辽河群变质泥质岩中变质重结晶作用和形作用的关系

辽河群变泥质岩中变斑晶种类繁多,有的具多个世代.同位素年代学证据表明它们都形成于吕梁变质期.通过2000多块薄片的详细显微构造分析,将吕梁变质期分成四个变质阶段.变斑晶微构造揭示 M1 发生于变形前埋藏过程中,M2、M3 属进变质阶段,M4 为退变阶段.变斑晶在各变质阶段以完整或不完整的基本结晶序列周期性地出现,成核具阶段性,生长既有阶段性的又有具连续性的.变斑晶在不同的变形条件下,具有不同的变形行为,如旋转与非旋转性.变斑晶的时空分布规律揭示,M2 期间垂向递增变质带与 D1 伸展构造样式密切相关;M3 期间侧向递增变质带样式与收缩挤压褶皱样式一致.     

滇西澜沧变质带变质作用和变形作用的关系

滇西澜沧变质带经历了两期变质变形事件，其时代分别为５１９Ｍａ和２８０～１９０Ｍａ。早期变质变形事件（Ｍ１Ｄ１）可由销长石和石榴石变斑晶的包裹体痕迹确定，形成近Ｅ－Ｗ向的变形构造格局。晚期变质变形作用（Ｍ２Ｄ２）以形成蓝片岩相矿物组合，如以蓝门石（青铝门石）＋多硅白云母＋绿泥石＋石英等为特征，并形成近Ｎ－Ｓ向的变形构造格局．钠质问石以青铝闪石和蓝闪石为主，白云母多为３Ｔ＋２Ｍ；型多硅白云母，其ｂｏ均值在９．０４０Ａ以上；蓝片岩相变质作用的Ｐ、Ｔ条件估计分别为０．６～０．７ＧＰａ和３００℃。晚期变质变形事件经历了二个主要阶段（Ｍ２ａＤ２ａ和Ｍ２ｂＤ２ｂ），分别伴随透入性面理（Ｓ２）和褶劈理（Ｓ３）的形成，蓝门石的４０Ａｒ－３９Ａｒ定年分别为２７９Ｍａ和２１４Ｍａ；Ｍ２ｃＤ２ｃ期局部受到热的扰动，以及出现大量的膝折带或宽缓褶皱。上述变质变形演化历史代表了澜沧变质带的隆升及剥蚀过程。     

高州大井岩组变质重结晶作用和变形作用的关系

高州大井岩组泥质岩中变斑晶种类繁多,变质重结晶作用分成四个阶段：Ｍ１发生于变形前埋藏过程中,Ｍ２、Ｍ３属进变质阶段,Ｍ４为退变阶段。变斑晶的生长主要集中在Ｄ１幕后Ｄ２幕前的一个相对“静态”的时期内,变形与变质重结晶作用存在一定的时间间隙。     

闽北政和地区晋宁期变质岩系的变形变质作用

政和地区变质岩形成于晋宁期，遭受了四期复杂的构造变形作用。其中，Ｄ１、Ｄ２和Ｄ３发生于晋宁期。Ｄ２期形变造就了区域性宏观面理构造和松源复背斜，岩石面理产状不代表原始沉积层理，屈轴面叶理。Ｄ４期变形为后期加里东运动的产物。变质岩石由绿泥石－黑云母带、石榴石带、十字石带和矽线石带组成一个热背斜式递增变质带，热背斜形态接近于松源复背斜。本区晋宁期变质作用可分为早期、主期和晚期三个变质阶段，各变质带的ＰＴ     

政和地区变质岩石的变质结晶作用与变形作用的关系

政和地区变质岩石在晋宁期遭受了３期构造变形作用（Ｄ）。以这３期构造变形作用为相对时间标志，讨论了变质砂泥质岩石中各种不同产状、不同种类变质矿物的生长期，确定了基质主要加粗期为Ｄ２－Ｄ３变形期间的静态期。进而将晋宁期变质作用划分为早期、主期和晚期３个变质阶段，变质作用的主期为Ｄ２变形期和Ｄ２－Ｄ３变形期间静态期。     

东南极拉斯曼丘陵麻粒岩相岩石中早期残留矿物组合的特征及其变质…

东南极拉斯曼丘陵出露的麻粒岩相泥质片麻岩和镁铁质麻粒岩经历了复杂的变形变质历史。代表前进的增厚事件的早期残留变质构造Ｄ１形成于１０００Ｍａ期间。对应于Ｄ１的变质峰期Ｍ１的变质组合以泥质片麻岩的石榴石和尖晶石变斑晶中的堇青石和夕线石包裹体以及镁铁质麻粒岩的石榴石变斑晶中的斜方辉石和斜长石包裹体为特征。在该区斯托罗斯半岛的紫苏黑云石英岩的粗粒紫苏辉石中发现了包裹的假蓝宝石＋磁铁石和假蓝宝石＋尖晶石＋夕     

剪切带中变斑晶的生长及包裹体痕迹的演化

韧性剪切带中,由于变形分解作用的存在,岩石发生递进变形过程中,产于共轴或非共轴递进缩短带内的变斑晶不发生旋转,而变斑晶内的包裹体痕迹是递进变形过程中遗留在变斑晶内的变形变质痕迹。利用未旋转斑晶中的包裹体痕迹可以确定早期面理的取向,寻找构造演化的时间标志,确定变形变质的关系及其演化史。对北祁连托勒牧场大型走滑韧性剪切带中石榴石、黑云母等变斑晶及包裹体痕迹的研究,揭示了变斑晶的生长和包、裹体痕迹与褶劈理的演化有着重要联系以及剪切变形过程中变形变质演化史、应变速率的变化。递进变形相应地发生递增变质,但两者存在着一定的差异性。     

剪切带中变斑晶的生长及包裹体痕迹的演化

韧性剪切带中，由于变形分解作用的存在，岩石发生递进变形过程中，产于共轴或非共轴递进缩短带内的变斑晶不发生旋转，而变斑晶内的包裹体痕迹是递进变形过程中遗留在变斑晶内的变形变质痕迹。利用未旋转斑晶中的包裹体痕迹可以确定早期面理的取向，寻找构造演化的时间标志，确定变形变质的关系及其演化史。对北祁连托勒牧场大型走滑韧性剪切带中石榴石、黑云母等变斑晶及包裹体痕迹的研究，揭示了变斑晶的生长和包、裹体痕迹与褶劈理的演化有着重要联系以及剪切变形过程中变形变质演化史、应变速率的变化。递进变形相应地发生递增变质，但两者存在着一定的差异性。     

西藏羌塘中部冈玛错-双湖变质带变质变形作用关系研究

通过对冈玛错-双湖变质带中蓝闪石矿物种属的划分及矿物特征的研究,以及对石榴石和钠长石变斑晶中包裹体痕迹的确定、铁蓝闪石和青铝闪石具明显环带的发现、一系列褶劈理和皱劈理变形及退变质作用特征的描述,并通过对蓝闪石40Ar/39Ar快中子活化分析,获得蓝闪石的年龄谱图.确认了该变质带经历了3期变质变形事件.指出各期变质变形特征的综合分析能指示冈玛错-双湖变质带形成及隆升的演化过程.     

新疆阿祖拜地区变质作用特征及构造演化

新疆阿祖拜地区发育两种类型的区域变质作用,第一种类型属于区域低温动力变质作用,第二种类型属于区域动力热流变质作用。变质作用时代发生在晚古生代华力西期,其间有3个阶段变形变质作用发生,早期阶段以形成低温绿片岩相变质岩石组合为主,构造片理(S1)与原岩沉积层理(S0)基本一致。中期阶段以区域动力热流变质作用为主,形成典型的递增变质带,并使早期构造片理(S1)发生紧闭褶皱,也是阿尔泰华力西期造山带变形变质的主期。晚期阶段为退化变质作用,变质作用轻微,变形作用不明显。不同阶段和不同的变形变质作用类型代表了不同的大地构造环境,记录了造山带的演化历史和动力学过程。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an     

PROSPECTING EXPLORATION

正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of