由GPS网融合得到的中国大陆及周边地区的地壳水平运动

提出将不同GPS网融合为一体的方法，实现中国大陆及周边地区高精度GPS网的融合，获得中国大陆及周边地区ITRF2000水平运动的速度场。在此基础上，得到了中国大陆及周边地区相对于具有整体旋转的欧亚板块的速度场和相对于具有整体旋转和均匀应变的欧亚板块的速度场。分析了中国大陆及周边地区速度场的基本特征，并探讨了该地区水平运动与变形的动力源。     

华南绍兴-恩平富碱侵入岩带的厘定及其动力学意义初探

根据野外地质及室内岩相学、矿物成分和岩石化学的研究，从华南腹地厘定了一条重要的中生代NE向富碱侵入岩带－绍兴－恩平富碱侵入岩带。该岩带全长约1400km，宽100－150km，不仅发育有狭义的碱性岩（方沸黑云橄榄黄长岩、白榴黄长煌斑岩、霞石正长岩、霓辉石正长岩、黑榴石正长岩和含霓石石英正长岩）和碱性花岗岩（钠闪石花岗岩、霓辉石钠闪石花岗岩），还发育有大量的正长岩类－二长岩类－碱长花岗岩或晶洞钾长花岗岩。这些富碱侵入岩主要形成于晚中生代。绍兴－恩平燕山期富碱侵入岩带的厘定将对研究华南中生代的动力学的背景与演化具有重要的意义。     

Tectonic and Geodynamic Setting of Oil and Gas Basins in China

About 26 sedimentary basins bearing oil and gas are developed in China. They can be classified into two main types , extensional basins and foreland basins . The former are chiefly distributed in the eastern part and the latter in the central and northwestern parts of the country . The present paper discusses the structural characteristics of these basins , including subsidence history , thermal history and structural style and kinematics . Combined with tectonic setting analysis of geophysical data and eruptive rocks , the geodynamic setting of the basins is established , and the formation mechanism of the basins is deduced to have been related to the subduction of the Izanagi and west Pacific plates and the closing of the Tethys ocean.     

大别山区变质岩中蓝晶石的几种退变质反应及其所指示的动力学过程

蓝晶石在大别山含柯石英和不含柯石英的榴辉岩、高压变质的副片麻岩、非高压变质的宿松群的变质沉积岩中都是重要的变质矿物。它们多有冠状或其它的变质反应结构，形成多样化的退变质反应矿物。有些退变质反应是十分罕见的。本文报道了８种蓝晶石的矿物组合和退变质反应，推测和计算了变质反应的温度－压力条件，从而探讨了它们代表的近等温降压、升温降压和流体为重要因素的降温降压的不同的动力学过程。这些数据与用其它变质矿物所得到的温度压力条件和ＰＴｔ演化基本一致。为探讨大别山超高压变质带的构造演化提供了新的依据。     

Types, Characteristics, and Geodynamic Settings of Mesozoic Epithermal Gold Deposits in Eastern China

Mesozoic epithermal gold deposits in eastern China are divided into calc‐alkaline and alkaline magma‐related gold deposits, and are also grouped as low‐sulfidation, intermediate‐sulfidation and high‐sulfidation types, of which the first two predominate. These gold deposits are distributed in the Tianshan–Yinshan–Great Xing’anling Variscan fold belt of North China craton, Qinling‐Dabie Indo‐Sinian fold belt of Yangtze craton, and South China fold belt or Cathaysian block, from north to south along the eastern China continent. Most of the epithermal gold orebodies are hosted either in volcanic rocks or their related granitoids, and volcanic breccia pipes. These orebodies are mainly associated with adularia–chalcedony–sericite, and alunite–kaolinite–quartz alteration. These orebodies formed in four mineralization pulses at 175, 145–135, 127–115, and 110–94 Ma. The first three pulses correspond to the post‐collision period between the North China and Yangtze cratons, an extension period during late‐stage rotation of the principal compressional stress from N‐S to E‐W, and a dramatic thinning period of the lithosphere, respectively. The last mineralizing pulse was the result of another extension in South China. Although the mineralizing pulses occurred at different times, they all occurred in extensional settings and were accompanied by crust and the mantle interaction.     

The Jiashan Syenite in northern Hebei: A record of lithospheric thinning in the Yanshan Intracontinental Orogenic Belt

The Early Cretaceous Jiashan Syenite is located in a region of late Jurassic crustal thickening. The Jiashan Syenite can be divided into three concentrically arranged units, the Jiangjiawan, Longtangou and Longtannangou units, which were intruded sequentially. Geochemically, the Jiashan Syenite has a high Ga/Al ratio (>3), is enriched in silica, alkalis, Fe, REE, Th, Ga, Nb, Zr and Hf, is depleted in Mg, Ba, Sr and Ti and in transition elements such as Cr, Co, Ni and V. The three units of the Jiashan Syenite have Ce/Pb ratios ranging from 6.12 to 13.41 and are enriched in light REE (LREE) with a moderate Eu negative anomaly. The ⁸⁷Sr/⁸⁶Sr initial ratios range from 0.701409 to 0.707405, with a mean of 0.70379. The ε_Nd (t) values of −2.27 to −5.58 indicate that the magma was probably derived from enriched mantle. The Jiashan Syenite is a post-orogenic intrusion, and can be considered to be an A-type granite. It was emplaced in an environment of lithospheric extension during asthenospheric mantle upwelling. This suggests that the regional compressional shortening and crustal thickening tectonic regime in the Yanshan Orogenic Belt during the Late Jurassic (ca. 135 Ma) changed to lithospheric extension and thinning in the Early Cretaceous.     

Geology and Geochemistry of the Shizitou Molybdenum Deposit,Jiangxi Province: Implications for Geodynamic Setting and Metallogenesis

The Shizitou molybdenum(Mo) deposit in Yongping, Jiangxi, is an important, recently discovered deposit in the eastern section of the Qin–Hang metallogenic belt. The Mo deposit is located in the outer contact zone between the porphyritic biotite granite and the Neoproterozoic migmatite, and present in the deep central part of the intrusion. Re–Os dating and S and Pb isotopic analysis have been conducted to assess the metallogenesis of the Shizitou Mo deposit. S, Pb and Re isotopes show that the ore–forming materials were derived from the porphyritic biotite granitic magma, which originated from the mixing of mantle and crust. Re–Os dating of molybdenite from the ores gives a model age from 156.9±2.2 to 158.5±2.4 Ma, with a weighted mean age of 158±1 Ma and an isochron age of 158.0±2.5 Ma. Geological and geochemical characteristics of the ore deposit and the related granitoids indicate that the Shizitou deposit is a Climax–type Mo deposit. Based on previous studies of the Qin–Hang metallogenic belt, two metallogenic events are believed to have occurred during 172–145 Ma and 137–132 Ma. These two metallogenic periods are consistent with the timing of two metallogenic peaks during the middle to late Jurassic and the Cretaceous in South China. These events represent responses to the partial back–arc extension associated with the subduction of the Izanagi plate beneath the Eurasian continent and the rapid northeastward movement of the subducting Izanagi plate.     

新疆西天山备战基性-超基性岩年代学和岩石地球化学研究及其对铁成矿背景的制约

对新疆西天山备战铁矿区附近的基性-超基性岩体———金云母辉石橄榄岩与侵入其中的闪长岩脉进行了年代学和岩石地球化学研究。金云母辉石橄榄岩中金云母~(40)Ar/~(39)Ar坪年龄为298.1±1.9 Ma,该岩石的锆石U-Pb年龄为302.5±1.3 Ma,与备战铁矿的成矿年龄相近。备战金云母辉石橄榄岩具有低Si O_2(42.51%~50.82%)、Al_2O_3(4.87%~7.38%)、Ti O_2(0.25%~0.77%)和全碱(Na_2O+K_2O=0.87%~1.87%)含量,而高Mg O(26.36%~30.17%)、TFe O(12.33%~15.99%)含量的特征,过渡元素丰度(Cr=523×10~(-6)~7 026×10~(-6),Ni=906×10~(-6)~1 088×10~(-6),Co=109×10~(-6)~132×10~(-6))和Mg~#值(0.76~0.79)均较高,表明岩浆经历了橄榄石堆晶作用。由橄榄石最高Fo值(0.79)和岩石的TFe O含量计算得其母岩浆为玄武质岩浆。所有的岩石具有相似的稀土、微量元素配分模式,均呈轻稀土元素富集的右倾型,且重稀土元素较平坦[(Gd/Lu)_N=0.70~2.00],明显富集大离子亲石元素Rb、Ba、U、K,亏损高场强元素Nb、Ta、Zr、Hf和Ti。总体上Sr、Nd同位素较均一,金云母辉石橄榄岩的(~(87)Sr/~(86)Sr)_i=0.704 4~0.704 7,εNd(t)=2.23~3.90,闪长岩(~(87)Sr/~(86)Sr)_i=0.704 4,εNd(t)=3.79~4.07,表明金云母辉石橄榄岩和闪长岩为同源演化的岩石。微量元素特征表明金云母辉石橄榄岩起源于尖晶石相,源区为受俯冲流体或熔体交代的软流圈地幔。结合区域构造背景,推测金云母辉石橄榄岩的形成与西天山造山带在晚古生代的山根拆沉引起的软流圈上涌有关,而备战铁矿晚期成矿事件很可能形成于相同的深部动力学背景下。     

青藏高原近南北向裂谷的时空分布特征及动力学机制

青藏高原南部发育的一系列近南北向裂谷是印度-欧亚大陆持续挤压作用下的大型伸展构造,也是揭示高原后碰撞构造演化过程的重要对象。目前,关于南北向裂谷的形成机制存在多种假说模型,并对裂谷时空分布特征做出了不同的预测,这成为约束裂谷成因机制的关键条件。综合关于裂谷启动时间的已有研究成果,进一步梳理了南北向裂谷的时空分布特征,结果表明近南北向裂谷的启动时间似乎具有自西向东逐步减小的趋势,这与拉萨地体广泛出露的后碰撞岩浆作用演化过程一致。在此基础上,结合地球物理观测,推断近南北向裂谷的动力学机制与印度板片向东拆离假说最为契合。印度板片自西向东的拆离建立了向东传播的重力势能梯度,从而驱动岩石圈向东流动,最终导致南北向裂谷依次向东发育。      

新疆东昆仑木孜塔格地区碎石沟花岗岩锆石 U-Pb年龄、岩石地球化学特征及地质意义

碎石沟花岗岩体位于东昆仑造山带西段木孜塔格地区,是该地区几个主要花岗岩体之一。为了查明该岩体的成因类型、物质来源及形成时代,并在此基础上进一步探讨木孜塔格地区的区域构造演化过程及东昆仑造山带地球动力学背景,对该岩体进行了详细的岩石学、地球化学及锆石U- Pb年代学研究。岩石学特征表明,碎石沟花岗岩主要由灰白色中细粒二长花岗岩组成,在岩体边部可见少量灰白色花岗闪长岩。岩石地球化学研究表明,该岩体具有高硅（SiO2=67.54 %~71.56 %）、高碱（Na2O=3.08%~4.50%、K2O=3.05%~4.20%）、富铝的特点（Al2O3=14.26%~16.58%）,属于准铝质—弱过铝质高钾钙碱性系列;稀土元素含量较高（126.31×10-6~160.13×10-6）,总体表现出轻稀土富集,重稀土亏损的右倾式配分模式,具有Eu的弱负异常（δEu=0.68~0.85）;微量元素相对富集Rb、Th、K等大离子亲石元素,亏损Nb、Ta、Hf、Sr等高场强元素,显示出 I 型花岗岩的特征。本次研究获得碎石沟岩体二长花岗岩的锆石U- Pb年龄为208.0±1.1 Ma（MSWD=1.0）,属于晚三叠世岩浆活动产物。结合区域构造演化特征,碎石沟花岗岩来源于下地壳物质部分熔融,并且在形成过程中存在幔源岩浆底侵及壳幔岩浆混合作用,其构造背景为后碰撞环境。