Study of tectonic layering motion and layering mineralization in the Tongling metallogenic cluster

TheTonglingarea,animportantmetallogeniccluster,isrichiniron,sulphurandgold.Mineralizationiscorrelatedcloselytotheevolutionofthestrata,magmatiteandtectonics[1—4].SkarnmineralizationdevelopedwellintheTonglingarea.ItappearsalongmainlyonseveralinterfacesofPe…     

大陆构造样式及大陆动力学模式初探

根据大陆构造的最新研究成果,总结了大陆构造的基本型式,提出了大陆五层两域的构造模型,并从物质流变和构造变形的有机联系出发,探讨了大陆动力学的层流隆陷机制。     

基于分层分区法的中国历史耕地数据的网格化重建

网格化历史耕地数据集能为历史时期耕地变化研究提供更精确的支持,并且为全球环境气候变化研究模型模拟提供驱动数据。本文综合考虑了中国历代土地利用开发的特点及自然人文因子对耕地的影响,设计了一套对中国耕地先分区再分层分配的网格化方法。基于国内3个主流区域耕地数据研究成果,采用上述方法建立了1820年（清仁宗嘉庆二十五年）和1936年（民国二十五年）中国10 km×10 km分辨率的耕地数据集,并绘制了分布图。本文还利用国内具有代表性的区域数据集对重建结果进行对比验证。结果表明,该方法可以保证耕地数量的权威性,并且建立具有区域性的高精度历史耕地数据集。     

针对CAD规划数据入库编码的研究

CAD规划数据作为城市基础地理信息系统平台的前端数据源,它要经过CAD到GIS数据的格式转换才能为基础地理信息系统所使用,而在转换过程中往往会产生数据丢失.为了解决这一问题,本文针对CAD规划数据的特点,制定了一套有效的地理编码方案,实现了对CAD规划数据的无损入库.     

Fluid-assisted fracturing,cataclasis, and resulting plastic flow in mylonites from the Moresby Seamount detachment,Woodlark Basin

The Moresby Seamount detachment (MSD) in the Woodlark Basin (offshore Papua New Guinea) is a large active low-angle detachment excellently exposed at the seafloor, and cutting through mafic metamorphic rocks. Hydrothermal infiltration of quartz followed by that of calcite occurred during cataclastic deformation. Subsequent deformation of these a priori softer minerals leads to mylonite formation in the MSD. This study aims at a better understanding of the deformation mechanism switch from cataclastic to plastic flow. Deformation fabrics of the fault rocks were analyzed by light-optical microscopy. Rheologically critical phases were mapped to determine distributions and area proportions, and EBSD was used to measure crystallographic preferred orientation (CPO). Strong calcite CPOs indicate dominant dislocation creep. Quartz CPOs, however, are weak and more difficult to interpret, suggesting at least some strain accommodation by diffusion creep mechanisms. When quartz aggregates are intermixed with the polymineralic mylonite matrix diffusion creep grain boundary sliding may be dominant. The syntectonic conversion from mafic cataclasites to more siliceous and carbonaceous mylonites induced by hydrothermal processes is a critical weakening mechanism enabling the MSD to at least intermittently plastic flow at low shear stresses. This is probably a crucial process for the operation of low-angle detachments in hydrated and dominantly mafic crust.     

陕西勉县后沟-大坪山矿区磷、锰分层成矿地质地球化学特征

后沟-大坪山矿区位于南秦岭磷、锰成矿带的中东段,近年来在下寒武统塔南坡组中发现了3条含磷、锰矿化带,并圈定出多个锰矿体和磷矿体。磷、锰矿体具有多层性,常表现为磷、锰的分层成矿,多呈上锰下磷的空间分布特征。通过分析Ⅱ矿化带内地表和深部样品的常量元素、微量元素和稀土元素的地球化学特征,发现磷、锰矿其物质来源具有一定的相似性,但是磷、锰矿石沉积的氧化-还原条件、沉积区域以及沉积水体条件都存在差别,这可能是引起磷、锰分离单独成矿的主要原因。     

正Q模拟与反Q滤波层位标定

作者应用Futterman模型的相速度频散关系式导出了地震记录的Q值正演模拟与反Q滤波层位标定方法，并将该方法分别应用到实际地震层位标定中，处理结果表明，这两种层位标定方法较目前常用的直接层位标定方法具有较明显的优点。     

Rheological properties of deep subducted oceanic lithosphere and their geodynamic implications

According to the experimental studies on the rheology of two important mantle rocks (eclogite and harzburgite), the rheological properties of the deep subducted oceanic lithosphere are investigated by assuming a simplified harzburgite type slab model with moderate thickness of basaltic layer. When the mantle convergence rate is small or the subducting slab has been trapped in the mantle for an enough long time, the strength profile of the slab is characterized by a strong subducting crustal component lying on a weak subducting upper mantle. However, if the convergence rate is large enough, the subducting slab will be featured only by a rigid cold center. Our study suggests that the detachment of the subducting crust component from the underlying upper mantle is only likely to happen in hot slow subducting slabs, but not the cold fast subducting lithosphere. Rheological properties of the harzburgitic and the eclogitic upper mantle vary with depths. The eclogitic upper mantle is stronger than the peridotitic upper mantle across the upper mantle. Transition zone is the high strength and high viscosity layer in the upper mantle except the lithosphere.     

浅谈堆载预压软基处理中的监测工作

通过工程现场实测成果，研究分析了堆载预压软基处理过程中孔隙水压力、地表沉降及分层沉降随时间、工况的变化规律。该项监测工作对施工起到了一定的指导作用，并为最后的工程验收提供了有效数据。