浅谈辽河群区域对比

辽河群广布于辽东地区,为一套古元古代层状中浅变质岩系.由于原岩存在沉积相变,加之后期变质变形的改造,各地岩性组合差异较大.经多年野外实地考察,将辽河群大致划分为两区、四相段,并进行较深入的建造与改造的研究,不仅解决了辽河群层序划分和区域对比问题,而且也解决了与邻区同时代地层对比的问题.     

Defining dynamic pelagic habitats in oceanic waters off eastern Australia

Although many species in the pelagic ocean are widespread, they are not randomly distributed. These species may have associations with particular water masses or habitats, but to best understand patterns in the ocean, these habitats must be identified. Previous efforts have produced static or seasonal climatologies, which still represent smearing over habitats. The Eastern Tuna and Billfish Longline Fishery (ETBF) targets a range of high trophic level species in oceanic waters off eastern Australia. In this study, dynamic ocean habitats in the region were identified for each month based on cluster analysis of five oceanographic variables averaged at a monthly time scale and a spatial scale of 0.5° for the period 1995-2006. A total of seven persistent habitats were identified off eastern Australia with intra and interannual variation in size and location, indicating the importance of spatial and temporal variation in the dynamics of the region. The degree to which these dynamic habitats were distinguished was tested using (i) stable isotope analysis of top fish predators caught in the region and (ii) estimates of variation in estimated abundance generated from catch data from the fishery. More precise estimates (measured as lower total CV) of isotopic values from swordfish (Xiphias gladius), yellowfin tuna (Thunnus albacares) and albacore (Thunnus alalunga) were obtained for 4 of 6 isotope comparisons using the dynamic habitat groupings, which indicate that stratifying by pelagic habitat improved precision. Dynamic habitats produced more precise abundance estimates for 7 of 8 large pelagic species examined, with an average reduction in total CV of 19% compared to when abundance was estimated based on static habitat stratification. These findings could be used to guide development of effective monitoring strategies that can distinguish patterns due to environmental variation, and in the longer term, climate change.     

狼毒种群小尺度空间分布格局及空间关联性研究

空间分布格局、空间关联性对尺度具有较强的依赖性,种群在不同的尺度上往往表现出多种空间分布格局和空间关联性。在黑河上游高寒退化草地,采用点格局分析方法,研究了小尺度上狼毒(Stellera chamaejasme)种群的分布格局和空间关联性。结果表明:小尺度上随着种群的发育,狼毒种群的空间分布格局由聚集分布逐渐向随机分布过渡;两个形体大小程度越接近的种群之间,空间关联性越有可能表现为正关联,随着种群的共同发育,空间关联性逐渐向不显著过渡,形体大小差异程度越大,则越有可能表现为负关联,而较大尺度上空间关联性趋于复杂化。种群个体之间的相互庇护促使狼毒个体的数量不断增长,并通过种内竞争使斑块不断扩张,狼毒种群合作与竞争机制的相互转变实现了种群的扩散。     

广西凭祥中三叠世盆地沉积特征与构造属性分析

凭祥中三叠世盆地位于印支地块与华南地块碰撞拼合的缝合带内,记录了沿华南地块南缘展布的古特提斯分支洋盆俯冲闭合、印支地块与华南地块碰撞拼合的过程。本文通过大比例尺实测地质剖面,详细测量了凭祥盆地沉积相序及其组合变化,分析了不同相序的沉积环境及其物源,并探讨了盆地构造属性。结果表明,凭祥盆地主要充填有深水盆地相、浊积扇相和三角洲相等不同环境的沉积物。中三叠世期间盆地呈现为一系列因碰撞拼合作用形成的构造高地间夹深谷的岩相古地理面貌。深水盆地相以发育大套深灰色泥页岩和裹夹碎屑流沉积为特征,碎屑流沉积发育于构造高地陡坡一侧。浊积扇相以发育槽模、正粒序、爬升波纹层理、包卷层理、双向交错层理、透镜状层理、平行层理为特征。三角洲相以发育大型板状交错层理、潮沟、厚层透镜状砂体和砖红色泥岩为特征,类似发育于俯冲汇聚环境下的牙买加型扇三角洲,可能发育于构造高地缓坡一侧。沉积作用分析表明,主要存在碎屑流、浊流等重力流作用,并识别出底流作用。古水流分析表明存在向南和向北两个方向的物质搬运。岩相学特征表明盆地砂岩成分成熟度和结构成熟度均较低,物源为再旋回造山带或碰撞造山带。本文研究结果认为：凭祥盆地是一个伴随古特提斯分支洋盆俯冲闭合而被强烈改造的残余弧前盆地,时空上与之相配套是北泗组岛弧型流纹斑岩。该弧盆系统可能于晚二叠世末开始发育,中三叠世末结束沉积充填,暗示印支地块和华南地块最终于中三叠世碰撞拼合。     

Geochemical monitoring of clays for diagenetic evolution of the Paleozoic–Lower Mesozoic sequence in the northern Arabian plate: Hazro and Amanos regions,Southeastern Turkey

Clay minerals in the diagenetic/very low-grade metamorphic–sedimentary series from southeastern Anatolia in Turkey were analyzed to determine their mineralogical and chemical compositions. In the Amanos region, the lowermost unit is composed of metaclastics with primary clastic textures, as well as slaty cleavages and chlorite-mica stacks including volcanic rock intercalations. The Lower Cambrian is composed of mainly very low-grade metamorphic clastic rocks, while the Ordovician units have siliciclastic and carbonate rocks. In the Hazro region, the Late Silurian–Lower Triassic units are represented by highly diagenetic carbonate and clastic rocks. All of the rock units include illite. In addition, chlorite, mixed-layered illite–chlorite and chlorite–vermiculite are present in the Amanos region, while calcite, dolomite, kaolinite, mixed-layered illite–smectite (I–S) and glauconite occur in the Hazro region. The illites are characterized by the dominance of 2M₁ polytype in the Amanos samples; and 1M_d + 2M₁ in the Hazro samples. The I–S, glauconite and kaolin have R1 and R3, 1M and kaolinite polytypes, respectively. The illites have greater tetrahedral and lower octahedral substitutions than the I–S. Total trace element contents, elemental substitutions and chondrite-normalized trace element and REE values decrease toward illite–I–S–kaolinite. There are obvious fractionations for some major – trace and rare earth elements with respect to each other and clear enrichment with respect to the chondrite, with strong anomalies of positive for Gd and negative for P, K and Eu in the clay minerals. The textural, morphological and geochemical data indicate that kaolinite and I–S in the Hazro area occur in supergene conditions with due to a full neoformation mechanism, whereas illites in the Amanos region represent the hypogene origin. In brief, the K₂O contents, ratios of Eu/Eu^* and La_N/Lu_N and δ¹⁸O and δD values of I–S and illite exhibit notable relationships with increasing diagenetic/metamorphic grade.     

基于县域单元的江苏省经济空间格局演化

通过ESDA相关分析,描述了20世纪90年代以来江苏省县域经济格局在空间上的变化状况.在经济总体空间格局上,江苏省县域经济发展水平表现出很强的空间自相关性,相似的地区在空间上集聚分布,热点区的空间结构多表现为以苏州、无锡为核心的罔状空间结构,且不断的向东南方向集聚.经济增长空间格局存空间分布上表现出更多的随机性和结构的不稳定性,热点区域切换频繁,没有明显的地理集中现象.江苏经济空间格局连续性和自组织性越来越强,空间分异格局中的随机成份在不断降低,而由空间自相关引起的结构化分异越来越显著,东北-西南方向经济发展的空间差异较小,而东南-西北方向经济发展空间差异最大.最后,将江苏省经济格局演化的驱动力归结为3个方面:历史发展基础、经济区位和区域发展政策.     

利用测井资料自动识别藻灰岩

藻灰岩在测井曲线图上具有不同于其它岩性的特征,据此确定了7种测井参数(自然伽玛、自然电位、井径、声波时差、补偿中子、补偿密度及深电阻率),将测井数据归一化后得到了相应的岩性判别样本参数。利用F-Means中速度较快的聚类迭代(LBG)算法对研究样本进行分类,优选了一组数据用于判别分析。在进行Q因子分析的基础上建立了用于岩性判别的3个判别函数,并对花土沟油田某井段进行了岩性识别预测分析。     

西藏双湖区帕度错一带早-中侏罗世色哇组的发现及地质意义

藏北帕度错一带出露的早—中侏罗世地层,其岩石组合特征不同于雁石坪群,与其香错一带出露的色哇组相当,在该套地层的上部层位产迄今为止藏北地区最为丰富的侏罗纪巴柔期菊石化石,该区色哇组的发现对研究藏北南羌塘地区早—中侏罗世地质发展历史有着重要意义,同时也对羌塘盆地油气普查工作有一定的指导作用。     

地震属性分析在岩性气藏描述中的应用

针对鄂尔多斯盆地上古生界二叠系盒8砂岩岩性气藏非均质性强、开发前期井少、井距大、储层预测难的特点,通过地震多种属性分析,并结合井资料,利用地质统计学方法优选出对砂岩厚度、储层物性及含气性较敏感的地震波形、地震波速度变异参数和地震子波吸收系数3种属性,根据这3种地震属性的分类特征对盒8砂岩厚度和储层含气性的平面分布进行了预测和描述,划分的Ⅰ+Ⅱ类含气有利区被确定为下一步的评价区块。地震属性分析应用于非均质岩性气藏的早期描述,为评价部署和开发方案编制提供了依据。     

胶东山城金矿地质与地球化学变量的关系

为研究胶东地区山城金矿的控制因素和预测隐伏矿体,利用R型因子分析和聚类分析揭示了各种地质和地球化学变量的关系。同时,针对聚类分析中难以有效显示变量间负相关问题提出了反序变换的方法。结果表明,该矿的黄铜矿化、脉状黄铁矿化、Au-Ag-Cu组合与As-Sb-Hg组合相关,并受主构造面走向波动控制;而较厚石英脉、菱铁矿化、星散状黄铁矿化、Pb-Ba组合与Co-Ni组合相关,并受主构造面倾向波动控制。这些结果与地质结论一致,但研究方法更简便快捷。