柬埔寨KW铜金矿床地质特征及控矿条件

柬埔寨KW铜金矿床产于安山质火山岩中,矿化受NE-NNE向断裂控制,为中低温热液脉型矿化;矿体一般长80~640m,厚0.13~7.05m,品位Cu0.56%~3.48%,Au0.36×10-6~2.56×10-6;矿石金属矿物以黄铜矿、黄铁矿、毒砂为主,非金属矿物以石英为主,含少量绢云母、绿泥石、方解石等,近矿围岩蚀变以硅化-绢云母化-绿泥石化。矿区安山岩属高钾低钠的钙碱性岩类,矿石与安山岩有相似的稀土配分特征,显示成矿与安山质岩浆活动有密切的成因联系。矿区青磐岩化、细脉状石膏较为普遍,显示可能存在与次火山岩体有关的蚀变岩型矿化,该类型矿化是下一步找矿突破的重要方向。     

Landslide susceptibility mapping in the Damrei Romel area, Cambodia using frequency ratio and logistic regression models

This study applied, tested and compared a probability model, a frequency ratio and statistical model, a logistic regression to Damre Romel area, Cambodia, using a geographic information system. For landslide susceptibility mapping, landslide locations were identified in the study area from interpretation of aerial photographs and field surveys, and a spatial database was constructed from topographic maps, geology and land cover. The factors that influence landslide occurrence, such as slope, aspect, curvature and distance from drainage were calculated from the topographic database. Lithology and distance from lineament were extracted and calculated from the geology database. Land cover was classified from Landsat TM satellite imagery. The relationship between the factors and the landslides was calculated using frequency ratio and logistic regression models. The relationships, frequency ratio and logistic regression coefficient were overlaid to make landslide susceptibility map. Then the landslide susceptibility map was compared with known landslide locations and tested. As the result, the frequency ratio model (86.97%) and the logistic regression (86.37%) had high and similar prediction accuracy. The landslide susceptibility map can be used to reduce hazards associated with landslides and to land cover planning.     

Sapphire within zircon-rich gem deposits,Bo Loei,Ratanakiri Province,Cambodia: trace elements,inclusions, U–Pb dating and genesis

Subordinate sapphire accompanies prevalent zircon megacrysts in the Bo Loei basaltic gem field, Ratanakiri Province, Cambodia. These deposits are important for heat-treated gem zircon. Dark blue sapphire, with rare blue-green, orange-brown and yellow stones, up to a few cm in size, include hexagonal-shaped and growth-zoned crystals. Analyses of the sapphires (electron microprobe and laser ablation-inductively coupled plasma-mass spectrometry) showed Fe as the main chromophore (0.6–2.7 wt%), with minor Ti (<0.7 wt%). Sapphire cores show enrichment in Fe relative to rims and some include exotic heavy elements (Nb up to 56, Ta up to 144, Sn up to 5 ppm). The sapphires show high Ga values (271–724 ppm) and Ga/Mg ratios (4.8–77.0) suggesting magmatic associations. Two sapphires with syngenetic inclusions (zircon, Nb-rich rutile) gave U–Pb (Th-disequilibrium corrected) ages at ca 0.93 ± 0.1 Ma. The Bo Loei sapphires show higher Fe and Ga than other magmatic sapphire suites elsewhere in Cambodia (Pailin), Laos (Ban Huai Sai, Ban Sam Sai), South Vietnam (Dak Nong, Dak Lac) and SE Thailand (Chanthaburi-Trat). This suggests potential for geographic typing of sapphire suites between these different fields.     

Contrasting sorption behaviours affecting groundwater arsenic concentration in Kandal Province,Cambodia

Natural arsenic(As)contamination of groundwater which provides drinking water and/or irrigation supplies remains a major public health issue,particularly in South and Southeast Asia.A number of studies have evaluated various aspects of the biogeochemical controls on As mobilization in aquifers typical to this region,however many are predicated on the assumption that key biogeochemical processes may be deduced by sampled water chemistry.The validity of this assumption has not been clearly established even though the role of sorption/desorption of As and other heavy metals onto Fe/Mn(hydr)oxides is an important control in As mobilization.Here,selective chemical extractions of sand-rich and clay-rich sediments from an As-affected aquifer in Kandal Province,Cambodia,were undertaken to explore the potential role of partial re-equilibrium through sorption/desorption reactions of As and related solutes(Fe,Mn and P)between groundwater and the associated solid aquifer matrix.In general,groundwater As is strongly affected by both pH and Eh throughout the study area.However,contrasting sorption behaviour is observed in two distinct sand-dominated(T-Sand)and clay dominated(T-Clay)transects,and plausibly attributed to differing dominant lithologies,biogeochemical and/or hydrogeological conditions.Sorption/desorption processes appear to be re-setting groundwater As concentrations in both transects,but to varying extents and in different ways.In T-Sand,which is typically highly reducing,correlations suggest that dissolved As may be sequestered by sorption/re-adsorption to Fe-bearing mineral phases and/or sedimentary organic matter;in T-Clay Eh is a major control on As mobilization although binding/occlusion of Fe-bearing minerals to sedimentary organic matter may also occur.Multiple linear regression analysis was conducted with groups categorised by transect and by Eh,and the output correlations support the contrasting sorption behaviours encountered in this study area.Irrespective of transect,however,the key biogeochemical processes which initially control As mobilization in such aquifers,may be "masked" by the re-setting of As concentrations through in-aquifer sorption/desorption processes.     

地磁异常数据处理技术在低纬度地区的应用研究——以柬埔寨王国Mesam金矿为例北大核心CSCD

柬埔寨王国位于低纬度地区,地质勘查程度较低,地面高精度磁测技术能够快速获取磁异常信息,进行找矿评价。在低纬度地区磁化方向主要以水平磁化为主,磁性体产生的磁异常以负磁异常为主。本文通过对柬埔寨王国Mesam金矿磁测数据进行倒相180°、化赤和低纬度化极处理对比,认为三种处理方法得到的结果都能够完整地反映磁场分布特点,在不能忽略剩磁影响的低纬度地区对实测数据进行低纬度化极后再进行解释更加贴近真实且细节更加丰富。通过对低纬度化极后的磁异常进行水平总梯度模和小波多尺度分解计算等位场异常处理,认为磁异常水平总梯度模计算能够较好地反映深部地质体的边界范围,小波多尺度分解计算能够提取特定深度地质体的空间信息,在该区选取的磁异常处理技术是有效的,为进一步扩大该金矿区远景储量提供了新的思路。     

‘Fire in the House’: Gendered experiences of drunkenness and violence in Siem Reap, Cambodia

After decades of turmoil and international isolation, Cambodia has embarked on a threefold transition: from armed conflict to peace, from political authoritarianism to liberal democracy, and from a socialist economic system to one based on market-driven capitalist growth. In this context of transition, the paper explores the perceived linkages that exist between drinking, drunkenness and gender-based violence in rural and urban Siem Reap, home to the global tourism site of Angkor. By considering the ways in which men and women relate alcohol use with violence, the paper questions what implications these social constructions have for tackling gender-based violence and concludes that challenging such external explanations for violence is needed in order for gender-based violence to be understood as the struggle for equality in men and women’s everyday lives.     

Is REDD+ effective,efficient, and equitable? Learning from a REDD+ project in Northern Cambodia

REDD+ is a global scale climate change mitigation program aiming at creating financial values for carbon stored in forests. According to the proponents, REDD+ is an effective, efficient, and equitable mechanism for reducing emissions from deforestation and forest degradation. Some scholars question this assumption, and some call for further analysis to understand how REDD+ can contribute to economic, environmental, and social goals, and what are the synergies and trade-offs between them. The purpose of this paper is to contribute to the debate about whether REDD+ projects can be brought to accommodate economic (efficiency), environmental (effectiveness), and social (equity) concerns at the same time by drawing on own field results from a REDD+ project in Cambodia. The paper follows three tracks. The first is to develop and explain the conceptual and analytical framework for our empirical investigations. The second is to explain the field results. The third track is to discuss what general lessons can be learnt. Our case illustrates some of the mechanisms that are likely to work against the willingness and ability of REDD+ projects to ensure local people’s net-gains, and the risk that effectiveness and equity will suffer if REDD+ projects rely solely on the private market. Our case thus indicates a tension between the objectives of creating financial value from carbon stored in trees through the private market, and environmental and social equity concerns. However, we call for more comparative studies of REDD+ projects, and hope our conceptual framework can assist such studies.     

Location of a pre-Angkor capital city in relation to geomorphological features of lower reach of the Stung Sen River,central Cambodia

The Sambor Prei Kuk archaeological site in lower reach of the Stung Sen River, central Cambodia, is the site of the capital city of the pre- Angkor state of Chenla. The location of Sambor Prei Kuk is discussed in relation to the geomorphological characteristics of lower reach of the Stung Sen River and the requirements of the inhabitants. The uplands were divided into upland I, which is characterized by hills, and uplands II and III, both of which have flat surfaces, with upland III lower than upland II. The present river follows a meandering course within a conspicuous meander scroll zone, and deposits along the channel are repeatedly eroded and redeposited. Back marsh areas have gradually filled with suspended flood water sediments during the last 4600 years at an accumulation rate of 0.6 mm/yr. The floodplain and lake plain were divided into five zones to evaluate the monsoonal flood risk and accessibility to upland, considering uplands distribution. Sambor Prei Kuk on upland II with the port town adjacent the river is situated on the place where water transport is feasible and the risk of monsoonal flood is low, which means the people accommodated to the highly different dry and monsoonal environment.     

Protected areas in mainland Southeast Asia, 1973–2005: Continuing trends

Since the 1970s, protected area networks in mainland Southeast Asian countries have developed significantly to occupy 4–25 per cent of their respective national areas, located mostly in the mountainous domains of ethnic minority peoples. Through this process, regions that were only nominally part of national geobodies until the 1950s have become more territorially integrated. The complexity of the characteristics and geographical impacts of this territorialisation have yet to be grasped. As a step in this direction, we briefly outline a multilevel systems approach that usefully contextualizes these issues together with a historical and cartographical assessment of the evolution of protected area networks for Burma, Thailand, Laos, Cambodia and Vietnam. Our main findings are intertwined. On the one hand, protected areas represent a new tool of state intervention in mountainous areas, clearly in keeping with past, notably colonial, actions. On the other hand, this evolution in state territorialisation and attendant power relations have disrupted, far more deeply than previous actions, the pre‐1970s sociogeographical organization in mountainous areas, where most of the region's residual forests remain.     

Maladaptation and development as usual? Investigating climate change mitigation and adaptation projects in Cambodia

ABSTRACT

Based on research into multiple types of climate change mitigation and adaptation (CCMA) projects and policies in Cambodia, this paper documents intersecting social and environmental conflicts that bear striking resemblance to well-documented issues in the history of development projects. Using data from three case studies, we highlight the ways that industrial development and CCMA initiatives are intertwined in both policy and project creation, and how this confluence is creating potentials for maladaptive outcomes. Each case study involves partnerships between international institutions and the national government, each deploys CCMA as either a primary or supporting legitimation, and each failed to adhere to institutional and/or internationally recognized standards of justice. In Cambodia, mismanaged projects are typically blamed on the kleptocratic and patrimonial governance system. We show how such blame obscures the collusion of international partners, who also sidestep their own safeguards, and ignores the potential for maladaptation at the project level and the adverse social and environmental impacts of the policies themselves.

Key policy insights

• Initiatives to mitigate or adapt to climate change look very much like the development projects that caused climate change: Extreme caution must be exercised to ensure policies and projects do not exacerbate the conditions driving climate change.

• Safeguards ‘on paper’ are insufficient to avoid negative impacts and strict accountability mechanisms must be put in place.

• Academic researchers can be part of that accountability mechanism through case study reports, policy briefs, technical facilitation to help ensure community needs are met and safeguards are executed as written.

• Impacts beyond the project scale must be assessed to avoid negative consequences for social and ecological systems at the landscape level.