西藏纳木错第四纪湖泊沉积与湖成地貌--兼论藏北高原古大湖问题

对西藏面积最大的湖泊——纳木错湖相沉积野外现察结果，发现了由水平层理十分发育的砂与粘土所组成的、高出湖面分别为3—12m、15—22m、25—30m与35—45m的4级湖岸阶地，覆于基岩之上、高出湖面60—150m的湖相沉积和多达50条左右、由扁圆湖滨相砾石所组成的湖岸堤，环湖广泛分布的湖成地貌。在连结纳木错与其西北的仁错约玛、仁错贡玛、久如错的分水岭宽谷底部(分别高出上述3湖20m、90m与60m)与北侧山坡，即纳木错的第二与第三级湖岸阶地，发现了组成阶地与异堤的湖相与湖滨相沉积。从而确证了纳木错与仁错-久如锴曾多次连通，即数度成为一个统一的大湖，而不是以河道相连的不同湖泊。古大湖分离时代为末次冰期间冰段。     

内波、内潮汐沉积形成过程中内波传播方向与沉积物搬运方向相反的定量解释

本文从海洋物理学角度出发,以内波波动理论为基础,通过建立两个不同密度的水层界面上的两层模型的波动方程对内波的传播特征进行定量解释。通过定量解释表达式可知:内波在两个不同密度的水层界面上传播时,两层内波流之水平速度方向相反,保持通过海底的整个截面的流通量为零。在密度界面之下,波谷处内波流的运动方向与内波前进方向相反,由于波谷相对于波峰更接近于海底,即波谷处截面积较小,故波谷下方的流速较波峰下方的流速大,容易形成与内波前进方向相反的单向优势流动,这种单向优势流动搬运沉积物的总趋势与内波的前进方向相反。     

基于特征分析法的琼南矽卡岩型矿床成矿预测研究

在系统总结琼南矽卡岩型矿床区域成矿地质背景与成矿规律的基础上,分析和提取了地质、物探、化探、重砂、遥感等多元有利找矿信息,具体包括碳酸盐岩地层、燕山晚期中酸性侵入岩、控矿断裂、航磁推断磁性蚀变带、化探Cu、Pb、Zn、Au、Ag单元素异常及Cu-W-Mo、Pb-Zn、Au-Ag组合元素异常、自然重砂Fe、Pb-Zn异常以及遥感羟基和铁染蚀变异常等。并利用上述找矿信息及6个模型控制单元(即已知含矿单元)建立了特征分析初始矿化模型M1,同时为解决模型M1中控制单元不足的问题,我们从中筛选了联系度f≥4的26个单元作为新的模型控制单元,重新建立了广义矿化模型M2,并据此圈定了4个A级、2个B和2个C级矽卡岩型矿床找矿预测靶区,为本区矽卡岩型矿床的找寻提供了重要的科学依据。     

Distribution Characteristics and Metallogenic Regularity of Graphite Deposits in Qinling Orogen, China

Qinling orogen is one of the five main repository distribution provinces of large scale graphite resources. Graphite occurrence strata are multitudinous including Neo Archaean group to Neopaleozoic. Mineral deposit types are complete consisting of crystal flaky graphite deposit and aphanitic graphite deposit, ore types of the former are main graphite gneiss, graphite schist and graphitized marble, and ore types of the latter are main graphite layer metamorphosised from coal bed and graphitic carbargilite. At present, most graphite deposits with low research degree only implement preliminary investigations of the graphite resource, which has a good prospect. Based on the basic material of dozens of graphite deposits, spots and plays discovered in the Qinling orogen, this paper applied geologic multidisciplinary analysis method to disclose the graphite deposit types of the Qinling orogen, mainly through outdoors geologic survey and specimen examination with analysis of some typical deposits: regional metamorphism crystal graphite deposits and thermo-contact metamorphic aphanitic graphite deposits, with the control of latitudinally trending regional tectonic, graphite deposits of the Qinling orogen distribute sublatitudinally trending three large ore belts: I the Neoarchean–Proterozoic basement crystal graphite enrichment deposits zone along the south margin of North China plate; II the Carboniferous intermountain basin group aphanitic graphite enrichment deposits zone near the Shangdan suture of the West Qinling; III Paleozoic crystal graphite enrichment deposits zone in the Qinling paleomicroplate of the west part of the East Qinling.Conclusions are reached from multiple inquiries: Qinling multi-cycle complex continental collision orogen zone has experienced multiple tectonic framework transformation and polyphase tectonic thermal event from Neo Archean Erathem adjointing multiple graphite tectonic mineralization cycle. In the light of chief control of mineralization and ore types, each of the three large graphite deposits belts of the Qinling orogen has its own genesis: I graphite deposits enriched metallogenetic zone is that regional tectogenetic movement from Neo Archaean caused polyphase metapepsis, which superimposed up and reconstructed Neo Archean Erathem to Proterozoic basement, forming regional metamorphic big flake crystal graphite deposits; II graphite deposits enriched metallogenetic zone is that polyphase regional tectogenetic movement associated with multiple heating caused by multiphase igneous intrusion, which resulted in original coal layers emerging multiple thermo-contact metamorphisms and formed thermo-contact metamorphic aphanitic graphite deposits. III graphite deposits enriched metallogenetic zone is that Palaeozoic cap–rock experienced polyphase metapepsis, forming regional metamorphic finely flake crystal graphite deposits. Comprehensive research of metallogenetic mechanism in graphite deposits and its associated profitable deposits of the Qinling orogen is importance for future exploration.     

Geochemical characteristics of Holocene aeolian deposits and their environmental significance in the Mu Us Desert,northern China

This paper addresses the surface and Holocene aeolian deposits in the southeastern Mu Us Desert, N. China, systematically analysing the evolution of the geochemical characteristics of aeolian sand–palaeosol sequences and their environmental significance. Our results indicate that the geochemical components of the Holocene aeolian deposits and surface deposits had the similar material sources, sediment transport and deposition processes in the study region, which were dominated by SiO₂, Al₂O₃, and Na₂O. In the weathering process of the Jinjie (JJ) profile, the Na, K, and Si presented the slight leaching and migration in general, while the other elements were relatively accumulated. The Holocene aeolian deposits and surface deposits incurred weaker geochemical weathering under cold and dry conditions and were only weakly leached, which implies a relatively arid environment in the Holocene epoch and the modern era. The weathering degree was controlled by the regional temperature and precipitation, and was probably more sensitive to the precipitation changes. In the sedimentary profile, the geochemical parameters and migration of elements demonstrated that there have been several alternating warm–wet and cold–dry intervals in the Mu Us Desert in the Holocene epoch; there were relatively warm and wet conditions prior to 4.6 ka, and it has been cold and dry since then. Six millennial‐scale dry events were recorded during the Holocene, which were not only accordant with the history of palaeoclimatic changes in the different latitudes and archives of the Northern Hemisphere, but also correspond to the millennial‐scale variation of cosmic radiation and solar activity during that period. Copyright © 2015 John Wiley & Sons, Ltd.     

吉林龙岗火山群火山碎屑基浪堆积特征与成因机理

吉林龙岗火山群火山碎屑基浪堆积是中国少数保存较好的、近代喷发的低平火山区之一。基于岩性、岩相与相序的识别与分析,火山碎屑基浪堆积序列由分选性和磨圆度较差的玄武质砂、砾和火山灰构成的毫米级-厘米级厚高频率韵律有序叠置而成,堆积物中发育大量的块状层理、似丘状层理、低角度板状交错层理、槽泊层理、平行层理、冲蚀槽等堆积构造。横向上低平火山由内至外其碎屑粒度、堆积构造、厚度存在着一定规律变化,与易混淆的火山岩区地面流水沉积和火山碎屑流堆积物存在明显的差别。岩浆射汽喷发晚期往往伴随斯通博利式喷发和夏威夷式熔岩流,三者构成一个完整火山活动旋回。     

桂西北微细浸染型金矿成矿地质特征及找矿远景区优选

“桂西北”是我国以微细浸染型金矿为主的重要金成矿集中区之一,具有重要的找矿前景和研究价值。本文通过对“桂西北”金矿集中区进行详细的野外地质工作,并以高龙、金牙两典型微细浸染型金矿床为主要研究对象,重点分析其地质特征、成矿地质条件,进而总结了研究区微细浸染型金矿的成矿作用机制、成矿模式。最后,结合桂西北地区特定的沉积古地理特征、构造、围岩蚀变等地质信息,已有的地球化学、矿产等资料以及前人研究成果,初步圈定了5个可供进一步找矿的远景区。     

Late Triassic-Early Jurassic Paleokarst from the Ligurian Alps and its geological significance (Siderolitico Auct., Ligurian Briançonnais domain)

In the Ligurian Briançonnais domain, the thick Middle Triassic carbonateplatform units, formally known as the Costa Losera Fm. and S. Pietro dei Monti Dolomites, are followed by a significant unconformity separating them from the Rio di Nava neritic limestones of Bathonian age. According to the evolution of a passive continental margin, the end of subsidence and subsequent uplift led to the progressive erosion of the Triassic carbonate platform from outer to inner units, i.e., in the direction of the Ligurian Tethys. This erosion, possibly acting on a fault-controlled block system, created sedimentary sequences of differential composition, and the virtual absence of the entire Triassic complex and even the underlying Permian rocks. In the study area (and in many other locations belonging to the external Ormea unit), the so-called “briançonnais sedimentary gap” shows more than a nondepositional surface: the associated deposits (known as “Siderolitico” Auct.) include both red pelites between the above-mentioned units, and deep-penetrating karstic red breccia within the Ladinian carbonates. We performed detailed stratigraphic, microfacies and compositional analyses on the karsts and paleosoils associated with the unconformity in order to define their character, genesis and age. In addition, we discuss the regional context and importance of these deposits in a large-scale comparison with the classic Briançonnais domain and other locations of the Western Alpine Arch with the same unconformity. In light of these data, we propose an Upper Triassic to Early Jurassic age (until the Upper Bajocian?) for the karstic event in the Ligurian Alps.     

Rational combination of mathematical methods for predicting ore deposits

Summary This study emphasizes the important role of a flexible, multipurpose data base, including both qualitative and quantitative information, for metallogenic investigations and prospect assessment. Information stored in such a data base allows processing by various methods for different purposes and obtaining efficient and comparable results.     

学习实践“改造成矿作用”理论——以滇中砂岩铜矿为例兼论改造作用的上、下限问题

"改造成矿作用"是涂光炽院士提出的新理论。这一理论有如下基本论点和鲜明特色:矿质来源的广泛性;成矿流体的特殊性;成矿元素的活泼性;改造作用的内生性;断裂构造的主导性;赋矿岩石的多样性;改造矿床的普遍性;成矿作用的独特性与应有地位——矿床分类的四分法。滇中大姚-牟定式砂岩铜矿是典型的沉积-成岩-后生-改造成因。其主要论据与以下要素有关:裂谷成矿背景;矿源层(K、J)、矿源岩(元谋古陆);矿体受地层层位、岩相、岩性控制,其生成与煤系(提供有机质)、盐层(提供卤素)密切相关;矿体形态产状、矿石结构构造、成矿流体性状与水的来源、有机质类型及其作用在不同成矿期、成矿阶段显著不同。从岩石学的名词概念来解读和划分"改造成矿作用"的上限与下限:上限确定在后生作用之后,下限在变生作用之末。