个旧地区地球化学元素的多重分形特征及找矿预测

应用多重分形的“C-A“模型(即含量-面积)方法,对云南个旧地区的水系沉积物样品的20项元素进行了研究分析.结果表明,成矿元素以及伴生元素呈模式Ⅱ的高丛集多重分形分布,非成矿元素呈模式Ⅰ的简单连续多重分形分布;根据个旧地区东部与西部地球化学元素分布的对比发现,在东部的分维值普遍比西部小,有的成矿元素如Cu、Au在东西部呈现不同的分布模式,而非成矿元素分布变化不大.     

矩分析法及其在粤北韶关地区金属成矿作用研究中的应用

采用多重分形矩分析法探讨了粤北韶关地区4292km^2内1448个基岩样品的25项元素的分形分布规律。结果表明，金属地球化学场元素的多重分形谱函数上凸且连续，其多重分形谱函数的开口大小在某种程度上能反映地球化学场的浓集程度。地球化学场中元素在空间上的分布具有连续多重分形特征，与成矿密切相关的微量元素一般服从左侧开口明显大于右侧开口的连续多重分形左偏模式，而非主要成矿元素则对应右侧开口大的连续多重分形右偏模式。     

西藏班戈地区化探数据的多重分形特征及其成矿意义

分形理论为精细研究地质体的复杂性结构提供了新的视角,已有研究表明元素含量在地球化学场中的分布具有分形或多重分形特征。应用元素"含量-面积"分形模型定量描述了西藏班戈地区8种微量元素的分形特征,其中W表现为低富集连续多重分形模式,其他7种元素表现为高浓集连续多重分形模式;应用"含量-面积"双对数分维数D值并结合地质背景分析认为区内Au、Sn两元素有一定的成矿潜力;与矽卡岩有关的Cu-Mo-Pb-Zn-Ag等多金属均有较好的成矿潜力,其中Cu元素的成矿潜力最大、Mo、Pb、Ag等元素成矿潜力较好、Zn元素成矿潜力相对较差;区内W元素的成矿潜力不大。     

基于“元素含量-面积”模型方法的地球化学场的多重分形模式分析

从多重分形理论出发，在赤峰地区的2个区域应用“元素含量-面积（C—A）”模型方法。对“元素含量-面积”双对数图的形态进行分析，将地球化学异常多重分形特征模式分为3种类型：模式Ⅰ为可拟合为2条直线段的简单多重分形模式，具有该模式的元素在研究区内没有成矿富集的趋势，不存在实质性的致矿异常；模式Ⅱ为可以拟合为3条直线段的高富集多重分形模式，它在模式Ⅰ的基础上叠加有高含量的异常场，具有该模式的元素在研究区内存在较强的局部富集，成矿的可能性很大：模式Ⅲ为可拟合成3条直线段的低富集多重分形模式，它在模式Ⅰ的基础上叠加的是较弱的异常场，具有该模式的元素在研究区内有较弱的矿化作用。在此基础上，分析了元素的成矿富集规律和空间分布特征，确定了区域异常和局部异常的异常下限，划分了地球化学背景、区域异常和局部异常。     

多重分形在个旧花岗岩凹陷带地球化学数据分析中的应用

应用多重分形方法对个旧花岗岩凹陷带的12个微量元素进行地球化学分形统计,根据曲线的形态可以分为2种多重分形模式.模式Ⅰ是具有2个无标度区的简单多重分形模式,第二直线段和曲线能够很好的拟合,具有该模式的元素为Hg、Mn、Sb、Mo、As、Zn,是一些与成矿元素无关和伴生的元素.模式Ⅱ是一种具有高丛集的多重分形模式,第二直线段与曲线拟合程度较差,有明显的偏离,它反映了元素的高含量点在模式Ⅰ上的叠加.具有该模式的元素有Sn、Cu、Pb、Ag、W、Bi,这些元素都在该区有很大的局部异常,其中主要的成矿元素Sn、Cu、Pb、Ag都形成了不同级别的矿床.     

青海阿尔茨托山地区地球化学（异常）场的多重分形研究

以研究区成矿地质背景为基础，将其划分为4个地球化学区，从多重分形理论出发，应用“元素含量—面积”模型方法，对各区主要成矿元素的地球化学(异常)场进行分析研究。结果表明，由于地质构造背景和化探元素富集的成因机理不同，各区元素地球化学(异常)场具有两种不同的多重分形特征模式：只有两个无标度区的简单多重分形模式和有两个以上无标度区的高丛集多重分形模式，具有相同成因的元素组合具有相似的多重分形特征。在此基础上．探讨了各区元素的成矿富集规律和空间分布特征，进而划分了地球化学背景和异常，经检验对比，证明了该方法的有效性和实用性。     

基于"元素含量-面积"模型方法的地球化学场的多重分形模式分析

从多重分形理论出发,在赤峰地区的2个区域应用"元素含量-面积(C-A)"模型方法.对"元素含量-面积"双对数图的形态进行分析,将地球化学异常多重分形特征模式分为3种类型:模式Ⅰ为可拟合为2条直线段的简单多重分形模式,具有该模式的元素在研究区内没有成矿富集的趋势,不存在实质性的致矿异常;模式Ⅱ为可以拟合为3条直线段的高富集多重分形模式,它在模式Ⅰ的基础上叠加有高含量的异常场,具有该模式的元素在研究区内存在较强的局部富集,成矿的可能性很大;模式Ⅲ为可拟合成3条直线段的低富集多重分形模式,它在模式Ⅰ的基础上叠加的是较弱的异常场,具有该模式的元素在研究区内有较弱的矿化作用.在此基础上,分析了元素的成矿富集规律和空间分布特征,确定了区域异常和局部异常的异常下限,划分了地球化学背景、区域异常和局部异常.     

应用复杂性-非线性理论开展成矿预测——奇异性理论-广义自相似性-分形谱系多重分形理论与应用

本文应用 “奇异性-广义自相似性-分形谱系”为核心的多重分形现代成矿预测理论与模型开展了云南兰坪、个旧等地区的成矿过程模拟与矿产资源定量评价。文中介绍了作为非线性、复杂性理论的重要领域之一的多重分形理论如何应用与矿产资源定量评价中，所涉及的“奇异性-广义自相似性-分形谱系”等概念和相关的模型能够合理地描述成矿系统、成矿过程、成矿富集规律、矿产资源时空分布，还提供了定量模拟和识别成矿异常（地质、地球物理、地球化学、遥感异常）的有效模型和实用方法。将多重分形原理与成矿过程、矿产资源分布规律、矿产资源信息获取研究相结合，可形成具有良好应用前景的现代成矿预测理论与模型。采用该多重分形矿产资源预测理论和在此基础上所开发的专用地学非线性空间信息GeoDAS GIS技术，对国内外多个金属成矿区带进行了矿产资源勘查与评价,均取得了较理想的预测效果。文中将以该理论方法在云南省多个地区开展矿产品定量预测的实例来说明该理论体系和方法技术的有效性和可行性。     

云南麻栗坡地区成矿元素的多重分形特征与成矿预测

对麻栗坡地区1∶5万水系沉积物测量数据的统计分析表明,W、Sn、Pb、Zn、Cu等主要成矿元素不完全服从正态分布和对数正态分布,而表现出多重分形结构特征。因此,采用传统的地质统计学方法提取异常显然不能客观地反映区域的成矿元素分布特征。本文引用了"C-A"多重分形模型来研究该地区成矿元素特征,并有效提取各元素异常下限值,结合区域成矿地质背景,对区内成矿潜力进行初步预测。实践表明,分形方法所提取的剩余异常与研究区的矿产分布较为相符,较好地反映了研究区成矿元素分布规律,为研究区成矿预测提供了依据。     

个旧锡多金属矿集区高松矿田矿化元素局部富集的奇异性特征

多重分形理论能够有效地分析地球化元素局部富集和贫化规律。对取自个旧高松矿田的1 783件断裂构造地球化学样品的13种元素进行了多重分形统计以及局部奇异性方法分析。结果表明:多重分形维谱函数α-f(α)曲线呈连续上凸的特征,曲线的不对称反映了元素局部富集程度差异,并据此将13种元素划分为包含Sn、Cu、Pb、Ag、As、Mn在内的主要成矿元素组合以及包含Zn、Sb、Cd、W、Mo、Bi、Hg的次要成矿元素或伴生元素组合。多重分形的特征值τ″(1)以及Dq的变化规律表明:在主要成矿元素中,Sn在断裂空间上局部富集程度最高,其次为Ag,而Cu相对最低,各元素的τ″(1)值与对应的变异系数的大小具有较为显著的相关性;各元素在空间上的奇异性指数α增强了地球化学富集地段的指示信息,可以作为判别局部富集的重要参数。运用多重分形方法可揭示矿化元素局部富集的奇异性特征以及空间局部富集规律。     

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.)