X荧光分析技术在航磁异常地面查证中的应用

西天山135号航磁异常点由于地质条件的限制,大型勘查设备测量和探槽揭露工作很难开展;此外,受气候条件限制,适合查证工作的时间较短。因此,采用X荧光分析技术结合传统物探方法的技术路线,在航磁异常查证阶段综合采用地面高精度磁法测量、γ能谱测量、野外现场X荧光快速分析和岩样物性分析方法完成航磁异常的检查。根据野外X荧光分析发现135号航磁异常西南部有新的铜元素含量异常点,结合现场踏勘捡样发现孔雀石矿化现象,判断135号航磁异常西南部有铜矿化点的存在。在铜矿化区域通过大比例尺现场X荧光分析快速定位两处新发现的铜异常,并圈定了矿化范围;在工程验证阶段采用"以钻代槽"技术,结合X荧光分析和微区X荧光分析方法研究矿化展布特征、矿物成分,评价矿化价值。通过135号航磁异常查证工作,结果表明X荧光分析技术是一种快速高效、经济的勘探方法,能够缩短野外勘查周期,高效地完成异常查证及矿产勘查工作。     

物化探成果在黑龙江滨东新立屯地区水系沉积物异常查找中的应用

利用1∶2万土壤测量、地面高精度磁法测量及激电中梯测量等方法对黑龙江滨东新立屯地区1∶5万水系沉积物异常进行查证,发现Mo等11种单元素土壤异常182处、组合异常29处、高磁异常1处、激电异常2处。在综合分析其地质背景基础上,对物化探异常套合处进行了槽探工程揭露,发现多处钼矿(化)体。     

黑龙江大兴安岭地区航磁异常特征及找矿效果

利用大兴安岭地区1∶5万高精度航磁资料,结合区域地质背景分析了该区航磁异常特征,依据地物化资料、已知矿(床)点的分布及成矿规律筛选出了一批航磁异常。在最新的高精度航磁图上,已知铁矿异常特征明显,经对比研究及综合查证发现了1处磁铁矿点及多处有色金属、贵金属矿点,在此基础上总结了查证经验,指明了今后采用航磁数据在区内的找矿方向。     

黑龙江大兴安岭地区航磁异常特征及找矿效果

利用大兴安岭地区1：5万高精度航磁资料,结合区域地质背景分析了该区航磁异常特征,依据地物化资料、已知矿（床）点的分布及成矿规律筛选出了一批航磁异常.在最新的高精度航磁图上,已知铁矿异常特征明显,经对比研究及综合查证发现了1处磁铁矿点及多处有色金属、贵金属矿点,在此基础上总结查证经验,指出了今后采用航磁数据在区内的找矿方向.     

物化探方法在黑龙江古金厂地区水系沉积物异常查证中的应用

利用1∶2万土壤测量、地面高精度磁法测量及激电中梯测量等方法对黑龙江黑河市古金厂地区1∶5万水系沉积物异常进行查证,发现Au等11种单元素土壤异常75处、组合异常6处、高磁异常5处和激电异常2处。在综合分析其地质背景基础上,对物化探异常套合处进行了槽探工程揭露,发现681.5高地金矿体。     

青海省野牛脊航磁异常的地质意义及找矿潜力分析

对野牛脊航磁异常进行地面查证工作,通过在重点查证小区开展地物化综合剖面测量、磁法剖面测量、土壤测量、地质草测、槽探揭露等勘查手段对航磁异常进行剖析,评价航磁异常的地质意义,在此基础上对该航磁异常对应范围的找矿潜力情况进行了初步评价,认为该航磁异常对应的深部具有进一步找矿的潜力。     

地物化方法在航磁异常查证中的应用

航磁异常查证是矿产勘查中的一个重要环节,其目的是通过地面查证,确定异常是否存在,追踪异常源,了解异常源所处的地质环境,对异常作出客观评价,提出进一步工作的建议,为后续资料解释提供依据.通过使用地物化综合方法对黑C-2011-02243号异常查证发现：地质剖面测量和土壤地球化学测量可在地表发现较好的找矿线索;高精度磁测及激电中梯测量则反映了深部地质体及矿化特征.依据查证结果认为,在进行航磁异常查证工作时,可优先进行剖面性的地质、高精度磁法及土壤地球化学测量工作;在分析上述测量结果的基础上安排剖面性的电法测量;如存在进一步找矿信息,可安排面积性物化探测量及工程验证工作.     

高精度航磁调查在新疆西天山地区的应用

介绍了高精度航磁调查在西天山地区的应用效果,在高精度航磁图上,磁异常信息极为丰富,不仅已知铁矿在图上反映明显,而且还新发现了50余处铁矿异常,在已经进行了查证的5处异常中,有4处见矿,分别为14号、20号、169号和374号。这4处异常的成功发现不仅带来了巨大的经济效益,也为今后利用高精度航磁调查进行找矿提供了典型的实例。根据该区高精度航磁调查实际效果,笔者认为在新疆西天山地区,乃至整个中国西部勘查程度较低的地区,进行高精度航磁测量,并进行快速的地面查证工作,是寻找铁磁性矿产行之有效的方法。     

地面综合物化探方法在航磁异常查证中的应用——以易家湾地区航磁异常为例

在钦杭成矿带湖南省衡山县易家湾初步圈定的航磁异常基础上,通过地面高精度磁测、激电测量、化探测量等综合方法,对航磁异常进行了查证、综合解释及效果评价,提高了航空物探异常解释的科学性和精确性,为该区进行全面的异常分析、评价和进行矿产资源预测提供了借鉴。     

一套基于X射线荧光测量的快速找矿方法

随着X荧光测量技术的发展,产生了土壤X荧光测量、岩石X荧光测量、钻孔X荧光测量和微区X荧光测量等多种多样的工作方法。笔者将土壤X荧光测量、浅钻X荧光测量和微区X荧光测量等快速获取异常信息手段应用于航磁异常查证,查明特克斯航磁异常主要由富含磁铁矿、褐铁矿的接触带安山岩所引起。对航磁异常查证,乃至找矿勘探工作的高效开展起到了良好的指导意义。     

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.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)