华北克拉通南缘中-新元古代沉积演化：以豫西地区黄连垛组和董家组为例*

左鹏飞 李雨 刘思聪 郑德顺**

1. 河南理工大学资源环境学院，焦作 4540002. 山东省沉积成矿作用与沉积矿产重点实验室，山东科技大学，青岛 266590

前人认为华北克拉通在中元古代到早古生代总体上处于伸展状态，未参与Rodinia超大陆的演化过程(Luetal., 2002，2008；陆松年等，2004；Zhaietal., 2015)。然而，大量古地磁及岩墙群的相关研究表明，华北在中元古代到新元古代早期与Laurentia、Siberia、Australia、India克拉通可能相邻(Hallsetal., 2000；Li and Powell，2001；Zhaietal., 2003；Peietal., 2006；Zhangetal., 2006，2009；相振群，2014；徐慧茹，2015；彭澎等，2018)。最新研究认为华北克拉通最可能与Laurentia存在某种联结(Wangetal., 2016；丁继凯，2017)，而Laurentia处于Rodinia超大陆的核心部分，发育完整的Grenville造山带(Rainbirdetal., 1992，1997，2012；Lietal., 2008；Mosheretal., 2008；Peaseetal., 2008；Spenceretal., 2015)。华北克拉通在中元古代末期发育了“芹峪抬升”和“蔚县抬升”，之后在燕辽地区缺失中元古代晚期地层(1350Ma到1100Ma)(杜汝霖等，1979；曲永强等，2010，2012；潘建国等，2013)，新元古代沉积作用也主要发育在徐淮、白云鄂博-渣尔泰-化德、熊耳地区(Huetal., 2016；潘桂棠等，2016；张克信等，2018)，最终形成了四个中-新元古代沉积盆地(图1a)。最近又在以上三个地区的中-新元古代地层中报道了大量的Grenville时期的碎屑锆石(胡波等，2009；高林志等，2010；Gaoetal., 2011；Yangetal., 2012；胡波，2013； Huetal., 2014a； Liuetal., 2014，2019；Caoetal., 2016；Heetal., 2017；杨敏，2017)。

由于华北克拉通(华北)南缘熊耳盆地内熊耳群形成时代限定于约1800～1750Ma(Zhaoetal., 2004；Heetal., 2009；Cuietal., 2011)，通过洛峪口组凝灰岩和下伏地层碎屑锆石年龄的约束，汝阳群-洛峪群的沉积时代基本限定于约1750～1600Ma，即熊耳群-汝阳群-洛峪群均形成于长城系(1800～1600Ma)(苏文博等，2012；苏文博，2016；李承东等，2017)。洛峪口组上覆黄连垛组和董家组为1980年河南地科所于鲁山下汤九女洞建立，在叶县、方城、陕县等地均有分布，时代为中元古代到新元古代早期(潘泽成，1980；关保德等，1988；河南省地质矿产局，1989)。因此，洛峪群-汝阳群被下压到长城系，导致传统上对华北南缘中-新元古代沉积和构造演化的认识需要重新调整，而上覆黄连垛组和董家组沉积环境和物源分析可为该区沉积-构造演化提供新的约束。

结合前人工作，本次通过对华北南缘黄连垛组和董家组岩石学和沉积学特征的研究，借助黄连垛组、董家组和早古生界辛集组碎屑锆石年代学分析，对比华北南缘中-新元古代沉积地层物源变化，揭示华北南缘中元古代到新元古代大地构造演化历史。

1 区域地质背景

华北南缘中元古代早期经历熊耳火山事件(1800～1750Ma)后，发育陆源碎屑岩-碳酸盐岩沉积体系(关保德等，1988；河南省地质矿产局，1989)。根据该地区中-新元古代不同沉降作用将其自北向南分为三个地层分区：嵩箕、渑池-确山和卢氏-栾川(图1b)(关保德等，1988；河南省地质矿产局，1989；河南省地质调查院，2009)。

图1 华北克拉通和北秦岭前寒武纪地质简图(a，据Dengetal., 2014a, b；Dongetal., 2014，2015；Huetal., 2014a，2016；Peng，2015修改)及豫西地区前寒武纪地质简图(b，据河南省地质调查院，2009[注]河南省地质调查院. 2009. 河南省矿产资源潜力评价；陕西省地质调查院，2009[注]陕西省地质调查院. 2009. 陕西省矿产资源潜力评价修改)

Fig.1 The location of the study area within the North China Craton(NCC)and North Qinling Terrane(NQT)(a，modified after Dengetal., 2014a, b；Dongetal., 2014，2015；Huetal., 2014a，2016；Peng，2015)，and simplified geological map of the western Henan(b)

渑池-确山地区在发育熊耳群火山-沉积岩之后，发育了冲积扇-扇三角洲相沉积地层(兵马沟组或小沟背组)，与上覆汝阳群呈平行不整合接触(图2a)。汝阳群下部(云梦山组和白草坪组)由河流-滨海相石英砂岩过渡为潮间-潮上带的砂岩、粉砂岩和页岩，上部(北大尖组)发育了潮间带泥质粉砂岩，顶部为白云岩及白云质砂岩。上覆整合覆盖的洛峪群(崔庄组、三教堂组和洛峪口组)自下而上分别为外陆棚、滨海和潮坪沉积，其顶部发育叠层石白云岩。黄连垛组为三角洲-滨浅海-碳酸盐岩沉积或滨海-潮坪沉积，董家组为三角洲-滨浅海-海湾泻湖或滨浅海-潮坪沉积，二者均与上下地层呈平行不整合接触(潘泽成，1980；周洪瑞等，1999)。上覆平行不整合覆盖的罗圈组和东坡组总体上属于冰湖相沉积(Guanetal.，1986；Le Heronetal.，2018)。早古生界辛集组不整合上覆盖于东坡组或董家组之上，为滨海相含少量碳酸盐岩的硅质碎屑岩(刘印环，1986；刘印环等，1991；刘群等，1994)。

图2 华北南缘熊耳地区中-新元古代盆地岩性柱状对比(据关保德，1996；河南省地质调查院，2009)MC-渑池；YC-伊川；LS-鲁山；LB-灵宝. 渑池兵马沟组和云梦山组古流向数据依据李文超(2013); 黄连垛组和董家组古流向据张玲华(1994); 高山河组古流向据河南省地质调查院(2009)Fig.2 General stratigraphic sequences and correlation of the Meso-Neoproterozoic strata of the Xiong’er Basin (after Guan, 1996)MC-Mianchi area; YC-Yichuan area; LS-Lushan area; LB-Lingbao area. Paleocurrents data of Yunmenshan and Bingmagou formations in MC from Li(2013); Huoliangudo and Dongjia formations from Zhang(1994)

嵩箕地区主要地层自下而上为兵马沟组、五佛山群、罗圈组及东坡组(图2b)。兵马沟组为一套扇三角洲相的砾岩、含砾砂岩、粗-细砂岩和粉砂岩沉积组合(张元国等，2011；赵太平等，2015；郑德顺等，2016a；Mengetal.，2018)。五佛山群(马鞍山组、葡峪组和何家寨组)自下而上沉积于河流-滨浅海-碳酸盐岩台地环境(河南省地质矿产局，1989；席文祥和裴放，1997)。最南部的卢氏-栾川地区自下而上发育了中元古界高山河组(群)和官道口群，以及新元古界栾川群(图2c)(河南省地质矿产局，1989；高林志等，2002；Gaoetal.，2009)。高山河组(群)不整合于熊耳群之上，主要为河流-滨海相的含砾石英砂岩。官道口群(龙家园组、巡检司组、杜关组、冯家湾组和白术沟组)主要为一套潮坪-内陆棚-潮间带-浅海相的碳酸盐岩(Lietal.，2019；河南省地质调查院，2009)。栾川群沉积于潮下带-浅海环境(河南省地质矿产局，1989；蒋干清，1993；蒋干清等，1994；关保德，1996；席文祥和裴放，1997；王跃峰，2000)。古生界陶湾群不整合上覆于栾川群，岩性为变质砾岩、碎屑岩及条带状不纯大理岩，原岩可能沉积于深水斜坡相(张维吉和李育敬，1989；王宗起等，2007，2009)。

华北南缘古-中元古代(1850～1500Ma)岩浆事件，包括熊耳群火山岩、镁铁质岩墙群和A型花岗岩，记录了华北南缘在最终克拉通化之后的构造演化历史(陆松年等，2003；Pengetal.，2008；Baoetal.，2011；Peng，2015；邓小芹等，2015；Deng and Wang，2016； Dengetal.，2016；Zhao and Deng，2016；师江朋，2017)。新元古代碱性粗面岩(860Ma)、辉长岩(830Ma)和正长岩(844Ma)，代表了伸展背景下的岩浆活动(柳永清等，2005；Baoetal.，2008；阎国翰等，2010；Wangetal.，2011)。

图3 黄连垛组野外特征及微观特征(a)黄连垛组底部含燧石条带石英砾岩(下汤)；(b)黄连垛组底部石英砾岩微观特征(正交偏光)(下汤)；(c)黄连垛组含硅质条带白云岩与泥晶白云岩(叶县)；(d)黄连垛组泥晶白云岩与含硅质条带白云岩(叶县)；(e)黄连垛组泥晶白云岩微观特征(正交偏光)(叶县)；(f)黄连垛组含硅质条带白云岩中存在的软沉积物变形(叶县). Q-石英Fig.3 Outcrop photographs and micrographs of the Huanglainduo Formation(a) pebbly quartz sandstones in the bottom of the Huanglianduo Formation(Xiatang)；(b)micrographs of pebbly quartz sandstones of the Huanglianduo Formation(crossed polars)(Xiatang)；(c) siliceous banded dolomites and dolomicrites of Huanglianduo Formation(Yexian)；(d) dolomicrites and siliceous banded dolomites of the Huanglianduo Formation(Yexian)；(e)micrographs of dolomicrite of the Huanglianduo Formation(crossed polars)(Yexian)；(f)siliceous banded dolomites of the Huanglianduo Formation，interbeded with soft-sediment deformation(Yexian). Q-quartz

图4 董家组野外沉积特征与镜下特征(a)董家组底部砂砾岩(叶县)；(b)董家组下段长石石英砂岩(叶县)，向上变细；(c)董家组下段长石石英粗砂岩微观特征(正交偏光)(叶县)；(d)董家组中段长石石英砂岩与泥质粉砂岩互层(叶县)；(e)董家组中段长石石英砂岩，夹泥质粉砂岩(叶县)；(f)董家组上段紫红色钙质泥岩(叶县). F-长石；L-岩屑Fig.4 Outcrop photographs and micrographs of the Dongjia Formation(a)glutenites in the bottom of the Dongjia Formation(Yexian)；(b)fining-upward feldspar-quartz sandstones in the lower unit of the Dongjia Formation(Yexian)；(c)micrographs of feldspar-quartz sandstone from the lower unit of the Dongjia Formation(crossed polars)(Yexian)；(d)feldspar-quartz sandstones with interbedding pelitic siltstone in the middle unit of the Dongjia Formation(Yexian)；(e)feldspar-quartz sandstones of the Dongjia Formation interlayered with pelitic siltstone in the middle unit(Yexian)；(f)purple-red calcareous marls in the upmost of the Dongjia Formation(Yexian). F-feldspar；L-fragment

2 黄连垛组和董家组沉积特征

黄连垛组岩性自下而上主要为砾岩-砂砾岩-硅质条带白云岩，顶部为条带状硅质层，与上下地层均为平行不整合接触(席文祥和裴放，1997)。董家组岩性自下而上主要为砾岩-含砾粗砂岩-长石石英砂岩-粉晶白云岩夹泥晶灰岩，与上覆罗圈组或辛集组呈平行不整合接触(席文祥和裴放，1997)。黄连垛组总体上为一套海进序列的三角洲、滨海、浅海相的陆源碎屑及碳酸盐岩沉积建造，海侵方向为自西向东；董家组是另一套海进序列的三角洲、滨海、浅海相陆源碎屑和海湾泻湖相碳酸盐岩建造，海侵方向为自南向北或自西南向北，后期沉积的碳酸盐岩形成于蒸发大于补给的沉积环境(潘泽成，1980；郑伟和刘顺喜，2012)。

本次研究主要选取鲁山下汤地区和叶县地区两条剖面。下汤地区黄连垛组下段岩性为土黄色含砾石英砂岩和长石砂岩，砾石粒径0.2～8cm，平均粒径约2cm，分选磨圆较差，砾石沿轴向存在定向排列，砾石成分主要为燧石、石英岩等(图3a)，基底-孔隙式胶结，杂基支撑为主(图3b)；中段岩性为具楔状交错层理的土黄色长石石英砂岩，接触式胶结，分选差，长石风化严重；上段岩性为成层性较好的含硅质条带白云岩。下汤东南叶县地区黄连垛组主要岩性为灰白色厚层泥晶白云岩与浅黄色厚层具纹层状含硅质条带白云岩，二者具多期次旋回性(图3c, d)。叶县地区黄连垛组泥晶白云岩强烈变形(图3d)，内部发育棱角状硅质碎屑，偶见石膏假晶(图3e)；含硅质条带白云岩内多发育软沉积物变形(图3f)。下汤地区黄连垛组底部砾岩多为棱角状，少数为滚圆状，分选差，磨圆较差，沿长轴方向具定向排列特征(图3a)，沉积于河口湾环境，缺乏冲积扇-河流相沉积。因此，下汤地区黄连垛组沉积于河口湾-潮坪沉积环境，南部叶县地区沉积于潮坪沉积环境，整体表现为自南向北的海进序列。

图5 黄连垛组、董家组和辛集组样品野外和微观特征(a)黄连垛组下段英砂岩，具不明显楔状交错层理(下汤)；(b)黄连垛组下段长石石英砂岩微观特征(正交偏光)(下汤)；(c)董家组下段长石石英砂岩(下汤)；(d)董家组下段长石石英砂岩微观特征(正交偏光)(下汤)；(e)辛集组底部薄板状石英砂岩，夹薄层粉砂质泥岩(下汤)；(f)辛集组底部石英砂岩微观特征(正交偏光)(下汤)Fig.5 Outcrop photographs and micrographs of the Huanglianduo Formation, the Dongjia Formation and the Xinji Formation(a)feldspar-quartz sandstones in the lower unit of the Huanglianduo Formation(Xiatang)；(b)micrographs of feldspar-quartz sandstone in the lower unit of the Huanglianduo Formation (crossed polars)(Xiatang)；(c)feldspar-quartz sandstones in the lower unit of the Dongjia Formation(Xiatang)；(d)micrographs of feldspar-quartz sandstone in the lower unit of the Dongjia Formation (crossed polars)(Xiatang)；(e)quartz sandstones in the lower part of Xinji Formation，interbeded with mudstone(Xiatang)；(f)micrographs of quartz sandstone in the lower part of the Xinji Formation (crossed polars)(Xiatang)

图6 华北南缘黄连垛组、董家组和辛集组碎屑岩代表性碎屑锆石CL图像Fig.6 Cathodoluminescence (CL) images of representative detrital zircon grains from the Huanglianduo, Dongjia and Xinji formations clastic rocks in the southern margin of North China Craton

图7 华北南缘黄连垛组、董家组和辛集组碎屑锆石U-Pb谐和曲线图和年龄分布柱状图Fig.7 U-Pb concordia diagrams and age probability histograms for detrital zircons from the Huanglianduo, Dongjia and Xinji formations clastic rocks in the southern margin of North China Craton showing their age distributions

叶县地区董家组底部岩性主要为灰白色中细粒石英砂岩和含长石石英砂岩；下段为土黄色中细粒石英砂岩，分选较好，磨圆较好；中段为灰白色粗-中粒石英砂岩或含长石石英砂岩，岩屑及云母含量较少，颗粒支撑，分选较好，磨圆一般；上段为青灰色或暗红色薄层状泥质灰岩及薄板状泥页岩。该区辛集组为紫红色含砾砂岩-土黄色薄板状石英砂岩，夹极薄层粉砂质泥岩，石英颗粒分选较好磨圆中等，呈轻微定向排列。叶县董家组底部岩性为黄褐色块状中-细砾砂砾岩，砾径2～5mm，平均粒径3mm，矿物成分主要为石英、燧石和长石，硅质胶结，磨圆好，分选中等(图4a)；下段岩性为黄褐色或暗红色中厚层粗-中粒含石英长石砂岩(图4b)，石英颗粒偶见溶蚀边(图4c)；中段岩性为中-细粒长石石英砂岩与土黄色粉砂质泥岩互层(图4d)，砂岩具楔状交错层理和浪成层理，泥岩具水平层理(图4e)；上段岩性为厚层紫红色薄板状钙质泥岩(图4f)。因此，叶县地区董家组底部砾岩可能为滨海沉积砾岩，董家组总体上应沉积于局限海盆的滨浅海环境。

3 测年样品和分析

3.1 样品采集与处理

黄连垛组下部样品(17HLD-04)采集自鲁山县下汤镇(图1c、图5a)。该样品为黄色中细粒长石石英砂岩，主要矿物为石英(63%～65%)、长石(31%～35%)，具少量岩屑，颗粒支撑，接触式胶结，次棱角状-次圆状，石英具次生加大边，可见条纹长石、微斜长石及斜长石；岩屑多呈次棱角状(图5b)。

董家组底部样品(17DJ-02)采集自鲁山县下汤镇(图1c)，中下部样品(MLA-04-2)采集自叶县常村镇(图1c)。董家组样品(17DJ-02)为黄色长石石英砂岩(图5c)，主要矿物为石英(51%～55%)、长石(40%～43%)、岩屑(4%～6%)，偶见云母，分选较好，磨圆一般，颗粒支撑，接触式胶结；石英为次棱角状-圆状，部分石英具次生加大边；长石为次棱角状-次圆状，偶见圆状，可见具格子双晶微斜长石，表面风化严重(图5d)。另一样品(MLA-04-2)为黄褐色粗-中粒长石石英砂岩(图4b)，主要矿物为石英(61%～65%)、长石(19%～23%)、岩屑(6%～8%)，少见燧石，部分石英具溶蚀边，长石具格子双晶和条纹结构(图4c)。辛集组样品(LTXJ-1-1)采集自鲁山县下汤镇(图5e)，为薄板状石英砂岩，分选好，磨圆中等(图5f)。

锆石首先由南京宏创地质勘探技术服务有限公司选取，采用场发射扫描电子显微镜(TESCAN，Mira 3 LMH)对其进行高分辨率阴极发光(CL)成像; 通过CL和透反射图像识别锆石内部结构并选择合适位置进行碎屑锆石U-Pb年代学分析。锆石U-Pb定年由武汉上谱分析技术有限公司采用激光剥蚀电感耦合等离子体质谱法(LA-ICP-MS)完成。激光剥蚀系统为Geolas 2005，激光脉冲频率为5Hz，剥蚀点直径为32μm。黄连垛组样品(17HLD-04)和董家组样品(17DJ-02)采用Agilent 7500a；董家组样品(MLA-04-2)和辛集组样品(LTXJ-1-1)采用Agilent 7900。锆石标样91500作为本次试验标样每6次进行两次分析。利用ICP-MS Datacal软件对锆石数据进行离线选择、背景分析及信号整合，以及时间漂移校正、定量校准(Liuetal., 2010；Spenceretal., 2016)。锆石的U-Pb年龄结果使用Isoplot 3.0软件(Ludwig，2003)计算。对锆石206Pb/238U年龄小于1500 Ma，使用206Pb/238U年龄做频率直方图，207Pb/206Pb年龄用于年龄比较老的样品(206Pb/238U>1500Ma)(Spenceretal.，2016)。选择谐和度(206Pb/238U-207Pb/235U或206Pb/238U-207Pb/206Pb)大于90%的测值进行年龄分布统计。

3.2 分析结果

黄连垛组样品(17HLD-04)中碎屑锆石多为半自形或圆形，粒径为40～250μm(图6)，绝大多数锆石具有环带结构，表明其为岩浆锆石，对其随机挑选96个点位进行测试。碎屑锆石中，1颗碎屑锆石偏离U-Pb演化曲线(图7a)，谐和度低于90%(表1)。统计95颗锆石年龄主峰值为1800Ma和2350Ma，次要峰值为2650Ma和2900Ma(图7b)。

表1 华北克拉通南缘下汤地区黄连垛组碎屑锆石U-Pb同位素年龄

Table 1 Zircon U-Pb isotopic data of sedimentary rocks from the Huanglianduo Formation in the Xiatang

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)17HLD-04 (长石石英砂岩)-176870.90.16050.010110.2940.67440.46340.011324611082462612455501-244341.30.15390.01049.71590.65670.45810.012923911172408622431571-3107721.50.18430.00913.4820.66390.52790.01212692812714472732511-4841350.60.15480.0079.94160.45670.46220.01012399782429422449441-530181.70.10630.00974.79780.42150.32830.011417361671785741830553-647600.80.16970.008911.6130.57970.49260.01352555882574472582581-782621.30.15160.00859.52870.52830.45110.01182365962390512400531-8692020.30.11180.0055.38690.240.34550.00771829801883381913372-9911120.80.18610.007514.0280.58210.54130.01182709672752392789492-1070322.20.11610.00815.70260.38660.35670.009918981261932591966472-11102631.60.10530.00614.71460.26910.3230.007117201111770481804342-1219310.60.17660.009612.540.71120.51240.01392621912646532667591-13961070.90.10630.00574.7140.25190.32040.00651739981770451791322-14424210.11140.00645.00260.30660.32390.007818331051820521809381-1530251.20.11030.00794.96170.34820.32710.007918061301813591824381-16798310.1430.00578.69050.36510.43980.00892265682306382350402-171211570.80.10590.00454.77620.21070.32650.00621731781781371822303-1874920.80.14720.00659.16840.42190.45160.00932314752355422402412-1973890.80.13930.00637.99290.37930.41590.00922220782230432242421-2024580.40.14050.00638.61760.40560.44380.01042235772298432368463-2158870.70.14910.00629.3090.39860.4510.00882336722369392400392-22103941.10.15340.00729.61950.47130.45140.00942384802399452402421-2364850.80.17640.008612.170.56490.49780.01052620812618442604451-2485531.60.15510.00939.64480.53110.44940.010524031022401512392471-251721850.90.16550.007811.3150.52620.49180.01072513802549432579462-261431830.80.10870.00584.96620.25670.32980.00771777971814441837372-272185070.40.13850.00528.03830.31730.41770.00752209652235362250341-283365600.60.14970.00579.3380.38130.44910.00812342652372372391361-294143001.40.10640.00534.77180.23960.32530.00691739921780421816342-3020720610.15530.00799.89250.53410.46020.00912405922425502440401-312523170.80.15090.00749.29120.49080.44450.00872367832367482371391-32330963.40.17270.01067.05680.41720.29820.007258410321195316833523-332533000.80.15680.006310.0850.42520.46430.00852421682443392459371-342094500.50.1090.00455.00510.20550.33190.00621783761820351847302-354192621.60.15480.008810.0170.54050.47030.01412400982436502485622-361591810.90.11160.00595.03710.27390.32490.00661825971826461814321-371601740.90.19910.009215.4950.70250.56140.01132818752846432872471-387154621.60.10970.0055.04440.22810.33120.00581795831827381844281-3912011610.11480.00715.20760.30920.32890.007318771121854511833362-40991620.60.17240.009211.9260.6260.50060.01082581842599492616461-412286540.40.13730.00767.6910.46380.40160.0092194962196542176411-4221320710.19210.012214.6480.96040.54870.011227611052793622820461-431992530.80.11290.00775.230.35550.33520.007318561241858581863351-443872401.60.16010.009510.5580.64030.47540.009324571002485562507411-45731060.70.18690.010314.120.77950.5470.01222715902758522813512-462093220.70.14650.00648.86930.4040.43610.00852306802325422333381-472673440.80.11520.00695.67750.3420.35630.007518831091928521965362

续表1

Continued Table 1

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)-481292290.60.11140.00545.2310.25820.33840.0071833871858421879342-4911711610.11090.00634.94630.27850.3230.007918151021810481805381-502263510.60.1090.00444.94690.20140.32750.0061783731810341826291-514936860.70.10890.00394.97770.1850.32940.00571781711816311836282-521531980.80.11340.00525.44430.25540.34690.00781854881892401920372-532171891.20.18780.007114.270.570.5480.01092724622768382817452-5469372710.15990.0069.92820.38550.44780.00842455632428362385382-552585120.50.11120.00475.43030.23470.35250.00741820771890371947353-561241650.80.13940.00628.26660.37420.42920.00932220772261412302422-573172921.10.10440.00454.68810.19620.32530.00711706811765351815343-581221800.70.14890.0069.29130.3620.45230.00872344702367362405382-592032980.70.1420.00528.53940.32310.43490.00862251632290342328392-6032580.60.21030.010317.0090.77640.58980.01512909792935442989612-612232420.90.15610.006910.2030.47460.47210.00992415742453432493432-62129991.30.15120.00879.56350.5350.45950.0112359982394512437492-633212141.50.17980.008513.2760.62790.5320.01032651782699452750432-642483990.60.14860.00849.52030.5250.46050.00872331962390512442383-6590521.70.10.01074.49520.47220.32520.011216252011730871815555-661421770.80.16130.014111.0330.90180.4920.011824691482526762579513-672481861.30.1440.01318.97930.77980.44710.010722761582336792382482-682086030.40.1080.00815.1680.37370.34250.00717661321847621899343-692653230.80.1890.020214.3611.54490.54420.0103274417727741022801431-70193862.20.11470.00825.70170.39740.35940.008818761301932601979413-713231931.70.10350.00594.71860.26630.3290.007716871071771471834374-7256900.60.17630.009112.7010.690.51920.01392618852658512696592-732823090.90.10680.00534.82720.23630.32590.00621746911790411819302-7412712610.11210.0065.05890.28270.32490.00691835981829471814341-7591741.20.11150.00715.03930.31950.32730.007718241151826541825371-762192320.90.1440.00568.78660.34610.44050.00782276672316362353352-773574600.80.10690.00434.81410.2030.32490.00571748741787351813282-782252770.80.14870.00629.16690.40010.44530.008423312712355402374371-792112550.80.14270.00628.22450.37710.41590.00892261802256422242411-80721700.40.14360.00658.83510.40530.44450.00972272772321422371433-811772680.70.15020.00589.30990.36420.44680.00772348662369362381341-822992711.10.15380.00659.70760.43270.45350.00882389722407412411391-831952550.80.1770.007612.250.50380.49870.00952625722624392608411-842591571.70.15070.00799.41490.45670.45120.00932354912379452401411-8569880.80.16460.008110.440.48140.45510.01132503822475432418503-86861590.50.15870.006510.020.38640.45270.00982442692437362407432-87892000.40.12720.00526.48990.26010.36610.00722061712045352011342-8868332.10.16120.008710.2190.56320.4560.01042469912455512422462-89571380.40.14150.00598.05750.35090.40960.0092256722237392213412-9043580.70.11360.00645.12780.29550.32580.007818571081841491818382-91731010.70.1520.00759.25020.46370.43940.01012368832363462348451-92701260.60.14720.00698.68880.40860.42630.00862313802306432289391-9316111.50.12160.02465.36811.05750.3250.0158198936818801691814774-94585710.15660.00749.83510.4680.45470.01032419802419442416461-9531570.60.21340.009116.4740.72630.5580.01122932692905422858462-96403910.15790.0089.94560.50110.4570.01072433852430472426471

表2 华北克拉通南缘下汤地区董家组碎屑锆石U-Pb同位素年龄

Table 2 Zircon U-Pb isotopic data of sedimentary rocks from the Dongjia Formation in the Xiatang

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)17DJ-02 (长石石英砂岩)-11091610.70.11440.00535.12190.23270.32380.0061872851840391808292-226300.90.11280.00835.14380.37220.33160.008518561331843621846411-360910.70.11360.00535.15580.24320.32790.00661857831845401828321-437920.40.10730.00514.92490.23570.33090.00611755871807401843302-543650.70.13880.00687.97480.36480.41590.00872213852228412242401-639660.60.11090.0065.15220.28220.3350.00741814931845471863361-757471.20.11470.00695.64540.32970.35560.007818761091923501961372-865920.70.11240.0065.15390.26070.33190.00731839961845431848351-9981790.60.10840.00485.11660.22030.3410.0071773751839371892343-1027380.70.11020.00685.13610.30380.33840.008318031181842501879402-1119240.80.11390.00825.4390.38650.3470.010118651291891611920482-12681010.70.11030.00585.16120.27380.33830.00721806961846451878352-1352680.80.10490.00634.65280.26710.32230.007417131111759481801363-14871360.60.10960.00495.10380.23540.33610.00661792821837391868322-1522270.80.12360.00845.90930.39930.3470.009320101211963591920443-16521070.50.12160.00536.14930.26750.36520.00811980771997382007381-1734010050.30.14030.00553.59810.18630.18580.008122316915494110984435-1832410.80.11310.00655.33760.30980.340.008318501041875501887401-1951680.80.11480.00635.48270.29510.34490.00871877981898461910421-2058960.60.15640.006510.2440.42940.47150.0092417712457392490402-21401020.40.13020.00587.18660.33430.39720.0082102772135412156371-2224201.20.11930.00975.53240.44040.33830.010819461451906681878522-231122360.50.13380.00585.75830.26630.31010.007721508119404017413811-2423290.80.11270.00825.11810.34960.3310.008818421311839581843431-2553441.20.15890.008710.34350.5540.47060.010224441262466502486451-2619270.70.16710.009510.9540.62150.47520.01312528962519532506571-271501021.50.10190.00714.47660.28860.31920.009516611291727541786464-2834301.10.11140.00734.97730.31450.32550.009318221191815531816451-2945600.80.10930.00644.9950.29150.33040.007817881071818491840382-3040440.90.1150.00655.26150.28830.33140.008218801061863471845401-3114131.10.11670.0115.33170.50120.33530.012219061691874801864591-3219280.70.10840.00764.86170.35290.32480.009317721281796611813451-3323211.10.1140.00775.16920.35540.32840.009518651221848591830461-3423340.70.10910.00665.01670.30740.33350.009417841161822521855452-35581330.40.14390.00548.84320.34110.44350.00862276652322352366382-3663581.10.11290.00585.24630.26910.33650.00811856931860441870391-37982130.50.10850.00494.46920.26710.29760.01271776771725501679633-3826201.30.21760.121214.8637.9050.50460.01322965104628075062633567-3924390.60.1110.00655.05560.27930.33120.008118171061829471844391-4051610.80.11170.00625.240.28270.33980.007118281011859461886342-4126300.90.11290.00785.18940.3360.33530.009618471251851551864461-42778110.11850.00596.05090.31530.36830.00821933891983452021392-4343510.80.20610.19369.46858.03570.36030.008328751033238477919843919-4423320.70.10920.00715.12690.32540.3420.009517871201841541896463-45891130.80.11830.0055.88580.25260.35920.00651931751959371978311-4670800.90.10910.00545.03220.24020.33440.0081785901825401859382-47601550.40.13960.00528.52950.34920.44080.00962222602289372354433

续表2

Continued Table 2

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)-4875900.80.10780.00515.06520.24970.33920.00771763861830421883373-491421281.10.15180.00639.53530.42060.45410.01082366702391412413481-5065511.30.10650.0064.75890.27570.32480.009817401041778491813482-51232210.11260.00825.11740.37180.33140.010418431331839621845501-52126881.40.17930.007112.8260.52020.51620.00972647662667382683411-5323310.80.10880.00814.83530.33630.32380.008917891351791591808431-541041470.70.11190.00575.16170.26690.33260.00691831601846441851341-5519151.30.11230.01065.2090.50020.33550.011718391711854821865561-5643590.70.11340.00625.25130.2950.33390.00841855981861481857411-5718260.70.11870.00925.49350.38470.34510.01919361391900601911911-5830540.60.11280.00615.17050.28010.33060.00661844981848461841321-5929330.90.14670.03918.08182.17520.39770.0085230947222402432158394-6021610.30.11260.00595.11790.27140.32780.00711843951839451828341-6157620.90.1660.008611.2890.57580.48960.01152518872547482569501-6248620.80.10880.00634.99090.2840.33090.008417891061818481843402-63721740.40.14080.00578.15140.3370.41570.00792239702248372241361-641111880.60.15230.0069.59640.38780.45270.00852372682397372407381-651471061.40.10980.00564.93610.23760.32460.00721798931808411812351-66727110.15830.008510.1150.52380.46040.00982437912445482441431-67791040.80.15460.00789.60870.48190.44720.00932398862398462383421-68452213293.40.18020.01147.48380.45150.30090.0081265511021715416964025-69861030.80.15950.006710.2270.42860.46170.00912450712456392447401-70691510.50.11070.00485.12410.21750.33350.00651813781840361855321-71139891.60.15140.00659.87180.43070.46960.00982362732423402482433-7254610.90.110.00634.96420.29220.32480.007318001051813501813351-7354600.90.1960.009415.1150.73930.55590.01242794742822472850511-742351541.50.10910.00545.05210.25060.33380.00611785911828421857302-75403910.11310.00765.16060.34230.33080.008318501231846561842401-7633540.60.17440.010612.1340.7370.50340.011226111022615572628481-77792360.30.13250.00857.06250.49070.38280.008721311132119622089412-78727010.19140.014514.61.15460.54920.012227541252789752822512-7967860.80.11190.00895.21390.42430.3370.007718311441855691872371-80132841.60.1860.05411.8463.090.46680.0087270649825922442469385-8124360.70.18430.011613.9560.8730.54920.012126921042747592822513-82721130.60.14550.00738.72720.46580.43250.00912294862310492317411-83931200.80.11320.00595.48920.29030.35050.00761854941899451937362-8442740.60.11140.00625.16880.2960.33480.007718331011847491862371-85393910.11030.00674.81160.28380.31650.007518061051787501773371-86781210.60.11020.00484.93930.22150.32370.00641802801809381808311-871702390.70.10770.00424.83130.19330.32410.00641761721790341810312-8851680.80.11170.00585.29060.27720.34310.00791828941867451901382-8974651.10.18540.007913.9090.6150.54240.01212702692744422794502-9023524810.15950.00689.88440.42840.44760.00892450722424402385402-91871750.50.11090.00525.4410.26190.35450.00761815851891411956364-9241560.70.13810.00698.2010.41730.430.00992203872253462306443-93102961.10.10420.0054.76150.22450.33150.00761702891778401846374-9441610.70.1520.00769.38430.4630.44760.00922368862376452385411-95681010.70.14490.00728.75020.44820.43650.00932287852312472335421-9611200.50.21970.01417.5641.08850.58190.01629791032966602957651

表3 华北克拉通南缘叶县地区董家组碎屑锆石U-Pb同位素年龄

Table 3 Zircon U-Pb isotopic data of sedimentary rocks from the Dongjia Formation in the Yexian

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)MLA-04-2 (长石石英砂岩)-1751340.60.11530.0055.92160.23860.36840.00651885781964352022313-2642410.30.11190.00445.61560.20550.360.00521831711918321982254-3541160.50.11620.00476.07180.2330.37540.00581898681986332055274-4441540.30.14840.00539.73650.3370.47110.00692327612410322488304-524600.11090.00615.30120.27830.34540.00718131011869451913333-649870.60.1360.00648.44850.37840.44750.00712176832280412384325-7757210.14560.00679.37020.42070.46360.00792295782375412456354-81111770.60.13950.00538.48030.31670.43810.00662220652284342342293-9571760.30.15180.00569.94660.3630.47220.00712366632430342493313-10611620.40.14110.0058.51470.30140.43480.0062240562287322327272-11272810.15730.008310.1070.50920.46560.00942427892445472464411-12951300.70.15540.00669.94740.42290.46180.00792406722430392447351-1369730.90.15390.00739.76240.4640.4580.00762391812413442431341-1414131.10.17360.011811.4020.70150.48230.01425921132557572537611-15631360.50.13680.0057.71540.29410.40710.0072187642198342202321-1650770.60.14820.0069.1920.3580.44950.00762325712357362393342-1761850.70.16030.006610.5170.42480.47480.00812459702481372505361-18911500.60.13940.00588.11370.34860.42070.00782220722244392263351-1914600.12070.00686.08360.34260.36610.007919661011988492011372-2064700.90.15720.006310.0650.42140.46320.00872428642441392454381-21971300.80.14610.00528.82330.31820.43680.00642302612320332336291-221801081.70.19980.006715.5510.53640.56370.00922824562850332882382-2348670.70.16480.00710.970.47590.48280.00912505712521402539401-2417300.60.18090.009112.080.67230.48240.01172661842611522538513-2550570.90.15870.007610.0410.4530.46330.01452443812439422454641-26801080.70.16210.006210.8040.43830.48170.00822477652506382534362-2770790.90.15810.00610.0450.38850.45930.00792435642439362436351-28565810.14090.00597.79640.33920.39980.00772239722208392168362-29541030.50.13970.00578.14780.32830.42120.00752224712248362266341-30121450.10.11990.00496.05150.24760.36370.00651955741983362000311-31791330.60.14250.0068.32080.36190.420.0082258722267392261361-3249830.60.12510.00526.56690.26820.37920.00672031732055362072311-33691060.70.1410.00538.14430.30190.41730.00672239652247342248311-3434241.40.15580.008710.3080.56630.48040.01032410942463512529453-35641000.60.15810.005610.3950.37580.47510.00742435602471342506322-36671410.50.13980.00577.86860.32060.40770.00742224702216372204341-3750610.80.11110.00575.31660.26640.34760.00721818941872431923343-381591481.10.16370.005811.1070.40640.49020.00822494612532342572352-39741480.50.11830.00455.99710.230.36590.00651931681975332010312-4047451.10.1610.006610.5370.43990.47220.009224661022483392493401-411612870.60.11580.00415.72430.19580.35650.00621892631935301965302-42881.10.11550.01195.40260.51510.34630.012418881811885821917602-43858510.15730.006510.3170.42350.47230.00932428712464382494412-44921020.90.20590.007417.0860.58780.59920.01252873592940333027503-452081351.50.11270.00425.01330.20810.32030.00741844671822351791362-461492520.60.15160.00519.7820.32890.46580.00822365582414312465363-47931410.70.15930.005810.58920.38620.48010.00832448622488342528362

续表3

Continued Table 3

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)-4846640.70.16170.00710.83750.4970.4840.01052473732509432544462-4960830.70.19270.008214.58440.64090.54650.00972765702789422811401-50721450.50.15420.00579.70660.36010.45560.00822394632407342420361-511171061.10.1580.005710.25170.38080.46940.00812434612458342481361-5225320.80.19030.008313.82680.62230.52690.01122746732738432728471-5351820.60.15790.006210.2560.40130.47040.00752435662458362486332-54923220.30.11310.00475.30010.22530.33890.0051850751869361881241-55929310.13510.00647.58010.36530.40740.00912166832183432203421-56868410.16210.006710.71840.47630.47770.00862477702499412517371-5747630.70.14320.00658.4010.380.42470.00662266782275412282301-5850550.90.12890.00596.75910.31050.37940.00652084482080412074301-591122570.40.11940.00436.08950.21550.36860.00541947631989312023252-6060770.80.23630.008420.73960.73910.63410.01053095563127353166412-611941551.30.15730.007510.06050.45480.46230.00842428812440422450371-625790.10.12370.00836.13990.39880.36050.008520101201996571985401-632703210.80.16430.00610.76560.39390.47220.00732502612503342493321-641882370.80.15920.006510.03620.40350.45490.00772447692438372417341-651831731.10.11830.00615.46030.27130.33430.00651931931894431859312-661723610.50.13340.00617.2010.32340.38970.00652143802137402121301-6760650.90.14250.00938.06590.52650.41070.010822581122238592218491-681481960.80.15820.00699.90860.41820.45270.00772436742426392407341-692684830.60.12240.00466.09190.23090.35930.00571990681989331979271-703215290.60.16540.005710.9550.37970.47750.00652522572519322516291-712354440.50.14720.00558.75250.33270.42870.00642314632313352300291-7221421110.11710.00595.45660.26590.33790.0071922911894421876341-731251061.20.16490.008310.9450.52410.4820.01062506842518452536461-741931631.20.16020.007210.4880.46070.47350.00922458762479412499401-751723650.50.14810.00539.27320.33130.45210.00742324612365332404332-766321554.10.12010.00556.13150.26760.37060.00771958831995382032362-773895330.70.15470.005510.3760.36780.48380.00732398602469332544323-7814014510.11420.00625.4050.29450.3430.00771866981886471901371-792333990.60.13460.00548.15060.32990.43760.00912158712248372340415-802623490.80.15220.00559.87590.35350.46860.00742372612423332477323-811031300.80.11010.00555.14620.2530.33850.00671811901844421879322-822322540.90.11810.0055.91130.24170.36230.005919271081963361993282-832782171.30.2090.007716.7810.61030.58030.00922898592922352950371-842803750.80.15850.006510.480.42610.47860.00882440702478382521392-852380.10.1390.01277.4480.62040.39780.014222151592167752159651-861943910.50.15850.005810.410.38650.47510.0082440632472342506352-871032010.50.17510.007212.5040.51470.51790.01012607702643392690432-881321710.80.1680.007211.2740.51040.48530.00912538722546422550391-893172791.10.16340.007110.9380.50790.48430.00832491732518432546362-903084990.60.14950.00729.50390.49460.460.00922340812388482439413-913325550.60.14710.00689.4080.4790.46190.00872313802379472448393-921382220.60.1570.007110.3310.48940.47610.00942424762465442510412-9339241210.12070.00516.23730.25430.37490.00751966762010362053353-942552341.10.12020.00575.42450.27450.32640.00851959851889431821414-955006040.80.14650.00629.21530.38390.45360.00812305722360382411363

表4 华北克拉通南缘下汤地区辛集组碎屑锆石U-Pb同位素年龄

Table 4 Zircon U-Pb isotopic data of sedimentary rocks from the Xinji Formation in the Xiatang

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)LTXJ-1-1 (石英砂岩)-11201720.70.16260.007811.20.51020.49760.00932482812540422603403-242741410.11040.00464.77570.19760.31170.00571806761781351749282-311011310.11060.00725.01620.3110.32940.007618091171822521835371-47707291.10.1140.0045.63120.19360.35630.00521865641921301964253-51991831.10.10780.00584.92680.24950.33090.00611765981807431843302-642845210.1570.006610.40.4220.4780.00752424722471382519332-72173360.60.10790.00494.41880.23170.29540.00961765881716431669483-82525900.40.17860.006812.5790.50620.50760.01132640632649382647491-93328590.40.11160.00463.23320.12820.2090.003818287514653112232018-10781200.70.1590.00710.5710.48590.47880.00962456752486432522422-11811050.80.11120.00645.07950.27710.33060.00721820991833461841351-121967420.30.11410.00532.44880.16090.15540.00841866791257479314730-1347411510.40.17390.0076.72640.3390.27830.0125956620764515835027-1456790.70.11280.00745.13280.32240.32920.007418561191842531835361-152143110.70.16170.006210.9320.43790.48680.01092474642517372557472-16652040.30.17860.007113.3250.52330.53830.01092640662703372776463-171042790.40.16620.01272.44330.23430.10870.007825201291255696654662-181241380.90.16550.00811.1390.52480.48570.012513812535442552441-19771040.70.11160.00764.83230.35160.31580.011718281241791611769572-201541740.90.16070.007110.80.48560.48440.01112465752506422547482-21871110.80.10780.00634.84230.26980.32620.007817621071792471820382-221203440.40.13770.00528.33120.31620.43570.00672198672268342331303-23115881.30.16610.00811.4390.5460.49770.00952520812560452604412-241743370.50.12250.00485.9230.24770.34850.00741994701965361927352-251752090.80.17450.007112.5530.53630.51990.00932602682647402699392-2626410.60.17520.008112.8050.60310.530.01112609772665442741473-271251590.80.13760.00547.22620.27730.38020.00542198682140342077253-2841440.90.11220.00625.04890.29410.32530.006518361001828491815321-2948740.70.17460.007112.4550.51040.5170.00962603342639392687412-301061820.60.13650.00557.36460.32420.39010.0082183642157392123372-31461080.40.13420.00577.66740.32420.4140.00752153752193382233342-3224310.80.17320.008311.5430.53920.48380.00992589802568442544431-331341930.70.09820.00394.01990.15830.29570.00471591731638321670232-3421300.70.11770.00715.32730.30480.32950.007519221091873491836373-3529580.50.11330.0065.33140.26760.34290.00911854961874431901442-3642371.10.16870.008611.4670.57820.49040.01062544852562472572461-37781180.70.16440.007110.8850.49670.47620.01132501722513422511491-3832291.10.16610.008611.6290.58370.50540.01022520872575472637443-3945680.70.16020.006610.8270.44940.48690.00832457692508392557362-4034311.10.18390.008713.4180.6430.52680.01122689782710452728471-41542100.30.12790.0054.96390.20710.27990.006620696918133515913314-42911390.70.14620.00618.91460.40650.43970.01152302722329422349521-43561000.60.16460.007310.5170.47720.46080.00952503742481422443422-4427350.80.16410.007910.9260.49870.48290.01052498812517422540461-4538460.80.1730.007312.0780.50040.50420.00942587702610392632401-461019810.11310.00495.1980.22610.33130.00571850801852371845281-47531260.40.1420.00657.78520.3580.39480.00782254782206412145363-4826290.90.12410.00825.860.36310.34460.010420171171955541909503

续表4

Continued Table 4

测点号ThU(×10-6)Th/U同位素比值同位素年龄(Ma)207Pb/206Pb207Pb/235U206Pb/238U207Pb/206Pb207Pb/235U206Pb/238U比值2σ比值2σ比值2σ比值2σ比值2σ比值2σ不协和度(%)-4951401.30.17580.008912.0140.59810.49350.01062613842605472586461-50951280.70.26870.010123.7390.87030.63690.01013298593258363177403-51781360.60.12040.00495.90210.22680.35440.00581962731962331956271-5242391.10.11160.0065.1510.26550.33510.00691826981845441863341-5363461.40.16940.007911.5990.55610.49550.01162551782573452594501-5472531.40.1710.007811.4860.53370.48530.00922568712563432550401-5514121.20.14380.0128.34740.68250.42480.012822741432269742282581-5644530.80.1090.00564.990.26270.33170.00831783931818451847402-5738910.40.16270.006311.0450.40570.49170.00852484652527342578373-581401141.20.16850.006111.6910.41870.50140.00822542602580342620352-5952680.80.56570.022549.0062.62290.62340.022844335839725331249024-6039331.20.16840.008511.990.59640.51580.01152543842604472681493-6119260.70.11280.00765.39560.36640.34610.008918561231884581916432-621661940.90.1020.00414.26420.17450.30180.00511661751686341700251-6323590.40.15850.006610.070.4440.45890.00962439702441412435431-64781020.80.11220.00465.2030.20830.3360.00631836741853341867301-6511712310.16660.006111.5280.43450.5000.00852524622567352614362-6639730.50.14570.00769.01010.53630.44410.00852296902339542369382-6758930.60.14120.00628.25410.37030.42310.00882243762259412275401-68132592.20.12290.00596.30590.2870.37250.0071999792019402041332-6933770.40.16360.006111.2430.42280.49730.00862494622544352602373-70781800.40.13790.00497.94750.29260.41660.00732211612225332245331-7154620.90.13690.0067.78860.35970.41130.00892188762207422221411-7250940.50.14770.00629.4560.39620.46320.00822320712383392454363-7387541.60.15990.007411.1390.52140.50390.01052455782535442630454-74431070.40.13520.00527.94070.31130.42400.00722166672224352279333-7534530.70.1090.00595.00270.27310.33140.00651783991820461845312-7638530.70.18890.007314.5020.57810.55310.01022733632783382838422-77484810.11110.00585.10990.26620.33240.0071817941838441850341-7874810.90.1630.007211.2820.48680.49870.00922487752547402608393-7976541.40.16520.008311.520.55030.50380.01052510792566452630453-8063920.70.18950.007814.4880.58840.55090.00982738682782392829412-81831440.60.07820.0042.22860.1090.2060.00371154981190341207202-8249930.50.13480.00537.98610.31690.42670.00722162682229362291323-8335440.80.11450.00615.3880.2890.34010.0071873961883461887341-84591190.50.17140.008211.8520.55310.49920.0082572752593442610341-852233290.70.17130.007211.9230.49390.50190.00882572702598392622381-863553930.90.13240.00516.91830.26240.37660.0062131682101342060282-871391051.30.1020.00714.15170.27190.29620.007116611281665541672361-881712050.80.11130.00535.03780.23330.32720.0071821871826391825341-891101570.70.18740.007913.9090.58810.53480.0112719692743402762461-903313790.90.17010.00711.5530.48060.48870.00992558692569392565431-912366080.40.15440.00648.51410.35050.39680.00812395712287372154376-921582260.70.11280.00515.36780.2390.34320.00731856821880381902352-931212940.40.11480.00475.6110.23150.35150.00661877691918361942322-942655450.50.15010.00529.40640.31780.45090.00822347592378312399371-95118951.20.11360.00735.41160.32580.34540.008218581151887521913392-9694913890.70.13680.0063.84170.18160.20190.006721877616023811863630-971792010.90.10910.00555.09330.24560.33670.00671784921835411871322-981952630.70.15660.006110.1390.38490.46630.00772420662448352467341

图8 华北南缘中-新元古界碎屑锆石年龄组成对比Fig.8 Comparison of age distribution patterns of detrital zircon from Meso- to Neoproterozoic sediments in the southern margin of North China Craton

下汤地区董家组长石石英砂岩样品(17DJ-02)中碎屑锆石多为半自形或圆形，粒径50～200μm(图6)，该样品锆石具有明显环带结构，应为岩浆成因，少量锆石具变质环带，对其随机选取96个点位。其中4颗锆石207Pb/206Pb年龄误差较大，分别为2965±1046Ma(-38)、2875±1033Ma(-43)、2209±472Ma(-59)、2707±498Ma(-80)(表2、图7c)，尽管编号为-59和-80的206Pb/238-207Pb/206Pb年龄的谐和度大于90%，但由于207Pb/206Pb年龄误差较大，也未在年龄频率分布图中使用。因此，董家组样品(17DJ-02)92颗碎屑锆石主峰值年龄为1800Ma，其次为2250Ma、2400Ma、2650Ma(图7d)。

董家组长石石英砂岩样品(MLA-04-2)中碎屑锆石多为半自形或圆形，粒径100～300μm(图6)，锆石具明显环带构造，部分锆石具一定磨圆，对其随机选取95个点位。分析结果显示碎屑锆石U-Pb年龄谐和度均大于90%(表3)，均落在年龄演化曲线上(图7e)，峰值年龄主要为2450Ma，次要峰值为1900Ma、2250Ma、2900Ma和3100Ma(图7f)。

辛集组石英砂岩样品(LTXJ-1-1)中碎屑锆石多为自形、半自形或圆形，粒径50～150μm(图6)，锆石具明显环带结构，部分锆石磨圆较好，部分具溶蚀边，对其随机选取98个点位。结果显示其中有7颗锆石协和度比较低，年龄分别为1223±24Ma(-09)、931±47Ma(-12)、1582±50Ma(-13)、665±46Ma(-17)、1591±33Ma(-41)、4433±58Ma(-59)、1186±36Ma(-96)(表4、图7g)，未在频率分布图中使用(图7h)。91颗碎屑锆石主峰年龄为1850Ma和2500Ma，次要峰值为1200 Ma、2200 Ma、2700 Ma和3300 Ma(图7h)。

图9 华北克拉通中-新元古界碎屑锆石年龄对比图(a)华北克拉通(Zhou et al.，2008；胡波等，2009；Gao et al.，2011；Wan et al.，2011；Ying et al.，2011；Zhu et al.，2011；胡国辉等，2012；Hu et al.，2012，2014a，b；Yang et al.，2012；李猛等，2013；Lan et al.，2014；Liu et al.，2014，2017a, 2019；马铭株等，2014；Zhong et al.，2015；Zhang et al.，2016a；Dong et al.，2018；王振涛等，2017；贾超，2018；Li et al.，2019；Meng et al.，2018；Zuo et al.，2019)；(b)徐淮盆地(Zhou et al.，2008；Gao et al.，2011；Hu et al.，2012；Yang et al.，2012；He et al.，2017)；(c)渣尔泰-白云鄂博-化德盆地(胡波等，2009；Hu et al.，2014a；马铭株等，2014；Liu et al.，2014，2019；Zhong et al.，2015；Li et al.，2019)；(d)燕辽盆地(Gao et al.，2011；Wan et al.，2011；Ying et al.，2011；王振涛等，2017)；(e)熊耳盆地(Zhu et al.，2011；胡国辉等，2012；李猛等，2013；Hu et al.，2014b；Lan et al.，2014；Zhang et al.，2016a；Liu et al.，2019；贾超，2018；Meng et al.，2018；Zuo et al.，2019)Fig.9 Comparison of age distribution patterns of detrital zircon from Meso- to Neoproterozoic sediments in the North China Craton(a)the North China Craton(Zhou et al.，2008；Hu et al.，2009，2012，2014a，b；Gao et al.，2011；Wan et al.，2011；Ying et al.，2011；Zhu et al.，2011；Yang et al.，2012；Li et al.，2013；Lan et al.，2014；Liu et al.，2014，2017a，2019；Ma et al.，2014；Zhong et al.，2015；Zhang et al.，2016a；Dong et al.，2018；Jia，2018；Li et al.，2019；Meng et al.，2018；Zuo et al.，2019)；(b)the Xuhuai Basin(Zhou et al.，2008；Gao et al.，2011；Hu et al.，2012；Yang et al.，2012；He et al.，2017)；(c)the Zhaertai-Bayan Obo-Huade Basin(Hu et al.，2009，2014a；Liu et al.，2014，2017a；Ma et al.，2014； Zhong et al.，2015；Li et al.，2019)；(d)the Yanliao Basin(Gao et al.，2011；Wan et al.，2011；Ying et al.，2011；Wang et al.，2017)；(e)the Xiong’er Basin(Zhu et al.，2011；Hu et al.，2012，2014b；Li et al.，2013；Lan et al.，2014；Zhang et al.，2016a；Liu et al.，2019；Dong et al.，2017；Jia，2018；Meng et al.，2018；Zuo et al.，2019)

4 讨论

4.1 碎屑锆石物源分析

华北克拉通在若干太古代陆核的花岗质片麻岩和变质沉积砂岩中发现3800～3000Ma的古老锆石(Liuetal.，1992，2007；万渝生等，2001，2009；翟明国，2006；Wuetal.，2008)。华北克拉通整体存在～2500Ma的构造-岩浆事件的证据，2350～1950Ma发育有多个古元古代构造活动带，如晋-豫活动带等(Zhaietal.，2003；翟明国和彭澎，2007；翟明国，2011)，在华北南缘发育有2350～1960Ma的嵩山群轻微变质碎屑岩夹碳酸盐岩(Liuetal.，2012)。小秦岭地区和熊耳山地区太华群碎屑锆石U-Pb年龄主要为2300～2000Ma(Huangetal.，2012；Yuetal.，2013；第五春荣等，2018)。1900～1850Ma期间，华北克拉通变质岩大部分经历混合岩化作用或钾化交代作用(Zhaietal.，2003，2015；Zhaoetal.，2010)。华北克拉通在1850～1500Ma期间，经历了伸展作用(Luetal.，2002，2008；Zhaietal.，2003；Zhaoetal.，2003；Zhangetal.，2009；翟明国，2013)，发育了非造山岩浆岩以及与裂谷有关的岩浆/火山活动和退变质作用(赵太平等，2001；Zhaoetal.，2004，2009)，其中包括熊耳群和基性岩墙群(赵太平等，2002；Zhaoetal.，2004，2009；Pengetal.，2007，2008；翟明国，2010)以及豫西南和陕东南部近年来发现的中元古代花岗岩带(Wangetal.，2003；邓小芹等，2015；Dengetal.，2016)。同时黄连垛组和董家组与下伏地层兵马沟组、云梦山组、白草坪组、三教堂组碎屑锆石年龄峰值分布类似(图8)，因此推断华北克拉通为黄连垛组和董家组的物源区。

早古生界辛集组年龄分布与黄连垛组和董家组存在区别，与何家寨组碎屑锆石相比存在少量中元古代晚期到新元古代早期碎屑锆石(图8)，同时近年来在华北南缘卢氏-栾川地区中元古代晚期地层以及在华北克拉通新元古-早古生代地层中也报道了大量同时期的碎屑锆石(初航等，2011；Huetal.，2012；Yangetal.，2012；胡波等，2013，2015；张文龙等，2016；Liuetal.，2019；Zuoetal.，2019)(图9)，辛集组发育的少量该时期碎屑锆石可能源于沉积物的再循环。

4.2 渑池-确山地区中-新元古代沉积演化分析

华北南缘中元古代早期约1800～1750Ma发育熊耳火山-沉积作用之后(赵太平等，2002；崔敏利等，2010；Cuietal.，2011；翟明国等，2014)，局部地区快速沉积兵马沟组(小沟背组)冲积扇-(扇)三角洲-滨海沉积(郑德顺等，2016b；岳亮和刘自亮，2017；Mengetal.，2018；Yueetal.，2018)，兵马沟组沉积结束后，渑池-确山地区发生短暂地壳抬升，形成兵马沟组与上覆汝阳群的区域平行不整合。汝阳群总体上由一套河流-滨海-潮坪相沉积组成，其顶部的北大尖组和洛峪群的崔庄组共同构成了潮间带到外陆棚带沉积，洛峪群的三教堂组和洛峪口组组成了滨海-潮坪沉积。通过洛峪群顶部洛峪口组斑脱岩夹层获得U-Pb谐和年龄约为1611Ma和1634Ma(苏文博等，2012；李承东等，2017)，其应划为中元古界长城系。因此，中元古代早期(1750～1600Ma)华北南缘渑池-确山地区发育的汝阳群-洛峪群可能为一套陆相过渡到海相的被动大陆边缘沉积。

之后，华北克拉通南缘发生区域构造抬升，黄连垛组沉积初期发育了河口湾沉积环境。伴随海侵扩大，在下汤地区沉积了潮上带长石石英砂岩与泥质粉砂岩，而叶县地区发育了潮间带泥晶白云岩。晚期下汤和叶县地区发育潮下带泥晶白云岩与含硅质条带白云岩。董家组与下伏黄连垛组为平行不整合接触，董家组沉积初期为陆源碎屑物质供给充分的滨海相，在下汤和叶县地区沉积底部细砾岩及长石石英砂岩。随后，下汤地区沉积滨海相长石石英砂岩，在叶县地区沉积潮坪相具交错层理长石石英砂岩与泥质粉砂岩。最后在下汤和叶县地区沉积局限台地钙质泥岩。尽管古流向显示黄连垛组和董家组存在多个方向的物源区(张玲华，1994；崔新省等，1996；董文明等，1999)，而碎屑锆石显示其物源均为华北克拉通，没有明显的变化，符合该套地层发育在局限盆地(海盆)的沉积环境。

4.3 对华北南缘中-新元古代沉积演化的启示

黄连垛组在豫西陕县、山西永济地区仍有分布，依据不同地区该套地层的岩性组合、叠层石、碳同位素负偏等特征以及区域内存在的不整合接触关系认为黄连垛组可能与官道口群龙家园组或巡检司组为同期沉积物(武铁山，1982，2002；Xiaoetal.，1997；高维等，2011；徐文超等，2015；苏文博，2016)。而董家组一般认为沉积于新元古代早期(武铁山，1982，2002；Guanetal.，1986；Yin and Guan, 1999；胡国辉等，2013；苏文博，2016)，碎屑锆石显示两套地层物源区没有明显的变化，均为华北克拉通。黄连垛组和董家组发育在局限盆地(海盆)的沉积环境一致，分布范围大体一致。通过区域地层对比，中元古代早期华北南缘沉积首先发育在嵩箕地区和渑池-确山地区，主要为五佛山群中下部和汝阳群-洛峪群滨浅海-潮坪沉积。之后沉积中心向卢氏-栾川地区迁移，沉积了中元古界官道口群和新元古界栾川群，而董家组和黄连垛组可能为该段时期盆地的边缘相沉积。

新元古界栾川群以及罗圈组和东坡组显示其沉积和构造环境发生了明显的变化(Zuoetal.，2019)。栾川群中发育的新元古代岩浆岩地化特征显示其处于伸展背景(孙枢等，1981，1982；蒋干清，1993；石铨曾等，1996)或碰撞后的伸展(阎国翰等，2010)。此外，华北南缘白术沟组和何家寨组中发现了大量中元古代末期到新元古代早期碎屑锆石，峰值年龄集中在1800～1000Ma(贾超，2018；Liuetal.，2019)。徐淮和渣尔泰-白云鄂博-化德地区中-新元古代地层中也发现了大量中元古代到新元古代的碎屑锆石(图9b, c)。尽管华北克拉通发育中元古代末期到新元古代早期(1300～900Ma)的镁铁质岩浆岩(Zhangetal.，2009，2016b，2017，2018；Yangetal.，2011；Pengetal.，2011; Peng，2015; Wangetal.，2016；Cope，2017)，但缺乏该时期的长英质岩浆活动。裂解模式认为，华北在中元古代(～1300Ma)和新元古代(～900Ma)，分别与Australian和West Congo-São Francisco裂开(Pengetal.，2011；Zhangetal.，2017，2018；彭澎等，2018)。此外，也有认为华北与Laurentia、Australia、Baltica、Siberia共同参与了Grenville-Sveconorwegian-Sunsas造山带作用(乔秀夫等，2007；曲永强等，2010，2012；苏文博等，2010；潘建国等，2013；Liuetal.，2019)，或者华北南缘中元古代末期到新元古代可能发生增生或者拼贴事件(Wangetal.，2011；Shietal.，2013；Dongetal.，2014，2015；Dong and Santosh，2016；Liuetal.，2019)。无论哪一种观点都认为，沉积物源的变化和区域抬升可能与该期构造事件有关。

5 结论

华北南缘中元古代早期发育熊耳期火山-沉积作用之后，局部地区快速沉积兵马沟组，随后发生大规模海侵，发育了一套河流-滨海-潮坪相沉积(汝阳群)和浅海-滨海-潮坪相沉积(洛峪群)。中元古代末期到新元古代早期发生了沉积盆地中心的转移，洛峪群上覆黄连垛组和董家组为局限海湾体系下滨浅海-潮坪沉积，可能构成了该时期盆地的边缘相沉积。黄连垛组和董家组碎屑锆石年龄主要峰值为1800Ma、2250Ma、2350Ma、2650Ma，两者物源均为华北克拉通。但早古生界辛集组碎屑锆石除1850Ma、2500Ma、2200Ma、2700Ma的主要峰值年龄外，还包括1200Ma的峰值。结合本次渑池-确山地区黄连垛组、董家组、辛集组以及嵩箕和卢氏-栾川地区的中-新元古代地层碎屑锆石年龄分布变化，指示了华北南缘在中元古代晚期到新元古代沉积物源变化以及沉积间断可能与华北克拉通该时期的构造演化有关。

致谢 本论文在野外工作中得到翟明国院士、赵太平研究员、苏文博教授和彭澎研究员的有益指导；在成文过程得到团队成员张碧云、孙江涛、祁帅帅、谷华昱以及杨东亮等研究生的帮助；审稿人王世炎教授级高工、柳永清研究员、胡国辉博士提出了建设性的修改意见。在此对他们一并表示衷心感谢！