福建建瓯万木林柑橘与锥栗凋落物数量、组成及动态   总被引：1，自引：0，他引：1  

刘强  王超  杨智杰  陈光水  黄锦学  黄蓉  田浩 《亚热带资源与环境学报》2011,6(4):29-34

2010年1-12月,对福建省建瓯市万木林保护区内的柑橘（CitrusreticulataBlanco）和锥栗（Castaneahenryi）凋落物的组成及动态进行观测研究,结果表明：柑橘和锥栗的年凋落物量分别为2315．47±149．02kg·hm^-2·a^-1和2414．62±211．05kg·hm^-2·a^-...  相似文献   

Evolution of permeability and microstructure of experimentally-created shear zones in Neogene siliceous mudstones from Horonobe,Japan     

《Journal of Structural Geology》2014

We report experimental measurements of bulk permeability changes due to a shear zone that is induced in siliceous mudstones collected from the Koetoi and Wakkanai Formations, northern Hokkaido, which are known to show different relationships between fault/fracture distribution and groundwater flow. We evaluate distributions of volumetric deformation in the induced shear zones by using micro-focus X-ray computed tomography. Measured permeability evolution while achieving the peak axial stress for specimens differed for the samples of the two formations. Permeability did not change obviously during shear for the Koetoi Fm. specimens, but in the Wakkanai Fm. specimens, the bulk permeability increased by a factor of 2.5 after reaching the peak stress. The difference in permeability change in these experiments can explain the differences in relationships between in situ groundwater flow and fracture distribution for the two formations. Analyses of the X-ray images reveal that this difference should reflect the differences of the volumetric deformation in the induced shear zones. Pore collapse occurred in the shear zone in the Koetoi Fm. specimen, which leads to porosity reduction, whereas fracture damages developed in the Wakkanai Fm. specimen, increasing porosity. These differences in the microstructure may reflect differences in yielding criteria for these host rocks.  相似文献   

Probabilistic block theory analysis for a rock slope at an open pit mine in USA     

《Computers and Geotechnics》2014

A new formulation is given to conduct a probabilistic block theory analysis. A new computer code (PBTAC) is developed to perform both deterministic and probabilistic block theory analysis. The variability of the discontinuity orientation and shear strength is incorporated in the probabilistic block theory analysis. Discontinuity orientation is treated as a bivariate random variable including the correlation that exists between the dip angle and dip direction. PBTAC code was applied to perform both deterministic and probabilistic block theory analyses for a part of an open pit mine in USA. Needed geological and geotechnical data for the analyses were obtained from field and laboratory investigations. The variability of the discontinuity orientations resulted in important differences between the probabilistic and deterministic block theory analyses results. The results confirmed that the design value selected for the maximum safe slope angle (MSSA) for a particular region in the open pit mine based on the deterministic block theory analysis can be on the unsafe side. In summary, the results showed clearly the superiority of probabilistic block theory analysis over the deterministic block theory analysis in obtaining additional important information with respect to designing rock slopes. The calculated values agree very well with the existing almost stable bench face angles reported by the mining company.  相似文献   

倾倒式岩质崩塌运动过程数值模拟分析     

袁志辉  陈志新  倪万魁  张文栋  王博 《中国地质灾害与防治学报》2014,(2):26-31

在延长县崩塌详细调查的基础上,采用数值模拟方法对倾倒式岩质崩塌运动过程进行了模拟,分析了其运动规律。根据崩塌的破坏形式和运动特点,将倾倒式崩塌的整个运动过程分为四个阶段：岩体原有节理的开裂变形阶段、岩体沿基座支点的倾倒运动阶段、崩塌体在一定初速度下的落体运动阶段、崩塌体的碰撞与堆积阶段。通过对倾倒式崩塌影响范围的理论计算结果、数值模拟结果和实际调查结果对比得出,数值模拟结果和实际调查结果基本一致,两者远大于理论计算结果,因此数值模拟结果可作为倾倒式崩塌的影响范围,可为崩塌灾害的防治提供科学依据。  相似文献   

云南保山黑牛凹破碎带蚀变岩型金矿     

马云良  邹蓉蓉  王基元 《云南地质》2014,(1):22-27

上寒武统核桃坪组上段赋矿,近南北向断层控矿,含金矿化主要为硅化、黄铁矿化、磁黄铁矿化、黄铜矿化、绿泥石化构造角砾岩;云南保山黑牛凹金矿属中—低温热液交代型蚀变岩型金矿床.  相似文献   

云南元阳小河边石英脉型金多金属矿     

吕会梅  和松文  彭一航 《云南地质》2014,(1):58-61

金矿赋存于晚古生代第一期闪长岩体、小新街断裂两侧次一级断层破碎带含金石英脉中.原生矿石中以粒状自然金为主,粗粒—细粒.尚见叶片状、针尖状、不规则状金.含金石英脉有四个成生阶段,以第二、第三阶段含金性较好.矿床属中—高温闪长岩次级压扭性断裂中石英脉型金矿.  相似文献   

Palynomorph fossil assemblages and ages of Muga-Gangri Rock Group in Gaize area of the middle and western part of Bangong Co-Nujiang suture zone in Tibet     

BAI Peirong  XIONG Xingguo 《中国地质调查》2014,7(4):60-66

The sedimentary age of Muga-Gangri Rock Group in the middle and western part of Bangong Co-Nujiang suture zone experienced the cleavage and extension of Bangong Co-Nujiang Ocean basin and the stage of extrusion convergence. The sedimentary age span is relatively large, but its sedimentation epoch limit is still inconclusive. In order to explore the relationship between the upper limit of the sedimentary age of Muga-Gangri Rock Group and the closure time of Bangong Co-Nujiang Ocean in the rectified area, through the field geological survey and indoor comprehensive research, the authors found the typical pollen molecule Dicheiropollis in Early Cretaceous. This discovery of pollen indicates that Muga-Gangri Rock Group in the middle and western part of Bangong Co-Nujiang suture zone continued to deposit in Early Cretaceous. These discoveries have great geological significance in the discussion of paleo geographical features, sedimentary environment and their development history in Mesozoic period in the middle and western part of Bangong Co-Nujiang suture zone.  相似文献   

蛇绿岩中的花岗质岩石成因类型与构造意义   总被引：27，自引：0，他引：27  

李武显  李献华 《地球科学进展》2003,18(3):392-397

花岗质岩石在蛇绿岩的岩石组合中只占很小部分（通常＜10％），但是对于蛇绿岩的成因研究，特别是对蛇绿岩形成和演化过程的精确年龄测定，具有重要的意义。简要回顾了蛇绿岩中花岗质岩石的研究历史。近年来的研究表明，蛇绿岩中的花岗质岩石不仅包括直接由大洋玄武质岩浆结晶分异形成的花岗质岩石，即传统意义上的大洋斜长花岗岩，还包括蛇绿岩在形成、演化过程中本身形成的和侵入的花岗质岩石。根据成因，可以将这些花岗质岩石分为 4类：结晶分异型花岗岩、剪切型花岗岩、俯冲型花岗岩和仰冲型花岗岩。系统地综述了它们的地球化学特征以及形成的构造背景。  相似文献   

基于数字岩心的含裂隙储层砂岩介电性质研究          下载免费PDF全文

李博  韩同城  符力耘 《地球物理学报》1954,63(12):4578-4591

了解储层岩石的介电特性在石油工业的各个方面都有重要的应用.小尺度裂隙是影响岩石介电性质的地质因素之一,获得裂隙对含裂隙岩石介电性质影响的定量关系具有重要的理论和实践意义.以含裂隙人造砂岩的三维微观数字结构为基础,通过基于三维有限差分算法计算的岩石介电性质与实验数据的对比验证数值计算方法的有效性.在此基础上,通过理论模型获得不同孔隙度基质的介电性质,并在不含裂隙人造砂岩的三维微观数字结构中人为添加以裂隙密度和纵横比为定量表征参数的裂隙,应用验证后的数值算法模拟随频率变化的含裂隙砂岩的介电性质,分析和研究不同孔隙度基质中定向排列裂隙对砂岩介电性质的影响.结果表明,当裂隙孔隙度随裂隙纵横比或裂隙密度发生改变时,含裂隙砂岩的介电性质与裂隙密度以及裂隙纵横比呈正相关关系,而当裂隙孔隙度保持不变时,含裂隙砂岩的介电性质随裂隙纵横比的减小而增大;裂隙参数的改变对不同基质孔隙度的含裂隙砂岩的介电性质的影响趋势较为一致,但随着基质孔隙度的减小,裂隙对砂岩介电性质的影响逐渐增大.裂隙参数和基质孔隙度对含裂隙砂岩介电性质影响的研究结果为基于介电特性的裂缝性油气储层的定量表征提供了依据,在油气勘探开发中具有重要的应用前景.  相似文献   

中国南极火成岩数据库数据结构和数据标准化的研究          下载免费PDF全文

尚如相  李德兴 《极地研究》1995,7(3):107-114

根据南极火成岩信息和数据类型多、数据关系复杂、样品间数据完整性和精度差异大的特点，中国南极火成岩数据库划分为主库、来源文献、岩体地质学、岩石学、主要氧化物、稀土元素、痕量元素和同位素８个数据库。通过岩体系统号、样品系统号和来源文献号三个字段使８个数据库相互关联。中国南极火成岩数据库包括了１４０多个基本字段，存储火成岩岩石描述信息和分析数据。根据国内外火成岩数据标准化的现状的分析，中国南极火成岩数据库采用了国际地科联岩石学数据库分委会规定的标准词汇和代码，并利用代码－名词术语转换技术改善了用户界面  相似文献