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| 1 | Tectonics of South China Continent and its implications显示文摘This paper aims at exploring the tectonic characteristics of the South China Continent(SCC)and extracting the universal tectonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic system.For this purpose,here we conduct a multi-disciplinary investigation and combine it with the previous studies to reassess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks,three types of tectonic units,four deformation systems,and four evolutionary stages with distinctive mechanism and tectonic characteristics since the Neoproterozoic.The four evolutionary stages are:(1)The amalgamation and break-up of the Neoproterozoic plates,typically the intracontinental rifting.(2)The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics,forming two composite tectonic domains.(3)The parallel operation of the Yangtze cratonization and intracontinental orogeny,and multi-phase reactivation of the Yangtze craton.(4)The association and differentiation evolution of plate tectonics and intracontinental tectonics,and the dynamic characteristics under the Meso-Cenozoic modern global plate tectonic regime. | ZHANG GuoWei GUO AnLin WANG YueJun LI SanZhong DONG YunPeng LIU ShaoFeng HE DengFa CHENG ShunYou LU RuKui YAO AnPing | 2013 | Science China Earth Sciences2013，56，11： | 88 |
| 2 | 河南登封地区嵩山石英岩碎屑锆石U-Pb年代学、Hf同位素组成及其地质意义显示文摘对河南登封地区广泛分布的古元古代嵩山石英岩中碎屑锆石进行了U-Pb定年和Hf同位素研究.研究结果对华北克拉通太古宙地壳的形成和演化提供了进一步的制约.嵩山石英岩碎屑锆石具有4组峰值年龄,其中以~2.50Ga的年龄峰值最为显著.此外尚有3.40,2.34Ga,2.75~2.80Ga等3组峰值年龄.嵩山石英岩中3.40Ga碎屑锆石的Hf同位素组成与华北克拉通东部发现的古老岩石中的锆石(如冀东和鞍山地区)具有较强的相似性.但是,根据最新的一些报道,华北克拉通南缘、华南地区、北秦岭构造带及其邻区均发现存在3.6Ga,甚至更为古老的地壳物质线索.因此很难明确地推测嵩山石英岩中发现的这些3.40Ga碎屑锆石的物源区.但综合迄今的研究成果,可以推测,3.4~3.6Ga的地壳物质曾经广泛地存在于古华北克拉通及其邻区.2.77~2.80Ga的碎屑锆石所占分额较小,样品中εHf(t)值最高可达6.1±1.6,接近于当时亏损地幔的Hf同位素值组成,且锆石的Hf单阶段模式年龄与形成年龄相近,表明其来于亏损地幔分异出的未经演化的物质.~2.50Ga的年龄数据约占所测数据的85%,锆石的Hf同位素组成显示其岩浆成因以新太古代地壳再造为主,伴有少量古老地壳物质的再循环.本次研究中获得最年轻的锆石年龄为(207Pb/206Pb)为(2337±23)Ma,可以作为嵩山群的下限年龄考虑(古元古代早期). | 第五春荣 孙勇 袁洪林 王洪亮 钟兴平 柳小明 | 2008 | 科学通报2008，53，16： | 64 |
| 3 | 扬子陆核的生长和再造:锆石U-Pb年龄和Hf同位素研究显示文摘对宜昌三峡附近崆岭杂岩中混合岩、片麻岩和变沉积岩以及莲沱砂岩进行了锆石U-Pb和Hf-O同位素研究,研究结果深化了我们对扬子陆核生长和再造的认识。在莲沱砂岩中发现了老达3.8Ga的碎屑锆石,说明扬子陆块可能存在这个年龄的地壳物质;其Hf同位素组成指示初生地壳生长出现在4.0Ga。崆岭杂岩中混合岩和片麻岩的U-Pb年龄表明,在3.2~3.3Ga和2.9~3.0Ga有两期重要的岩浆活动,指示扬子陆核可能于中太古代就开始形成。锆石Hf同位素研究则指示,其原岩至少从3.5Ga就开始从亏损地幔分异出来。混合岩和变沉积岩中所记录的1.9~2.0Ga变质事件,是扬子陆核再造并发生克拉通化的主要时期。而广泛分布于扬子陆块周边的新元古代岩浆活动不仅导致了许多太古宙和古元古宙地壳重熔,而且引起了初生地壳的快速再造。 | 张少兵 郑永飞 | 2007 | 岩石学报2007，23，2： | 45 |
| 4 | 扬子克拉通北缘约2.5Ga岩浆事件:来自南秦岭陡岭杂岩锆石U-Pb年代学和Hf同位素证据显示文摘陡岭杂岩是南秦岭构造带中发育于新元古代-古生代浅变质-未变质地层中的一个结晶基底,地质年代学研究基础薄弱. 本文对构成陡岭杂岩主体的条带状闪长质-花岗质片麻岩进行LA-MC-ICPMS锆石U-Pb定年,获得5个样品的原岩侵位年龄分别为2469±22,2479±12,2497±21,2501±17和2509±14 Ma,同时在变质沉积岩中也得到一个约2.48 Ga的重要峰值,证明在扬子克拉通北缘存在2.51-2.47 Ga的岩浆活动. 由锆石Hf同位素分析获得的εHf(t)值介于-5.5-+0.3之间,计算出的两阶段Hf模式年龄为3.30-2.95 Ga. 考虑到3.3-3.2和2.95-2.90 Ga是扬子克拉通地壳两个重要生长时期,推测陡岭杂岩中的闪长质-花岗质片麻岩是扬子克拉通北缘古-中太古代地壳在约2.5 Ga再造的产物. 此外,在一个闪长质片麻岩和变质沉积岩中获得变质锆石增生边的年龄分别为837±8和818±10 Ma,说明陡岭杂岩的主期角闪岩相变质作用发生在新元古代,其地质意义有待于进一步明确. | 胡娟 刘晓春 陈龙耀 曲玮 李怀坤 耿建珍 | 2013 | 科学通报2013，58，34： | 49 |
| 5 | 南秦岭武当山群碎屑锆石U-Pb年代学及其地质意义显示文摘报道了武当山群沉积地层碎屑锆石的U-Pb年代学特征,并对其地质意义进行了探讨.样品采自武当山群底部的杨坪组和中部双台组火山岩层之上的石英砂岩,并对切割两地层组水系中的河砂进行了采集.对碎屑锆石进行激光剥蚀-等离子体质谱原位分析,结果显示,杨坪组碎屑锆石的年龄主要为830~780Ma,少数为新元古代早期(约1.0~0.84Ga),含少量新太古代(~2.6Ga)、古元古代(~2.4Ga)和中元古代(~2.0Ga)锆石;双台组砂岩除少量的1.9~0.86Ga锆石外,主要由~755Ma的锆石(交点年龄)组成,与武当山群火山岩形成年龄相同.两件河砂样品中碎屑锆石的年龄组成分别与杨坪组和双台组砂岩锆石相似.武当山群碎屑锆石的U-Pb年代学特征表明,该地层的最早形成时代<780Ma;主要由约1.0~0.85和约830~780Ma两组碎屑锆石组成,与华南陆块西北缘汉南地区新元古代岩浆作用记录相似,指示了其物源区来自汉南或相似地区.武当山地区记录了~755和~680Ma两期具陆内拉张性质的岩浆事件,指示其经历了与汉南地区不同的构造-岩浆演化过程.因此,南秦岭地区~755Ma岩浆作用可能指示了华南陆块北缘与Rodinia超大陆之间的裂解事件,而~680Ma发生的岩浆事件标志了南秦岭与另一未知陆块之间的进一步分离. | 凌文黎 段瑞春 柳小明 程建萍 毛新武 彭练红 刘早学 杨红梅 任邦方 | 2010 | 科学通报2010，55，12： | 35 |
| 6 | U-Pb dating of detrital zircons from the Wudangshan Group in the South Qinling and its geological significance显示文摘U-Pb dating was made by the LA-ICP-MS method for detrital zircons from the Wudangshan volcanic-sedimentary succession in the South Qinling. Samples comprise quartz sandstones of the Wudangshan Group collected from the base of the Yangping For-mation and an upper layer of the Shuangtai Formation overlain its volcanic sequence, and two river-sand collections from the drainage systems cutting across the two formations, respectively. The results show that the Yangping detrital zircons are domi-nated by 830–780 Ma grains with a minor population of ~1.0–0.84 Ga and sporadic grains of ~2.6, ~2.4 and 2.0 Ga, whereas the Shuangtai zircons yield an upper intercept age of 763±33 Ma, identical to the timing of the Wudangshan volcanism within error, with few concordant grains of 1.9 and 0.86 Ga. Age spectra for the two river-sand samples are similar to those of the Yangping and Shuangtai Formations, respectively. It thus suggests that the Wudangshan strata are less than 780 Ma, whereas their major detrital zircon populations of 1.0–0.85 Ga and 830–780 Ma are consistent with timing of the Hannan magmatic activities along the northwestern margin of the South China Block. This suggests a Hannan or adjacent area provenance for the Wudangshan strata. The Wudang area is characterized by rift-related igneous events at ~755 and ~680 Ma, respectively, pointing to a tectono-magmatic history different from the Hannan area. It is inferred that the ~755 Ma magmatism is likely to indicate a separation of the South China Block from the supercontinent Rodinia, while the ~680 Ma event suggests a further split between the South Qinling and some unknown continent. | LING WenLi DUAN RuiChun LIU XiaoMing CHENG JianPing MAO XinWu PENG LianHong LIU ZaoXue YANG HongMei REN BangFang | 2010 | Chinese Science Bulletin2010，55，22： | 24 |
| 7 | 桂东早古生代地层碎屑锆石U-Pb同位素年代学及其对华夏陆块加里东期构造事件性质的约束显示文摘对广西东部大瑶山-大明山地区分别位于早古生代不整合面之下和之上的寒武纪和泥盆纪地层进行了系统的碎屑锆石U-Pb同位素年代学研究.除少数为早太古宙锆石外,寒武纪地层碎屑锆石的年龄主要有2.7~2.6、~1.8、1.4~1.1和~1.0Ga四组峰值及分别为250Ma和105Ma的热液改造年龄记录;泥盆纪地层碎屑锆石除少数具有古太古代年龄外,其余主要形成于~1.7和~1.0Ga,并记录了强烈的~100Ma的热改造事件.这些特征表明,研究区具有华夏陆块的属性,扬子与华夏陆块的边界应位于该区西北以远;经加里东构造事件后,研究区沉积盆地的物源区发生了改变,因而加里东期岩浆作用在本区并没有显示.结合前人研究成果分析,加里东事件可能指示了已裂开古陆块与华夏陆块间发生的斜向碰撞,而大瑶山-大明山地区为沿垂直于该碰撞方向挤压形成的被动盆地.区域地层中部分碎屑锆石U-Pb同位素组成的重置和热液锆石的形成,反映了研究区在印支期和燕山期存在大规模流体参与的热改造事件,这些热液对流作用应是导致本地区乃至整个华南褶皱带陆缘Au-Cu多金属矿带形成的重要原因之一. | 李青 段瑞春 凌文黎 胡明安 张军波 杨振 | 2009 | 地球科学(中国地质大学学报)2009，34，1： | 22 |
| 8 | Crustal evolution of the Shiwandashan area in South China:Zircon U-Pb-Hf isotopic records from granulite enclaves in Indo-Sinian granites显示文摘标明日期的 U-Pb 在东南的 Guangxi 省从 Shiwandashan 区域在 Jiuzhou peraluminous 花岗石从 metasedimentary granulite 被外国领地包围的土地在锆石上结合了 Hf 同位素分析,华南在这份报纸被介绍。结果证明这些 granulite 被外国领地包围的土地的 protoliths 主要由有一座山峰的碎屑状的材料在 822 妈变老的 Neo-Mesoproterozoic (5641061 妈) 组成。这些材料可能从在 Rodinian Supercontinent 的 Neoproterozoic 决裂期间是 emplaced 的火的岩石被导出。辅助沉积包括 Paleoproterozoic (17782227 妈) ,有最旧的 U-Pb 的甚至 Meso-Paleoarchean 材料在 3551 | ZHAO Liang GUO Feng FAN WeiMing LI ChaoWen QIN XiaoFeng LI HongXia | 2010 | Chinese Science Bulletin2010，55，19： | 18 |
| 9 | Detrital Zircon Geochronology and Provenance of Core Sediments in Zhoulao Town,Jianghan Plain,China显示文摘In our study,the U-Pb age spectrum of detrital zircons from terrigenous sediments is used to determine the sources.The Middle and Upper Reaches of the Yangtze River drain the western Yangtze craton and eastern Tibetan plateau,and take lots of sediments to the Jianghan (江汉) plain.Detrital zircons collected from Zhoulao (周老) core provide an ideal sample for the provenance studies.Here we report LA-ICP-MS U-Pb ages of 125 detrital zircons from one sand sample in the core sediments,which is recovered from a depth of 86.76-88.58 m and the paleomagnetic age is about 800 kaBP,in Zhoulao Town.The 125 zircons reveal nine major age peaks of >3.0,2.5-2.3,2.0-1.7 Ga,838-723,453-415,257,212,166 and <17 Ma.Only two zircons have ages of 14.8 and 16.5 Ma,their appearance indicates that the headwater of the Yangtze River had reached the Tibetan plateau about 800 ka ago.Our results also show that the Hanjiang (汉江) River did not influence the sediments of the Zhoulao core obviously at that time. | 王节涛 李长安 杨勇 邵磊 | 2010 | Journal of Earth Science2010，21，3： | 13 |
| 10 | Detrital Zircon Ages of Hanjiang River:Constraints on Evolution of Northern Yangtze Craton,South China显示文摘Clastic sedimentary rocks are natural samples of the exposed continental crust over large areas. The Hanjiang (汉江) River drains the northern Yangtze craton,including the South Qinling (秦岭) belt and the northern parts of the Yangtze craton. Detrital zircons from this river thus provide an ideal sample for studying the formation and evolution of the northern Yangtze craton. Here we report laser ablation inductively coupled plasma mass spectrometer U-Pb ages of 122 detrital zircons from one sand sample of the Hanjiang River. The 110 concordant zircons reveal four major age groups of 768,444,212,and 124 Ma,which well correlate with known magmatic events in the northern Yangtze craton. A minor group is present at 1 536 Ma,which is less known in the study area. Only seven zircons have ages of >1 750 Ma. Our results show that the Early Paleozoic,Late Triassic,and Early Cretaceous are important episodes of zircon growth and crustal growth/reworking in addition to the previously documented Neoproterozoic event. Our results suggest very limited exposures of Paleoproterozoic and Archean rocks in the northern parts of the Yangtze craton. | 杨婕 高山 袁洪林 弓虎军 张红 谢士稳 | 2007 | Journal of China University of Geosciences2007，18，3： | 12 |
| 11 | Formation and evolution of the Archean continental crust of China:A review显示文摘The mainland of China is composed of the North China Craton,the South China Craton,the Tarim Craton and other young orogehie belts.Amongst the three cratons,the North China Craton has been studied most and noted for its widely-distributed Archean basement rocks.In this paper,we assess and compare the geology,rock types,formation age and geochemical composition features of the Archean basements of the three cratons.They have some common characteristics,including the fact that the crustal rocks prior to the Paleoarchean and the supracrustal rocks of the Neoarehean were preserved,and Tonalite-Trondhjemtite- Granodiorite (TTG)magmatism and tectono-magmatism occurred at about 2.7 Ga and about 2.5 Ga respectively.The Tarim Craton and the North China Craton show more similarities in their early Precambrian crustal evolution.Significant findings on the Archean basement of the North China Craton are coneluded to be:(1)the tectonic regime in the early stage (>3.1 Ga)is distinct from modem plate tectonics;(2)the continental crust accretion occurred mostly from the late Mesoarchean to the early Neoarehean period;(3)a huge linear tectonic belt already existed in the late Neoarchean period,suggesting the beginning of plate tectonics;and (4)the preliminary cratonization had already been completed by about 2.5 Ga. Hadean detrital zircons were found at a total of nine locations within China.Most of them show clear oscillatory zoning,sharing similar textures with magmatic zircons from interrnediate-felsic magmatic rocks. This indicates that a fair quantity of continental material had already developed on Earth at that time. | Yu-sheng Wan Shou-jie Liu Hang-qiang Xie Chun-yan Dong Yuan Li Wen-qian Bai Dun-yi Liu | 2018 | China Geology2018，1，1： | 12 |
| 12 | 黄河源头区碎屑锆石U-Pb年龄及其地质意义显示文摘利用LA-ICP-MS分析技术,对黄河源头区沉积物碎屑锆石进行U-Pb年代学研究,据此分析黄河源头区地壳物质的来源.结果显示,黄河沉积物碎屑锆石年龄主要分布于以下区间:200—230 Ma、240—320 Ma、350—490 Ma、1700—2000 Ma和2300—2650 Ma,少量碎屑锆石年龄分布于700—900 Ma.分析表明,1700—2000 Ma和2300—2650 Ma的碎屑锆石主要来自于华北块体;350—490 Ma的碎屑锆石主要来自于东昆仑造山带、祁连造山带、柴达木板块和秦岭造山带;240—320 Ma的碎屑锆石主要来自于东昆仑造山带和柴达木板块北缘;200—230 Ma的碎屑锆石来自于区域内出露的印支期花岗岩.由于黄河源头区沉积物主体反映了松潘—甘孜造山带西部三叠系沉积物的组成,因此,碎屑锆石年龄结构指示该区三叠系沉积物主要来自于华北块体、东昆仑造山带、柴达木板块、祁连造山带和秦岭造山带,无明显扬子块体和大别造山带地壳物质的加入.松潘—甘孜造山带西部与东北部在沉积物源组成上具有较好的一致性,反映它们属于同一个沉积中心. | 郭亮 张宏飞 徐旺春 蔡宏明 | 2008 | 自然科学进展2008，18，12： | 8 |
| 13 | A^2.5 Ga magmatic event at the northern margin of the Yangtze craton:Evidence from U-Pb dating and Hf isotope analysis of zircons from the Douling Complex in the South Qinling orogen显示文摘The poorly studied Douling Complex is a crystalline basement that developed in the Neoproterozoic-Paleozoic weakly metamorphosed to non-metamorphosed strata at the South Qinling tectonic belt.Five banded dioritic-granitic gneiss samples from the Douling Complex were chosen for LA-MC-ICPMS U-Pb zircon dating,which yielded protolith emplacement ages of 2469±22Ma,2479±12 Ma,2497±21 Ma,2501±17 Ma and 2509±14 Ma,respectively.An important peak age of^2.48 Ga was also obtained for a metasedimentary rock in the same region.These discoveries suggest the occurrence of magmatic activity of2.51–2.47 Ga at the northern margin of the Yangtze craton.The age-correctedεHf(t)values obtained from in situ zircon Hf isotopic analysis are mainly between 5.5 and+0.3,and the two-stage zircon Hf model ages range from 3.30 to 2.95 Ga.Considering two important periods of^3.3–3.2 Ga and^2.95–2.90 Ga for the continental crustal growth in the Yangtze craton,we infer that the dioritic-granitic gneisses from the Douling Complex are the products of reworking of Paleo-to Mesoarchean crust at the northern margin of the Yangtze craton at^2.5 Ga.In addition,metamorphic ages of 837±8 Ma and 818±10 Ma were obtained for zircon overgrowth rims from a dioritic gneiss and a metasedimentary rock,indicating that the main phase amphibolite facies metamorphism of the Doulng Complex occurred during the Neoproterozoic,although its geological meaning remains ambiguous. | HU Juan LIU XiaoChun CHEN LongYao QU Wei LI HuaiKun GENG JianZhen | 2013 | Chinese Science Bulletin2013，58，28： | 6 |
| 14 | Detrital Zircon U-Pb Geochronologyof Sinian–Cambrian Strata in the Eastern Guangxi Area, China显示文摘The Eastern Guangxi area locates in the southwestern part of the transition zone between Yangtze and Cathaysia blocks, which is an important region because the boundary between two blocks probablycrosses there. We determined LA-ICPMS U-Pb ages for detrital zircons extracted from three sandstone samples in the Sinian-Cambrian strata in this region. The resulting ages are in the range of the Archeozoic and Neoproterozoic, with three notable concentrates at 991 Ma, 974 Ma, and 964 Ma, all of which are coeval to the Grenvillian magmatic activity. The new age distribution is similar to the data reported in the Precambrian strata of the adjacent southwestern Cathaysia Block, suggesting that most of our detrital zircons are likely derived from the Cathaysia Block. Combined with others' research, we are more inclined to accept the opinion that there was not an ocean basin between the two blocks during the Sinian-Cambrian period in Eastern Guangxi area if the timing of collision is the Early Neoproterzoic. But if the timing of collision is the Early Paleozoic, we conclude that Luzhai uplift(i.e., the uplift between Guilin-Yongfu faultand Lipu fault) beyond the west of Dayaoshan regoin might be one part of southwestern sedimentation boundary of Cathaysia Block and Yangtze Block. We also get a few of detrital zircons with ages of ~590 Ma which probably sourced from northeastern Gondwana and 13 detrital zircons with over 3 000 Ma U-Pb ages which record the early formation of the earth. | Ruxin Ding Heping Zou Kyoungwon Min Feng Yin Xiaodong Du Xuxuan Ma Zhangxin Su Wenjie Shen | 2017 | Journal of Earth Science2017，28，2： | 5 |
| 15 | 高邮凹陷戴南组稀土元素和锆石U-Pb年代特征及构造意义显示文摘通过对苏北盆地高邮凹陷古近系戴南组一段35件泥岩样品的稀土元素和4件碎屑岩的锆石U-Pb年代学分析,对苏北戴南组地层的物源及苏北盆地基底构造演化进行了深入探讨,恢复了沉积盆地与源区之间的耦合关系。全岩稀土元素特征表明苏北盆地古近系戴南组沉积物主要来自大别—苏鲁造山带广泛分布的新元古代浅变质酸性火成岩,具体母岩可能为高钾I型花岗片麻岩。376组协和年龄数据主要集中在2450~2600Ma、1700~2000Ma、750~850Ma、100~300Ma四个区间,其中2450~2600Ma这个年龄峰与全球新太古代晚期古陆核生长事件基本一致;1700~1900Ma这组年龄指示下扬子陆块东北部存在古元古代变质和岩浆事件,说明下扬子地块存在古元古代统一变质基底;750~850Ma这组年龄为指示扬子与华夏板块最终聚合的年龄;在100~300Ma这个年龄段中,250~300 Ma年龄锆石指示扬子地块发生裂解导致玄武岩喷发及后期伴生酸性岩浆侵入;200~250Ma为三叠纪华南陆块俯冲进入华北陆块之下形成大陆碰撞型造山带构造事件在本区的记录;100~200Ma对应于侏罗纪-白垩纪(燕山期),指示苏北盆地及周围有晚白垩纪侵入岩物源的存在,大别山-苏鲁造山带侵入岩的侵位时间可能要推迟到晚白垩世。本次测试最小年龄为94±2Ma,早于仪征运动的时间(83.5Ma),说明高邮凹陷南部陡坡带戴南组沉积物多为再旋回沉积物,沉积物来自扬子地块基底的古老岩石和大别—苏鲁造山带的新元古代浅变质岩基底,并受张八岭隆起区南段的中生代火成岩影响。 | 周健 李迪 林春明 张妮 于洪洲 张关龙 张奎华 | 2018 | 地质学报2018，92，12： | 2 |
| 16 | 黄陵基底北部古元古代洋板块地质与石墨成矿显示文摘湖北省黄陵基底北部(简称北黄陵)是中国南方重要的晶质石墨矿产地。石墨赋存在前寒武纪基底中,其形成过程与古元古代地质过程关系密切。北黄陵发育相对完整的水月寺俯冲增生杂岩(含蛇绿岩),其记录了古元古代洋板块形成、俯冲消减以及最终陆—陆碰撞造山的地质过程,是开展洋板块地质研究的理想对象。北黄陵古元古代洋板块演化过程中的早期海相沉积作用提供了石墨矿形成的炭质,中晚期变质、岩浆—混合岩化事件导致了石墨成矿。区域古元古代洋板块的物质厘定、结构划分及演化过程解剖有助于认识石墨成矿作用,并指导找矿。 | 陈超 朱江 | 2021 | 资源环境与工程2021，35，6： | 2 |
| 17 | Zircon U–Pb Ages and Lu–Hf Isotope of the Dongchuan Group in Central Yunnan, China, and their Geological Significance显示文摘On the southwestern margin of the Yangtze Block, the Dongchuan Group consists of slightly metamorphosed sedimentary rocks, including silty slate, argillaceous slate, clayey slate, arkose, dolomite, and minor volcanic rocks. To date, it is still a controversy over the depositional age and stratigraphic sequence of the Dongchuan Group. In this study, we analyzed five samples of meta-sedimentary rocks and one sample of meta-tuff from the Yinmin, Luoxue and Etouchang Formations of the Dongchuan Group in the Yuxi region for detrital zircon U-Pb ages and Lu-Hf isotope. The detrital zircon ages of the meta-sediments vary from 3073 to 1703 Ma, mainly clustered at three periods, from 1889 to 1840, 2490 to 2008 and 2878 to 2844 Ma. The youngest age peak of all the samples is ~1859 Ma, with the εHf(t) values of the zircons ranging from-20.3 to +4.3 and more than 90% being negative, indicating that the Paleoproterozoic crustal accretion on the southwestern margin of the Yangtze Block was dominated by reworking of the ancient crustal materials involved in the assembly and breakup of the Columbia supercontinent. Another important age range is between 2490 Ma and 2008 Ma, with εHf(t) values from-14.7 to +8.9 and 70% of them are negative, suggesting that the magmatism in the source area was also dominated by reworking and recycling of the ancient crustal materials, with minor juvenile mantle substances added. The detritus was probably derived from the Paleoproterozoic crystalline basement in the southern Yuxi region. The oldest peak age is ~2847 Ma and the εHf(t) values are from-7.7 to +7.0 with 50% of both positive and negative values, demonstrating a possible ~2.85 Ga ancient continental nucleus on the southwestern margin of the Yangtze Block and substantial growth in juvenile crust materials during this period. Besides, the weighted average age of the zircons from the meta-tuff of the Etouchang Formation is 1677 ± 14 Ma. Combining the previous research data and this study, we can constrain the depositional age of the Dongchuan Group in central Yunnan Province to the period from the late Paleoproterozoic to early Mesoproterozoic, slightly earlier than that of the Dongchuan Group in the Dongchuan area near to the southwestern Sichuan Province. The depositional age of the Dongchuan Group is older than that of the Kunyang Group. | HAN Kunying ZHANG Heng DING Xiaozhong REN Liudong SHI Chenglong PANG Jianfeng | 2020 | Acta Geologica Sinica(English Edition)2020，94，4： | 1 |
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