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The debate about open registers (ORs) is not a new matter, and throughout centuries States have taken advantage of other flags for their own profit in order to overcome any kind of restrictions. To understand this system in depth it is necessary to know about its origins, development and consolidation. Eradicating substandard registers calls for the application of specific directions like the ones presented, which are a result of many years of researching and working for international organizations aiming at the modernization and consolidation of some ORs. This has led to an increase in the levels of safety and credibility of the maritime administrations where they were applied.  相似文献   
2.
韩栋材  靳二举  陈显 《探矿工程》2013,40(2):44-46,50
绳索取心液动锤技术集绳索取心技术与液动潜孔锤技术优势于一体,可比普通绳索取心钻进提高纯钻速30%~150%,在坚硬、脆性、“打滑”地层中钻进效果更为明显。介绍了绳索取心液动潜孔锤钻进技术在利比里亚邦州邦山铁矿详查中的应用情况,并对其应用效果进行了分析讨论。  相似文献   
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A number of fisheries development projects are undertaken every year in recognition of the important role fisheries play in many coastal communities. The objectives vary, but typically go beyond a limited focus on fisheries management and the ecosystem. This makes it difficult to evaluate the contribution of a project, particularly in data poor environments such as most developing countries. This paper used the recently developed Fisheries Performance Indicators (FPIs) to evaluate the impact of a World Bank development project in a Liberian coastal community. FPIs are designed to capture economic and social performance of a fisheries system in addition to the management and environmental impacts. The results show improvements in most ecological dimensions, and also in many social and economic dimensions targeted by the project. Hence, the project intervention appears to be positive. However, some indicators, particularly in relation to general governance in Liberia, showed a negative development which was not caused by the project.  相似文献   
4.
The Man craton in West Africa is an Archaean craton formerly joined to the Guyana craton (South America) that was rifted apart in the Mesozoic. Kimberlites of the Man craton include three Jurassic-aged clusters in Guinea, two Jurassic-aged clusters in Sierra Leone, and in Liberia two clusters of unknown age and one Neoproterozoic cluster recently dated at 800 Ma.

All of the kimberlites irrespective of age occur as small pipes and prolific dykes. Some of the Banankoro cluster pipes in Guinea, the Koidu pipes in Sierra Leone and small pipes in the Weasua cluster in Liberia contain hypabyssal-facies kimberlite and remnants of the so-called transitional-facies and diatreme-facies kimberlite. Most of the Man craton kimberlites are mineralogically classified as phlogopite kimberlites, although potassium contents are relatively low. They are chemically similar to mica-poor Group 1A Southern African examples.

The Jurassic kimberlites are considered to represent one province of kimberlites that track from older bodies in Guinea (Droujba 153 Ma) to progressively younger kimberlites in Sierra Leone (Koidu, 146 Ma and Tongo, 140 Ma). The scarcity of diatreme-facies kimberlites relative to hypabyssal-facies kimberlites and the presence of the so-called transitional-facies indicate that the pipes have been eroded down to the interface between the root and diatreme zones. From this observation, it is concluded that extensive erosion (1–2 km) has occurred since the Jurassic. In addition to erosion, the presence of abundant early crystallizing phlogopite is considered to have had an effect on the relatively small sizes of the Man craton kimberlites.  相似文献   

5.
白洋 《地质与勘探》2023,59(4):909-920
水系沉积物样品作为区域化探工作的主要测试分析物质,其成份组成具有明显的空间异质性,通过对元素含量数据进行滑动衬值标准化处理,可以有效解决该异质性造成的异常信息提取失真的问题。本次研究以利比里亚Harper地区1:25万区域化探数据为依据,以研究区优势成矿元素Fe2O3及其伴生元素V、BIF型铁矿的找矿指示元素Mn为主要研究对象,利用滑动衬值法对Fe、V元素含量数据进行处理,并以处理后的数据的85%、90%、95%分位数值作为各元素异常的外、中、内带值进行单元素异常圈定。处理结果表明该方法可有效提取出低背景区的Fe及其它相关元素的地球化学异常信息,结合Mn原始含量异常分布特征,本次共圈定出Fe2O3-V-Mn组合异常12处,通过对各组合异常的规模进行评序,结合区域成矿地质条件分析,最终在研究区优选出Karloken-Kronoken及Harper两处Fe有利成矿远景区。  相似文献   
6.
西非地区比里姆(Birimian)岩系经历了伊本尼(Eburnean)造山运动,成为全球金矿商业投资的主要含矿岩系之一,该岩系在利比里亚覆盖约36%国土面积.通过对西非尤其是利比里亚地质背景分析,初步建立了利比里亚区域地质构造格架,梳理出比里姆岩系中33处重要意义的岩金矿点,其分布与比里姆绿岩带、区域剪切构造带密切相关...  相似文献   
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