Estimation of undiscovered deposits in quantitative mineral resource assessments—examples from Venezuela and Puerto Rico

Quantitative mineral resource assessments used by the United States Geological Survey are based on deposit models. These assessments consist of three parts: (1) selecting appropriate deposit models and delineating on maps areas permissive for each type of deposit; (2) constructing a grade-tonnage model for each deposit model; and (3) estimating the number of undiscovered deposits of each type. In this article, I focus on the estimation of undiscovered deposits using two methods: the deposit density method and the target counting method.In the deposit density method, estimates are made by analogy with well-explored areas that are geologically similar to the study area and that contain a known density of deposits per unit area. The deposit density method is useful for regions where there is little or no data. This method was used to estimate undiscovered low-sulfide gold-quartz vein deposits in Venezuela.Estimates can also be made by counting targets such as mineral occurrences, geophysical or geochemical anomalies, or exploration plays and by assigning to each target a probability that it represents an undiscovered deposit that is a member of the grade-tonnage distribution. This method is useful in areas where detailed geological, geophysical, geochemical, and mineral occurrence data exist. Using this method, porphyry copper-gold deposits were estimated in Puerto Rico.     

中国西北干旱地区城市化过程及空间分异规律

通过对实地调研和大量文献分析,对我国西北干旱地区城市发展与自然环境的关系进行论述,认为城市化过程本质上就是人地关系的集中凸现,是自然要素与人文要素长期互相作用的结果。自古以来,城市就是人类聚居的主要场所,屯垦是西北干旱地区最能体现人地关系的耦合点。在西北干旱地区现代城市化过程中,屯垦和矿产资源开发有较大的带动作用。由于自然因素和社会因素的双重影响,人口分布和聚居程度极不均衡,社会经济分异较大,城镇功能单一,部分地区和城镇的人口城镇化水平较高,并不是社会经济整体发展的结果,而是资源开采、行政建制的设立、极端自然条件下生存的需要等多种因素形成的。城市分布空间格局以带状、团状、串珠状为主,有着不同于其他地区的演化模式,城镇发展表现出多元复合的特征,是政治、经济、生态环境、资源、民族与文化等诸多因素相互关联、起伏变化的结果。城镇高速发展、城市化速度加快是未来西北干旱地区社会经济发展的必然结果,面对脆弱的生态环境和有限的资源,提出在西北干旱地区建设只有城镇、没有村落的新型城市社会,以达到社会经济和生态环境可持续发展的目标。     

勘查地球化学的过去与未来的发展

勘查地球化学经过了半个多世纪的发展，其工作范围在不断扩大。另一方面，应用地球化学虽经多年发展，但它仍不能解决环境和资源方面的重大问题。全球观点、地球化学图是促使应用地球化学起巨大作用的最基本东西，否则，应用地球化学就不可能有巨大的发展，勘查地球化学应该进入应用地球化学的行列。2l世纪以来，勘查地球化学已发展到应用地球化学，从研究分散模式发展到研究分布模式，从只研究成矿后的地质过程发展到研究从地球形成开始的所有地质过程中所有元素的行为，从局部到全球，从资源到环境，从发现、开发、监控到修复，从岩石圈、土壤圈到水圈、生物圈、人类圈。这样的发展趋势必将为应用地球化学解决环境和资源的重大问题做出巨大贡献。     

A Web-based resource discovery facility for a Geo-Data Server

This article deals with the design of a resource discovery system, based on a Web interface, for searching and downloading data stored in a Geo-Data Server. The main features of the Geo-Data Server are the design of a cartographic and image database, following international standards, a relational catalogue, containing meta-information on the archived data, and a high-level interface to access the system. The Geo-Data Server implements a distributed system where data are appropriately organised for remote consultation.     

基于元数据和数据集管理的应用模型研究

元数据是解决数据共享的技术手段之一 ,现有以元数据为基础的管理模型和管理系统主要针对元数据本身的管理 ,元数据和数据集在管理上是相对独立的 ,这直接导致了元数据和数据集的不一致性。在元数据与数据集内在联系的基础上 ,本文提出了实现元数据和数据集一体化管理的应用模型 ,该模型由综合管理层、服务层、应用层三层体系结构组成 ,通过服务流、数据流、元数据流的交互 ,实现元数据和数据集的同步一体化管理。从数据集对象的建立、数据集对象的查询和获取、数据集对象的变更三个应用方面 ,文章详细阐述了该应用模型的实现流程。     

黑龙江省国土资源遥感影像数据库系统相关技术研究

本文介绍了黑龙江省国土资源遥感影像数据管理系统的相关功能,并对实现这些功能所采用的空间数据引擎技术、遥感影像金字塔技术进行了分析与探讨。     

关于网格资源调度的探讨

随着计算机网络技术的飞速发展, 出现了第三代Internet技术网格计算(Grid Computing)。 网格是一种异构、 动态、 分布式的计算环境。 网格资源管理是网格的核心组件, 文中介绍了网格资源管理的特点, 分析了Globus工具集网格资源管理的核心组件。 网格资源调度是网格资源管理的核心部分, 也是网格资源管理中极其繁琐复杂的问题。 基于分析网格计算环境中资源管理的结构特点, 分析和总结了网格调度策略, 提出了多级资源调度模式, 给出了多级资源调度的模式。     

关于在平行断面法资源/储量估算中限制使用梯形体公式的建议

通过理论推导,指出在平行断面法资源／储量估算中,在块段相邻剖面不具有相等对应边的情况下,梯形体公式只是一个近似估算公式,存在着一定的误差。而截面圆锥体公式则是一个精确的通用公式,其使用不受相对面积差大小的限制。因此,在这种情况下,建议放弃使用梯形体公式,而统一使用截面圆锥体公式。     

Trade measures and the combat of IUU fishing: Institutional interplay and effective governance in the Northeast Atlantic

The use of trade measures to combat illegal, unreported and unregulated (IUU) fishing in the Northeast Atlantic has evolved from unilateral denial of the landing of fish taken outside international quota arrangements to a multilateral Scheme of Control and Enforcement under the North-East Atlantic Fisheries Commission (NEAFC). International trade rules have not constrained this development, mostly due to successful management of the interplay between international resource management and trade regimes. States protect resource management objectives from such constraint by inserting clauses that establish a normative hierarchy, or they employ various means for adapting IUU measures to the ‘environmental window’ of the global trade regime. The fact that regional states have introduced trade restrictions only when non-restrictive or less restrictive measures have failed enhances such compatibility, as do the gradual shift from unilateral to multilateral measures and the rise in transparency, openness and target-state involvement. None of those features reduces the effectiveness of regional trade measures; they minimize tension with trade commitments and largely strengthen their clout in the struggle to combat IUU fishing in the Northeast Atlantic.     

Fisher's behaviour with individual vessel quotas—Over-capacity and potential rent: Five case studies

Internationally, individual vessel quotas (IVQ) have become an increasingly popular management tool. The main attraction of IVQs is the incentives they create for cost savings, autonomous capacity adjustment and, subsequently, rent generation. In this paper, the extent to which different IVQ systems have facilitated resource rent generation and capacity adjustment in five European countries—Denmark, Iceland, Norway, Sweden and the UK—is examined. The potential economic rents and the capacity reduction necessary to achieve these rents in each of the fisheries are also estimated. Reasons why IVQs have not achieved their potential economic benefits in these fisheries are also examined.