华北地台前寒武纪变质基底的Sm－Nd同位素地质信息

华北前寒武纪变质基底的Ｓｍ－Ｎｄ同位素资料，主要来自冀东、辽东、内蒙古中部，五台－太行、河南和鲁西等地早前寒武纪以基性岩为主的表壳岩和深成酸性侵入体，也有少量副变质岩的分析结果。已搜集的华北地台前寒武纪变质基底的３０４个Ｓｍ－Ｎｄ分析资料表明，除同位素年龄信息外，作为壳－幔演化示踪剂，给出了岩石圈早期演化的重要信息：除已由Ｕ－ｐｂ法证实的冀东曹庄、辽东鞍山有≥３．８Ｇａ的地壳残留外，Ｓｍ－Ｎｄ资料还暗示吕粱和登封一带存在＞３．５Ｇａ的古老地壳。在华北地台上，除＞３．５Ｇａ的早期壳－幔分离事件外，３．２～３．６Ｇａ，２．６～３．０Ｇａ和２．０～２．２Ｇａ分别为三次造壳的高峰时间。来自华北不同地区的Ｓｍ－Ｎｄ资料还表明，在３．０Ｇａ以前即存在一个规模较大的古老地壳，加之晚太古的造壳规模，太古宙地壳规模之宏大已与现代地壳相近似。除壳－幔分离的造壳事件外，华北地台早前寒武纪地壳活化再造十分强烈。活化再造形成的酸性侵入体的Ｓｍ－Ｎｄ同位素资料显示Ｔ＿（ＤＭ）＝２．６～２．８Ｇａ是活化再造的最高峰时期。     

桐柏北部燕山期花岗岩对地壳深部物质组成的地球化学示踪

通过对桐柏北部燕山期老湾岩体和梁湾岩体花岗岩主元素、微量元素和Ｐｂ－Ｓｒ－Ｎｄ同位素地球化学的研究,分析了岩浆的物质来源,并用来指示地壳深部组成。结果表明,老湾 和梁弯花岗岩均属壳源型花岗岩,岩浆物质并不一自于北在底和华北克拉通南缘基底,而是来自南秦岭构造块体中桐柏杂岩的部分熔融。这表明在桐柏北部的深部地壳中,含有南秦岭的地壳物质,从而进一步证明了早期南秦岭陆壳向北俯冲并叠置于北秦岭块体之下的认识     

南秦岭宁陕地区花岗岩类Pb,Sr,Nd同位素组成及其深部地质信息

本文报道了南秦岭印支期（—２００Ｍａ）宁陕岩体群中８个花岗岩类岩体的Ｐｂ、Ｓｒ、Ｎｄ同位素组成。宁陕岩体群花岗质岩石以低放射成因Ｐｂ同位素组成为特征，初始（８７Ｓｒ／８６Ｓｒ）ｔ比值变化于０．７０４９５—０．７０９０８之间，εＮｄ（ｔ）值变化于－２．４１—－８．５５之间，Ｎｄ同位素模式年龄（ＴＤＭ）变化于１．２０—１．７１Ｇａ之间，从该岩体群的东部到西部，呈现εＮｄ（ｔ）逐渐降低而ＴＤＭ逐渐增高的规律变化。宁陕岩体群的岩浆源区主要来自于南秦岭的深部地壳，在岩浆源区中，类似南秦岭耀岭河群的基性火山岩占有主要比例，南秦岭较古老的地壳物质仅有少量参与，然而，从该岩体群的东部到西部，这种古老地壳物质参与比例逐渐增高。根据花岗岩对深部地壳物质组成的指示，佛坪穹窿的深部地壳主要由垫托于佛坪群之下的晚元古代基性岩浆物质组成。从该穹窿的东部到西部，地壳深部含有古老地壳物质的比例逐渐增高，由此反映佛坪穹窿的深部地壳物质呈现出东西分带，具南北向构造，这不同于佛坪穹窿地表浅部物质的环形分布特征。     

晋宁期后华南陆壳增生作用—海相碳酸锰矿的Nd同位素制约

扬子地台南缘早震旦世，古生代和晚三叠世海相碳酸锰矿石的εＮｄ（Ｔ）值分别是－４．６－－５．５，－８．１－－９．０和－３．５－－４．２。Ｚ１－Ｃ１期间，它们的Ｎｄ模式年龄Ｔ２ＤＭ平均为１９３１±４６Ｍａ，εＮｄ（Ｔ）－Ｔ演化线与亏损地幔演化线交点年龄为１９５０Ｍａ，ｄ（Ｔ）／ｄσ＝０．９６。Ｎｄ同位素组成特征表明：华南陆壳晋宁期前的增生作用主要发生在早元古代的１９３１±４６Ｍａ前，晚元古代地壳增生作     

华南火成岩中捕获锆石的早元古代－太古宙U－Pb年龄信息

本文以火成岩中捕获锆石为测年对象，用单颗粒锆石Ｕ－Ｐｂ稀释法，对华南地区扬子地块南部和华夏地块进行了比较广泛系统的取样和测年工作。测年结果表明，华南地区火成岩中普遍存在早元古代－太古宙的捕获锆石，最大年龄达３．１Ｇａ，表明华南地壳深部在较大范围内存在早元古代－太古宙的地壳再循环物质，华南大陆地壳可能最初形成于３．１Ｇａ之前。根据捕获锆石年龄信息，华南早元古代之前大陆地壳生长集中于～３．１Ｇａ，～２．７Ｇａ，～２．５Ｇａ，～２．２Ｇａ和１．８－２．１Ｇａ几个时期。     

广州-佛冈地区显生宙花岗岩类Nd-Sr同位素示踪研究

广州－佛冈地区显生宙花岗岩类岩体ＩＳｒ为０．７０１６￣０．７３９１,Ｎｄ同位素Ｔ２ＤＭ值在１．１７￣２．２７Ｇａ之间。广佛地区极可能具有统一的属华夏古陆一部分的元古代基底,其Ｎｄ同位素Ｔ２ＤＭ值为２．１１￣２．２７Ｇａ。具低Ｔ２ＤＭ值（１．１７￣１．３５Ｇａ）的古生代和中生代花岗岩类岩体的存在,表明广佛地区在古生代和中生代有一定的地壳增长,相应花岗岩岩体的成岩物质有幔源成分的加入,其中燕山晚期的地     

怀安蔓菁沟早前寒武纪高压麻粒岩混杂岩带地质特征,岩石学和同位素…

华北克通北缘中段怀安蔓菁沟高压麻粒岩混杂岩带产在太古宙怀安杂岩南缘与花岗岩带交界处，由高压其性麻粒岩，辉长质麻粒岩，英云闪长质麻粒岩和少量夕线石榴片麻岩相间排列的席状岩层物估算的早期高压变质作用条件：Ｔ＝８００Ｃ，Ｐ＞１．４ＧＰａ。环绕斑晶的后成合晶反应边矿物组合的变质条件为：Ｔ＝８２０Ｃ，Ｐ为０．７－０．９ＧＰａ。全岩Ｓｍ－Ｎｄ等时时线年龄２．６５Ｇａ，矿物Ｓｍ－Ｎｄ等年龄１．８２Ｇａ，锆石Ｕ－     

华北克拉通古元古代区域构造格架及其板块构造演化探讨

华北克拉通古元古代区域构造至少可以划分出三大构造单元：（１）陆内裂谷带（２．３０～２．６０Ｇａ）;（２）陆缘造山带（２．３０～２．６０Ｇａ）;（３）再造的太古代克拉通区（麻粒岩相带）（大于２．５０Ｇａ）．太古代末—古元古代重要的区域性构造－热事件序列依次为：（１）克拉通中部不同地壳层次伸展及裂谷盆地的发育;（２）克拉通北缘构造活动、增生及陆壳基底再造;（３）与大陆裂谷盆地闭合过程相联系的板内造山－前陆盆地发育．板块构造模式可以很好地解释上述构造作用类型．     

扬子南缘沉积岩的Nd同位素演化及其大地构造意义

本文系统分析了扬子块体南缘中元古代到二叠纪各个时代地层中泥质沉积岩的Ｓｍ－Ｎｄ同位素组成。中元古代（１．６～１．ＯＧａ）沉积岩具有一致的Ｎｄ模式年龄（ｔＤＭ）（≈１．８Ｇａ）；晚元古代早期（０．９～０．７７Ｇａ）沉积岩的ｔＤＭ年龄从≈１．８Ｇａ急剧降低至。１．３Ｇａ；震旦纪晚期到二叠纪（０．６６～０．２７Ｇａ）沉积岩的ｔＤＭ年龄又恢复到大约１．８Ｇａ。晚元古代早期沉积岩ｔＤＭ年龄的显著降低，表明这个时期扬子南缘的沉积物源区加入了大量新的幔源物质。沉积岩的Ｎｄ同位素结果对中国东南部的大地构造演化提供了新的制约。地质、地球化学和年代学资料均表明扬子南缘的板溪群是一正常的元古代地层单位。华南一扬子晚元古代（晋宁期）碰撞造山运动导致了上述沉积岩的“Ｎｄ同位素漂移”。     

华北克拉通古元代区域构造格架及其板块构造演？…

华北克拉通古元古代区域构造至少可以划分出三大构造单元：（１）陆内裂谷带（２．３０￣２．６０Ｇａ）;（２）陆缘造山带（２．３０￣２．６０Ｇａ）;（３）再造的太古代克拉通区（麻粒岩相带）（大于２．５０Ｇａ）,太古代末－古元古代重要的区域性构造－热事件序列依次为：（１）克拉通中部不同地壳层次伸展及裂谷盆地的发育;（２）克拉通北缘构造活动、增生及陆壳基底再造;（３）与大陆裂谷盆地闭合过程相联系的板内造山－     

Episodic crustal growth of North China as revealed by U-Pb age and Hf isotopes of detrital zircons from modern rivers

Clastic sedimentary rocks are samples of the exposed continental crust. In order to characterize the crustal growth history of North China and its possible regional variations, 479 concordant detrital zircons in three sand samples from the lower reach of the Yellow River (which drains the Tibet-Qinghai Plateau, the Western Qinling Orogen, the Qilian Orogen and the North China Craton) and two sand samples from the Luan River and the Yongding River (which run entirely within the North China Craton) were measured for U-Pb age and Lu-Hf isotopic compositions by excimer laser-ablation ICP-MS and MC-ICP-MS. Although regional variations exist, concordant detrital zircons from the Yellow River reveal three major age groups of 2.1-2.5 Ga, 1.6-2.0 Ga, and 150-500 Ma. Detrital zircons from the smaller Luan and Yongding Rivers show three broadly similar major age groups at 2.3-2.6 Ga, 1.6-2.0 Ga, and 140-350 Ma, but with narrower age ranges. Compared to the Luan and Yongding River zircons, the Yellow River zircons are characterized by a significant number of Neoproterozoic grains. Although Hf isotopic compositions show both juvenile crustal growth and crustal reworking for all age groups, much of the crustal growth of North China occurred in the Neoarchean and Mesoproterozoic. All three rivers are characterized by a common prominent group of Hf crust formation model ages at 2.4-2.9 Ga with a peak at 2.7-2.8 Ga. A less significant age group lies between 1.4 and 1.8 Ga for the Yellow River, and between 1.6 and 1.9 Ga for the Yongding River and Luan River. Crustal growth rates based on Hf continental crust formation model ages suggest 45% and 90% of the present crustal volume was formed by 2.5 Ga and 1.0 Ga, respectively, for the drainage area of the Yellow River. In comparison, 60% and 98% of the present crustal volume of the North China Craton was generated by 2.5 Ga and 1.0 Ga, respectively, for the Luan and Yongding Rivers. The 2.7-2.8 Ga age peak observed in all river samples agrees well with the coeval major peak for global crustal growth. However, the other suggested global peaks of crustal growth at 3.4 and 3.8 Ga are insignificant in North China. Taken together with our previous studies of the Yangtze Craton, which show insignificant crustal growth at 2.7-2.8 Ga, we suggest that these advocated worldwide crust formation peaks be re-examined and treated carefully. Our results also show that Phanerozoic zircons may have been derived from crustal sources separated from the mantle up to 2.0 Ga ago before the zircons crystallized, suggesting long-term preservation, reworking and recycling of the continental crust.     

Formation and Evolution of Early Precambrian Continental Crust in Alxa Block

By the analysis of the published zircon U-Pb ages and Hf isotope data, this paper firstly presents a comprehensive review about the staggered growth and reworking of early Precambrian continental crust in Alxa Block. The results show that the ancient crustal remnants of Alxa Block was formed in Meso-Paleo Archean, which was recorded by 3.0~3.6 Ga detrital zircons and Hf model ages. The early crustal growth of Alxa Block could be traced back to early Paleo-archean. Currently, the oldest zircon U-Pb age is about 3.6 Ga. Analogous to the other places of North China Craton, the Alxa Block underwent two-stage crustal growth at 2.7~2.9 Ga and 2.5~2.6 Ga respectively, and the former might be wider. The ~2.5 Ga (TTG) tectono-magmatic event, which represents the North China continent’s cratonization, also existed in Alxa Block. The corresponding zircon Hf isotope data indicate that the TTGs were mainly derived by melting of 2.7~2.9 Ga juvenile crust, possibly by mixing with a certain ancient crust, and a small portion was produced by instant reworking of 2.5~2.6 Ga juvenile crust. Proceeding to Paleo-proterozoic, the Alxa Block underwent multi-stage tectono-magmatic events, approximately peaked at 2.30~2.35 Ga, 2.15~2.17 Ga, 2.00~2.10 Ga, 1.95~1.98 Ga and ~1.90 Ga. The continental crust was mainly formed by reworking of 2.7~2.9 Ga and 2.5~2.6 Ga juvenile crust, simultaneously by a fraction of ~2.1 Ga juvenile crust. In Paleo-proterozoic, not only the Archean crustal reworking but also the juvenile crustal growth existed in Alxa Block.     

http://www.sciencedirect.com/science/article/pii/S1674987114000206

The North China Craton（NCC） has a complicated evolutionary history with multi-stage crustal growth,recording nearly all important geological events in the early geotectonic history of the Earth.Our studies propose that the NCC can be divided into six micro-blocks with ＆gt;～3.0-3.8 Ga old continental nuclei that are surrounded by Neoarchean greenstone belts（CRB）.The micro-blocks are also termed as highgrade regions（HGR） and are mainly composed of orthogneisses with minor gabbros and BIF-bearing supracrustal beds or lenses,all of which underwent strong deformation and metamorphism of granulite- to high-grade amphibolite-facies.The micro-blocks are,in turn,from east to west,the Jiaoliao（JL）,Qianhuai（QH）,Ordos（ODS）,Ji’ning（JN） and Alashan（ALS） blocks,and Xuchang（XCH） in the south.Recent studies led to a consensus that the basement of the NCC was composed of different blocks/terranes that were finally amalgamated to form a coherent craton at the end of Neoarchean.Zircon U-Pb data show that TTG gneisses in the HGRs have two prominent age peaks at ca.2.9-2.7 and2.6-2.5 Ga which may correspond to the earliest events of major crustal growth in the NCC.Hafnium isotopic model ages range from ca.3.8 to 2.5 Ga and mostly are in the range of 3.0-2.6 Ga with a peak at2.82 Ga.Recent studies revealed a much larger volume of TTG gneisses in the NCC than previously considered,with a dominant ca.2.7 Ga magmatic zircon ages.Most of the ca.2.7 Ga TTG gneisses underwent metamorphism in 2.6-2.5 Ga as indicated by ubiquitous metamorphic rims around the cores of magmatic zircon in these rocks.Abundant ca.2.6-2.5 Ga orthogneisses have Hf-in-zircon and Nd wholerock model ages mostly around 2.9-2.7 Ga and some around 2.6-2.5 Ga,indicating the timing of protolith formation or extraction of the protolith magma was from the mantle.Therefore,it is suggested that the 2.6-2.5 Ga TTGs probably represent a coherent event of continental accretion and major reworking（crustal melting）.As a distinct characte     

Nd isotopic constraints on crustal formation in the North China Craton

Recent tectonic analysis suggests that the North China Craton consists of two Archean continental blocks, called the Eastern and Western Blocks, separated by the Paleoproterozoic Trans-North China Orogen. Although the published geochronological data are not sufficient to constrain the detailed tectonothermal evolution of the craton, the available Nd isotopic data show some important differences in Nd model ages between the tectonic units. The Eastern Block shows two main Nd model age peaks, one between 3.6 and 3.2 Ga and the other between 3.0 and 2.6 Ga. Limited Nd isotopic data from the Western Block show a large range of model ages between 3.2 and 2.4 Ga. These differences are consistent with the recently-proposed model.The Nd isotopic data from mantle-derived mafic rocks indicate that the mantle beneath the North China Craton was depleted in the Archean, consistent with major crustal growth during this period. In the Paleoproterozoic, however, the mantle-derived mafic rocks show negative ε_Nd(t) values, implying crustal contamination. This may have resulted from subduction and collision between the Eastern and Western Block, implying that the mechanisms of crustal formation and evolution may have been different between the Archean and Paleoproterozoic.The North China Craton was re-activated by addition of mantle-derived magma into the lower crust in the late Mesozoic, resulting in rejuvenation of the lower crust. This indicates that underplating is also an important mechanism for continental addition, although in this case it may not equate to crustal growth, since it was preceded by removal of lithospheric mantle and possible some lower crust.     

东秦岭造山带两类元古宙地壳基底及其地壳增生

通过研究南秦岭地区陡岭群、武当群和北秦岭地区秦岭群的变质基性岩等的铅同位素和微量元素组成，揭示出东秦岭造山带分布有两种性质及不同归属的元古宙地壳，指出中、古元古代时可能一个统一的地壳基底；南秦岭的中、古元古代地壳是在扬子陆地基底上通过岛弧的侧向加积形成和，北秦岭元古宙地壳则可能垂向增生于一个富入射性成因铅同位素组成的、具古洋壳幔性质的微地块之上，研究还表明陡岭群不是北秦岭地区的秦岭群，而应属于南秦     

海南岛地壳生长和基底性质的Nd同位素制约

通过对海南岛花岗岩、变质沉积岩等地壳岩石SmNd同位素的详细剖析,探讨了海南岛的基底性质及其地壳生长史。研究表明:海南岛九所—陵水断裂的南、北经历了不同的构造演化史。断裂以北地壳岩石的ε_Nd(t)分布在3.3至-17.2之间,Nd模式年龄分布在1.2～3.2Ga之间,并在1.4～1.6Ga和2.0Ga形成统计峰值。断裂以北地壳主要以幕式生长形成,太古代时期形成若干陆核(距今3.1～3.2Ga或更早?),1.4～1.6Ga和1.8～2.0Ga为地壳生长的主要时期。断裂以北地壳岩石的SmNd同位素特征和地壳生长史与华夏古陆的相似,其基底是华夏古陆的一部分,断裂以南可能是亲东冈瓦纳(澳大利亚)的裂解块体。     

塔里木地块东南缘新太古代安南坝石英闪长片麻岩的成因及其对地壳演化的启示

目前塔里木地块东南缘早前寒武纪岩石形成时代和成因机制研究较为薄弱,制约了人们对塔里木大陆地壳形成和早期演化的认识.岩石地球化学及锆石Hf同位素组成表明塔里木地块东南缘安南坝石英闪长片麻岩原岩岩浆为下地壳变玄武岩部分熔融形成,并有少量幔源物质的加入.LA-ICP-MS锆石U-Pb测年结果显示石英闪长片麻岩成岩年龄为2 662±12 Ma、2 676±15 Ma,结合已有资料综合说明塔里木东南缘太古宙岩石形成时代主要集中在2.55~2.70 Ga,变质年龄分别为1 980±30 Ma、1 828±20 Ma~2 087±29 Ma,是古元古代中晚期与造山作用有关的岩浆-变质事件的地质记录.石英闪长片麻岩中锆石两阶段模式年龄T_DM2为2 954~3 742 Ma,峰值为~3.24 Ga,据此认为~3.2 Ga是塔里木东南缘大陆地壳生长的主要时期,并于2.55~2.70 Ga发生地壳再造,古老地壳再循环可能是该地区新太古代中晚期大陆地壳演化的重要方式.      

Detrital zircon evidence for Hf isotopic evolution of granitoid crust and continental growth

We have determined U-Pb ages, trace element abundances and Hf isotopic compositions of approximately 1000 detrital zircon grains from the Mississippi, Congo, Yangtze and Amazon Rivers. The U-Pb isotopic data reveal the lack of >3.3 Ga zircons in the river sands, and distinct peaks at 2.7-2.5, 2.2-1.9, 1.7-1.6, 1.2-1.0, 0.9-0.4, and <0.3 Ga in the accumulated age distribution. These peaks correspond well with the timing of supercontinent assembly. The Hf isotopic data indicate that many zircons, even those having Archean U-Pb ages, crystallized from magmas involving an older crustal component, suggesting that granitoid magmatism has been the primary agent of differentiation of the continental crust since the Archean era. We calculated Hf isotopic model ages for the zircons to estimate the mean mantle-extraction ages of their source materials. The oldest zircon Hf model ages of about 3.7 Ga for the river sands suggest that some crust generation had taken place by 3.7 Ga, and that it was subsequently reworked into <3.3 Ga granitoid continental crust. The accumulated model age distribution shows peaks at 3.3-3.0, 2.9-2.4, and 2.0-0.9 Ga.The striking attribute of our new data set is the non-uniformitarian secular change in Hf isotopes of granitoid crusts; Hf isotopic compositions of granitoid crusts deviate from the mantle evolution line from about 3.3 to 2.0 Ga, the deviation declines between 2.0 and 1.3 Ga and again increases afterwards. Consideration of mantle-crust mixing models for granitoid genesis suggests that the noted isotopic trends are best explained if the rate of crust generation globally increased in two stages at around (or before) 3.3 and 1.3 Ga, whereas crustal differentiation was important in the evolution of the continental crust at 2.3-2.2 Ga and after 0.6 Ga. Reconciling the isotopic secular change in granitoid crust with that in sedimentary rocks suggests that sedimentary recycling has essentially taken place in continental settings rather than active margin settings and that the sedimentary mass significantly grew through addition of first-cycle sediments from young igneous basements, until after ∼1.3 Ga when sedimentary recycling became the dominant feature of sedimentary evolution. These findings, coupled with the lack of zircons older than 3.3 Ga in river sands, imply the emergence of large-scale continents at about 3.3 Ga with further rapid growth at around 1.3 Ga. This resulted in the major growth of the sedimentary mass between 3.3 and 1.3 Ga and the predominance of its cannibalistic recycling later.     

Slab break-off model for the Triassic syn-collisional granites in the Qinling orogenic belt,Central China: Zircon U-Pb age and Hf isotope constraints

Numerous Triassic granitoids in the Qinling orogenic belt related to the Late Triassic collision between the North China Craton (NCC) and the Yangtze Block (YB) are important for determining the crustal composition at depth and the geodynamic processes by which the orogen formed. Most of the Triassic plutons in the Qinling orogen were emplaced between 205 and 225 Ma. The granitoid rocks from the southern margin of the NCC, North Qinling, South Qinling, and the northern margin of the YB that were emplaced during this interval have two-stage Hf model ages of 0.60–2.52 Ga (average 2.19 Ga), 0.90–2.66 Ga (average 1.29 Ga), 0.41–3.04 Ga (average 1.48 Ga), and 1.00–1.84 Ga (average 1.34 Ga), respectively, and mean ε_Hf(t) values of ?14.5, ?0.32, ?1.36, and ?3.98, respectively. The Hf isotope compositions of the granitoids in different tectonic units differ significantly, mirroring the diverse history of crustal growth of the four units.

The temporal and spatial distribution and Hf isotope compositions of the granitoids suggest that there was a unified geodynamic process that triggered the magmatism. Formation of the Triassic granitoid plutons at 225–205 Ma was a consequence of slab break-off or E–W-striking slab tearing, related to slab rollback in the west part of the Qinling orogen and oblique continental collision in the east. Upwelling of the asthenospheric mantle led to partial melting of the subcontinental lithospheric mantle and the lower crust, and mixing and/or mingling of the resulting magmas resulted in the formation of granitoids with diverse geological and geochemical characteristics.     

中国西秦岭碎屑锆石U-Pb年龄及其构造意义

西秦岭是北接华北克拉通、西接祁连与柴达木、南接松潘—甘孜地块的东秦岭造山带的西延。文中研究了该区从前寒武纪到三叠纪的碎屑沉积岩。这些碎屑沉积岩中分离出的锆石由LA-ICPMS(激光剥蚀等离子体质谱)进行了U-Pb定年。全岩Nd亏损地幔模式年龄类似于扬子克拉通年龄,主要分布于1.55~1.98Ga,峰值为1.81Ga,而与华北克拉通主要为古元古代与太古宙的模式年龄形成明显的对比。泥盆系中的碎屑锆石930~730Ma的U-Pb年龄指示其与扬子克拉通具亲缘性。930~730Ma是源区地壳的强烈增长阶段。二叠系—三叠系的碎屑沉积岩主体以含老于1600Ma的碎屑锆石为特征。碎屑锆石U-Pb年龄与Sm-Nd同位素组成指示此时华北克拉通南缘的基底岩石成为二叠系—三叠系碎屑沉积岩的重要物源。扬子克拉通在三叠纪时与华北克拉通拼接。西秦岭二叠系—三叠系碎屑沉积岩含有高达50%的华北克拉通南缘的基底岩石。