巴布亚新几内亚构造演化与找矿潜力     

王天刚  姚仲友  黄宾  朱意萍  赵晓丹 《火山地质与矿产》2014,(2):130-135

巴布亚新几内亚在大地构造位置上位于欧亚板块、印度-澳大利亚板块和太平洋板块的结合部位.本文介绍了自晚白垩世以来巴布亚新几内亚经历的复杂地质构造演化过程,不同板块间的汇聚、碰撞、俯冲和拆离、扩张等地质作用形成了以区内南部克拉通、中部褶皱带及北部岛弧带为特点的地质构造单元,在区内形成了具有活动大陆边缘特色的成矿系统,对寻找以斑岩型和浅成低温热液型铜金矿、红土型镍矿为主要成矿类型具有重要意义.  相似文献   

几内亚博凯矿区风化残积型铝土矿钻探工艺          下载免费PDF全文

王兴民  卢耀东  崔建华 《探矿工程》2014,41(6):31-34

几内亚博凯地区铝土矿勘探项目中分别采用无冲洗介质岩心钻探和螺旋钻探2种工艺,通过工程实践和对比试验结果表明：在风化残积地层中无冲洗介质岩心钻探存在着效率低、成本高、岩心质量难以保障、工人劳动强度高等问题。采用螺旋钻探工艺施工,其钻探质量不仅能够满足规范设计要求,而且可以降低成本、提高钻探效率,其钻探效率是岩心钻探的6.77倍,综合施工效率是岩心钻探的3.5倍。  相似文献   

Community perceptions of REDD+: a case study from Papua New Guinea     

Matthew Leggett  Heather Lovell 《Climate Policy》2013,13(1):115-134

REDD projects have received considerable attention for their potential to mitigate the effects of climatic change. However, the existing literature has been slow to assess the impacts of proposed REDD projects on the livelihoods of forest communities in the developing world, or the implications of these local realities for the success of REDD+ initiatives in general. This study presents ethnographic research conducted with communities within the April-Salomei pilot REDD+ Project in Papua New Guinea (PNG). Several cases of institutional biases and uneven power relationships have been exploited by local elites to prevent landowners from making free and informed choices about their involvement in the project, although landowners and local communities are well positioned to capture forthcoming project benefits. By underestimating the scale and impact of traditional shifting cultivation practices, the credibility of the REDD+ project design and the value of any future carbon credits are critically undermined. Based on the actual practices found in PNG, the authors' radical proposal is to call for a halt on REDD development in PNG while institutional enabling conditions are improved, comprehensive landowner consultations conducted, and detailed mapping and genealogical surveys of landowners completed. Without these developments, future REDD+ projects in PNG are unlikely to benefit either the global climate or local development.  相似文献   

Millennial‐scale precipitation changes over Central Africa during the late Quaternary and Holocene: evidence in sediments from the Gulf of Guinea     

Achakie C. Itambi  Tilo von Dobeneck  Adesina T. Adegbie 《第四纪科学杂志》2010,25(3):267-279

We combine environmental magnetism, geochemical measurements and colour reflectance to study two late Quaternary sediment cores: GeoB 4905‐4 at 2° 30′ N off Cameroon and GeoB 4906‐3 at 0° 44′ N off Gabon. This area is suitable for investigating precipitation changes over Central and West Africa because of its potential to record input of aeolian and fluvial sediments. Three magnetozones representing low and high degree of alteration of the primary rock magnetic signals were identified. The magnetic signature is dominated by fine‐grained magnetite, while residual haematite prevails in the reduced intervals, showing increase in concentration and fine grain size at wet intervals. Our records also show millennial‐scale changes in climate during the last glacial and interglacial cycles. At the northern location, the past 5.5 ka are marked by high‐frequency oscillations of Ti and colour reflectance, which suggests aeolian input and hence aridity. The southern location remains under the influence of the Intertropical Convergence Zone and thus did not register aeolian signals. The millennial‐scale climatic signals indicate that drier and/or colder conditions persisted during the late Holocene and are synchronous with the 900 a climatic cycles observed in Northern Hemisphere ice core records. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

赤道几内亚里奥穆尼盆地石油地质特征及勘探方向   总被引：2，自引：1，他引：1  

吕福亮  徐志诚  范国章  邵大力  毛超林 《海相油气地质》2011,16(1):45-50

位于赤道几内亚的里奥穆尼盆地是裂谷盆地与被动大陆边缘盆地叠加的中-新生代复合型含油气盆地.盆地的构造演化经历了裂谷期、过渡期和漂移期三个阶段.盆地地层以过渡期盐岩层为界,盐下为裂谷期层序,盐上为漂移期层序.盆地生储盖组合可以划分为上、中、下三套,中组合最为有利.盐下裂谷期圈闭类型以断块圈闭和背斜圈闭为主,盐上漂移期以盐...  相似文献   

几内亚西南部莫拉铁矿区地质特征及找矿方向          下载免费PDF全文

曹健  田麒  李宏臣  付方建  江胜国 《地质找矿论丛》2016,31(1):71-76

莫拉(Mola)铁矿区位于几内亚金迪亚省,西非克拉通莱奥(Leo)地盾西部边缘的太古代Kenema-Man Domain地盾与西侧罗克列德褶皱带(Rokelide Fold Belts)的接壤地带。区内发育铁角砾岩型、似条带状赤铁矿型2类矿体。研究认为,铁角砾岩型铁矿主要由后期风化淋滤作用对原生赤铁矿改造并富集形成,赋存于地表;似条带状赤铁矿矿体是经初始海底热液喷溢沉积和后期构造作用改造而富集形成。  相似文献   

A reporting compliance of national Fisheries Authority of Papua New Guinea     

《Marine Policy》2015

Through textual analysis, this paper takes into account documentary evidence of the Auditor-General׳s audit commentaries of the reporting compliance of the National Fisheries Authority of Papua New Guinea for the period 2006–2012. The results of the analysis show that the National Fisheries Authority׳s financial statements are late, unprepared or qualified. The study suggests ways the authority might improve its reporting compliance at relatively little cost, and how using national reporting compliance instruments may enhance national fisheries policy. The findings are of critical importance for fishing authority local managers, policy-makers and practitioners interested in providing compliant financial and operational reporting to meet the decision needs of its key stakeholders.  相似文献   

Marine ecosystem variability and human community responses: The example of Ghana,West Africa     

R. Ian Perry  U. Rashid Sumaila 《Marine Policy》2007

This study describes variability in the marine ecosystem of Ghana, West Africa, on several temporal and spatial scales and discusses how the human communities using this ecosystem respond to this variability to cope socially and economically. Ghanaian marine waters are part of an upwelling system with strong seasonal and inter-annual variability. Much of this variability is forced at large spatial scales in the tropical Atlantic and by El Niño—Southern Oscillation events in the Pacific Ocean, which influence inter-annual variability of sea surface temperature and pelagic fish landings off Ghana. At decadal scales, Ghanaian marine waters experienced cool sea temperatures and low fishery landings during the 1960s, rapid warming and increases in fishery landings during the late 1970s and 1980s, and variable temperatures and fishery landings during the 1990s. In the late 1990s, pelagic and demersal fish populations appeared to be declining, partly due to over-fishing, although the per capita supply (domestic production plus net imports) of fish was kept high by increased imports. Artisanal fishers and fishing communities in Ghana have devised strategies to deal with variability on seasonal and inter-annual scales. These livelihood strategies include: (i) exploiting marine and terrestrial natural resources more intensively, initially at local scales but expanding to regional scales; (ii) ensuring multiple and diversified income sources; (iii) investing in social relationships and communities for support; and (iv) undertaking seasonal or permanent migrations. In addition, the national government imports fish to deal with shortages. However, these strategies may be less adapted to variability at decadal scales, and may not be sustainable when viewed at the larger scales of environmental change.  相似文献   

基于WWATCH模式和高度计数据的几内亚湾海域海浪的数值计算     

李庆红  张永刚  张磊  刘天波 《海洋技术学报》2007,26(4):30-34

我国与非洲国家的经济往来和能源合作日益密切,研究几内亚湾及其附近海域海浪特点对此具有重要意义。将第三代海浪数值模式WWATCH模式应用于几内亚湾及其附近海域,以美国国家环境预报中心(NCEP)的再分析风场资料作为模式输入,对该海域2004年的海浪场进行了数值计算。利用计算结果分析了2004年2月和8月几内亚湾及附近海域的海浪特点,将模式计算的有效波高与Topex/Poseidon高度计观测的有效波高进行对比,结果表明,模式有效波高的大小和变化趋势与T/P高度计有效波高具有良好的一致性,其中在深海海域计算效果好于浅海海域。  相似文献   

Natural diversion of the ramu river in Papua New Guinea     

John M. A. Chappell   《The Australian geographer》1991,22(2):161-167

At present, the Ramu River in Papua New Guinea flows directly into the Bismarck Sea, while the adjacent Keram flows into the Sepik River. There is evidence to suggest that the Ramu previously occupied the existing Keram water course, and has been gradually diverting its discharge into its present channel, probably over the last 4,000 years. The diversion process is not complete yet, and during the wet season flood water still travels across these two rivers. The most direct evidence to support this proposal of river diversion is that there are much larger meander bends on which the existing Keram stream channel is superimposed. The diversion of the Ramu is believed to be a result of relative sea‐level rise in the late Quaternary which altered the gradients of the Keram and Ramu rivers, and may have been facilitated through neo‐tectonic movement of the floodplain.  相似文献