济阳孔店构造转型期沉积盆地的特征及勘探意义   总被引：1，自引：0，他引：1  

陈洁 《地球物理学进展》2004,19(2):392-398

济阳孔店组的归属问题一直是济阳盆地演化研究的焦点．通过大量的构造、沉积的基础性研究,提出孔店组是中生代向新生代转换的构造转型期,孔店期盆地叠置于中生代北西向半地堑之上,恰逢印度板块碰撞冈底斯及太平洋板块向欧亚板块俯冲,构造应力场具有双重性质,使得孔店组沉积盆地构造特征复杂,由于不同部位构造应力场强度的不同,虽为同期沉积盆地但是构造特征、盆地充填方式具有较大的差异,济阳盆地孔店组主要分布在惠民凹陷和东营凹陷,勘探重点应放在这两个凹陷．  相似文献   

转型期测绘复合创新、知识服务型人才培养模式创新与质量保障     

柯福阳  赵显富  丁海勇  孙景领  祝善友  缪启龙 《测绘通报》2019,(4):138-142

审视分析当前测绘工程专业人才培养存在的问题，以"测绘4.0"与智能测绘对测绘人才的新要求为导向，南京信息工程大学遥感与测绘工程学院结合实际情况，依托优势特色，在培养方案制定、课程体系构建、教学手段和模式、评价方式、工程实训等人才培养方面进行一系列的创新与实践，构建了闭环的人才培养质量保证体系，人才培养成效和社会声誉显著，为测绘高校复合创新、知识服务型高级人才的培养提供了重要参考。  相似文献   

Paleoenvironmental implications of two relative indicator rodent taxa during the Pleistocene to Holocene transition in south‐eastern Washington state,USA          下载免费PDF全文

R. LEE LYMAN 《第四纪科学杂志》2014,29(7):691-697

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International wood trade and forest change: A global analysis     

Thomas Kastner  Karl-Heinz ErbSanderine Nonhebel 《Global Environmental Change》2011,21(3):947-956

Throughout history, humans have transformed natural forests into agricultural land, settlement areas and managed forests. Studies on the dynamics of forest change are one of the mainstays in land change science. The forest transition theory offers a powerful tool to analyze changes in human interference with forests. At the national level, a range of factors have been found to influence a country's forest change. The role of international wood product trade has, however, rarely been studied based on empirical data. We offer a global assessment of how this trade helps shape observed forest change, by relating forest stock change to net trade of wood products for the period 1997-2007 and by localizing the origin of wood consumed in a given nation. For many nations, traded wood products have a relevant impact on the course of ongoing forest transitions. We develop a general typology of how wood product trade can influence forest change and place various nations within this framework. We find that many wealthy nations with returning forests seem to accelerate this return by importing wood products. These imports appear to be provided by two main types of wood exporters: (a) by wealthy countries with low population densities and stable forests and (b) by relatively poor countries with declining forests, employing increasing population and welfare levels. We discuss these findings in the light of general theories on land use transitions and forest change and conclude by highlighting implications for national forest policies and global environmental governance, aiming at reducing negative impacts of wood products and enhancing the positive role they can play in replacing more fossil fuel intensive products.  相似文献   

The Campanian Ignimbrite (Y5) tephra at Crvena Stijena Rockshelter, Montenegro     

Mike W. Morley  Jamie C. Woodward 《Quaternary Research》2011,75(3):683-696

Clearly defined distal tephras are rare in rockshelter sediment records. Crvena Stijena, a Palaeolithic site in Montenegro, contains one of the longest (> 20 m) rockshelter sediment records in Europe with deposits ranging in age from Middle Pleistocene to mid-Holocene. A distinctive tephra is clearly exposed within the well stratified record approximately 6.5 m below the present land surface. We present geochemical data to confirm that this tephra is a distal equivalent of the Campanian Ignimbrite deposits and a product of the largest Late Pleistocene eruption in Europe. Originating in the Campanian volcanic province of southwest Italy, this tephra has been independently dated to 39.3 ka. It is a highly significant chronostratigraphic marker for southern Europe. Macrostratigraphic and microstratigraphic observations, allied with detailed particle size data, show that the tephra layer is in a primary depositional context and was transported into the rockshelter by aeolian processes. This site is unique because the tephra forms an abrupt boundary between the Middle and Upper Palaeolithic records. Before they can be used as chronostratigraphic markers in rockshelter and cave-mouth environments, it is essential to establish the stratigraphic integrity of distal tephras and the mechanisms and pathways involved in their transport and deposition.  相似文献   

A new approach for phase transitions in miscible multi-phase flow in porous media   总被引：1，自引：0，他引：1  

A. Lauser  C. Hager 《Advances in water resources》2011,34(8):957-966

The tightly coupled, strongly nonlinear nature of non-isothermal multi-phase flow in porous media poses a tough challenge for numerical simulation. This trait is even more pronounced, if miscibility is also considered. A primary reason why inclusion of miscibility tends to be problematic are the difficulties stemming from phase transitions: on the one hand, phase transitions need to be included since the presence or absence of fluid phases has a major impact on the flow behavior; on the other hand, convergence of the nonlinear solver may be severely affected if they are not handled robustly.In this work, we present a mathematically sound approach to include phase transitions in the nonlinear system of equations: first, the transition conditions are formulated as a set of local inequality constraints, which are then directly integrated into the nonlinear solver using a nonlinear complementarity function. Under this scheme, Newton-Raphson solvers exhibit considerably more robust convergence behaviour compared to some previous approaches, which is then illustrated by several numerical examples.  相似文献   

岩浆到热液演化的包裹体记录——以骑田岭花岗岩体为例   总被引：3，自引：2，他引：1  

单强  廖思平  卢焕章  李建康  杨武斌  罗勇 《岩石学报》2011,27(5):1511-1520

骑田岭花岗岩是燕山期花岗岩早期多阶段侵入复式岩体,岩石化学的研究表明它是富碱的、高分异的A型花岗岩,形成于板内拉张的构造环境。在其第二阶段中细粒黑云母花岗岩内广泛发育着厘米级至米级似伟晶岩囊状体和石英晶洞, 它们是富挥发份岩浆固结的产物,代表岩石形成过程经历了明显的岩浆-热液过渡阶段。包裹体显微岩相学研究在骑田岭黑云母花岗岩的石英中发现熔体-流体包裹体和流体包裹体共存,这一结果进一步证实骑田岭中细粒黑云母花岗岩中的似伟晶岩囊状体和石英晶洞是花岗质熔体在岩浆-热液过渡阶段的产物。显微测温结果显示,熔体-流体包裹体的捕获温度大于530℃,说明岩浆热液过渡阶段的温度不低于该温度;闪锌矿中流体包裹体的均一温度在285~417℃之间,盐度为11.7% NaCleqv,代表了成矿流体的温度和盐度;流体包裹体的均一温度为172~454℃,代表热液阶段流体的温度。从中细粒黑云母花岗岩到似伟晶岩囊状体再到石英晶洞,岩浆-热液体系经历了富挥份熔体→熔体+高盐度流体→高盐度流体→低盐度流体的完整演化过程,形成了CaCl₂-NaCl-H₂O-CO₂体系的岩浆热液流体。包裹体岩相学及激光拉曼探针分析结果显示,在流体包裹体和多晶熔体-流体包裹体中含有长石、方解石、金红石及金属氧化物等子矿物,暗示其所捕获的流体具有较强的成矿能力。  相似文献   

陕西陈耳金矿床不同构造－岩相带微量元素地球化学特征及构造控矿机理   总被引：1，自引：1，他引：0       下载免费PDF全文

李建波蒋振频  鲁勇花郭 磊 史兴俊 曾 涛 《中国地质》2011,38(6):1551-1561

通过对陈耳金矿床两类不同构造-岩相带微量元素分布特征分析,发现元素特别是成矿元素Au的含量从片理化带→破碎蚀变带→石英脉逐渐增强。构造-岩相带内变形岩石的石英Rf/φ法有限应变测量表明,片理化带应变强度最大,破碎蚀变带应变强度小,应变集中在韧性剪切带边部的片理化带内。R型聚类分析表明Au与Ag、Cu、Pb及Zn的相关系数远大于Au与Ni、Co元素的相关系数,甚至接近于1。研究认为:破碎蚀变带内由于应变软化导致脆性裂隙大量发育,易于成矿流体的迁入与淀积而强富集;片理化带由于应变集中,造成成矿流体的迁出而弱富集。韧性剪切带脆-韧性变形转换不仅控制了矿体就位空间,同时也决定着元素迁移的方向。  相似文献   

热液矿床水相变控矿理论初探   总被引：2，自引：0，他引：2  

胡宝群  吕古贤  孙占学  李满根  廖玉婷  郭国林  白丽红 《地质通报》2011,30(4):565-572

在综合水物理化学性质、热液矿床、溶解度实验研究等资料的基础上,曾提出热液矿床水相变控矿理论框架.在此进一步完善该理论:①当水发生相变时可引起热容、水中矿质溶解度、压缩系数、膨胀系数等物理化学性质突变,特别是在临界点处二级相变时还出现"临界奇异性"、部分参数趋于无穷大,与水在非相变区物理化学性质的小幅度渐变区剐明显,必将...  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987110000149     

Xiang Wu  Shan Qin  Leonid Dubrovinsky 《地学前缘(英文版)》2011,2(1):107-114

The structural stability of manganese titanate MnTiO3 at high pressure was investigated by X-ray diffraction and Raman spectroscopy with diamond anvil cells. Ilmenite-type MnTiO3 is stable at least to 26.6 GPa, and lithium niobate type MnTiO3 reversibly transforms at room temperature to perovskite at 2.0 GPa. Bulk moduli (K300) of ilmenite, lithium niobate and perovskite are 174(4) GPa, 179(8) GPa, and 208(5) GPa, respectively (at fixed first pressure derivative K′ = 4). The Grüneisen parameter γ has been estimated to be 1.28 for ilmenite and 1.75 for perovskite. In ilmenite phase, TiO6 octahedra become more regular with increasing pressure. In perovskite phase structural distortion increases with pressure increase.  相似文献