易门狮子山铜矿床构造岩微量元素特征及构造地球化学异常模式   总被引：2，自引：1，他引：1  

李强  韩润生  黄应才  李德 《大地构造与成矿学》2011,35(1):149-155

易门狮子山铜矿床位于昆阳裂谷易门裂陷盆地内,属沉积-改造型中型铜矿床。矿体主要赋存于落雪组白云岩中,并严格受狮子山背斜及北东向压扭性断裂控制。应用构造地球化学方法,重点研究了断裂构造岩微量元素分布特征及其异常分带规律,结果表明:断裂破碎带矿化蚀变强烈,构造岩中Cu、Bi、Mo、Co、Mn、Ag、Pb等成矿元素富集;矿床具有自上而下的轴向分带序列Ba-Mn-Ag-Zn-Cu-Pb-Co-Bi-Mo;横向上Cu-Bi-Mo-Co-Mn为矿体的近矿指示元素,Ag-Pb为远程指示元素;纵向上从矿床东部至西部,矿化强度及异常规模明显减弱,反映了该类型矿床分带明显的特征。根据地球化学找矿标志,3～8号勘探线间近矿晕规模大,是深部隐伏矿的主要靶区。  相似文献   

Hydrogeology and groundwater flow in a basalt-capped Mesozoic sedimentary series of the Ethiopian highlands     

Ine Vandecasteele  Jan Nyssen  Wim Clymans  Jan Moeyersons  Kristine Martens  Marc Van Camp  Tesfamichael Gebreyohannes  Florimond Desmedt  Jozef Deckers  Kristine Walraevens 《Hydrogeology Journal》2011,19(3):641-650

A hydrogeological study was undertaken in the Zenako-Argaka catchment, near Hagere Selam in Tigray, northern Ethiopia, during the rainy season of 2006. A geological map was produced through geophysical measurements and field observations, and a fracture zone identified in the north west of the catchment. A perched water table was found within the Trap Basalt series above the laterized upper Aram Aradam Sandstones. A map of this water table was compiled. Water-level variation during the measurement period was at least 4.5?m. Variation in basal flow for the whole catchment for the measurement period was between 12 and 276?m³/day. A groundwater flow model was produced using Visual MODFLOW, indicating the general direction of flow to be towards the south, and illustrating that the waterways have only a limited influence on groundwater flow. The soil water budget was calculated for the period 1995?C2006, which showed the important influence of the distribution of rainfall in time. Although Hagere Selam received some 724?mm of rainfall per year over this period, the strong seasonal variation in rainfall meant there was a water deficit for on average 10?months per year.  相似文献   

Validation Techniques for Geological Patterns Simulations Based on Variogram and Multiple-Point Statistics   总被引：2，自引：2，他引：0  

S. De Iaco  S. Maggio 《Mathematical Geosciences》2011,43(4):483-500

Traditional simulation methods that are based on some form of kriging are not sensitive to the presence of strings of connectivity of low or high values. They are particularly inappropriate in many earth sciences applications, where the geological structures to be simulated are curvilinear. In such cases, techniques allowing the reproduction of multiple-point statistics are required. The aim of this paper is to point out the advantages of integrating such multiple-statistics in a model in order to allow shape reproduction, as well as heterogeneity structures, of complex geological patterns to emerge. A comparison between a traditional variogram-based simulation algorithm, such as the sequential indicator simulation, and a multiple-point statistics algorithm (e.g., the single normal equation simulation) is presented. In particular, it is shown that the spatial distribution of limestone with meandering channels in Lecce, Italy is better reproduced by using the latter algorithm. The strengths of this study are, first, the use of a training image that is not a fluvial system and, more importantly, the quantitative comparison between the two algorithms. The paper focuses on different metrics that facilitate the comparison of the methods used for limestone spatial distribution simulation: both objective measures of similarity of facies realizations and high-order spatial cumulants based on different third- and fourth-order spatial templates are considered.  相似文献   

The Bulgheria canyon-fan: a small-scale proximal system in the eastern Tyrrhenian Sea (Italy)     

Francesca Budillon  Alessandro Conforti  Renato Tonielli  Giovanni De Falco  Gabriella Di Martino  Sara Innangi  Ennio Marsella 《Marine Geophysical Researches》2011,32(1-2):83-97

The Bulgheria canyon-fan system in the eastern Tyrrhenian Sea displays well-developed, small-scale, fluvial-like features and has formed alongside the northern slope of the Sapri peri-Tyrrhenian basin. This study reveals, for the first time, the morphology and course of the present-day system as well as the buried elements based on a Digital Terrain Model and high-resolution seismic profiles interpretation. Two adjacent canyons (Infreschi and Luna) originate in the Cilento outer shelf at a short distance from each other and feed an intraslope basin fan through two main sub-parallel channels that run about 12 and 8 km, respectively. Channel and levee development seems to be controlled primarily by the local slope gradient and by Coriolis forces that induce a faster vertical growth of the right-side features, as is often observed in the Northern Hemisphere. Centrifugal forces, on the other hand, have induced episodic flow-stripping at the meander loops and bends, causing local destruction of the main channel levees rather than new levee growth at the outer bends. Overbank deposits are associated with overspill turbidite deposition in the mid fan where a topographic constraint occurs, whereas large-sediment, low-angle wave fields are mainly developed on the outer fan. Buried features and relict morphologies suggest that the Infreschi channel experienced at least two phases of re-incision since the final stages of the middle Pleistocene. Local re-adjustment of outer lobe growth due to channel avulsion and meander abandonment is possibly a consequence of relative base-level fluctuations. The sedimentary record of the mid and outer fan includes outrun mass wasting deposits from extensive failures of the Sapri slope. Indeed, a marked scar is present on the eastern side of the modern outer lobe that indicates the persistency of mass flow passages up to recent times. In addition to the environmental factors that are currently considered to cause canyon formation on the shelf margin, this study proposes the possibility that the head canyon branch close to the mainland was incised by massive and persistent underground freshwater flow from the adjacent aquifer when the sea-level was lower than at present.  相似文献   

Carbonate sedimentation and hydrodynamic pattern on a modern temperate shelf: The strait of Bonifacio (western Mediterranean)     

Giovanni De Falco  Sandro De Muro  Tiziana Batzella  Andrea Cucco 《Estuarine, Coastal and Shelf Science》2011

The sedimentary features of the inner-middle shelf of the strait of Bonifacio (western Mediterranean) were analyzed to evaluate the relationship between the production and transport of biogenic carbonate sediments and the basin morphology and hydrodynamics. A three-dimensional hydrodynamic modeling was performed in order to simulate the influence of waves and currents at seabed level. Superficial sediments were collected at depths ranging from 5 to 80 m and were analyzed for grain size, mineralogical composition and skeletal carbonate composition. Posidonia oceanica seagrass meadows border the coasts in a narrow strip on both sides of the strait down to a depth of 40 m. At greater depths, the seabed is characterized by the presence of plateaus and ridges which are controlled by outcropping bedrock morphology.  相似文献   

Fortress conservation at sea: A commentary on the Chagos marine protected area     

E.M. De Santo  P.J.S. Jones  A.M.M. Miller 《Marine Policy》2011

The world's largest no-take Marine Protected Area in Chagos is examined in light of the Convention on Biological Diversity's provisions on Access and Benefit Sharing, as well as terrestrial experiences with fortress conservation. It is acknowledged that this closure presents a unique opportunity to preserve an ecologically 'pristine' area. However, the means by which the political process unfolded are brought into question. In particular, the fact that the UK proceeded with designating the area whilst the European Court of Human Rights was deliberating the right of native Chagossians to return to the island is questioned. In addition it is argued that the scale of the area poses significant management and enforcement challenges, which are not necessarily taken into consideration in the rush for large, no-take Marine Protected Areas.  相似文献   

Environmental justice implications of Maritime Spatial Planning in the European Union     

Elizabeth M. De Santo 《Marine Policy》2011

This paper examines the implications of environmental justice in the regime for Maritime Spatial Planning (MSP) currently developing in the European Union (EU). An ‘ecosystem-based approach’ to marine management is enshrined in the new Integrated Maritime Policy and Marine Strategy Framework Directive and forms the basis of MSP. This concept is intended to encompass all aspects of an ecosystem, including the human element. Yet the modes of including meaningful public participation in the decision-making process for MSP remain undetermined. At the same time, the Aarhus Convention (on access to information, public participation in decision making and access to justice in environmental matters) empowers non-governmental organisations to hold EU Member States to account. Consequently the issue of transparency will gain increased importance, as will linkages between human and environmental rights. Such public interest-based activism on the part of NGOs has the potential to enforce the developing framework for stakeholder engagement within MSP, but it also has implications worth considering regarding the appropriate role of interest-based organisations in the international political arena.  相似文献   

Bioturbation effects of Corophium volutator: Importance of density and behavioural activity     

A. De Backer  F. Van Coillie  F. Montserrat  P. Provoost  C. Van Colen  M. Vincx  S. Degraer 《Estuarine, Coastal and Shelf Science》2011

Bioturbation is one of the major processes influencing ecosystem functioning. Population parameters such as species density, burrow density and species-specific life modes, determine the impact of bioturbation on the ecosystem. A laboratory experiment was developed, using microcosms mimicking a marine intertidal sediment–water interface which allowed for quantification of different population parameters. The vertical redistribution, bioturbation rate and maximum penetration depth of two sizes (41 and 129 μm) of luminophores were measured in five treatments (control, low density of burrows with and without Corophium (1989 ind./m²), and high density of burrows with and without Corophium (14,921 ind./m²)) after 1, 7 and 14 days. Results indicate that the behavioural activities of Corophium are of the utmost importance in sediment reworking, since they contributed to a five-fold increase in bioturbation rate compared to the passive transport induced by the static structure of the burrows. Furthermore, density is an important parameter because only high densities play a prominent role in particle transport and hence in organic matter processing, while the role of low Corophium densities is limited in sediment reworking. No evidence for differentiation in sediment size fractions was observed. Finally, bioturbation rates in this study were low compared to other studies, and these results suggest an influence of the tidal rhythmicity in the behavioural activity of Corophium on the bioturbation rate.  相似文献   

基于WebGIS的气象服务产品自动加工关键技术     

丰德恩  唐卫  王慕华  惠建忠  郝江波  王澎涛  李雁鹏 《气象与环境科学》2020,43(1):130-136

针对融媒体时代对气象服务产品加工个性化、准实时、智能化新诉求,以SOA架构组件式开发思想为指导,归纳气象服务产品加工业务共性,提出一套集成应用WebGIS、并行计算和大数据技术的气象服务产品自动化加工解决方案。利用组件开发和工作流引擎技术,搭建面向服务体系架构的产品加工模型装备框架,对产品加工组件进行模型编排,实现无须编程情况下的产品加工模型快速构建;利用基于分布式架构的加工服务器集群技术,搭建加工服务器集群环境,对产品加工模型服务进行发布和管理,实现产品加工任务的秒级高并发处理;利用基于消息和定时机制的加工任务调度技术,开发了产品加工任务调度器,通过设置消息主题和定时计划策略,实现加工任务参数智能解析和适配应用,统一协调触发各加工模型服务进行自动化作业。智能化气象服务产品自动加工系统自业务化运行以来,在加工效率、美观性和扩充性等方面表现出很好的应用价值。以温度、降水、风速、相对湿度全国实况格点服务产品加工为例进行实验,加工耗时由797 s缩减至14 s,效率提高50倍以上。  相似文献   

Erratum to: Simulating cold season snowpack: Impacts of snow albedo and multi-layer snow physics     

D. Waliser  J. Kim  Y. Xue  Y. Chao  A. Eldering  R. Fovell  A. Hall  Q. Li  K. N. Liou  J. McWilliams  S. Kapnick  R. Vasic  F. De Sales  Y. Yu 《Climatic change》2013,116(2):425-425

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