河北涞源─八达岭岩基段单元－超单元特征及其成因

涞源－八达岭地区花岗岩类是华北地区中生代燕山期岩浆侵入活动的典型代表，它对研究中国东部乃至亚洲东部地壳的形成、发展、演化都具有重要意义．本文从花岗岩类单元－起单元入手，对涞源－八达岭岩基段进行了划分，探讨了单元－超单元的主要特征，指出本岩基段是在太平洋板块俯冲机制下走滑造山作用的结果，岩浆来源于下地壳未经地表地质作用的深变质火山岩的部分熔融，并有地幔衍生岩浆的混合。     

新疆天山东部尾亚超单元组合特征

运用岩浆同源性及岩石区的有关理论，通过花岗岩类区1：5万区域地质调查，对尾亚椭圆形复式岩株进行解体，经过对其单元、超单元的归并，发现并确认尾亚复式岩株的外环及内环是两个完全不同成分系列，不同岩浆源的独立岩浆作用，沿同一通道就位的产物。因此，外环建立尾亚超单元，内环建立环形山超单元。而将尾亚复式岩株建为尾亚超单元组合。区别于将天山东部尾亚车站所在的尾亚椭圆形复式岩株外环的辉长岩、石英正长岩及内环的花岗闪长岩、二长花岗岩、钾长花岗岩，统划为同一岩浆源、同一侵入期不同侵人次产物的认识。     

河北涞源岩基中的超镁铁质岩研究

以窑沟橄榄辉石角闪石岩岩体为代表,他涞源岩基中超镁铁质岩石。超镁铁质岩石是涞源岵基最早的一次独立岩浆活动形成的,角闪石岩岩浆来源于上地幔,沿深大断裂上升侵位。角闪石岩与之后的第二阶段闪长岩－花岗闪长岩－二长花岗岩－斑状花岗岩－白岗岩有很大差别。涞源岩基在晚三叠纪就开始形成,岩浆活动持续时间在１２０Ｍａ以上。     

黄陵花岗岩基的成因

黄陵花岗岩基位于扬子地台北缘，它连同汉南和鲤鱼寨岩基一起构成扬子地台北缘的低钾花岗岩等，形成于晋宁晚期扬子地台北侧的“秦岭洋”壳向南俯冲导致的大陆边缘造山运动过程中。黄陵花岗岩基可解体为三斗坪、黄陵庙、大老岭、晓峰4个岩套和14个单元，侵位于832－750Ma之间。三斗坪和黄陵庙两个岩套主要由英云闪长岩、奥长花岗岩花岗闪地组成，是在近南北向区域挤压下于约16km深部塑性域定位的同构造花岗岩，前者主要依靠岩浆在构造弱面逐次强力楔入创造定位空间，后者主要在处于活动状态的韧性拉张剪切带内定位。钙碱性系列的大老岭和晓峰岩套则是在本区地壳迅速隆起过程中分别在5km和＜1．5km深度的脆性域定位的构造晚期花岗岩。根据岩石化学和同位素组成推断，三斗坪岩套的源岩主要是晚太古代大陆拉斑玄武岩，母岩浆相当于英安质，岩套内的成分变化主要受角闪石分离结晶作用控制；黄陵庙岩套除受分离结晶作用影响外，成分变化主要与英安质母岩浆和某种长英质岩浆的混合有关；大老岭岩套的源岩亦为早前寒武纪火山岩。     

冀北张宣高变质花岗岩-绿岩带花岗岩类岩石学、地球化学及锆石铀-铅地质年代学

张宣高变质花岗岩－绿岩带内早期花岗质侵入体是以英云间长岩和花岗间长岩为主体的ＴＴＧ岩系，经历了麻粒岩相高级变质作用的改造，已变质成以含紫苏辉石为特征的片麻岩类岩石。麻粒岩相峰期变质作用的时代为２３９０±１９Ｍａ。紫苏花岗岩属典型岩浆成因侵入岩，其侵位成岩时代为２３９０±２４Ｍａ，是区域麻粒岩相峰期变质作用期间长英质熔浆直接结晶的产物。钾质花岗岩类具多种不同的岩石类型，为一系列小规模的富钾质花岗岩侵入体，是与紫苏花岗岩同一构造岩浆活动事件的产物。麻粒岩相峰期变质作用、岩浆活动时代的一致性，表明了本区太古宙末－古元古代早期，由于大规模构造运动，麻粒岩相变质作用由峰期变质条件向相对低温低压条件演化、花岗岩－绿岩带基底岩石由地壳深部向地壳浅部抬升、并同时伴随紫苏花岗岩及钾质花岗岩等大规模岩浆侵入活动的区域地壳演化规律。     

苗儿山花岗岩体单元—超单元特征及其定位机制

根据苗儿山花岗岩体单元－超单元新理论将苗儿岩体划分为13个单元，归并为两个超单元，两个独立单元。不同单元、超单元的性质特征揭示了不同构造期古老岩石重熔的岩浆，沿北东向基底断裂上侵在隆起核部冷凝成岩的演化规律。雪峰期形成猫儿界单元线浅成相裂隙喷溢型火山岩；加里东期以NE向基底断裂的中心式扩展定位形成中深成相黄金超单元主体，自中心往外，岩体由新至老分布；印支－燕山期延续 了加里东期岩浆活动特征；因环状裂隙影响，印支期光旺岭单元侵入体总体呈NE向展布，且以加里东期岩浆侵位中心呈半环状排列；燕山期八角亭超单元3个NE向带，是岩浆呈岩墙式扩张定位的具体表现。     

胶东西北部玲珑、郭家岭超单元花岗岩成因探讨

玲珑、郭家岭超单元花岗岩的源岩均为胶东岩群变质岩；玲珑超单元花岗岩表现出岩石的不均匀性，其成因为原地、半原地交代一重熔型花岗岩；郭家岭超单元花岗岩则属于有幔源物质参人的同熔型花岗岩。两个花岗岩均经历了多期构造一岩浆作用，最终形成于燕山期；郭家岭超单元最终形成晚于玲珑超单元花岗岩。     

大别造山带东部燕山晚期区域变质－岩浆活动与区域构造抬升的同位素地质年代学证据

应用Ｒｂ－Ｓｒ同位素地质年代学方法，系统地研究了大别山东部两类不同构造环境（同构造花岗岩和非构造花岗岩）成因的花岗岩及大别杂岩混合二长片麻岩的冷却就位和构造－变质时代．结合区域上大别杂岩和花岗岩已有的同位素地质年代学成果分析，结果表明：（１）大别山东部燕山晚期区域变质－混合岩化－岩浆活动是同一构造－热事件的产物；（２）大别杂岩与中生代花岗岩具有相似的热历史，中下地壳大别杂岩的出露是燕山晚期区域构造抬升的结果     

大别造山带东部燕山晚期区域变质——岩浆活动与区…

应用Ｒｂ－Ｓｒ同位素地质年代学方法，系统地研究了大别山东部两类不同构造环境成因的花岗岩及大别杂岩混合的冷却就位和构造－变质时代，结合区域辊杂岩和花岗岩已有的同位素地质年代学成果分析，结果表明：（１）大别山东部燕山晚区域变质－混合岩化－岩浆活动是同一构造－热事件的产物；（２）大别杂岩与中生代花岗岩具有相似的热历史，中下地壳大别杂岩的出露是燕山晚期区域构造抬升的结果。     

关于造山带花岗岩类填图方法的讨论——以西秦岭天水地区为例

花岗岩类的分类理论决定其填图方法。现行的单元－超单元填图方法是依据花岗岩类的Ⅰ型、S型分类理论和同源岩浆演化理论而建立的。由于同源岩浆演化理论的不完善性，造山带地壳结构及地质结构特征的复杂性、地质作用过程的多样性，导致了形成花岗岩类源岩组分的复杂性，使得Ⅰ型、S型分类在造山带具有不确定性，因而单元－超单元填图方法在造山带实践中存在较多问题和矛盾。造山带花岗岩类填图方法应以基本岩石分类方案为依据，以野外可识别、易掌握的客观岩石学、矿物学、组构学为准则，客观、真实地反映造山带花岗岩类的特色。     

阿巴拉契亚造山带(纽芬兰岛)阿克利巨型花岗岩基地球化学填图及其成矿制约

阿巴拉契亚造山带加拿大纽芬兰岛东南部发育一晚泥盆纪阿克利巨型花岗岩基(～2500 km2).该岩基侵位于甘德和阿瓦隆地块的多佛-赫米蒂奇湾巨型断层带之间,内部发育钨-锡-钼矿床及相关的矿化.本文锆石年代学研究显示,岩基中Tolt单元侵位于378±2 Ma,各单元年龄基本一致,为同期岩浆多次侵位的产物.岩基中主要岩石类型...     

新疆阿拉套山花岗岩类的K-Ar和~(40)Ar-~(39)Ar同位素定年

新疆西北部阿拉套山南坡的花岗岩体的４０Ａｒ－３９Ａｒ和Ｋ－Ａｒ定年结果表明它们都是海西期侵入体。侵入活动可分为三个阶段：最早的是东部的岩基，岩性为花岗间长岩和钾长花岗岩，年龄约３０５Ｍａ，而后是西部的二长花岗岩和钾长花岗岩，与钨锡成矿有关，年龄约２９０Ｍａ；最晚的是最西部的二长花岗岩，年龄约２８０～２７０Ｍａ。岩浆活动中心有自东或北东向西或南西迁移的趋势。     

Petrogenesis of U- and Mo-bearing A2-type granite of the Gattar batholith in the Arabian Nubian Shield,Northeastern Desert,Egypt: Evidence for the favorability of host rocks for the origin of associated ore deposits

Hydrothermal ore deposits associated with granitic rocks are the result of combinations and series of successive processes, events and conditions in a magma system and at post-magmatic stage. The metal content of a granitic magma as well as fractional crystallization, metal–ligand complexation, emplacement mechanisms and tectonic processes influence the metal precipitation and content of a hydrothermal ore deposit. The present study of the Gattar batholith evaluates how these processes contribute to the generation of an ore deposit. Gattar batholith in the north Eastern Desert of Egypt as part of the northern region of the Arabian–Nubian Shield (ANS) is geographically, mineralogically and geochemically divided into two distinctive areas. The southern part mainly consists of syenogranite while the northern part is dominated by highly evolved alkali-feldspar granite. Uranium and Mo mineralization occurring here is mostly limited to the margin of the highly evolved alkali-feldspar granites. New U–Pb zircon geochronology within this study indicates an age of ~ 620–600 Ma, although high common Pb and discordant age data of many zircon grains reflect alteration by F-rich fluids. Some zircons with distinct older U/Pb ages were considered to be inherited from the wall rocks representing juvenile crust of the ANS. The two different granitic rocks are comagmatic in origin and have A-type characteristics generated by partial melting of lower juvenile crust of the ANS. Geochemical data are in good agreement with a magmatic origin of the alkali-feldspar granites, suggesting fractional crystallization of a syenogranitic source as the most favorable process of their formation. Petrography, geochemistry, and geochronology studies of the Gattar granites along with field observations provide evidence for multiple intrusions as a result of successive magma pulses with different chemical composition. This led to the formation of reverse zoning within the intrusive complex. This kind of magma emplacement promotes the escape of exsolved metal-bearing volatile-rich fluids into the boundary of the Hammamat Sedimentary Rocks (HSR) and Gattar granite at the northern part of the batholith. Build-up of volatiles is a common phenomenon in granitic rocks and typically results in enhanced contents of F, alkalis and ore metals released at subsolidus stage.     

桂东北大宁岩体锆石SHRIMP年代学和地球化学研究

大宁岩体位于扬子板块与华夏板块结合带,岩性组合为二长闪长岩-花岗闪长岩-二长花岗岩-钾长花岗岩.岩体中广泛存在壳幔混合包体.本文利用锆石sHRIMPU-Pb法,获得大宁岩体成岩年龄上限为(419.1±6.4)Ma(MSWD=1.03),属加里东晚期.岩体的地球化学研究显示,大宁岩体属弱过铝高钾钙碱性岩石,富大离子亲石元素和轻稀土,显Nb、Ba、Sr、Eu组合异常.岩石具有较高的I_(Sr)值(0.7112～0.7196),较低的εNd(t)值(-6.77～-7.53)和T_(DM)值(1.40～1.71Ga).结合邻区加里东花岗岩壳幔混合特征,本文认为,大宁岩体为幔源岩浆底侵诱发的下地壳变砂屑岩部分熔融形成,形成过程中有显著的幔源组分加入.     

变质核杂岩中高Sr低Y型花岗岩的发现及其地质意义

在星子变质核杂岩和武功山变质核杂岩中发现了高Sr低Y型花岗岩。这是变质核杂岩构造中高Sr低Y型花岗岩的首次报道。地球化学研究结果表明,它们具有与adakite相似的地球化学特性。在时空分布上,属于中国东部adakite。它们是由玄武岩岩浆底侵到加厚的陆壳底部导致下地壳麻粒岩部分熔融形成的。结合花岗岩的地球化学特片及现有的资料探讨高Sr低Y型花岗岩的形成与变质核杂岩构造之间的成因关系。     

再论南岭侏罗纪“铝质”A型花岗岩的成因及其对古地温线的制约

对南岭地区侏罗纪4个典型"铝质"A型花岗岩岩基——柯树北、寨背、西山和南昆山的成因分析表明:柯树北、寨背岩基中的低分异花岗岩SiO2≈70%,A/CNK<1.1,CaO≥1%,高Zr、Ba含量,是下地壳部分熔融产物;而SiO2含量较高者由低分异花岗岩岩浆通过分离结晶演化而来。西山花岗质火山-侵入杂岩也是下地壳部分熔融产物。南昆山花岗岩为高硅花岗岩,贫Zr、低Ba、Sr和Eu/Eu*值,但具有高的Nb、Ga、REE含量和Ga/Al比值,在Whalen等(1987)图解中地球化学参数落在A型花岗岩区域内。碱性玄武岩浆分离结晶的成岩模式无法解释南昆山岩基较大的体积、均一的成分和低的Nb/Ta比值。详细的成岩分析表明,南昆山花岗岩可能是先期侵入的(幔源)碱性正长岩在富水和相对低温低压条件下发生部分熔融的产物。由这些"铝质"A型花岗岩的熔融温压条件估算得出热流值达到80~95mWm-2的南岭地区侏罗纪古地温线。由古地温线推算出的岩石圈厚度45~75km。南岭侏罗纪高热流背景及其对应的花岗质岩浆活动可能与后碰撞造山阶段岩石圈地幔拆沉或被"热侵蚀"有关,但并不一定意味着岩石圈伸展的大地构造环境。     

新疆西准噶尔花岗岩类的时代及其成因

在西准噶尔地区存在两期不同成因的花岗岩类,一期为与弧后盆地封闭有关的海西中期(305—320Ma)、以小岩体产出的花岗闪长岩-石英闪长岩;另一期为后造山的海西晚期(240—280Ma)的以巨大岩基形式产出的碱长花岗岩。     

北秦岭灰池子花岗岩基成岩物质来源探讨

本文主要通过Ｎｄ，Ｓｒ和Ｏ同位素示踪研究，分析了灰池子花岗岩基的成岩物质来源，初步查明该岩体的岩浆源区由６９％的地幔物质和３１％的陆壳物质混合而成，属壳幔型花岗岩。     

Identification of Magma Mixing: A Case Study of the Daocheng Batholith in the Yidun Arc

The Daocheng batholiths, located in the east of the Yidun arc, consist of granite, granodiorite and K-feldspar granite. Abundant massive mafic microgranular enclaves (MMEs) mainly developed within the granodiorite and K-feldspar granite, and they have clear contacts with the hosted granites. The MMEs are characterized by the quartz eye structure, quenched apatite, and plagioclases phenocrysts with obvious oscillatory zones. Petrographical studies on MMEs and host granites, zoned plagioclase and whole-rock geochemical analysis were carried out to identify the presence of magma mixing. Combined with the previous studies on the whole-rock Sr-Nd-Hf isotopic signatures, the petrogenesis of Daocheng batholith was discussed. The zoned plagioclases from MMEs have An contents varying between 29 and 44, while those from the host granites have An contents of 21~50. The compositional variations and corrosion structure of plagioclase are probably related to magma mixing. Geochemically, the MMEs have relatively low SiO₂ contents (56.34~60.91wt%), high Al₂O₃ contents of 16.06~17.98wt%, and are enriched in magnesium and iron, belonging to metalumnious series (A/CNK=0.82~0.98). The Daocheng batholith belongs to high-K calc-alkaline series, which have high alkaline contents (Na₂O+K₂O=6.25~7.79wt%) and low CaO contents (1.40~3.22wt%). Furthermore, both the MMEs and hosted granites are enriched in LILEs (K, Rb and Pb) and LREEs and depleted in HFSEs (Nb, Ta, Zr, Hf, P and Ti), showing affinities of typical arc magmas. Compared with the host granites, the MMEs are characterized by lower (La/Yb)_N ratios of 1.99 to 2.46, and much more obvious Eu depletions (Eu/Eu^*=0.30~0.50). The host granites have Rb/Sr ratios ranging from 1.0 to 1.9, and they are consistent with the crust-derived materials (Rb/Sr>0.5). Their Zr/Hf ratios range from 27.5 to 36.9, which are close to the transitional Zr/Hf ratios between mantle-and crust-derived materials. This indicates that the formation of Daocheng batholith is genetically related to the mixing between mantle-and crust-derived materials. In addition, the relatively low silica contents and high Mg# values, and the linear patterns of MgO, Al₂O₃ and Fe₂O₃ with SiO₂ contents from the MMEs and host granites, show that the formation of MMEs is genetically related to magma mixing. Overall, the parent magmas of Daocheng granites are derived from the partial melting of Late Triassic arc lower crust, with the input of minor mantle-derived materials. The MMEs are generated by the mixing of the mafic magma with felsic magma.