华蓥山地区天青石矿稀土元素地球化学特征

华蓥山地区天青石矿各类型天青石的稀土总量(∑REE)均较低,为轻稀土富集型。巨晶天青石和条带状矿石之白色条带状天青石具铕的正异常,为热卤水成因,层状和条带状矿石之暗色条带天青石具δ Eu的负异常,与碳酸盐岩围岩一致,为沉积成因。区内天青石、碳酸盐岩表现为δ Ce的轻度负异常或无异常,与该区早三叠世嘉陵江组沉积时期所处的含膏泻湖相沉积环境有关。     

武当地区条带状“变基性岩”成因的岩石地球化学证据

对武当岩群中条带状“变基性岩”的暗色带和浅色条带与区域上大面积分布的厚层状变基性火山岩和变酸性火山岩分别进行对比研究,结果表明,暗色条带与变基性火山岩、浅色条带与变酸性火山岩的岩石结构构造、矿物组成及岩石地球化学特征十分相似,均形成于岛弧环境,结合其变形特征,认为条带状“变基性岩”是由基性火山岩与酸性火山岩交互形成的原始成分层经强烈顺层剪切置换而成。     

一种可能的新碳酸岩类型:壳源成因碳酸岩

本文是对大冶铁矿床接触带"大理岩"及其中分布的"条带状辉石-石榴石大理岩"进行专门研究的阶段性结果.在野外观察到"大理岩"呈岩墙、岩枝和细脉侵入石英闪长岩.根据石准立等的趋势面分析资料,在深部,本矿区"大理岩"与石英闪长岩的接触带总是以突入石英闪长岩内为特征.在"大理岩"与灰岩接触带附近观察到大理岩粒度由于温度冷却快而变细和在"大理岩"中有灰岩残留体."大理岩"本身的方解石粒度中部粗两侧细.本矿区的"大理岩"矿物结晶颗粒比长江中下游许多接触热变质形成的大理岩粗."大理岩"内部浅色大理岩为白色,常具有定向的细条纹构造(可能为流动构造或构造事件引起的线性构造),局部产状变化急剧.在尖山矿段产在"大理岩"中的"条带状辉石-石榴石大理岩",主要含辉石和石榴石条带,其条带走向与"大理岩"岩体延伸方向斜交,且与区内一组断裂构造有关.显微镜观察结果表明,在制备的约65块包裹体切片中均观察到熔融包裹体或流体-熔融包裹体及流体包裹体.包裹体加热实验结果显示,"大理岩"中方解石及"条带状辉石-石榴石大理岩"中的石榴子石和方解石中熔融包裹体接近均一的温度为880～1 055℃,流体-熔融包裹体均一温度为645～740℃."大理岩"及"条带状辉石-石榴石大理岩"的C和O同位素组成与长江中下游的灰岩大致一致,在δ13C-δ18O相关图中的投影点落在沉积碳酸盐范围.电子探针分析表明,在"条带状辉石-石榴石大理岩"的方解石中的一个熔融包裹体为含Si、Ca、Mg、Al和K的混合物(即玻璃)."大理岩"中的圆形固体包裹体成分经电子探针检查为方解石.能谱分析结果表明,"白云质大理岩"的白云石中圆形固体包裹体成分与白云石类似,但与寄主矿物略有区别.在上述初步研究基础上认为,本文所报道的"大理岩"和"条带状辉石-石榴石大理岩"不是由于接触变质引起方解石重结晶的产物,而可能是一种新的碳酸岩类型--壳源成因碳酸岩.     

冀西北太古宙条带状麻粒岩的岩石学和地球化学特征

条带状麻粒岩是冀西北太古宙麻粒岩相带中特殊而重要的一种岩类，它由浅色条带和暗色条带组成，条带含量的比例变化不大。浅色条带由较多的斜长石、紫苏辉石、透辉石和一定量的石英组成，伴生少量小而细的磁铁矿；暗色条带由较多的紫苏辉石、透辉石和普通角闪石以及一定量的斜长石组成，伴生有较多较大的磁铁矿。少量黑云母在两种条带中均有所见。两种条带中的同种矿物的光性特征基本相同，而化学成分和稀土元素特征只有很少的差别。暗色条带为基性麻粒岩属ＴＨ２型拉斑玄武岩，而浅色条带的岩石为中酸性麻粒岩，相当英云闪长质类型。这种条带状的岩石形成于不同时期不同性质的岩浆作用和特定的构造环境。暗色条带的物源来自较早的（约２．８Ｇａ）亏损地幔，而浅色条带的物源来自较晚（约２．５Ｇａ）基性岩的部分熔融，与周围的大片区域性英云闪长岩的侵位大致同时。条带状麻粒岩不宜归入ＴＴＧ岩系     

浙江八面山萤石矿床氢氧同位素地球化学

浙江常山八面山萤石矿床具有矿源层——岩浆岩侵入体——断裂构造"三位一体"的控矿模式,矿石类型以深灰色块状与条带状细粒萤石矿石为主,该类矿石外貌特征与灰岩极其相似,呈黑灰色、深灰色,比重较灰岩大;其次为紫色与翠绿色粗、巨晶块状萤石矿石,此类矿石主要产出于陡倾斜脉状矿体中.通过对不同矿石类型矿物原生包裹体水δ180和δD分...     

新疆西昆仑切列克其铁矿成因——地球化学及流体包裹体证据

新疆切列克其铁矿位于西昆仑造山带南带,矿体呈层状、似层状产于志留系温泉沟组地层中。在对矿床地质特征进行研究的基础上,开展了详细的岩矿石地球化学及流体包裹体研究,探讨了切列克其铁矿的成因。切列克其铁矿经历了2期成矿作用:早期为海底热水喷流成矿作用,是主要成矿期,主要形成层状、纹层状和条带状矿体,硅质条带中流体包裹体均一温度为140~160℃,盐度为4.79%~5.09%Na Cl eqv,成矿流体为低温低盐度流体;晚期为岩浆热液成矿作用,该期成矿作用造成了菱铁矿的活化迁移,形成了细脉状菱铁矿石,通过对含菱铁矿石英脉中包裹体的研究,可见气液两相、含子矿物三相和富气相3种类型包裹体,成矿流体包括中高温高盐度流体和中低温低盐度流体。     

广西贺州平桂区水井山矿区大理石矿床地质特征及成因

"贺州白"是我国白色大理石具有代表性的三个品种之一,贺州平桂区水井山矿区的大理石矿石材品种即属"贺州白"系列。本文通过野外调查与样品测试分析等手段,基本查明了水井山矿区大理石矿床的地质特征和成因。研究发现,矿体主体以层状产出,赋存于上泥盆统融县组地层,成因类型为热接触变质型。矿石主要由方解石组成,根据矿石类型,将石材品种分为"云团白"(岩性为白色、灰白色含暗色团块中粒大理岩)、"红线白"(岩性为白色、灰白色含铁质红色色线中粒大理岩)和"雪花白"(岩性为白色中细粒大理岩)三种。矿石作为石材其影响装饰性能的金属矿物含量不高、物理性能优良、放射水平极低、完整性较好、荒料率较高,是优质的饰面石材矿。     

湖南沃溪W Sb Au矿床成因的流体包裹体证据

系统研究了沃溪WSbAu矿床层状矿体的流体包裹体特征,均一温度集中在120～180℃,盐度变化于2.9%～8.9% NaCl之间,由包裹体均一温度与盐度计算得出的流体密度介于0.94～0.96 g/cm3。流体包裹体稀土元素地球化学组成表明,成矿流体为一种进化的海水,即海水在海底下沉积柱循环过程中萃取矿质,形成120～180℃温度的低密度成矿流体。当其回返上升到海底后,形成悬浮热液柱,并与冷海水逐渐掺和,发生化学和机械－化学沉积,在海底形成层状矿体。流体包裹体均一温度和盐度的变化范围与很多沉积喷流（SEDEX）矿床极为相似,暗示与这些矿床具有相似的成因机制。同一矿层、条带状矿石中同一条带的石英中包裹体均一温度和盐度的规律性变化,支持沃溪WSbAu矿床的同生热水沉积成因观点。     

浙江八面山萤石矿床流体包裹体地球化学研究

八面山萤石矿床流体包裹体可分为三大类型:Ⅰ气液包裹体,Ⅱ气体包裹体,Ⅲ含子矿物的多相包裹体;矿床成矿温度变化不大,主要集中在120～240°C之间。细粒条带状萤石矿石包裹体温度变化在115～250℃之间;巨晶块状萤石矿石和石英脉型萤石矿石包裹体温度集中在135～170℃之间。萤石矿床流体包裹体以低盐度成矿流体为主。成矿过程中起作用的成矿流体为KCl-H2O体系和CO2-CaF2-H2O体系,成矿溶液的离子类型属K+-Ca2+-HCO--F-型,KCl-H2O体系反映岩浆期后热液作用的结果,而CO2-CaF2-H2O体系可能反映了寒武纪矿源层成矿体系。通过包裹体研究,认为八面山萤石矿床是受地层-岩体-层间断裂共同控制"三位一体"的热液成因矿床。     

云南省永善县务基磷矿床地质特征及成因分析

云南省永善县务基磷矿赋存于下寒武统梅树村组中谊村段地层中,矿石矿物以胶磷灰石为主,具砂屑、砾屑及鲕粒结构,薄-中层状、块状及条纹条带状构造,矿石自然类型为砾屑状磷块岩、条纹状白云质磷块岩、条带状白云质磷块岩、硅质磷块岩。通过分析矿区所处古构造、古地理特征和矿石结构特征,认为务基矿区磷矿为浅海相沉积磷块岩矿床。     

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