要包括下元古界崇山群、大勐龙群,中上元古界澜沧群和西盟群。

崇山群变质岩系出露范围较广,北起碧江、昌宁、云县、双江一线以东,云龙、永平、临沧一线以西,呈NNW-ESE向狭窄的带状分布。除部分与印支-燕山期花岗岩呈侵入接触外,两侧均与澜沧群及古生代地层呈断层接触。主要由各类混合岩、片麻岩、片岩、变粒岩以及少量大理岩、斜长角闪岩等组成,厚度大于2000m。原岩是一套具复理石沉积特征的砂泥质、钙质岩,并夹基性火山岩,由东向西有粒度渐细之势,经后期构造变动产生强糜棱岩化,但局部地段出现矽线石、钾长石矿物,系澜沧群的北延(胡斌,2002)。崇山群的时代归属亦有不同意见,有将其划归为中-上元古界(胡斌,2002),亦有划归为下古生界的认识(熊家镛,1989地质矿产部三江地质编委会地质图编图组,1986)。划分依据分别为岩性组合特征、变质程度及片麻岩中锆石922Ma的U-Pb年龄(陈炳蔚,1991罗君烈,1994吴世泽等,1984),侵入于崇山群之斑状花岗岩的585.5Ma的Rb-Sr等时线年龄(陈炳蔚,1991)。

大勐龙群主要出露于景洪以南的大勐龙、小街一带,呈NE-SW向展布,向南延入缅甸境内。由于受印支、燕山期花岗岩体的侵入及第三系覆盖而断续出露。东侧以澜沧江深断裂带为界与中生界及部分古生界相邻,其西侧与澜沧群呈断层接触。大勐龙群以赋存变钠质基性火山铁矿而著称,主要由不同程度混合岩化的片岩、变粒岩、片麻岩及大理岩、角闪岩等组成,厚度大于750m。原岩主要为砂泥质岩石,并夹中-基性火山岩及少量碳酸盐岩、炭质岩。原岩与澜沧群类似,系澜沧群东延的基底断块(罗君烈,1994)。该群变质程度基本与崇山群一致,其准确时代未知。据变质程度、微古植物、大勐龙群黑云母变粒岩全岩Rb-Sr法年龄1176.7Ma(罗君烈等,1994),将其原岩层位定为中元古界下部。然而大勐龙群中的斜长角闪岩Sm-Nd等时线年龄1436.6±17Ma,Nd模式年龄为1700~1900Ma(钟大赉等,1998)。

澜沧群变质岩分布于澜沧江变质带的中南部,呈南北向展布,延长达400km,东界为澜沧江大断裂、临沧-勐海花岗岩带,出露于临沧、双江、勐海等地,向南延至缅甸掸邦。东侧与崇山群呈断层接触,或与临沧花岗岩呈侵入接触,西侧多与古生界呈断层接触,仅局部见泥盆系及中侏罗统不整合其上。澜沧群变质岩系为一套夹有变质基性火山岩的浅变质微晶片岩、片岩和少量变粒岩,夹多层沉积变质铁矿,厚度巨大,总厚度可达8000m,除局部变质程度较深外,绝大部分为浅变质,变质程度为绿片岩相-低角闪岩相,岩性主要为千枚岩、微晶片岩、片岩,常保留有原岩的结构构造、变形不强烈,片理、片麻理走向近南北(谢力华,2000)。原岩为长石石英砂岩、粉砂质泥岩、夹基性火山岩及灰岩,具复理石特征。据部分微古植物、叠层石及牙形刺等组合面貌和特征及同位素年龄(Rb-Sr等时线年龄约715Ma,K-Ar年龄784Ma和U-Pb年龄581Ma)(陈炳蔚,1991地质矿产部三江地质编委会地质图编图组,1986),将其划归中上元古界或上元古界,亦有人将其划归为下中寒武统(陈炳蔚,1991地质矿产部三江地质编委会地质图编图组,1986胡斌,2002)。惠民地区澜沧群中微古植物化石,其时代应为晚古生代,云县羊头岩剖面发现的牙形刺化石,可能延至寒武纪。澜沧群中一套蓝闪石片岩Sm-Nd测年获得蓝闪石形成年龄为409.8±23Ma(范承钧和张翼飞,1993)。因此,一般将澜沧群的时代定为中晚元古-早古生代。此外,亦有研究认为澜沧群可能存在双变质带,即西侧为高压低温带,东侧为高温低压带,中间为构造-糜棱岩带。已测的两变质带的Rb-Sr年龄对应很好,高压带为282~260~241~226Ma,高温带为250~236~210Ma(叶伯丹等,1986)。

西盟群出露于中缅交界的南卡江区,是一套以片麻岩夹片岩为主的岩群,局部见混合岩,厚度大于834m。早期孟宪民等称其为西盟片麻岩(陈炳蔚,1991),只包括老街子组、怕可组(云南省地质矿产局,1990)。原岩为中细粒碎屑岩到变基性岩、碳酸盐岩建造,变质程度为高绿片岩、低角闪岩相及混合岩化(变斑岩Rb-Sr年龄688Ma,罗君烈等,1994),其与大勐龙群可对比。原岩初步定为中元古界下部,向南延至缅甸后可能包括更老的一些岩层(陈炳蔚等,1991)。岩石组合由片麻岩、变粒岩、混合岩夹大理岩、斜长角闪岩等组成。

3 野外样品特征和年代学 3.1 样品野外特征

澜沧江构造带北段隔怒江与高黎贡山变质岩带接触,中段在昌宁东北转向近E-W向,云县又转为近N-S向,南段与临沧花岗岩基接触。本文仅选取昌宁-耉街靠近澜沧江边的崇山群和西盟群及南端的大勐龙群作为研究对象。

样品08cn-5采自昌宁-耉街剖面近澜沧江边(GPS: 24°56′05″N,99°44′02″E,海拔1566m),岩性为条带状花岗质片麻岩(图 2a),片麻理走向为315°,局部岩石糜棱岩化。08xm-2 采自西盟县新老县城岔口向西路边(GPS: 22°40′19″N,99°29′00″E,海拔1183m),岩性为花岗质糜棱岩(图 2b),产状为110°∠80°,变质程度已达低角闪岩相。08dm-2采自景洪嘎洒镇-勐龙镇路边(GPS: 21°42′42″N,100°40′25″E,海拔680m),岩性为条带片麻状花岗岩(图 2c)。

图 2 澜沧江构造带变质岩样品野外露头照片
(a)-崇山群花岗质片麻岩;(b)-西盟群花岗质糜棱岩;(c)-大勐龙群片麻状花岗岩
Fig. 2 The photographs of the samples outcrop in the Lancang River tectonic zone
(a)-granitic gneiss in Chongshan Group;(b)-granitic mylonite in Ximeng Group;(c)-gneissic granite in Damenglong Group
3.2 锆石SHRIMP年代学方法

锆石按常规方法分选,最后在双目镜下挑纯。将锆石与一片RSES参考样SL13及数粒TEMORA 1置于环氧树脂中,然后磨至约一半,使锆石内部暴露,用于阴极发光研究及随后的SHRIMP U-Pb分析。锆石阴极发光照相研究(CL图像)在中国地质科学院矿产资源研究所电子探针研究室完成。锆石SHRIMP U-Pb同位素分析在北京离子探针中心SHRIMP Ⅱ上进行。激光束斑大小为20~30μm,为防止锆石表面的普通铅和镀金过程中的污染,测定过程中先对每个分析点进行2~3min的表面清洗。锆石样品分析原理和流程参见Compston et al.(1992)Williams(1998),样品靶制作可见宋彪等(2002)。标样为澳大利亚国立大学(ANU)的SL13和TEMORA 1。SL13(宝石级锆石,U含量为238×10-6,年龄为572Ma)用于样品U-Th-Pb含 量标定;TEMORA 1(母岩为澳大利亚堪培拉附近一闪长岩体,年龄为417Ma,206Pb/238U比值为0.0668)用于样品年龄标定,采用公式为206Pb+/238U+=A(254UO+/238U+);用204Pb进行普通铅年龄校正(Cumming and Richarda, 1975),数据处理采用SQUID和ISOPLOT程序(Ludwig, 2002ab)。单个数据的误差为1σ,加权平均年龄误差为2σ,具95%的置信 度。

远程操作测试流程是在中国地质科学院地质研究所北京离子探针中心的网络虚拟实验室完成,通过SHRIMP远程共享控制系统(SHRIMP Remote Operation System,SROS)远程控制位于澳大利亚Curtin理工大学(Curtin University of Technology)的SHRIMP II仪器而获得的。SHRIMP远程共享控制系统(SROS)由北京离子探针中心,中国计量科学研究院和吉林大学共同研发,可以实现通过Internet公共网络,远程控制SHRIMP II仪器,远程选取样品待测点和实时远程实验数据输出打印等功能。前期锆石分选制靶照相等处理和后续测试流程与北京离子探针中心测试流程相同。远程测试分析过程中采用的标准锆石为M257,详细的分析方法请参见Nasdala et al.(2008)

3.3 锆石U-Pb测年结果

在澜沧江构造带采集变质岩样品(08cn-5、08dm-2和08xm-2),挑选出其中锆石颗粒进行SHRIMP U-Pb年代学测试分析,具体年代学测试和谐和年龄详见表 1

表 1 澜沧江构造带变质岩锆石U-Pb SHRIMP测试结果 Table 1 Zircon U-Pb SHRIMP data from the metamorphic rocks in Lancang River tectonic zone

崇山群样品08cn-5,岩性为条带状花岗质片麻岩。其中CL图像显示锆石颗粒呈短柱状,半自形-自形,颗粒长约120~180μm,宽约为50~70μm,绝大部分锆石颗粒由核部和边部两部分组成,核部呈亮白色,边部灰白色,部分锆石颗粒可见环带结构。SHRIMP测试选取16颗锆石进行17点的测试分析,大部分测试点位于颗粒边部(图 3),锆石U和Th含量变化范围较大,分别为79×10-6~3066×10-6和27×10-6~261×10-6,相应Th/U比为0.02~1.34,其中只有16.1点的Th/U比为1.34,其余点均小于0.4(表 1)。结合CL图像揭示为变质增生锆石。所有测试点的206Pb/238U年龄范围在72.5~907Ma之间,核部年龄范围在160~907Ma(剔除1.1,7.1,8.1,15.1测试点,极有可能为混合年龄),边部年龄集中在72.5~85.5Ma;其中6粒锆石边部测试点的206Pb/238U-207Pb/235U年龄加权平均值为73.9±1.8Ma(MSWD=1.3,N=6,图 4)。

图 3 澜沧江构造带崇山群花岗质片麻岩(08cn-5)阴极发光图像 Fig. 3 CL images of zircons from sample(08cn-5)of Chongshan Group in Lancang River tectonic zone


图 4 澜沧江构造带花岗质片麻岩(08cn-5)锆石SHRIMP U-Pb谐和年龄图 Fig. 4 Zircons SHRIMP U-Pb concordia diagram of sample(08cn-5)in Lancang River tectonic zone

大勐龙群样品08dm-2岩性为条带片麻状花岗岩。锆石CL图像显示锆石颗粒呈长柱状,自形,灰白色,岩浆振荡环带极发育,颗粒长为220~300μm,宽为100~150μm(图 5)。U-Pb年代学测试选取15颗锆石进行15个点的测试分析,U和Th含量变化范围较大,分别为248×10-6~1374×10-6和97×10-6~492×10-6,相应的Th/U比为0.20~1.08。其中只有3.1点的Th/U比为1.08,其余点均小于0.44(表 1)。结合锆石CL图像分析揭示其锆石为岩浆结晶锆石。所有测试点的206Pb/238U年龄范围在222.0~605.4Ma之间,其中仅3.1测试点的年龄为605.4±7.7Ma其余测试点均小于241.6Ma。所有测试点中11颗锆石206Pb/238U-207Pb/235U年 龄加权平均值为232.3±1.9Ma(MSWD=1.6,N=11)(图 6)。

图 5 澜沧江构造带南端大勐龙群条带片麻状花岗岩(08dm-2)阴极发光图像 Fig. 5 CL images of zircons from sample(08dm-2)of Damenglong Group in Lancang River tectonic zone

图 6 澜沧江构造带大勐龙群样品(08dm-2)锆石SHRIMP U-Pb谐和年龄图 Fig. 6 Zircons SHRIMP U-Pb concordia diagram of sample(08dm-2)in Lancang River tectonic zone

西盟群样品08xm-2岩性为花岗质糜棱岩,变质程度已达低角闪岩相,划归为西盟群。CL图像显示锆石颗粒呈白色-灰白色、浑圆状-短柱状、半自形-他形,环带结构不发育。锆石颗粒长轴为100~120μm,短轴为50~70μm(图 7)。U-Pb年代学测试选取13颗锆石进行13个点分析,U和Th含量变化范围较大,分别为94×10-6~628×10-6和12×10-6~508×10-6,相应的Th/U比为0.12~1.22(表 1),结合CL图像揭示其为变质残余锆石。测试获得有3个锆石颗粒的207Pb/206Pb年龄范围1802~1057Ma,4粒锆石颗粒206Pb/238U年龄在973~880Ma之间,6粒锆石颗粒的206Pb/238U年龄在656~524Ma之间(图 7)。所有测点年龄未获得一致的谐和年龄,但均落在一致线附近(图 8)。

图 7 澜沧江构造带西盟群花岗质糜棱岩(08xm-2)阴极发光图像和年龄结果 Fig. 7 CL images of zircons and dating results from sample(08xm-2)in Lancang River tectonic zone


图 8 澜沧江构造带西盟群样品(08xm-2)锆石SHRIMP U-Pb谐和年龄图 Fig. 8 Zircons SHRIMP U-Pb concordia diagram of sample(08xm-2)in Lancang River tectonic zone

4 讨论 4.1 前寒武纪结晶基底

滇西澜沧江地区是否存在前寒武纪结晶基底,各古老变质岩群的年代学和所经历的构造事件年代学框架均不是很清楚,除了云南省地质矿产局(1990)和零星的极少数年代学数据报道外,没有进行过详细系统的年代学研究工作。本次对澜沧江构造带南段变质岩系获得较详细的年代学数据。其中西盟群样品08xm-2的锆石SHRIMP U-Pb年龄范围变化比较大,未获得一致的谐和线年龄,各年龄均落在一致线附近(图 8),该样品共获得13个206Pb/238U年代学数据,其中4个颗粒的207Pb/206Pb年龄范围在1802~1057Ma之间,3个颗粒的年龄范围在968~880Ma之间,6个颗粒的年龄范围在656~524Ma之间,分别属于古元古代、中元古代和新元古代,结合锆石CL图像揭示西盟群变质岩系比较复杂,西盟地区存在前寒武纪结晶基底。澜沧江中段昌宁-耉街乡剖面近澜沧江边崇山群样品08cn-5中锆石CL图像显示为变质增生锆石。最老颗粒锆石年龄907Ma和812Ma,其次为421Ma和160Ma(测试点1.1,7.1,8.1和15.1为混合年龄),锆石边部谐和年龄为73.9±1.8Ma(N=6,MSWD=1.3),表明样品经历了复杂地质事件的影响,记录了原特提斯、古特提斯和新特提斯的演化信息。同时怒江上游马吉段早古生代片麻状花岗岩中锆石SHRIMP U-Pb测试分析,11颗锆石加权平均年龄为487±11Ma,残余锆石核部年龄为773±12Ma和794±12Ma(宋述光等,2007)。澜沧江构造带南段片麻状花岗岩样品(08dm-2)中锆石SHRIMP U-Pb谐和年龄为232.3±1.9Ma(N=11,MSWD=1.6),为花岗岩的结晶年龄,与临沧花岗岩基和点苍山-哀牢山变质岩带中的锆石年龄数据相一致(施小斌等, 2006ab彭头平,2006彭头平等,2006李宝龙等,2008),记录滇西地区三叠纪时的区域性构造事件。

澜沧江构造带中南段变质岩系主要有由澜沧群、西盟群、崇山群和大勐龙群组成,云南地质志把上述群组暂归为中元古代(云南省地质矿产局,1990)。澜沧江构造带是特提斯演化的昌宁-孟连主洋盆所在地,构造运动特别强烈再加上印支期临沧花岗岩基的侵入改造,极少保留前寒武纪的地质记录。昌宁县城东北昌宁-耉街乡剖面近澜沧江边崇山群样品(08cn-5)两个锆石颗粒获得811~907Ma的年龄信息,西盟群样品(08xm-2)获得1727~524Ma的SHRIMP 锆石年龄,共同记录了古元古界、中元古界和新元古界的年代学信息。最老时代1727Ma为古元古代,与大红山群相当;中元古代年龄1054Ma和1229Ma;新元古代年龄为906~961Ma、812Ma和623~727Ma。综合云南省地质矿产局(1990)钟大赉等(1998)的研究,西盟群最老时代为古元古代,记录有中元古代和新元古代的构造事件的影响;崇山群最老时代为新元古代,之后记录了多期次复杂的构造事件。早三叠世晚期,西南三江地区的古特提斯洋盆的俯冲闭合最终完成,中三叠世早期发生陆-陆/弧碰撞,晚三叠世开始进入碰撞后裂谷时期,直至三叠纪末才结 束古特提斯的演化(范蔚茗等,2009)。故澜沧江构造带存在区域前寒武纪结晶基底,只是由于三叠纪岩浆作用对基底改造比较强烈。

在区域范围内,滇西地区的深变质岩系变质和变形特征在不同地区有所差异,均遭受后期强烈的岩浆侵入和构造热事件的改造,变质和变形作用强烈,并使变质岩系呈零星条带状出露于地表。点苍山-哀牢山变质变形带是研究区东侧出露最好的深变质岩系之一,也是研究程度较高的一条变质变形带,前人曾对其进行了较详细的研究工作。点苍山花岗糜棱岩曾获得1672Ma和1971Ma的Sm-Nd模式年龄,是变质火山岩的形成年龄(13~14亿年),进而认为该变质岩是点苍山地区的古老陆壳基底,是扬子基底的一部分(翟明国和从柏林,1993)。哀牢山墨江-二台坡花岗片麻岩和滑石板-元江斜长角闪岩的Sm-Nd年龄为1367.1±46.1Ma,归属于扬子板块基底(翟明国等,1990)。近年来研究也获得了许多精确锆石SHRIMP U-Pb年代学资料。点苍山变质岩系混合岩之中花岗岩脉的锆石单颗粒SHRIMP年龄842.5±9.9Ma和833±9Ma,是深变质杂岩的混合岩化作用与花岗岩脉的结晶年龄,并反映点苍山地区遭受的一期构造事件(刘俊来等,2008)。哀牢山变质带的深变质岩系的锆石核部SHRIMP U-Pb测试结果(SM07-1:800~2654Ma;AL-4:676~700Ma;08JP-5:748~804Ma;08HK-1:828±6.2Ma)表明该地区存在前寒武纪结晶基底(李宝龙等, 20082012李宝龙,2010)。只是在哀牢山变质带北段由于遭受改造强烈残留信息较少,而南段保留较多。点苍山-哀牢山变质变形带的基底出露较好,特别是点苍山附近和哀牢山南段(元阳以南),精确的年代学测试数据就是很好的证明(刘俊来等,2008; 李宝龙等,2012; Li et al., 2014)。澜沧江构造带的锆石核部SHRIMP测试分析表明该带存在前寒武纪基底(08cn-5:811±9.9Ma和907±23Ma;08dm-2:605.4±7.7Ma;08xm-2:656~1802Ma),大勐龙群条带片麻状花岗岩(08dm-2)中11颗锆石206Pb/238U-207Pb/235U谐和线年龄为232.3±1.9Ma(MSWD=1.6,N=11)(图 6),记录大勐龙地区遭受三叠纪花岗岩侵入构造事件的影响,澜沧江构造带南段因临沧花岗岩基的出露对该带变质岩系强烈改造,基底信息仅在西盟地区保留最好(08xm-2),景洪南大勐龙群和昌宁东北部的崇山群遭受强烈后期改造致使基底信息保留较少。该带北段未进行相关数据测试分析,但也有理由相信存在前寒武纪基底。此外,高黎贡山变质变形带中高黎贡山群的锆石测试结果为524±6.6Ma(08gl-3)和1686±31Ma(08lx-2-4.1),说明该带是寒武纪结晶基底集中出露区(李宝龙,2010)。

综合研究认为滇西地区普遍存在前寒武纪结晶基底,伴随临沧花岗岩基主体侵位形成于中三叠世(约230Ma)(表 2),滇西地区变质岩系(苍山群、哀牢山群、瑶山群、大勐龙群)普遍遭受一期广泛的三叠纪岩浆构造事件的影响(徐夕生等,1987; 刘昌实等,1989; 朱勤文,1993; 朱勤文等, 19981999; 李兴林,1996; 刘登忠等,1999; 秦元季,1991; 沈上越等,2002; 俞赛赢等,2003; 刘海龄等,2004; 陈新跃等,2006; 施小斌等, 2006ab; 彭头平,2006;彭头平等,2006; Wang et al., 2006; 张波,2007; Akciz et al., 2008; 梁晓等,2009; 孙会磊等,2012; 王硕等,2012; 王硕,2011; 孙会磊,2011; 李钢柱等, 20112012; 李宝龙等, 20082012; 李宝龙,2010),重熔了当时的地壳,致使前寒武纪变质岩群均遭受后期强烈的岩浆侵入和构造热事件的改造,保留的变质岩系呈零星条带状出露于地表,仅保存部分残余古老锆石颗粒,反映了滇西地区在三叠纪地壳物质的重新调整。

表 2 澜沧江构造带南段地区花岗岩和变质岩类同位素年龄数据统计 Table 2 The age data of granitoid and metamorphic rocks in the south segment of Lancang River structure zone
4.2 澜沧江构造带中段变质时限

崇山群之条带状花岗质片麻岩(08cn-5),镜下显微观察显示变质程度达角闪岩相,锆石SHRIMP U-Pb测试分析获得206Pb/238U年龄范围在72.5~907Ma之间,核部年龄范围在160~907Ma,边部年龄集中在72.5~85.5Ma。其中6颗锆石边部测试点的206Pb/238U谐和年龄为73.9±1.8Ma(MSWD=1.3,N=6,图 4)。结合CL图像特征,锆石颗粒边部年龄范围72.5~85.5Ma为澜沧江构造带崇山段变质岩系遭受变质事件的记录,谐和年龄73.9±1.8Ma代表峰期变质事件的年龄,故认为澜沧江构造带崇山段变质岩系遭受变质事件的起始时间为晚白垩世。怒江上游马吉段早古生代片麻状花岗岩中锆石SHRIMP U-Pb测试分析亦获得了年轻锆石暗色边缘年龄为71±1Ma,说明锆石的暗色边缘是白垩纪晚期变质作用过程中流体对原始锆石改造的结果(宋述光等,2007),这一锆石变质时限与08cn-5样品的年龄结果相一致。

Zhang et al.(2010)对崇山剪切带北段进行详细的野外和年代学测试,认为55~38Ma是一期重要的浅色花岗岩脉熔融侵位和变质发生时期,这一事件有可能一直持续到36Ma,早于左行剪切作用,左行走滑起始于~32Ma,主期发生在19~14Ma。此外,澜沧江构造带也获得~30Ma和22~15Ma两期250~350℃构造热事件的年代学记录(Akciz et al., 2008; 陈新跃等,2008)。澜沧江变质岩带北段同构造糜棱岩化花岗岩中含钾矿物40Ar/39Ar热年代学结果为13.43~17.77Ma,表明存在15.31~13.43Ma的构造事件,记录了澜沧江构造带从右行剪切作用早期阶段(17.7~16.2Ma)到右行剪切晚期阶段(15.3~13.4Ma)构造变形事件的完整过程(张波,2007),约36Ma先于崇山剪切带走滑运动(32Ma)前经历一期变质事件的改造(Zhang et al., 2010)。崇山剪切带中同构造角闪石、白云母和黑云母的40Ar/39Ar坪年龄为~32Ma,剪切带初始剪切运动时限与高黎贡剪切带、红河-哀牢山剪切带和王朝剪切带相同(早渐新世),但剪切终止时间存在差别(Wang et al., 2006)。澜沧江构造带的北段片麻状浅色花岗岩中独居石U/Pb年龄和黑云母40Ar/39Ar年龄分别为34~41Ma和15.83±0.67Ma,花岗闪长质片麻岩中白云母和黑云母的40Ar/39Ar年龄为19.41±0.42Ma和17.28±0.69Ma,记录了崇山剪切带的活动时限(Akciz et al., 2008)。澜沧江变质变形带双江粟义剖面和凤庆-小湾公路糜棱岩中白云母和黑云母的40Ar/39Ar年龄分别为31.5±0.2Ma和28.3±0.1Ma,是左旋走滑剪切带变形期年龄(陈新跃等,2006)。以往的研究认为澜沧江断裂带为新生代左旋断裂体系,构造作用与红河-哀牢山构造带相似(Wang and Burchfiel, 1997)。澜沧江构造带同构造新生黑云母、白云母和角闪石40Ar/39Ar年代学指示该构造带崇山段存在27~32Ma的左旋剪切走滑运动(Wang et al., 2006; 陈新跃等,2006)。而近年来的研究成果揭示澜沧江构造带自北向南连续展布,但北段与中段、南段构造岩中存在明显运动学差异,北段为右旋运动,南段则为左旋走滑,而非前人认为的统一左行走滑运动体系(Wang and Burchfiel, 1997; Wang et al., 2006; 陈新跃等,2006)。

结合研究区其他热年代学年龄结果,综合研究认为澜沧江构造带崇山段的变质时限为73.9~36Ma,显示为晚白垩世-古近纪的变质事件结果,之后于~32Ma开始经历左行走滑运动,峰期走滑发生在19~14Ma,变质事件早于走滑运动的时限。 5 结论

澜沧江构造带南段变质岩系古老锆石SHRIMP U-Pb年龄结果为1802Ma、1404Ma、1092Ma、906~961Ma、812Ma和623~727Ma,时代为古元古代、中元古代和新元古代,揭示研究区存在前寒武结晶基底,在西盟地区、大勐龙和昌宁县城西北等地表现较显著,之后经历一期区域性的三叠纪(230Ma)岩浆事件,破坏改造了古老前寒武纪结晶基底,仅在部分残余锆石的核部得以保留古老基底信息。

澜沧江构造带昌宁东北的崇山群中锆石颗粒边部年龄集中在72.5~85.5Ma,谐和年龄为73.9±1.8Ma,为澜沧江构造带崇山段变质岩系遭受变质事件的记录,变质事件的起始时间为晚白垩世(85~74Ma),并有可能一直持续到36Ma,约32Ma之后构造带发生走滑运动,变质事件明显早于走滑运动的时限。

参考文献
[1] Akciz S, Burchfiel BC, Crowley JL, Yin JJ and Chen LZ. 2008. Geometry, kinematics, and regional significance of the Chong Shan shear zone, Eastern Himalayan Syntaxis, Yunnan, China. Geological Society of America, 4(1): 292-314
[2] Bureau of Geology and Mineral Resources of Yunnan Province. 1990. Regional Geology of Yunnan Province. Beijing: Geological Publishing House (in Chinese)
[3] Chen BW. 1991. The Main Problem of Geotectonic and Its Relationship with Mineralization in the Sanjiang Region. Geological Report: Five·11. Beijing: Geological Publishing House (in Chinese)
[4] Chen H, Li F, Jian RT, Luo SL and Yao W. 2010. Zircon SHRIMP dating of the Laochang granite porphyry in Lancang, Yunnan and its geological significance. Acta Geologica Sinica, 84(4): 485-491 (in Chinese with English abstract)
[5] Chen XY, Wang YJ, Fan WM and Peng TP. 2006. Microstructural characteristics of Chongshan shear zones in Yunnan Province and 40Ar/39Ar geochronological constraints. Geotectonica et Metallogenia, 30(1): 41-51 (in Chinese with English abstract)
[6] Compilation Group, Editorial Board of Sanjiang Geological Map, Ministry of Geology and Mineral Resources. 1986. The Regional Geological Map of Nujiang, Lancangjiang and Jinshajiang Area Instruction. Beijing: Geological Publishing House (in Chinese)
[7] Compston W, Williams IS, Kirschvink JL, Zhang Z and Ma G. 1992. Zircon U-Pb ages for the Early Cambrian Time-Scale. J. Geol. Soc. London, 149(2): 171-184
[8] Cumming GL and Richarda JR. 1975. Ore lead isotope ratios in a continuously changing earth. Earth and Planetary Science Letters, 28(2): 155-171
[9] Dewey JF, Cande S and Pitman WC. 1989. Tectonic evolution of the India-Eurasia collision zone. Eclogae Geologicae Helvetiae, 82(3): 717-734
[10] Fan CJ and Zhang YF. 1993. On the structural pattern of western Yunnan. Yunnan Geology, 12(2): 139-181 (in Chinese with English abstract)
[11] Fan WM, Peng TP and Wang YJ. 2009. Triassic magmatism in the southern Lancangjiang zone, southwestern China and its constraints on the tectonic evolution of Paleo-Tethys. Earth Science Frontiers, 16(6): 291-302 (in Chinese with English abstract)
[12] Feng QL, Shen SY, Liu BP, Helmcke D, Qian XG and Zhang WM. 2002. The radiolarian, chert and basalt study in Daxinshan Group from Lancangjiang structural zone, southwestern Yunnan. Science in China (Series D), 32(3): 220-225 (in Chinese)
[13] Gao R, Xiao L, He Q, Yuan J, Ni PZ and Du JX. 2010. Geochronoloy, geochemistry and petrogenesis in Weixi-Deqin, West Yunnan. Earth Science, 35(2): 186-200 (in Chinese with English abstract)
[14] Houseman G and England P. 1993. Crustal thickening versus lateral expulsion in the Indian-Asian continental collision. Journal of Geophysical Research, 98(B7): 12233-12249
[15] Hu B. 2002. Metallogeny of copper ores from the Lancangjiang metallogenic belt in western Yunnan. Ph. D. Dissertation. Changsha: Central South University, 1-99 (in Chinese with English summary)
[16] Jian P, Liu DY and Sun XM. 2003a. SHRIMP dating of Carboniferous Jinshajiang ophiolite in western Yunnan and Sichuan: Geochronological constraints on the evolution of the Paleo-Tethys oceanic crust. Acta Geologica Sinica, 77(2): 217-228 (in Chinese with English abstract)
[17] Jian P, Liu DY and Sun XM. 2003b. SHRIMP dating of Baimaxueshan and Ludian granitoid batholiths, northwestern Yunnan Province, and its geological implications. Acta Geoscientia Sinica, 24(4): 337-342 (in Chinese with English abstract)
[18] Leloup P and Kienast JR. 1993. High-temperature metamorphism in major strike-slip shear zone: The Ailao Shan-Red River, People's Republic of China. Earth and Planetary Science Letters, 118(1-4): 213-234
[19] Li BL, Ji JQ, Fu XY, Gong JF, Song B, Qing JC and Zhang C. 2008. Zircon SHRIMP dating and its geological implications of metamorphic rocks in Ailao Shan-Diancang Mountain ranges, West Yunnan. Acta Petrogica Sinica, 24(6): 2322-2330 (in Chinese with English abstract)
[20] Li BL. 2010. Thermal evolutional history and geochronological constrains on metamorphic-deformational zones in West Yunnan Province. Ph. D. Dissertation. Beijing: Peking University, 1-157 (in Chinese with English summary)
[21] Li BL, Ji JQ, Wang DD and Ma ZJ. 2012. Neoproterozoic magmatism in South Yunnan: Evidence from SHRIMP zircon U-Pb geochronological results of high-grade metamorphic rocks in the Yaoshan Group. Acta Geologica Sinica, 86(10): 1584-1591 (in Chinese with English abstract)
[22] Li BL, Ji JQ, Wang DD, Gong JF and Ma ZJ. 2014. Determination of Eocene-Oligocene (30-40Ma) deformational time by zircon U-Pb SHRIMP dating from leucocratic rocks in the Ailao Shan-Red River shear zone, Southeast Tibet, China. International Geology Review, 56(1): 74-87
[23] Li GZ, Su SG, Lei WY and Duan XD. 2011. Precise ID-TIMS zircon U-Pb age and whole-rock geochemistry of the Nanlinshan mafic intrusion in the southern Lancangjiang arc terrane, Sanjiang area, SW China. Earth Science Frontiers, 18(5): 206-212 (in Chinese with English abstract)
[24] Li GZ, Su SG and Duan XD. 2012. Precise ID-TIMS zircon U-Pb age, whole-rock geochemistry and plate tectonic setting of the Banpo Complex in the southern Lancangjiang arc terrane, Sanjiang area, SW China. Earth Science Frontiers, 19(4): 96-109 (in Chinese with English abstract)
[25] Li YQ. 2009. Metamorphic-deformation characteristics of Tuanliangzi-Daxishan metamorphic zone, in Lancang River region, Yunnan. Master Degree Thesis. Beijing: China University of Geosciences, 1-67 (in Chinese with English summary)
[26] Liang X, Wang GH and Yang GQ. 2009. Genesis and deformation of quartz veins in the Lower Paleozoic tectonic schists along the bank of Lancang River, Jinggu area, western Yunnan, China. Geological Bulletin of China, 28(9): 1342-1349 (in Chinese with English abstract)
[27] Lin XL. 1996. Basic characteristics and formation structural environment of Lincang composite granite batholith. Yunnan Geology, 15(1): 1-18 (in Chinese with English abstract)
[28] Liu CS, Zhu JC, Xu XS, Chu MJ, Cai DK and Yang P. 1989. Study on the characteristics of Linchang composite granite batholith in West Yunnan. Yunnan Geology, 8(3-4): 189-204 (in Chinese with English abstract)
[29] Liu DL, Liu JS, Zhang CH and Zhou YG. 2008. Geological characteristics and tectonic setting of Yunxian granite in the northern part of South Lancangjiang convergent margin, western Yunnan Province. Acta Petrologica et Mineralogica, 27(1): 23-31 (in Chinese with English abstract)
[30] Liu DZ, Wang GZ, Li YG, Zhu LD, Tao XF and Xu XH. 1999. New progress in the study of isotope geochronology of the northern segment of the Lancang River suture zone. Regional Geology of China, 18(3): 334-335 (in Chinese with English abstract)
[31] Liu HL, Wang ZJ, Shi XB, Qiu XL, Zhang BY, Yan B and Xia B. 2004. High-temperature high-pressure experimental simulation on granite in Lancangjiang section of Tethyan suture zone in SW China. Journal of Tropical Oceanography, 23(2): 10-18 (in Chinese with English abstract)
[32] Liu JL, Wang AJ, Cao SY, Zou YX, Tang Y and Chen Y. 2008. Geochronology and tectonic implication of migmatites from Diancangshan, western Yunnan, China. Acta Petrologica Sinica, 24(3): 413-420 (in Chinese with English abstract)
[33] Ludwig KR. 2002a. Isoplot/Ex Version, A Geochronology Toolkit for Microsoft Excel. Berkeley Geochronology Centre Spec. Pub.1a, Berkeley, CA, USA
[34] Ludwig KR. 2002b. Squid 1.02: A User's Manual. Berkeley Geochronology Centre. Special Publication No.2. 2455 Ridge Road, Berkeley, CA 94709, USA
[35] Luo JL. 1994. The Tethyan Evolution of West Yunnan and the Mineralizaiton of the Main Mineral Deposit. Geological Report: Four·45. Beijing: Geological Publishing House (in Chinese)
[36] Mi YC, Fang PY, Hu YX and Zhang YM. 2012. The division and evolution of tectonic unit in Changdu-Puer massif of mid sector of Lancangjiang. Yunnan Geology, 31(4): 512-515 (in Chinese with English abstract)
[37] Mo XX, Lu FX, Shen SY, Zhu QW and Hou ZQ. 1993. Tethyan Volcanism and Mineralization of the Sanjiang Area. Beijing: Geological Publishing House, 1-267 (in Chinese)
[38] Mo XX, Shen SY, Zhu QW, Xu JR, Wei QR, Tan J, Zhang SQ and Chen HL. 1998. Volcanic-Ophiolite and Mineralization of Middle-Southern Sanjiang Area. Beijing: Geological Publishing House, 1-128 (in Chinese)
[39] Mou CL and Yu Q. 2002. The age of volcanic rock of the Pantiange Formation in the Lanping basin, Yunnan Province. Journal of Stratigraphy, 26(4): 289-292 (in Chinese with English abstract)
[40] Nasdala L, Hofmeister W, Norgerg N, Mattinson JM, Corfu F, Drr W, Kamo SL, Kennedy AK, Kronz A, Reiners PW, Frei D, Kosler J, Wan YS, Gze J, Her T, Krner A and Valley JW. 2008. Zircon M257: A homogeneous natural reference material for the ion microprobe U-Pb analysis of zircon. Geostandards and Geoanalytical Research, 32(3): 247-265
[41] Peng TP. 2006. The Triassic post-collisional magmatism for the southern Lancangjiang tectonic zone, southwestern China: Petrogenesis and its tectonic implication. Ph. D. Dissertation. Guangzhou: Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (in Chinese with English summary)
[42] Peng TP, Wang YJ, Fan WM, Liu DY, Shi YR and Miao LC. 2006. The zircon U-Pb dating and its tectonic implications of Early Mesozoic acidic igneous in the southern section of Lancang River. Science in China (Series D), 36(2): 123-132 (in Chinese)
[43] Qin YJ. 1991. The basic characteristics and tectonic emplacement mechanisms of the Lincang granitoid batholiths in the western Yunnan. Ph. D. Dissertation. Beijing: Institute of Geology, Chinese Academy of Geological Sciences, 1-78 (in Chinese with English summary)
[44] Shen SY, Feng QL, Liu BP and Mo XX. 2002. Tectonomagmatic types of volcanic rocks in South Lancang River belt, Jinshajiang River-Lanchangjiang River-Nuiang River area in China. Journal of Mineralogy and Petrology, 22(3): 66-71 (in Chinese with English abstract)
[45] Shi XB, Qiu XL, Liu HL, Chu ZY and Xia B. 2006a. Thermochronological analyses on the cooling history of the Lincang granitoid batholith, western Yunnan. Acta Petrologica Sinica, 22(2): 465-479 (in Chinese with English abstract)
[46] Shi XB, Qiu XL, Liu HL, Chu ZY and Xia B. 2006b. Cenozoic cooling history of Lincang granitoid batholiths, western Yunnan: Evidence from Fission track data. Chinese Journal of Geophysics, 49(1): 135-142 (in Chinese with English abstract)
[47] Song B, Zhang YH, Wan YS and Jian P. 2002. Mount making and procedure of the SHRIMP dating. Geological Review, 48(Suppl.): 26-30 (in Chinese with English abstract)
[48] Song SG, Ji JQ, Wei CJ, Su L, Zheng YD, Song B and Zhang LF. 2007. The determination of Nujiang River Early Paleozoic gneissic granite in Northwest Yunnan and its tectonic implications. Chinese Science Bulletin, 52(8): 927-930 (in Chinese)
[49] Sun HL. 2011. Geochemistry, geochronology and petrogenisis of Lincang granites in southern Lancangjiang zone of Sanjiang area. Master Degree Thesis. Beijing: China University of Geosciences, 1-73 (in Chinese with English summary)
[50] Sun HL, Dong GC, Mo XX, Zhao ZD, Zhu DC, Wang S, Li R and Wang QL. 2012. Petrogenesis of Lincang granites in Sanjiang area of western Yunnan Province: Constraints from geochemistry, zircon U-Pb geochronology and Hf isotope. Acta Petrologica Sinica, 28(5): 1438-1452 (in Chinese with English abstract)
[51] Tapponnier P, Peltzer G and Armijo R. 1986. On the mechanics of the collision between India and Asia. In: Coward MP and Ries AC (eds.). Collision Tectonics. Geological Society of London Special Publication, 19: 115-157
[52] Wang BD, Wang LQ, Qiangba ZX, Zeng QG, Zhang WP, Wang DB and Cheng WH. 2011. Early Triassic collision of northern Lancangjiang suture: Geochronological, geochemical and Hf isotope evidences from the granitic gneiss in Leiwuqi area, East Tibet. Acta Petrologica Sinica, 27(9): 2752-2762 (in Chinese with English abstract)
[53] Wang E and Burchfiel BC. 1997. Interpretation of Cenozoic tectonics in the right-lateral accommodation zone between the Ailao Shan shear zone and the eastern Himalayan syntaxis. International Geology Review, 39(3): 191-219
[54] Wang LQ, Li DM, Guan SP and Xu JR. 2002. The Rb-Sr determinations of the "bimodal" volcanic rocks in the Luchun-Hongponiuchang superimposed rift basin, Deqen, Yunnan. Sedimentary Geology and Tethyan Geology, 22(1): 65-70 (in Chinese with English abstract)
[55] Wang S. 2011. Petrological, geochemical, geochronological characteristics and their tectonic significance of Triassic volcanic rocks in southern Lancangjiang zone. Master Degree Thesis. Beijing: China University of Geosciences, 1-67 (in Chinese with English summary)
[56] Wang S, Dong GC, Mo XX, Zhao ZD, Zhu DC, Kong HL, Wang X and Nie F. 2012. Petrological and geochemical characteristics, Ar-Ar geochronology study and their tectonic significance of Triassic volcanic rocks in southern Lancangjiang zone. Acta Petrologica Sinica, 28(4): 1148-1162 (in Chinese with English abstract)
[57] Wang YJ, Fan WM, Zhang YH, Peng TP, Chen XY and Xu YG. 2006. Kinematics and 40Ar/39Ar geochronology of the Gaoligong and Chongshan shear systems, western Yunnan, China: Implications for Early Oligocene tectonic extrusion of SE Asia. Tectonophysics, 418(3-4): 235-254
[58] Williams IS. 1998. U-Th-Pb geochronology by ion microprobe. In: Mckibben MA, Shanks Ⅲ WC and Ridley WI (eds.). Application of Microanalytical Techniques to Understanding Mineralizing Processs. Rev. Exon. Geol., 7: 1-35
[59] Wu SZ, Tao YY, Feng GR, Wei GY and Luo ZW. 1984. The characteristics of volcanic rocks of Chongshan Group and Lancang Group. Yunnan Geology, 4(4): 439-446 (in Chinese with English abstract)
[60] Xie LH. 2000. The prospect of copper (gold)-polymetallic ore in the magmatic, metamorphic and tectonic mobile zone of Lancangjiang, western Yunnan Province, China. Ph. D. Dissertation. Changsha: Central South University, 1-155 (in Chinese with English summary)
[61] Xiong JY. 1989. The summary of strata in Yunnan Province. Yunnan Regional Geology, 7: 10-31 (in Chinese with English abstract)
[62] Xu XS, Cai DK, Zhu JC and Liu CS. 1987. Characteristics and origin of Hercynian-Indosinian granitoids in the Lanchang River collision belt, western Yunnan. Geotectonica et Metallogenia, 11(3): 247-258 (in Chinese with English abstract)
[63] Xu ZQ, Yang JS, Li WC, Li HQ, Cai ZH, Yan Z and Ma CQ. 2013. Paleo-Tethys system and accretionary orogen in the Tibet Plateau. Acta Petrologica Sinica, 29(6): 1847-1860 (in Chinese with English abstract)
[64] Yang X, Liu YH, Sun GQ, Liu XW, Wang BZ and Zheng JJ. 2010. Initial exploration to Mesozoic Basin-Orogen dynamical coupling of "Sanjiang" (Nujiang River-Jinsha River-Lancang River) region, western Yunnan. Geological Review, 56(2): 196-204 (in Chinese with English abstract)
[65] Yang YQ, Yang JM, Xu DC and Yang JH. 2006. Volcanic rock evolution and metallogenic features of copper-polymetallic deposits in southern Lancang River valley, Yunnan Province. Mineral Deposits, 25(4): 447-462 (in Chinese with English abstract)
[66] Ye BD et al. 1986. National Isotopic Age Data Compilation (No.3 and 4) Beijing: Geological Publishing House (in Chinese)
[67] Yin A and Harrison TM. 2000. Geologic evolution of the Himalayan-Tibetan orogen. Annual Reviews Earth Planet Science, 28(1): 211-280
[68] Yu SY, Li KQ, Shi YP and Zhang HH. 2003. A study on the granodiorite in the middle part of Lincang granite batholith. Yunnan Geology, 22(4): 426-442 (in Chinese with English abstract)
[69] Zhai MG, Cong BL, Qiao GS and Zhang RY. 1990. Sm-Nd and Rb-Sr geochronology of metamorphic rocks from SW Yunnan orogenic zones, China. Acta Petrologica Sinica, 6(4): 1-11 (in Chinese with English abstract)
[70] Zhai MG and Cong BL. 1993. The Diancanshan-Shigu metamorphic belt in West Yunnan, China: Their geochemical and geochronological characteristic and Division of metamorphic domains. Acta Petrologica Sinica, 9(3): 227-239 (in Chinese with English abstract)
[71] Zhang B. 2007. Kinematics and deformational mechanism of the Cenozoic sinistral Transpression along the Lancangjiang structural belt, western Yunnan, China. Ph. D. Dissertation. Beijing: Peking University, 1-99 (in Chinese with English summary)
[72] Zhang B, Zhang JJ and Zhong DL. 2010. Structure, kinematics and ages of transpression during strain-partitioning in the Chongshan shear zone, western Yunnan, China. Journal of Structural Geology, 32(4): 445-463
[73] Zhang CH, Liu JS, Zhang HP, Liu WM and Wu ZC. 2012. Geochemistry characteristics of Late Triassic potash-rich volcanic rocks and their origins in southern Lancangjiang belt, western Yunnan Province, China. The Chinese Journal of Nonferrous Metals, 22(3): 669-679 (in Chinese with English abstract)
[74] Zhang H, Jin CH, Fan WY, Shen ZW, Zhang Y and Gao JH. 2013. Zircon LA-ICP-MS U-Pb dating of gabbro of the Banpo Pt-Pd-polymetallic deposit in Jinggu, Yunnan Province, and its geological significance. Geology in China, 40(5): 1433-1442 (in Chinese with English abstract)
[75] Zhang YQ, Xia B, Liang HY, Liu HY and Lin QC. 2004. Characteristics of zircons for dating from Daping mylonitzed alkaline granite in Yunnan and their geologic implications. Geological Journal of China Universities, 10(3): 378-384 (in Chinese with English abstract)
[76] Zhao J, Zhong DL and Wang Y. 1994a. A preliminary study on deformation sequence and metamorphism in Lancang metamorphic belt of West Yunnan. Scientia Geologica Sinica, 29(4): 366-372 (in Chinese with English abstract)
[77] Zhao J, Zhong DL and Wang Y. 1994b. Metamorphism of Lancang metamorphic belt, the western Yunnan and its relation to deformation. Acta Petrologica Sinica, 10(1): 27-40 (in Chinese with English abstract)
[78] Zhong DL. 2000. Paleotethyan Orogenic Belts in Yunnan and Western Sichuan. Beijing: Science Press, 1-231 (in Chinese)
[79] Zhong WF, Feng QL, Chonglakmani CP, Monjai D and Zhang ZB. 2012. Permian-Triassic stratigraphic correlations between Laos and Yunnan and their tectonic significance. Earth Science, 37(Suppl.2): 73-80 (in Chinese with English abstract)
[80] Zhu QW, Shen SY, Yang KH and Xue YX. 1991. Volcanic tectonic-magmatic type and Tethyan evolution of Lancangjiang belt. In: Qinghai-Tibet Plateau Geological Anthology (21). Beijing: Geological Publishing House, 125-140 (in Chinese)
[81] Zhu QW. 1993. Tectonic setting of Triassic volcanic rocks along Lancangjiang belt in Southwest Yunnan. Acta Petrologica et Mineralogica, 12(2): 134-143 (in Chinese with English abstract)
[82] Zhu QW, Zhang SQ and Tan J. 1998. Geochemical evidence of volcanic rocks for determining the South Lancangjiang suture zone. Acta Petrologica et Mineralogica, 17(4): 298-307 (in Chinese with English abstract)
[83] Zhu QW, Zhang SQ and Tan J. 1999. Magmatic genesis of volcanic rocks of southern Lancangjiang convergent margin: Magmatism about ocean ridge, ocean island and island arc. Geoscience, (2): 137-142 (in Chinese with English abstract)
[84] 陈炳蔚. 1991. 三江地区主要大地构造问题及其与成矿的关系, 地质专报: 五·11. 北京: 地质出版社
[85] 陈珲, 李峰, 坚润堂, 罗思亮, 姚巍. 2010. 云南澜沧老厂花岗斑岩锆石SHRIMP定年及其地质意义. 地质学报, 84(4): 485-491
[86] 陈新跃, 王岳军, 范蔚茗, 彭头平. 2006. 云南崇山剪切断裂系显微构造特征及其40Ar/39Ar年代学约束. 大地构造与成矿学, 30(1): 41-51
[87] 地质矿产部三江地质编委会地质图编图组. 1986. 怒江、澜沧江、金沙江区域地质图(1︰100万)说明书. 北京: 地质出版社
[88] 范承钧, 张翼飞. 1993. 云南西部地质构造格局. 云南地质, 12(2): 139-181
[89] 范蔚茗, 彭头平, 王岳军. 2009. 滇西古特提斯俯冲-碰撞过程的岩浆作用记录. 地学前缘, 16(6): 291-302
[90] 冯庆来, 沈上越, 刘本培, Helmcke D, 钱祥贵, 张伟明. 2002. 滇西南澜沧江构造带大新山组放射虫、硅质岩和玄武岩研究. 中国科学(D辑), 32(3): 220-225
[91] 高睿, 肖龙, 何琦, 袁静, 倪平泽, 杜景霞. 2010. 滇西维西-德钦一带花岗岩的年代学、地球化学和岩石成因. 地球科学, 35(2): 186-200
[92] 胡斌. 2002. 滇西澜沧江成矿带铜成矿学研究. 博士学位论文. 长沙: 中南大学, 1-99
[93] 简平, 刘敦一, 孙晓猛. 2003a. 滇川西部金沙江石炭纪蛇绿岩SHRIMP测年: 古特提斯洋壳演化的同位素年代学制约. 地质学报, 77(2): 217-228
[94] 简平, 刘敦一, 孙晓猛. 2003b. 滇西北白马雪山和鲁甸花岗岩基SHRIMP U-Pb年龄及其地质意义. 地球学报, 24(4): 337-342
[95] 李宝龙, 季建清, 付孝悦, 龚俊峰, 宋彪, 庆建春, 张臣. 2008. 滇西点苍山-哀牢山变质岩系锆石SHRIMP定年及其地质意义. 岩石学报, 24(6): 2322-2330
[96] 李宝龙. 2010. 滇西地区变质变形带变质时限和热史演化研究. 博士学位论文. 北京: 北京大学, 1-157
[97] 李宝龙, 季建清, 王丹丹, 马宗晋. 2012. 滇南新元古代的岩浆作用: 来自瑶山群深变质岩SHRIMP锆石U-Pb年代学证据. 地质学报, 86(10): 1584-1591
[98] 李钢柱, 苏尚国, 雷玮琰, 段向东. 2011. 三江地区澜沧江带南段南林山基性岩体锆石U-Pb年龄及岩石地球化学特征. 地学前缘, 18(5): 206-212
[99] 李钢柱, 苏尚国, 段向东. 2012. 三江地区澜沧江带南段半坡杂岩体锆石U-Pb年龄、岩石地球化学特征及板块构造环境. 地学前缘, 19(4): 96-109
[100] 李元庆. 2009. 云南澜沧江地区团梁子-大新山变质岩带变质变形特征. 硕士学位论文. 北京: 中国地质大学, 1-67
[101] 梁晓, 王根厚, 杨广全. 2009. 滇西景谷地区澜沧江沿岸早古生代构造片岩中石英脉的成因与变形. 地质通报, 28(9): 1342-1349
[102] 李兴林. 1996. 临沧复式花岗岩基的基本特征及形成构造环境的研究. 云南地质, 15(1): 1-18
[103] 刘昌实, 朱金初, 徐夕生, 楚雪君, 蔡德坤, 杨平. 1989. 滇西临沧复式岩基特征研究. 云南地质, 8(3-4): 189-204
[104] 刘德利, 刘继顺, 张彩华, 周余国. 2008. 滇西南澜沧江结合带北段云县花岗岩的地质特征及形成环境. 岩石矿物学杂志, 27(1): 23-31
[105] 刘登忠, 王国芝, 李佑国, 朱利东, 陶晓风, 徐新煌. 1999. 澜沧江结合带北段同位素地质年代学研究新进展. 中国区域地质, 18(3): 334-335
[106] 刘海龄, 王子江, 施小斌, 丘学林, 张伯友, 阎贫, 夏斌. 2004. 古特提斯缝合带澜沧江段花岗岩高温高压实验模拟. 热带海洋学报, 23(2): 10-18
[107] 刘俊来, 王安建, 曹淑云, 邹运鑫, 唐渊, 陈越. 2008. 滇西点苍山杂岩中混合岩的地质年代学分析及其区域构造内涵. 岩石学报, 24(3): 413-420
[108] 罗君烈. 1994. 滇西特提斯的演化及主要金属矿床成矿作用, 地质专报: 四·45. 北京: 地质出版社
[109] 米云川, 方沛英, 胡永兴, 张有名. 2012. 澜沧江中段昌都-普洱地块构造单元划分与演化. 云南地质, 31(4): 512-515
[110] 莫宣学, 路凤香, 沈上越, 朱勤文, 侯增谦. 1993. 三江特提斯火山作用与成矿. 北京: 地质出版社, 1-267
[111] 莫宣学, 沈上越, 朱勤文, 须同瑞, 魏启荣, 谭劲, 张双全, 程惠兰. 1998. 三江中南段火山岩-蛇绿岩与成矿. 北京: 地质出版社, 1-128
[112] 牟传龙, 余谦. 2002. 云南兰坪盆地攀天阁组火山岩的Rb-Sr年龄. 地层学杂志, 26(4): 289-292
[113] 彭头平. 2006. 澜沧江南带三叠纪碰撞后岩浆作用、岩石成因及其构造意义. 博士学位论文. 广州: 中国科学院广州地球化学研究所, 1-108
[114] 彭头平, 王岳军, 范蔚茗, 刘敦一, 石玉若, 苗来成. 2006. 澜沧江南段早中生代酸性火成岩SHRIMP锆石U-Pb定年及构造意义. 中国科学(D辑), 36(2): 123-132
[115] 秦元季. 1991. 滇西临沧花岗岩基的基本特征和构造侵位机制. 博士学位论文. 北京: 中国地质科学院地质研究所, 1-78
[116] 沈上越, 冯庆来, 刘本培, 莫宣学. 2002. 三江地区南澜沧江带火山岩构造岩浆类型. 矿物岩石, 22(3): 66-71
[117] 施小斌, 丘学林, 刘海龄, 储著银, 夏斌. 2006a. 滇西临沧花岗岩基冷却的热年代学分析. 岩石学报, 22(2): 465-479
[118] 施小斌, 丘学林, 刘海龄, 储著银, 夏斌. 2006b. 滇西临沧花岗岩基新生代剥蚀冷却的裂变径迹证据. 地球物理学报, 49(1): 135-142
[119] 宋彪, 张玉海, 万渝生, 简平. 2002. 锆石SHRIMP样品靶制作、年龄测定及有关现象讨论. 地质论评, 48(增刊): 26-30
[120] 宋述光, 季建清, 魏春景, 苏犁, 郑亚东, 宋彪, 张立飞. 2007. 滇西北怒江早古生代片麻状花岗岩的确定及其构造意义. 科学通报, 52(8): 927-930
[121] 孙会磊. 2011. 三江地区南澜沧江带临沧花岗岩的地球化学、年代学与成因. 硕士学位论文. 北京: 中国地质大学, 1-73
[122] 孙会磊, 董国臣, 莫宣学, 赵志丹, 朱弟成, 王硕, 李荣, 王乔林. 2012. 滇西三江地区临沧花岗岩的岩石成因: 地球化学、锆石U-Pb年代学及Hf同位素约束. 岩石学报, 28(5): 1438-1452
[123] 王保弟, 王立全, 强巴扎西, 曾庆高, 张万平, 王冬兵, 程万华. 2011. 早三叠世北澜沧江结合带碰撞作用: 类乌齐花岗质片麻岩年代学、地球化学及Hf同位素证据. 岩石学报, 27(9): 2752-2762
[124] 王立全, 李定谋, 管士平, 须同瑞. 2002. 云南德钦鲁春-红坡牛场上叠裂谷盆地"双峰式"火山岩的Rb-Sr年龄值. 沉积与特提斯地质, 22(1): 65-70
[125] 王硕. 2011. 澜沧江南带三叠纪火山岩岩石学、地球化学、年代学特征及其构造意义. 硕士学位论文. 北京: 中国地质大学, 1-67
[126] 王硕, 董国臣, 莫宣学, 赵志丹, 朱弟成, 孔会磊, 王霞, 聂飞. 2012. 澜沧江南带三叠纪火山岩岩石学、地球化学特征、Ar-Ar年代学研究及其构造意义. 岩石学报, 28(4): 1148-1162
[127] 吴世泽, 陶有义, 冯国荣, 卫管一, 罗再文. 1984. 澜沧群、崇山群变质火山岩系特征. 云南地质, 4(4): 439-446
[128] 谢力华. 2000. 滇西澜沧江岩浆-变质-构造活动带铜(金)多金属找矿远景研究. 博士学位论文. 长沙: 中南大学, 1-155
[129] 熊家镛. 1989. 云南地层概述. 云南区域地质, 7: 10-31
[130] 徐夕生, 蔡德坤, 朱金初, 刘昌实. 1987. 滇西澜沧江碰撞带海西-印支期花岗岩类的特征和成因. 大地构造与成矿学, 11(3): 247-258
[131] 许志琴, 杨经绥, 李文昌, 李化启, 蔡志慧, 闫臻, 马昌前. 2013. 青藏高原中的古特提斯体制与增生造山作用. 岩石学报, 29(6): 1847-1860
[132] 杨鑫, 刘燕红, 孙国强, 刘兴旺, 王保忠, 郑建京. 2010. 滇西三江地区中生代盆-山动力学耦合初论. 地质论评, 56(2): 196-204
[133] 杨岳清, 杨建民, 徐德才, 杨建华. 2006. 云南澜沧江南段火山岩演化及其铜多金属矿床的成矿特点. 矿床地质, 25(4): 447-462
[134] 叶伯丹等. 1986. 全国同位素年龄数据汇编(第3和第4集). 北京: 地质出版社
[135] 俞赛赢, 李昆琼, 施玉萍, 张惠华. 2003. 临沧花岗岩基中段花岗闪长岩类研究. 云南地质, 22(4): 426-442
[136] 云南省地质矿产局. 1990. 云南省区域地质志. 北京: 地质出版社
[137] 翟明国, 从柏林, 乔广生, 张儒瑗. 1990. 中国滇西南造山带变质岩的Sm-Nd和Rb-Sr同位素年代学. 岩石学报, 6(4): 1-11
[138] 翟明国, 从柏林. 1993. 对于点苍山-石鼓变质带区域划分的意见. 岩石学报, 9(3): 227-239
[139] 张波. 2007. 滇西澜沧江构造带新生代左行挤压走滑(Transpression)的运动学特征和变形机制. 博士学位论文. 北京: 北京大学, 1-99
[140] 张彩华, 刘继顺, 张洪培, 刘卫明, 吴自成. 2012. 滇西南澜沧带晚三叠世富钾火山岩地球化学特征及成因. 中国有色金属学报, 22(3): 669-679
[141] 张海, 金灿海, 范文玉, 沈战武, 张玙, 高建华. 2013. 云南景谷半坡铂钯多金属矿床辉长岩锆石U-Pb同位素定年及其意义. 中国地质, 40(5): 1433-1442
[142] 张玉泉, 夏斌, 梁华英, 刘红英, 林清茶. 2004. 云南大平糜棱岩化碱性花岗岩的锆石特征及其地质意义. 高校地质学报, 10(3): 378-384
[143] 赵靖, 钟大赉, 王毅. 1994a. 滇西澜沧变质带的变形序列与变质作用初步研究. 地质科学, 29(4): 366-372
[144] 赵靖, 钟大赉, 王毅. 1994b. 滇西澜沧变质带变质作用和变形作用的关系. 岩石学报, 10(1): 27-40
[145] 钟大赉. 1998. 滇川西部古特提斯造山带. 北京: 科学出版社, 1-231
[146] 钟维敷, 冯庆来, Chonglakmani CP, Monjai D, 张志斌. 2012. 老挝与云南二叠纪-三叠纪地层对比及其构造意义. 地球科学, 37(S2): 73-80
[147] 朱勤文, 沈上越, 杨开辉, 薛迎喜. 1991. 澜沧江带火山岩构造-岩浆类型与特提斯演化. 见: 青藏高原地质文集(21). 北京: 地质出版社, 125-140
[148] 朱勤文. 1993. 滇西南澜沧江带三叠纪火山岩大地构造环境. 岩石矿物学杂志, 12(2): 134-143
[149] 朱勤文, 张双全, 谭劲. 1998. 确定南澜沧江缝合带的火山岩地球化学证据. 岩石矿物学杂志, 17(4): 298-307
[150] 朱勤文, 张双全, 谭劲. 1999. 南澜沧江结合带火山岩岩浆成因——洋脊-洋岛与弧岩浆作用的性质. 现代地质, (2): 137-142