对北秦岭2个最大的S,I型花岗岩进行了锆石年代学和相关地球化学研究.漂池S型花岗岩锆石SIMS年龄为(495±6)Ma,εNd(t)=-8.2～-8.8,锆石εHf(t)=-6～-39.灰池子I型花岗岩锆石LA-ICPMS,SIMS年龄分别为(421±27)和(434±7)Ma,εNd(t)=-0.9～0.9,锆石εHf(t)=-11～8.4.结合收集的28个锆石年代学资料的统计,将北秦岭古生代花岗岩浆的演化分为3个阶段.第一阶段(505～470Ma)主要发育于北秦岭东段,具有I型弧岩浆的特点,伴生有漂池等S型花岗岩.它们与榴辉岩等(超)高压变质岩石的时空关系密切,揭示了完整的陆缘俯冲造山作用.第二阶段(450～422Ma)广布全区,以灰池子岩体为代表的I型花岗岩为主,解释为有地幔物质混入的下地壳的部分熔融,形成于块体碰撞过程及略后的抬升环境;第三阶段(415～400Ma)仅发育于北秦岭中段,以I型花岗岩为主,形成于碰撞晚期阶段.北秦岭古生代花岗岩带的时空演变揭示,秦岭古生代俯冲碰状造山作用具有长期连续性、阶段性的特点;俯冲首先从北秦岭东段开始起动,早于祁连-柴达木北缘、大别山北麓,说明中国中央造山系古生代俯冲增生直到碰撞具有多块体、不等时的拼合特点.

Zircon U-Pb dating of the granitoids in the middle segment of the Sino-Mongolian border has yielded ages of 459-454Ma (Bainaimiao gneissic quartz diorite), 268±6.9Ma (Daituojikashan miarolitic syenogranite of Xilin Hot), 261.7±6.1 Ma (Baiyichagan hornblende biotite granodiorite of Xianghuang Banner), 262.7±6.0 Ma (Xianghuang Banner monzogranite), 277.2±2.9 Ma (Hadamiao biotite quartz diorite of Xianghuang Banner), 231.1±7.6 Ma (Bayanxile syenogranite of Xilin Hot), 216.9±5.4 Ma (Sonid Left Banner/Dongsu monzogranite) and 152.1±2.5 Ma (Shaertala alkali feldspar granite of Sonid Left Banner), respectively. Based on these ages and the chronological data already available, the authors hold that the granitoids have regular spatial and temporal dis-tribution, i.e., the granitoids were emplaced along three main belts and the intrusive epoch can be divided into five major stages, namely Early-Middle Paleozoic (490-387 Ma), Carboniferous (342-302 Ma), Permian (282-257 Ma), Triassic (249-204 Ma) and Late Mesozoic (152-118 Ma). There exist two giant alkaline granite belts in this area, i.e., Permian alkaline granite belt near Dongwuzhumuqin and Late Triassic alkaline syenite belt along the northern margin of North China Craton, with magmtic activities being asymmetric. Regional geological, petrological and chronological evidence indicates that the Hegenshan ophiolite belt near the southern margin of the Siberian plate and Solonker-Xaro Morn ophiolite belt near the northern margin of Sino-Korean plate represent two oceans respectively. The Hegenshan Ocean was closed before middle Permian, and the Solonker-Xaro Morn Ocean (residual Paleo-Asian Ocean) was closed during the Late Permian-Early Triassic period, and the terminal collision between Sino-Korean and Siberian plates should have occurred at this time. Lots of granite-related mineral deposits have been found in this area, which include copper, tungsten, zinc and other deposits, produced mostly in the regional large-scale extensional setting of the post-orogenic or lithosphere delamination.

本文精确地厘定了中蒙边境中段白乃庙片麻状石英闪长岩(459-454 Ma)、锡林浩特代托吉卡山中粒晶洞正长花岗岩(268±6.9 Ma)、镶黄旗巴音察汗灰白色中细粒角闪黑云母花岗闪长岩(261.7±6.1 Ma)、镶黄旗二长花岗岩(262.7±6.0 Ma)、镶黄旗哈达庙黑云母石英闪长岩(277.2±2.9 Ma)、锡林浩特白音锡勒中细粒正长花岗岩(231.1±7.6 Ma)、苏尼特左旗(东苏)二长花岗岩(216.9±5.4 Ma)、苏尼特左旗沙尔塔拉碱长花岗岩(152.1±2.5 Ma)的时代。并在前人工作的基础上, 总结了本地区花岗岩的时空分布规律: 区内花岗岩空间上呈3条近东西向的条带分布, 时间上可划分为5个重要期次:早-中古生代(490-387 Ma)、石炭纪(342-302 Ma)、二叠纪(282-257 Ma)、三叠纪(249-204 Ma)和晚中生代(152-118 Ma), 峰期间隔约为40 Ma, 并存在两条巨型碱性花岗岩带(东乌珠穆沁旗一带的二叠纪碱性岩带、华北板块北缘的晚三叠世碱性正长岩带), 岩浆活动呈现不对称性。结合区域地质、岩石、年代学等证据说明, 北部贺根山蛇绿岩与南部索伦山-西拉木伦蛇绿岩代表两个洋盆体系, 贺根山洋闭合早于中二叠世, 而索伦山-西拉木伦缝合带所代表残留古亚洲洋关闭, 中朝板块与西伯利亚板块最终碰撞拼合的时代应在晚二叠世-早三叠世。同时, 区内与花岗岩有关的矿产发育, 包括铜、钨、锌等矿种, 多产于造山后伸展或岩石圈拆沉, 区域大规模伸展环境。

This study introduces the concept of stitching pluton because a stitching pluton can provide an upper-age bound for the timing of an accretionary or a collisional event in orogens, with an emphasis on the geochronological constraints from the stitching plutons crosscutting major suture zones on the timing of accretionary and collisional events in North Xinjiang. A combination of the oldest stitching plutons and the youngest ophiolitic rocks within the major suture zones in North Xinjiang may tightly constrain the timing of these major suture zones. The Irtysh-Zaysan suture zone between the Altai terrane in the north and the Zharma-Saur magmatic arc in the south, the North Tian Shan suture zone between the Junggar terrane in the north and the Kazakhstan-Yili terrane in the south, and the South Tian Shan suture zone between the Kazakhstan-Yili terrane in the north and the Tarim craton in the south were formed during the Late Carboniferous, whereas the other ophiolite zones in East Junggar and West Junggar during the Early Carboniferous or earlier. The western Junggar accretionary complex was commonly crosscut by many Late Carboniferous stitching plutons, but it is unclear that these plutons were generated by either subduction-related or post-collisional magmatism during the Late Carboniferous so that more work needs to be done in the future in order to eliminate the uncertainty. The pre-existing data are in support of Late Paleozoic orogens, without evidence for Triassic collision, in North Xinjiang. Particularly, the stitching plutons within the South Tian Shan provide an upper-age bound for the timing of the South Tian Shan suture zone and strong evidence against the suspected Late Permian radiolarians from the Baleigong ophiolite, and they also help re-interpret the Triassic zircon U-Pb ages from the high and ultrahigh pressure metamorphic rocks within the suture zone.

本文介绍了钉合岩体的概念，强调钉合岩体在造山带研究中具有重要的大地构造意义。在科迪勒拉增生造山带中，钉合岩体是在增生事件之后形成的；而在喜马拉雅碰撞造山带中，钉合岩体是在碰撞事件之后形成的。因此可以区分后增生和后碰撞两类钉合岩体，它们可以为限定增生或碰撞事件的时间上限提供年代学约束。特别是在缝合带被钉合岩体侵入的情况下，缝合带的形成时限（即增生或碰撞事件的起止时间）可以根据缝合带中最年轻的蛇绿岩质岩石和最老的钉合岩体给予严格限定。应用这种方法，能够限定新疆北部的主要缝合带（如额尔齐斯-斋桑缝合带、北天山缝合带和南天山缝合带等，东准噶尔和西准噶尔的蛇绿岩带）最晚是在晚石炭世形成的。西准噶尔增生杂岩也是在在晚石炭世形成的，但当时是否存在洋壳俯冲还需要进一步研究。目前的资料显示，虽然新疆北部各主要缝合带的形成时限存在一定差异，但没有三叠纪形成的缝合带。特别是南天山缝合带内发育的钉合岩体不但有效地限定了缝合带的时间上限，而且还从地质上约束了受到质疑的晚二叠世放射虫化石的可靠性和高压-超高压变质岩中三叠纪锆石U-Pb年龄的解释的合理性。

The Central Asian Orogenic System (CAOS) is one of the largest accretionary orogenic belts characterized by the highest rate of Phanerozoic continental growth in the world. In recent years, extensive studies of the orogenic belts have been conducted, focused mainly on Paleozoic accretionary processes and granitic magmatism. By contrast, Mesozoic magmatism and tectonism are poorly understood. This paper tries to analyze and discuss temporal-spatial distribution and tectonic setting of the early Mesozoic granite magmatism. According to zircon U-Pb ages, the Early Mesozoic granitoids in the middle-south segment of the Central Asian Orogenic System can be roughly divided into two stages, i.e., early-middle Triassic (251～227 Ma) and late Triassic-early Jurassic (226～195 Ma). The early-middle Triassic rocks consist mainly of the monzogranite-granodiorite_syenite assemblage. These granitoids are distributed in such areas as the east-middle part of the East Tianshan orogenic belt, the north-middle part of the Beishan orogenic belt, the central Mongolian block, the western part of the Altay orogenic belt and the middle-western region of the Inner Mongolia-Jilin orogenic belt. They are spread along or near the suture zones. The granitoids have metaluminous-weakly peraluminous, calc-alkaline-high-K calc-alkaline or weak alkaline features. I-, S- and A-type or I-A type granites are all exposed. Some ultramafic-mafic rocks are associated with these granitoids. The late stage rocks widely occurring in every orogenic belt are composed of the alkali feldspar granite-K-feldspar granite-monzogranite-alkali feldspar quartz syenite assemblage. They are characterized by metaluminous-wealy peraluminum, high-K calc-alkaline or alkaline granites. Most of them are of A-type and I-A type. Some of them have the characteristics of highly fractionated I-type granites. There exist voluminous coeval ultramafic-mafic rocks. The early-middle Triassic granitoids have a higher ΣREE content, while the late ones have a significant negative Eu anomaly and are more depleted in Ba, Nb, Sr, P and Ti. The Sr-Nd isotopic characteristics reveal that the granitoids in the northern margin of the North China Craton show very low εNd（t） values (-19.6～-5.4) and the old tDM values (1.23～2.09 Ga), suggesting derivation from an ancient continental crust: those in the north Mongolia-west Transbaikalia orogenic belt and Inner Mongolia-Jilin orogenic belt were derived from a young source, whereas those in central Mongolian block, Altay orogenic belt, East Tianshan orogenic belt and Beishan orogenic belt were derived from an ancient micro-continental crust with some contributions of young mantle-derived components. In general, the early-middle Triassic granitoids were derived from dual-sources, while the late Triassic-early Jurassic granitoids mainly from the mantle source. Mantle-derived components have an increasing trend from early to late ones. Juvenile�� compositions of major sources for the granitoids were distributed in the Okhotsk belt and its adjacent areas, and also contributed by the ancient continental crust through underplating of young mantle-derived magma, leading to vertical continental growth in the post-orogenic or post-collision stage. According to recent researches, the early-middle Triassic granitoids in the eastern and western regions show some differences in tectonic settings. The north Mongolia-west Transbaikalia orogenic belt seems to show an intraplate tectonic setting of the continental rift. The central Mongolian block may represent the late stage of the syn-orogenic setting. The Altay orogen and the East Tianshan orogen are described as a post-orogenic extensional setting. The Beishan orogen reflects the late orogenic collision or post-orogenic tectonic setting. The Inner Mongolia-Jilin orogenic belt has the syn-orogenic characteristics. The late Triassic granitoids mainly reflect a post-orogenic, non-orogenic or intraplate extensional tectonic setting.

依据锆石U-Pb年龄，中亚造山系中南段早中生代花岗岩类大致可以划分出早中三叠世（251～227 Ma）和晚三叠世―早侏罗世（226～195 Ma）两个阶段。早中三叠世花岗岩类，主要分布于东天山造山带中东部、北山造山带中北部、中蒙古地块、阿尔泰造山带西段及内蒙古－吉林造山带中西部地区，多沿板块缝合带及附近展布，具有准铝质－弱过铝质的钙碱性－高钾钙碱性或弱碱性花岗岩的特点，I型、S型和A型或I-A型花岗岩均有出露，且同期的超镁铁质－镁铁质岩少见。晚三叠世―早侏罗世花岗岩类，较广泛分布于全区各造山带，具有准铝质－弱过铝质的高钾钙碱性－碱性花岗岩的特点，大都为A型和I-A型花岗岩，部分具有高分异Ⅰ型花岗岩的特点，且同期的超镁铁质－镁铁质岩较发育。早期花岗岩类的稀土元素总量（ΣREE）高于晚期，但晚期较早期具显著负铕异常，晚期花岗岩Ba、Nb、Sr、P和Ti的亏损程度较早期更明显一些。花岗岩Sr-Nd同位素特征显示，华北北缘具有非常低的εNd（t）值（-19.6～-5.4）和老的tDM值（1.23～2.09 Ga），以古老陆壳为其主要源区；北蒙古－西外贝加尔造山带和内蒙古－吉林造山带主体以年轻物源为主；中蒙古地块、阿尔泰造山带、东天山造山带和北山造山带在以古老微陆块为花岗岩源区的构造背景下，有部分年轻幔源组分的贡献，总体显示出早期以壳源和幔源的双源为特点，晚期以幔源为主，从早期到晚期有年轻幔源组分递增的趋势。大量新生地壳主要分布在鄂霍茨克带及其邻区，但在一些老的微陆块上，后造山或后碰撞阶段也有较多年轻幔源岩浆的底侵而导致地壳垂向生长。早中三叠世花岗岩类在中亚造山系西部地区为后造山构造背景，东部地区为同造山作用的晚期阶段；晚三叠世―早侏罗世花岗岩类为后造山或非造山或板内伸展构造背景。

摘　要： 柴北缘西段出露的花岗岩主要有赛什腾山、团鱼山、嗷唠河和三岔沟等岩体，这些岩体的走向为北 西向，与区域构造线方向基本一致．岩体的锆石SHRIMP U—Pb定年结果表明，它们的时代从早古生代的奥陶纪到晚古生代的泥盆纪和二叠纪．其中，赛什腾山岩体为（465．4±3．5）Ma，团鱼山岩体两期侵入 岩的年龄分别为（469．7±4．6）和（443．5±3．6）Ma；它们均属早古生代奥陶纪；而嗷唠河岩体的石英闪长岩为（372．1±2．6）Ma， 属晚古生代泥盆纪；三岔沟岩体也由两期侵入岩组成，其年龄分别为（271．2±1．5）和（260．4±2．3）Ma，属二叠纪．花岗岩的岩石地球化学特 征表明，柴北缘早古生代花岗岩具有岛弧或活动大陆边缘花岗岩的属性，原岩可能为中元古代（1．03～1．15Ga）形成的、来源于亏损地幔的拉斑玄武质洋 壳，它们的形成与板块的俯冲作用有关；晚古生代花岗岩继承了早古生代花岗岩的特点，其原岩可能为中元古代（1．18—1．29Ga）的岛弧根部下地壳，岩 浆物质成分以壳幔混合源为主，它们的形成与造山隆起后不同块体之间的均衡调整有关．

Zircon SHRIMP dating of granitoids from the middle segment of North Qilian showed that they are 512 Ma and 501 Ma for plagiogranite and quartz diorite from Kokoli, 508Ma for Yemazhui granite, and 424Ma for Jinfusi granite, respectively. Based on petrogeochemistry of granites and occurrence in tectonics, combined with the dating of other granites and regional geological data, we think that North Qilian oceanic plate was subducted southward under the Middle Qilian terrane, which caused two episodes of magmatism, one was forming Kokoli plagiogranite (512Ma), Yemazui granite (508Ma) and Kokoli quartz diorite (501Ma), another forming Niuxinshan granite (477Ma). Lately, subduction polarity for the North Qilian basin changed from southward to northward because it was blocked by the deep subduction of Qaidam continental plate northward on the south of Qilian, which formed Minleyaogou granite (463Ma). After about 440 Ma, the Qilian Ocean was closed because of collision between Qaidam and Alax terrane, forming the North Qilian orogen. The post-collision granites such as Jinfusi granite (424Ma) and Niuxinshan quartz diorite (435Ma), and so on, were formed in the North Qilian Orogen where different blocks stretched and collapsed because of lithosphere delamination below the orogen.

北祁连山中段花岗岩锆石SHRIMP定年结果表明,柯柯里岩体的斜长花岗岩和石英闪长岩的年龄分别为512Ma和501Ma,野马咀和金佛寺花岗岩的年龄分别为508Ma和424Ma。结合区内其它花岗岩体的定年资料,根据花岗岩的岩石地球化学特征及岩体产出的构造位置、区域地质资料等,我们认为,早古生代北祁连洋板块向南俯冲,至少引发了两期花岗质岩浆作用,第一次岩浆作用形成柯柯里斜长花岗岩(512Ma)、野马咀花岗岩(508Ma)和柯柯里石英闪长岩(501Ma),第二次花岗质岩浆作用形成牛心山花岗岩(477Ma)。由于往南俯冲的板块受到柴达木板块向北俯冲的影响,俯冲受阻,继而俯冲极性发生变化,转向北俯冲,形成了民乐窑沟(463Ma)等花岗岩侵入体。大约440Ma之后,洋盆闭合,柴达木陆块和阿拉善陆块对接碰撞,形成北祁连造山带。由于造山带根部岩石圈发生折沉作用,造山带上不同的块体伸展、滑塌,形成一系列碰撞后花岗岩如金佛寺花岗岩(424Ma)及牛心山岩体的石英闪长岩(435Ma)等。

The Central Asian Orogenic System (CAOS) is one of the largest accretionary orogenic belts characterized by the highest rate of Phanerozoic continental growth in the world. In recent years, extensive studies of the orogenic belts have been conducted, focused mainly on Paleozoic accretionary processes and granitic magmatism. By contrast, Mesozoic magmatism and tectonism are poorly understood. This paper tries to analyze and discuss temporal-spatial distribution and tectonic setting of the early Mesozoic granite magmatism. According to zircon U-Pb ages, the Early Mesozoic granitoids in the middle-south segment of the Central Asian Orogenic System can be roughly divided into two stages, i.e., early-middle Triassic (251～227 Ma) and late Triassic-early Jurassic (226～195 Ma). The early-middle Triassic rocks consist mainly of the monzogranite-granodiorite_syenite assemblage. These granitoids are distributed in such areas as the east-middle part of the East Tianshan orogenic belt, the north-middle part of the Beishan orogenic belt, the central Mongolian block, the western part of the Altay orogenic belt and the middle-western region of the Inner Mongolia-Jilin orogenic belt. They are spread along or near the suture zones. The granitoids have metaluminous-weakly peraluminous, calc-alkaline-high-K calc-alkaline or weak alkaline features. I-, S- and A-type or I-A type granites are all exposed. Some ultramafic-mafic rocks are associated with these granitoids. The late stage rocks widely occurring in every orogenic belt are composed of the alkali feldspar granite-K-feldspar granite-monzogranite-alkali feldspar quartz syenite assemblage. They are characterized by metaluminous-wealy peraluminum, high-K calc-alkaline or alkaline granites. Most of them are of A-type and I-A type. Some of them have the characteristics of highly fractionated I-type granites. There exist voluminous coeval ultramafic-mafic rocks. The early-middle Triassic granitoids have a higher ΣREE content, while the late ones have a significant negative Eu anomaly and are more depleted in Ba, Nb, Sr, P and Ti. The Sr-Nd isotopic characteristics reveal that the granitoids in the northern margin of the North China Craton show very low εNd（t） values (-19.6～-5.4) and the old tDM values (1.23～2.09 Ga), suggesting derivation from an ancient continental crust: those in the north Mongolia-west Transbaikalia orogenic belt and Inner Mongolia-Jilin orogenic belt were derived from a young source, whereas those in central Mongolian block, Altay orogenic belt, East Tianshan orogenic belt and Beishan orogenic belt were derived from an ancient micro-continental crust with some contributions of young mantle-derived components. In general, the early-middle Triassic granitoids were derived from dual-sources, while the late Triassic-early Jurassic granitoids mainly from the mantle source. Mantle-derived components have an increasing trend from early to late ones. Juvenile�� compositions of major sources for the granitoids were distributed in the Okhotsk belt and its adjacent areas, and also contributed by the ancient continental crust through underplating of young mantle-derived magma, leading to vertical continental growth in the post-orogenic or post-collision stage. According to recent researches, the early-middle Triassic granitoids in the eastern and western regions show some differences in tectonic settings. The north Mongolia-west Transbaikalia orogenic belt seems to show an intraplate tectonic setting of the continental rift. The central Mongolian block may represent the late stage of the syn-orogenic setting. The Altay orogen and the East Tianshan orogen are described as a post-orogenic extensional setting. The Beishan orogen reflects the late orogenic collision or post-orogenic tectonic setting. The Inner Mongolia-Jilin orogenic belt has the syn-orogenic characteristics. The late Triassic granitoids mainly reflect a post-orogenic, non-orogenic or intraplate extensional tectonic setting.

依据锆石U-Pb年龄，中亚造山系中南段早中生代花岗岩类大致可以划分出早中三叠世（251～227 Ma）和晚三叠世―早侏罗世（226～195 Ma）两个阶段。早中三叠世花岗岩类，主要分布于东天山造山带中东部、北山造山带中北部、中蒙古地块、阿尔泰造山带西段及内蒙古－吉林造山带中西部地区，多沿板块缝合带及附近展布，具有准铝质－弱过铝质的钙碱性－高钾钙碱性或弱碱性花岗岩的特点，I型、S型和A型或I-A型花岗岩均有出露，且同期的超镁铁质－镁铁质岩少见。晚三叠世―早侏罗世花岗岩类，较广泛分布于全区各造山带，具有准铝质－弱过铝质的高钾钙碱性－碱性花岗岩的特点，大都为A型和I-A型花岗岩，部分具有高分异Ⅰ型花岗岩的特点，且同期的超镁铁质－镁铁质岩较发育。早期花岗岩类的稀土元素总量（ΣREE）高于晚期，但晚期较早期具显著负铕异常，晚期花岗岩Ba、Nb、Sr、P和Ti的亏损程度较早期更明显一些。花岗岩Sr-Nd同位素特征显示，华北北缘具有非常低的εNd（t）值（-19.6～-5.4）和老的tDM值（1.23～2.09 Ga），以古老陆壳为其主要源区；北蒙古－西外贝加尔造山带和内蒙古－吉林造山带主体以年轻物源为主；中蒙古地块、阿尔泰造山带、东天山造山带和北山造山带在以古老微陆块为花岗岩源区的构造背景下，有部分年轻幔源组分的贡献，总体显示出早期以壳源和幔源的双源为特点，晚期以幔源为主，从早期到晚期有年轻幔源组分递增的趋势。大量新生地壳主要分布在鄂霍茨克带及其邻区，但在一些老的微陆块上，后造山或后碰撞阶段也有较多年轻幔源岩浆的底侵而导致地壳垂向生长。早中三叠世花岗岩类在中亚造山系西部地区为后造山构造背景，东部地区为同造山作用的晚期阶段；晚三叠世―早侏罗世花岗岩类为后造山或非造山或板内伸展构造背景。

Zircon U-Pb dating for three large granitoid batholiths, geochemical and Hf isotope analyses for two of them have been carried out in the different blocks of the Qinling. Zircon dating by LA-ICPMS for the Lantian granitoid in the southern margin of the North China Block gives an age of 133 +/- 1Ma. The granitoids show whole-rock epsilon(Nd)(t) = -11.8 similar to -18.3, zircon epsilon(Hf)(t) = -37.7 similar to -5.7. The Muhuguan and the Mangling granitoids in the North Qinling orogen yield zircon LA-ICPMS and SHRIMP age of 150 +/- 1Ma and 149 +/- 2Ma, respectively. The Muhuguan granitoids show whole-rock epsilon(Nd)(t) = -7.6 similar to -11.4 and zircon epsilon(Hf)(t) = - 7.3 similar to -17.4. Combined with statistical analyses of 26 zircon ages and 3 Ar-Ar ages of granitoid plutons collected from the literature, the Late Mesozoic magmatism in the Qinling can be divided into two stages. The first-stage magmatism (160 similar to 130Ma) widely occurred in the southern margin of the North China Block, the North Qinling and occasionally in the South Qinling, and has features of I-type granitoids. The second-stage magmatism (120 similar to 100Ma) characterized by transition of I-to A-type and A-type granitoids took place in the North Qinling and the eastern part of the southern margin of the North China Block. The first-stage magmatism occurred in a transition from contractional to extensional settings, while the second-stage in the extension selling. The formation of the grantoids are interpreted as partial melting of old crust, mixed with juvenile mantle component. The second-stage granitoids contain more juvenile component than the first-stage. The isotope data of the granitoids show that juvenile compositions of the basement increas from the southern margin of the North China Block to the Shangdan suture.

秦岭晚中生代花岗岩主要发育于秦岭北部的华北地块南缘和北秦岭,南秦岭仅有零星出露。本文报道了3个晚中生代大岩体的年代学和其中2个岩体的地球化学和同位素数据,并系统收集了发表的相关资料,对秦岭晚中生代花岗岩进行了初步总结。华北地块南缘蓝田花岗岩的锆石LA-ICPMS U-Pb年龄为133±1Ma, ε Nd ( t )=-11.8~-18.3, 锆石 ε Hf ( t )=-37.7~-5.7。 北秦岭构造带中牧护关花岗岩的锆石LA-ICPMS U-Pb年龄为 150±1Ma, ε Nd ( t )=-7.6~-11.4, 锆石 ε Hf ( t )=-7.3~-17.4;蟒岭花岗岩的锆石SHRIMP U-Pb年龄为149±2 Ma。 依据收集到的26个锆石U-Pb和3个黑云母Ar-Ar年代学资料, 秦岭晚中生代花岗岩浆的演化可分为2个阶段:第一阶段为160~130Ma(晚侏罗世-早白垩世), 以I-型花岗岩为主, 主要发育于华北地块南缘和北秦岭,在南秦岭仅零星分布;第二阶段为120~100Ma(早白垩世中晚期), 以I-A过渡型和A-型花岗岩为主,主要分布在华北地块南缘的东部和北秦岭,出露面积比第一阶段小。第一阶段(160~130Ma)花岗岩主要形成于古老地壳物质的部分熔融,并有年轻幔源组分的参与,形成于挤压向伸展转换的构造环境。第二阶段(120~100Ma)花岗岩的形成除了古老地壳物质的部分熔融外,有更多的年轻幔源组分加入,发育于陆内伸展环境。花岗岩的同位素特征显示,从华北地块南缘到南秦岭,底基物质中年轻组分有增加的趋势,花岗岩的物源受深部地壳物质组成特征的控制。

中国阿尔泰山和俄罗斯阿尔泰山 均属于阿尔泰山脉的组成部分,地理上互相连接,地质上具有相似的古生代演化历史,同样都发育中生代花岗岩及伴生的稀有金属矿床。中国阿尔泰山和俄罗斯阿尔 泰山的中生代花岗岩及其稀有金属矿床既表现出一定的相似性,也存在一定的差别。两地与稀有金属矿床有关的中生代花岗岩主要为S型花岗岩,属于非造山花岗岩 类,但在俄罗斯阿尔泰山发育以岩珠和岩脉型钨-钼、锂-钽为主的稀有金属矿床,时限为晚三叠世和早侏罗世,而中国阿尔泰山则发育以花岗伟晶岩脉型锂-铍- 铌-钽为主的稀有金属矿床,时限从晚三叠世到晚侏罗世。这些花岗岩具有相似的Sr- Nd同位素特征,但~(87)Sr/~(86)Sr初始比值变化很大,可能是岩浆-流体作用的结果,而变化较小的ε_(Nd)(t)值与富集地幔来源的岩 浆基本相当,或者可以解释为幔源岩浆与地壳物质混合的结果。

对阿尔泰北部山区喀纳斯及琼库尔花岗岩体进行锆石LA-ICPMS U-Pb定年分别获得398±5Ma（MSWD=2.3）和399±4Ma（MSWD=1.2）的生成年龄，确定其形成于早泥盆世。结合近期研究成果，进一步表明，阿尔泰造山带花岗岩主要形成于早一中古生代，峰期在400Ma左右。这两个花岗岩同阿尔泰其它400Ma左右的花岗岩具有相同或相似的野外产状、岩石学、地球化学特征和同位素组成，如高硅、富钾、铝，轻稀土富集，具有Eu负异常，富集大离子亲石元素（Rb、Ba、K），具有明显的Nb、Ta、Sr、P、Ti负异常，具有负的БNd（t）值（-1.5～-0.1）和相对于区内其它花岗岩较老的Nd同位素模式年龄tDM（1.15～1.35Ga），表明这些花岗岩具有钙碱性-高钾钙碱性特征，其物源源除了地幔物质的贡献，可能有更多地壳物质的加入。推断这些花岗岩可能是在洋壳俯冲过程中，可能是熔自深部地壳（可能是弧物质）的岩浆与来源于亏损地幔的镁铁质岩浆发生混合形成的。结合区域地质背景分析，显示喀纳斯、琼库尔岩体形成于陆弧环境，与其它同期花岗岩一起揭示了阿尔泰造山带最为强烈的一次俯冲、裂解和拼合事件。为我们已经提出的构造演化模式提供了新的证据。

Two generations of Late Paleozoic plutons, Early Carboniferous subduction-related plutons and Late Carboniferous-Middle Permian post-collisional A-type granites, were recently recognized in northern West Junggar, Xinjiang, and they are distinguishable by their spatial distribution and geochemistry. Early Carboniferous plutons include diorites, granodiorites, and monzonitic and K-feldspar granites, and they are exclusively restricted within the Late Paleozoic Zharma-Saur arc. The formation of these plutons may be related to the southward subduction of the Irtysh-Zaysan Ocean between Kazakhstan in the south and Altai in the north. Geochemically, they are metaluminous to weak peralunimous, with A/CNK and A/NK ratios of 0.86~1.03 and 1.24~1.86, respectively, and are characterized by relative high Al 2 O 3 , CaO, Na 2 O and Na 2 O/K 2 O (>1.2). They show strong fractionations between LREE and HREE ((La/Lu) N =4.50~26.03), with negligible Eu anomalies, and enrichment in LILE (K, Rb, Ba), Pb and Sr and depletion in Nb, Ta, P and Ti. All they are typical of I-type granitoids. The Early Carboniferous plutons show a wide range of initial Sr isotopic ratios ( I Sr =0.70408~0.70912), relatively constant ε Nd ( t ) values (+6.09~+7.25) and young Nd model ages ( t DM1 =527~593 Ma). All these data suggest that Early Carboniferous plutons, except for the Abudula monzonitic granite, were probably formed by fractional crystallization of mantle-derived magma which was generated by partial melting of the metasomatized depleted mantle and underwent a magma mixing process. Additionally, the Abudula monzonitic granite was likely to be derived from partial melting of subducted slab. By contrast, Late Carboniferous-Middle Permian plutons, mainly K-feldspar granites, are widespread across all the tectonic units in northern West Junggar and adjacent areas, and they were the products of post-collisional magmatism. These plutons are metaluminous and have A/CNK and A/NK ratios of 0.92~0.99 and 1.03~1.27, respectively, low Al 2 O 3 , MgO, CaO, moderate Na 2 O/K 2 O ratios (0.9~1.1), high total alkali (8.6%~9.7%) and REE concentrations (average 196×10 -6 ), weak fractionations between LREE and HREE ((La/Lu) N =3.32~5.36) with striking negative Eu anomalies, significant depletion in Ba, Sr, P, Ti, Nb and Ta. All these are consistent with those of A-type granites. Their ε Nd ( t ) values (+5.26~+7.26) and young Nd model ages ( t DM1 =502~655Ma) indicate that Late Carboniferous-Middle Permian A-type granites might be produced by highly fractional crystallization of ascending basaltic magma, which was possibly originated from fluid-metasomatized depleted mantle and mixed with juvenile crustal melts, as a result of slab break-off in a post-collisional setting.

西准噶尔北部发育构造环境截然不同的晚古生代两期侵入岩体，它们的空间分布与地球化学特征存在明显差异。早石炭世侵入岩包括辉石闪长岩、二长闪长岩、花岗闪长岩、二长花岗岩和钾长花岗岩,仅分布于晚古生代扎尔玛-萨吾尔岩浆弧内，可能与额尔齐斯-斋桑洋的南向俯冲有关。它们的A/CNK和A/NK比值变化范围分别为0.86~1.03和1.24~1.86，属于偏铝质-弱过铝质岩石。Al 2 O 3 、CaO、Na 2 O含量较高，Na 2 O/K 2 O比值普遍大于1.2；LREE、HREE分馏明显，(La/Lu) N =4.50~26.03，无明显的Eu异常；富集大离子亲石元素（K、Rb、Ba）、Pb和Sr，亏损Nb、Ta、P和Ti，具有I型花岗岩的特征。早石炭世侵入岩的Sr同位素初始比值（ I Sr ）为0.70408~0.70912， ε Nd ( t )值为+6.09~+7.25，单阶段Nd模式年龄（ t DM1 ）为527~593 Ma。元素和同位素地球化学特征表明早石炭世岩体（不包括阿布都拉二长花岗岩）可能是受交代的亏损地幔部分熔融并发生岩浆混合之后再经过结晶分异形成的，而阿布都拉二长花岗岩可能来源于洋壳的部分熔融。晚石炭世-中二叠世侵入岩以钾长花岗岩为主，遍布西准噶尔北部及相邻的各个构造单元，是后碰撞岩浆活动的产物。它们的A/CNK和A/NK比值变化范围分别为0.92~0.99和1.03~1.27，属于偏铝质岩石。Al 2 O 3 、MgO、CaO的含量很低，全碱含量很高（8.6%~9.7%），Na 2 O/K 2 O比值为0.9~1.1；REE总量很高（平均值为196×10 -6 ），LREE、HREE分镏程度较弱，(La/Lu) N =3.32~5.36，Eu负异常明显；强烈亏损Ba、Sr、P、Ti，中度亏损Nb和Ta，具有A型花岗岩的特征。 ε Nd ( t )值为+5.26~+7.26，单阶段Nd模式年龄（ t DM1 ）为502~655Ma。元素和同位素地球化学特征表明晚石炭世-中二叠世A型花岗岩体可能是由被流体交代的亏损地幔熔融生成的玄武质岩浆在上升过程中（可能发生岩浆混合）发生高度结晶分异之后的产物，是后碰撞环境下的板片断离导致软流圈物质上涌的结果。

靠近中蒙边界的内蒙古西部呼伦陶勒盖地区的中元古界和石炭系中产出数个花岗岩体,其中以英格特-巴格毛道岩体的出露面积最大,岩性变化显著,包括石英闪长岩、花岗闪长岩和花岗岩,含有围岩的残留体,并被年轻的花岗岩和伟晶岩等侵入.以前的资料显示该岩体是晚古生代形成的,而其他红色的花岗岩和钾长花岗岩小岩体(如库楚乌拉和一连)是中生代形成的.SHRIMP锆石UPb定年结果显示,英格特-巴格毛德岩体的年龄为313±5 Ma,相当于晚石炭世.原定为中生代的库楚乌拉和一连两个红色花岗岩体的年龄分别为277±2 Ma和278±4 Ma,相当于早二叠世,而侵入于英格特巴格毛道岩体中的石英二长岩的年龄为130±2 Ma,相当于早白垩世.晚石炭世花岗岩具有IA型过渡的元素地球化学特征,而早二叠世花岗岩具有A型花岗岩的特征,属于铝质A型花岗岩.晚古生代花岗岩的共同特征是均以具正的εNd(t)值(0.90～3.43)为特征,具有新生地壳的性质,是内蒙古西部地区陆壳生长的标志.而早白垩世石英二长岩的εNd(t)值为-8.71,指示岩浆起源可能以壳源物质为主,有地幔物质参与.

Mesozoic granitoids in Central Asian Orogenic Belt (CAOB), Central Orogenic Belt of China (COBC) and North China Craton (NCC) have been newly identified. In combination with zircon U-Pb ages and geochemical data available, the authors summarized temporal and spatial framework, genesis and source characteristics of Mesozoic granitoids in China and adjacent regions, revealed several kinds of tectonic settings, and preliminarily compiled Map of Mesozoic Granitoids of Asia on the basis of a property-driven database. Furthermore, tectonic settings of Triassic granitoids in Asia and evolution of granitic magma corresponding to Jurassic–Cretaceous transformation of the continental crust from contraction to extension in Northeast Asia were newly proposed in the light of the assemblage of Asian continent. This is for the first time that the temporal and spatial framework of Mesozoic granitoids of Asia has been summarized, and the results achieved by the authors will not only improve our knowledge on the Mesozoic tectono-magmatism of Asia but also have great significance for further studies of Mesozoic tectonic evolution and ore-forming setting of Asia.

在中亚、中央造山带、华北克拉通周边等地区, 新鉴别出一批中生代花岗岩, 结合收集的锆石U-Pb年龄和地球化学数据, 集成已有成果, 初步总结了中国及邻区中生代花岗岩时空分布框架、成因演化及物源特征, 揭示出了多种构造环境, 编制了基于属性数据库的亚洲中生代花岗岩地质图。从亚洲大陆拼合角度论述了三叠纪花岗岩带的构造背景; 揭示了东北亚侏罗纪—白垩纪地壳由挤压增厚到伸展减薄过程中花岗质岩浆性质演变的响应关系。这是亚洲中生代花岗岩分布框架的一次尝试性总结, 有助于提高亚洲中生代构造岩浆作用的整体认识, 对深入探讨亚洲中生代大地构造演化和成矿背景有重要意义。