珠江口盆地流花油田新近系碳酸盐岩白垩状结构化成因机理探讨

珠江口盆地白垩状结构(白垩化)碳酸盐岩是礁滩相沉积体内碳酸盐沉积物在多期白垩化"作用"环境下经成岩作用改造及地下水"漂洗"形成的淡色、疏松、晶间多微孔生物泥晶灰岩。流花油田下中新统珠江组为礁滩相叠加白垩状结构化形成的局部白垩化储层。本文结合流花油田钻井白垩化灰岩分布、显微结构以及碳氧同位素和油田水作用,探讨分析了其成因机制。分析认为白垩化可以分为:缝合线内白垩化、含油层段中等程度白垩化和底水段强白垩化三类,白垩化程度与孔隙度和δ13C呈正相关性。缝合线内白垩为成岩早期大气淡水溶蚀淋滤和晚期压溶作用产物,中等白垩化由成岩早期选择性溶蚀、退变新生变形作用及成岩中-晚期上覆泥岩压实"再造水"非选择性溶蚀作用共同控制,强白垩是前期白垩化成型后受氯化钠型油田水的溶蚀淘洗结果。白垩状结构化经过初期定型,中期强化与孔隙保持,后期加强三个阶段形成。     

Dating Fault Activity Based on Surface Texture of Quartz Grains from the Bailong River Fault

Much important information referring to fault motion （e.g., fault activities period, intensity, frequency, and even dynamic background） can be revealed by resolving fault gouge, which is the result of fault motion while extruding or grinding. The field investigation encompassed sample collecting from the Bailong River fault system of the western segment of the Qinling Orogenic Belt （QOB）; 44 samples of fault gouges were collected for quartz micro-morphology analysis. These samples were analyzed using field emission scanning electron microscopy. In addition, 14 samples were tested for thermo-luminescence dating. The results showed that most of the surface textures of quartz grains are characterized by fish scale, moss-like texture, and stalactite. However, a small amount of orange peel-like fractures and worm-hole-like shaped surface texture were observed. Moreover, a few typical conchoids or subconchoidal fractures in quartz grains can be seen. This implies that the Bailong River Fault was active repeatedly during the Quaternary period, but the main motion period is the Pleistocene. The 14 thermo-luminescence dating values showed two age groups： 343.29-184.06 ka and 92.18-13.87 ka. These study data reveal that fault movement started during the Pliocene, occurred frequently in the early-middle period of the Pleistocene, and the peak frequency of the motion was reached in the early Pleistocene. The fault motions were stopped terminated in the early Holocene. The results are significant for the natural disaster risk evaluation in the western segment of the QOB.     

Worldview-2数据在沉积岩地区的遥感岩性增强方法初探——以新疆喀什阿尔塔什地区为例

为了进一步探讨Worldview-2数据在岩性识别工作中的应用效果,笔者选择新疆喀什地区阿尔塔什沉积岩区进行遥感岩性增强方法研究。通过对研究区内实测岩石波谱曲线和Worldview-2数据进行分析,对比不同岩性之间的光谱差异,在综合考虑异物同(近)谱、表层浅覆盖等的基础上,结合WorldView-2数据的波段特点和数据统计特征,确立了波段组合-波谱增强-去相关增强-纹理信息融合的处理方法。有效提高了不同岩性之间的对比度,改善了外界因素对光谱信息的干扰,为精确识别不同岩性提供了可靠基础。     

三维城市建筑物的纹理映射综述

纹理是影响三维模型真实感的一个重要因素。三维纹理映射的最终目的是得到高精度、全自动、高保真的三维模型,它是计算机视觉等领域的一个热点问题。本文介绍了三维纹理映射的原理和过程;针对三维建筑模型进行纹理映射这一研究方向,在投影变换中参数化应用、纹理坐标转换的处理、影像与模型的匹配等方面总结现有的解决方法,并针对多幅建筑物立面的倾斜影像及屋顶垂直遥感影像与三维几何模型的纹理映射,将一些有代表性的研究方法和成果进行对比分析;最后根据当前的研究现状和应用需求,提出一些问题和解决途径。     

一种干旱半干旱地区决策树分类方法

以内蒙古自治区伊金霍洛旗为研究区,利用Landsat TM影像,对干旱半干旱地区土地利用信息进行提取。在ENVI软件的支持下,分析了影像的光谱特征及NDVI,NDBI,NDWI特征变量,并运用灰度共生矩阵对影像进行纹理特征提取,得到熵纹理特征图像,确定各类地物的阈值,运用决策树分类法对影像进行分类。结果表明,结合光谱特征和纹理特征的决策树分类方法,提取干旱半干旱地区土地利用信息可行且准确性较高。     

富挥发分岩浆补给对斑岩型铜-钼矿床形成的关键作用:以西藏尼木岗讲矿床为例

西藏冈底斯带中段的岗讲斑岩铜-钼矿床发育多期次侵入体,而成矿作用主要与其中一期岩体(流纹英安斑岩)密切相关。为探究其原因,本文对岗讲斑岩铜-钼矿床中发育的各期次侵入体进行了全岩主、微量元素分析,并重点研究各期次侵入体内部新鲜斑晶(黑云母、斜长石)和副矿物(锆石、磷灰石)的化学成分和结构特征。结果表明,矿区各期次侵入岩均属于高钾钙碱性系列,具有相近的锆石饱和温度,都来自较为氧化的岩浆。此外,相比其他期次侵入岩,主成矿期的流纹英安斑岩中的磷灰石具有较高的SO_3、Cl含量,较低的F含量;黑云母含有较高的Cl含量和较低的F含量;同时,斜长石发育反环带。这些证据表明,在主成矿期岩浆就位之前,存在富S、Cl的偏基性岩浆注入了深部岩浆房,并发生岩浆混合作用,这不仅导致了主成矿期斑岩体的就位,同时还诱发流体出溶进入浅部岩浆房,并最终形成岗讲斑岩铜-钼矿床。     

Bayan Obo Carbonatites: Texture Evidence from Polyphase Intrusive and Extrusive Carbonatites

<正>Most of the so-called Bayan Obo fine-grained dolomite marbles collected from the main and east orebodies show a microporphyritic texture,namely the microphenocrysts are set in a very finegrained matrix,although nearly all of them have undergone recrystallization caused either by deformation or alteration.The texture seems likely to have maintained the original features.It is known that one of the most characteristic textures of volcanic rocks is the porphyritic texture,and the microporphyritic texture is a variety in which both the phenocrysts and the matrix are only distinguishable with the microscope.Therefore,the dolomite marbles in the main and east orebodies may be related to the extrusive carbonatites.In addition,there also occur some carbonatite sills and dykes with different textures at Bayan Obo.Thus,the Bayan Obo carbonatites are polyphase intrusive and extrusive carbonatites.     

定量化火成岩结构分析与岩浆固结的动力学过程

定量化火成岩结构分析将传统的定性或半定量化的岩相学研究提高到了与岩石地球化学分析相比拟的定量化程度,实现了诸如晶体粒度分布、晶体空间分布、晶体定向程度分析和二面角测量等方面的定量化研究。集中介绍了以上4种国际上应用广泛的定量化火成岩结构分析方法,包括各种研究方法的基本理论公式、岩浆动力学意义和实现方式。详细介绍了定量化火成岩结构分析中处于核心地位的晶体粒度分布理论,概括了二维岩石薄片法、三维连续剖面法和X射线层析技术,在定量化火成岩结构分析中的应用原理和现状。对晶体粒度分布分析中数据的封闭性和有效性检验进行了简要论述。综合阐述了晶体成核生长,晶体的聚集、分离和分解,岩浆混合,压滤、压熔和岩浆流动,结构的调整和平衡等一些基本的岩浆动力学过程中晶体粒度分布特征的表现。结合一些已发表的晶体粒度分布和晶体空间分布数据,简要概括了重要的基本定量化火成岩结构参数所表达的封闭和开放岩浆体系的特征,以及参数间协变关系所反映的岩浆固结动力学过程。最后给出了二维岩石光薄片分析法的基本流程和注意事项,认为今后定量化火成岩结构分析和地球化学分析结合在一起的综合方法,将成为研究成岩成矿动力学过程的重要手段,也将会逐步扩展到岩浆相关矿床中成岩成矿机制分析和成矿预测的方向。     

Characteristics and Mineralization Age of the Fukusen No. 1 Vein,Hishikari Epithermal Gold Deposits,Southern Kyushu,Japan

The Fukusen No. 1 vein is located in the southeastern part of the Yamada deposit, Hishikari epithermal gold deposits, southern Kyushu, Japan. ⁴⁰Ar/³⁹Ar plateau ages of adularia from the margin and the center of the Fukusen vein are determined to be 0.617 ± 0.024 Ma and 0.606 ± 0.009 Ma, respectively. The Fukusen No. 1 vein shows banding structure composed mainly of quartz, adularia and clay minerals. Colloform texture is displayed by cryptocrystalline to amorphous silica material that is associated with fine-grained electrum and sulfides near the center of the vein. Pyrite in the Fukusen No. 1 vein often shows acicular shape resulting from inversion from marcasite. Near the center of the vein, primary marcasite occurs associated with colloform texture of silica. The Fukusen No.1 vein preserves primary texture and materials which were deposited from the ore-forming hydrothermal solution. The Fukusen No. 1 vein was formed in a short period and is one of the youngest veins in the Hishikari deposits.     

“分形-视距”（FVD）多分辨率纹理生成及组织方法

纹理数据是三维建筑模型中的重要组成部分,通常会消耗大量的内存,导致模型较难实现流畅稳定的动态可视化。针对这个问题,本文提出了一种面向三维模型可视化的“分形-视距”（FVD）多分辨率纹理生成及纹理组织方法。该方法首先利用分形对纹理进行压缩并将其存入纹理数据库,然后按照视距及目标立面的可见性情况创建和组织对应纹理：当视距符合纹理调用条件且目标立面可见时,根据不同视距,执行多分辨率纹理创建,按照各类三维模型数据间的属性关系建立索引,存入关系数据库;当视距不符合纹理调用条件但该立面又可见时,利用纹理分割算法创建颜色纹理树,将节点合并表示立面纹理。最后根据变化的视角和距离调用相应纹理,实现三维模型的动态流畅可视化。本文选择山东省济南市历下区作为研究区域,使用的纹理数据共5290幅。实验结果表明,与3ds Max、SketchUp Pro相比,本文提出的方法减少内存占用分别约为36.5%和49.1%,帧速率提高约7%和10.9%,极大地提高了大场景三维模型可视化的渲染效率和速率。本文提出的方法在三维建筑模型渲染效率和视觉质量之间取得了很好的平衡,这一问题的改善将为建立智慧城市提供快速有效的科学支撑。