安页1井志留系龙马溪组页岩有机质拉曼光谱特征及其地质意义   总被引：3，自引：2，他引：1  

张聪  夏响华  杨玉茹  白名岗  代峰  熊杰 《岩矿测试》2019,38(1):26-34

我国下古生界海相页岩有机质热演化程度普遍高、陆源植物镜质体缺乏,显微组分难以区分,现有镜质体反射率、岩石热解、Tm/Ts等生物标志化合物指标的测试方法难以有效评价泥页岩有机质成熟度。本文以贵州正安地区安页1井志留系龙马溪组页岩为研究对象,利用场发射扫描电镜观察和激光拉曼光谱检测相结合,不依赖于有机质显微组分类型,直接获取高演化页岩中不同赋存状态有机质的拉曼谱图,利用拉曼谱图衍生参数评价高演化页岩的有机质成熟度。结果表明:安页1井志留系龙马溪组页岩发育着生物结构型、脉状或团块状、自形边界填隙状、他形边界填隙状4种类型有机质,其中自形边界填隙状有机质孔径大于80nm,他形边界填隙状有机质孔径小于60nm,这两种填隙状占比在90%以上,是页岩储层的主体储集空间;4种形态的有机质热演化程度不一致。激光拉曼面扫描取谱方式获得大量数据计算的拉曼成熟度主体介于2. 8%～3. 0%,各类型有机质的拉曼成熟度数量占总数量的比例与场发射扫描电镜观测的半定量统计结果一致。该方法为刻画我国高-过成熟度页岩有机质成熟度提供了一种行之有效的手段。  相似文献   

重砂分级-扫描电镜-能谱等技术研究湖南张家界黑色页岩贵金属元素赋存状态     

周姣花  周晶  牛睿  徐畅 《岩矿测试》2019,38(6):649-659

黑色岩系是多种有用元素的重要载体,Cu、Pb、Zn、Ni、Mo、V、U、Au、Ag、稀有和稀土元素在黑色岩系中异常富集,某些黑色岩系的贵金属(铂族元素、Au、Ag)也异常富集,其含量甚至部分超过了基性和超基性岩,这类黑色页岩矿床中铂族元素(PGEs)的赋存状态至今尚未有一个确切的定论。本文采集了湖南张家界属寒武系牛蹄塘组黑色页岩中Mo-Ni矿层作为研究样品,通过化学分析表明矿石中含Pt 531×10~(-9),Pd 514×10~(-9),Os 185×10~(-9),PGEs合量为1259.43×10~(-9),Au 332×10~(-9),Ag 12.2×10~(-6),已富集成矿。进一步利用重砂分级、化学分析、X射线衍射、扫描电镜及能谱技术研究了贵金属元素赋存状态,结果表明:①Ag:主要以独立矿物形式存在,少量以类质同象形式赋存在其他矿物中。独立矿物有砷铜银矿、硫锑铜银矿、硫锑铅银矿、锑银矿、硫银锡矿、硫砷银铅矿、银黄锡矿、辉银矿、锑-银-锡互化物;类质同象主要是银黝铜矿-银砷黝铜矿、含银方铅矿和含银砷铜矿等。②Au:未发现独立矿物,黄铁矿是重要载金矿物。③PGEs:未见独立矿物,在不同重砂分级样品中没有富集,具分散性,推测铂族矿物很可能是以纳米形式存在,建议今后研究选矿工艺时,可考虑从制取纳米材料的思路进行应用研究。本文Ag-Sn-Sb互化物的发现为研究黑色岩系多元素富集成因机制提供了重要物证。  相似文献   

原地生成宇宙成因核素测年技术思考(一):稳态侵蚀等式解出的ε是当前地表侵蚀速率     

黄费新  李岩  程杨 《地质与勘探》2019,55(1):145-151

原地生成宇宙成因核素测年技术可以方便地计算出地表的暴露年龄和侵蚀速率,从而成为研究地表演化过程的有力工具。在利用原地生成宇宙成因核素测年方法研究地表的侵蚀过程中,常常将稳态侵蚀状态下浓度与侵蚀速率的关系式所计算出的侵蚀速率当成暴露时间内的地表平均侵蚀速率,这其实是不准确的。本文通过数学计算和理论推导,证明由当前稳态侵蚀关系式解出的侵蚀速率是地表当前侵蚀速率(或称为最后恒定侵蚀速率),显然与地表平均侵蚀速率所代表的地质含义是不同的。  相似文献   

三维应力状态下粗粒料强度特性试验研究     

姜景山  程展林  左永振  丁红顺 《岩土力学》2018,39(10):3581-3588

粗粒料所处的应力状态具有随时间和空间而变的特点,往往处于较复杂的三维应力状态下。通过粗粒料大型真三轴各向等压固结等比例加载试验,研究了不同中主应力系数条件下粗粒料的强度特性。试验结果表明：中主应力对粗粒料的强度有重要影响,三维应力状态下,粗粒料的强度比常规三轴应力状态下有较大提高,大小主应力之差与大主应变关系曲线也更加陡峭;中主应力系数b从0增大到0.25时,破坏时大小主应力之差增加了39%～50%;摩尔–库仑强度参数咬合力c和内摩擦角? 均随着中主应力系数b的增大而增大,其中咬合力c的增长较为显著,特别是b从0增大到0.25时;相同小主应力条件下,b = 0时,破坏偏应力与球应力之比最小,b = 0.25时,破坏应力比达到最大值,随着b的增大破坏应力比又有所减小;相同中主应力系数条件下,随着小主应力的增大,破坏应力比逐渐减小。  相似文献   

散粒介质临界状态细观力学结构特征的数值模拟与分析     

刘洋  李爽 《岩土力学》2018,39(6):2237-248

基于离散单元法对不同密实度理想散粒体进行了双轴剪切试验的宏微观数值模拟,通过网格剖分将Voronoi多边形表征的loop单元作为散粒介质细观力学结构的基本单元,模拟了剪切过程中不同类型loop单元数量、几何形态和力学特征的演化过程,并重点分析了临界状态时散粒介质的细观力学结构特征。模拟结果显示,初始密实度不同的试样在向临界状态发展的过程中,高阶单元与低阶单元的发展规律完全不同,不同初始密实度试样中同阶loop单元的发展规律也不相同,但同阶loop单元的数量比例、几何形态、颗粒接触力及单元内滑动率最终均达到了各自的临界状态。从细观角度分析,散体介质的临界状态是高阶和低阶loop单元在荷载作用下相互转化的结果,是所有loop单元物理力学状态的综合平均与外在表现,临界状态时不同阶数的loop单元处于一个动态平衡状态,宏观上表现为常剪应力和常体积下剪切变形的不断发展。数值模拟结果也表明,loop细观结构单元包含了丰富的信息,其数量、几何形态、受力特征及接触稳定性的发展与散粒体的强度、剪胀以及临界状态的发展密切相关,可以将其作为散粒介质细观尺度的分析单元。  相似文献   

压力水作用下硬石膏岩膨胀性研究     

任松  吴建勋  欧阳汛  刘戎  王亮 《岩土力学》2018,39(12):4351-4359

针对隧道工程中硬石膏围岩在压力水作用下的膨胀现象,设计加工了多功能膨胀仪。使用该仪器及MTS815岩石力学测试系统,对不同水压条件下硬石膏岩的轴向膨胀应变及侧向膨胀应力进行了测试,对压力水作用后硬石膏岩的含水状态及力学特性进行了测试。结果表明：水压越大,硬石膏岩的最大轴向膨胀应变及最大侧向膨胀应力越大,膨胀起始时间越短;随水压的增大,硬石膏岩的吸水率增大,结晶水率逐渐增大并趋于吸水率,而自由水率逐渐减小并趋于0;硬石膏岩的弹性模量和峰值强度随水压的增大而增大。这些说明水压能影响其含水状态,增强硬石膏岩的膨胀性,促进其膨胀的激活,提高其力学性能。基于试验结果,建立了压力水作用下的硬石膏岩吸水状态方程,并改进了湿度场理论体系中的膨胀本构模型。  相似文献   

Control of magmatic oxidation state in intracontinental porphyry mineralization: A case from Cu (Mo–Au) deposits in the Jinshajiang–Red River metallogenic belt,SW China     

《Ore Geology Reviews》2017

The Jinshajiang–Red River porphyry Cu (Mo–Au) metallogenic belt (JRMB) is the most important intracontinental porphyry Cu (Mo–Au) mineralizing zone in the Sanjiang region, southwest China. The belt contains a number of giant deposits, including Yulong (6.50 Mt Cu) and Beiya (315 t Au) in the northern and center parts, and several small deposits in the southern part (e.g., Tongchang, 0.03 Mt Cu + Mo; Chang'anchong, 0.04 Mt Cu + Mo; Habo, 0.57 Mt Cu + Mo; and Chang'an 31 t Au). In order to investigate the mechanisms controlling the variation in size of these deposits, the LA-ICP-MS zircon U–Pb dating, bulk-rock geochemistry, and zircon trace-element analyses have been performed on the mineralization-related porphyries from the Tongchang district. Zircon U–Pb dating yielded concordant ages of 34.2 ± 0.6 Ma (Tongchang), 33.7 ± 0.8 Ma (Chang’anchong), 35.7 ± 0.5 Ma (Habo) and 34.6 ± 1.2 Ma (Chang’an). These porphyries are peraluminous with relatively high potassium contents (K₂O: 4.2–5.7 wt%), and show shoshonitic affinities. Bulk rock Fe₂O₃/FeO ratios vary from 0.51 to 0.97, typical of moderately oxidized to strongly oxidized magmas. Zircon Ce⁴⁺/Ce³⁺ values vary between 25.9 and 371.8 with a mean of 129.3. The log(ƒo₂) values vary from −20.7 to −9.6, and plot within the range of FMQ (fayalite-magnetite-quartz oxygen buffer) to MH (magnetite- hematite oxygen buffer), indicating an oxidizing parental magma. The mineralized porphyries from the Yulong and Beiya deposits, which were previous considered to have formed under the same tectonic conditions as those in the Tongchang district, have higher mean zircon Ce⁴⁺/Ce³⁺ values of 249.4 and 399.5, suggesting that the oxygen fugacities of the porphyries in the Tongchang district is relatively lower. This might imply that oxygen fugacity is an important factor that led to the differentiation of deposit size in the JRMB, and that larger porphyry deposits are associated with more oxidized magmas.  相似文献   

卷破波作用下沙质岸滩剖面形态判别式初探     

蒋昌波  伍志元  陈杰  邓斌  隆院男  李廉洁 《海洋学报(英文版)》2017,36(9):91-100

通过波浪水槽实验,开展不同类型波浪作用下的沙质岸滩演化规律研究工作。本次实验研究不考虑比尺,采用1:10与1:20组成的复合沙质斜坡对岸滩进行概化,选取规则波和椭圆余弦波两种典型波浪作用,对波浪的传播、变形和破碎、上爬、回落过程以及波浪作用前后沙质岸滩床面地形进行了观测,探讨波浪作用下沙质岸滩剖面演化规律。本文实验工况中,规则波作用下,岸滩剖面呈现出沙坝剖面和滩肩剖面,椭圆余弦波作用下的岸滩剖面均呈滩肩形态,发现岸滩剖面形态不仅与波浪作用类型、强度、周期等因素相关,还与波浪破碎的强度等因素有关。通过对实验过程中现象的进行观察和分析,引入了卷破波水舌冲击角的概念。对波浪卷破破碎后形成的水流挟沙运动与岸滩剖面形态的关系进行定性分析,对水舌冲击角与Irribarren参数之间的关系进行定量分析,基于Irribarren参数与岸滩剖面形态的关系初步建立了波浪作用下沙质岸滩剖面形态判别关系式。通过本文实验结果和前人实验结果对趋势线进行拟合,求得其判别系数,判别式能够较好地划分淤积型岸滩、侵蚀型岸滩及过渡型岸滩三种岸滩形态。  相似文献   

Seafarers' access to jurisdictions over labour matters     

《Marine Policy》2017

The Maritime Labour Convention, 2006 outlines a framework for states to enforce jurisdiction over maritime labour matters, including the Flag State, Port State and Labour Supplying State. However, the Convention does not provide explicit guidance on jurisdiction determination. This article argues that seafarers should have the right to access the jurisdictions of member states, and that future amendment to the Convention should confirm this right. This paper first analyses current theories of maritime labour jurisdiction. Secondly, it conducts a comparative doctrinal analysis regarding adjudicative jurisdiction principles in common law and civil law systems. Thirdly, in three case studies involving concurrence jurisdictions of member states, this article finds that the authority of any single member state is not reliably accessible to seafarers, in particular when the state has no strong link with the seafarers. This article recommends that seafarers’ rights in the Convention to choose one jurisdiction from relevant member states should be confirmed in a future amendment.  相似文献   

Nautical cartography competences and their effect to the realisation of a worldwide Electronic Navigational Charts database,the performance of ECDIS and the fulfilment of IMO chart carriage requirements     

《Marine Policy》2017

This paper is concerned with the implementation and realisation of a Worldwide Electronic Navigational Charts Database (WEND), adopted by the International Hydrographic Organization (IHO) and its members in supporting marine navigation. It identifies the issue of gaps and overlaps between adjoining Electronic Navigational Charts (ENCs) and explores its consequences to the operation of Electronic Chart Display and Information Systems (ECDIS) and the fulfilment of International Maritime Organization (IMO) chart carriage requirements. As the ENCs production is directly dependent on states’ cartographic competences, this paper delves into the coastal states’ jurisdiction in accordance with international law of the sea, and in particular the United Nations Convention on the Law of the Sea, and ΙΗΟ and IMO instruments. Through a case study on recently produced ENCs in the Mediterranean and more specifically in the Aegean Sea, this paper documents the necessity to respect states’ cartographic competences in realising the WEND concept and cautions that, otherwise, new and extended overlaps emerge, which pose a risk to the safety of navigation, and, at the same time, become means through which states may promote their geopolitical aspirations as to jurisdiction over certain marine areas.  相似文献