西菲律宾海晚第四纪沉积地球化学特征

对１９８８对取自西菲律宾海区的３个沉积物柱样进行系统的地球化学研究。结果表明，本区的沉积物属半远洋沉积物，其地球化学特征受控于陆源沉积作用、海洋生物沉积作用和海底火山常积作用。据主要化学元素和ＣａＣＯ５的柱状变化进行地层划分和古气候的恢复，区分出末次冰期的亚间冰期沉积、冰期最盛期沉积和全新世沉积。本区的ＣａＣＯ３变化表现出两种类型，ＷＰ１柱样属大西洋型溶解旋回；ＷＰ２和ＷＰ４０柱样属太平洋型溶解旋     

Resource use conflicts in Mabini and Tingloy,the Philippines

This paper presents the results of an analysis of resource use conflicts in areas near marine protected areas in Mabini–Tingloy, the Philippines. The author found large differences between groups of stakeholders in terms of perceived benefits and costs of conservation and tourism, and these inequalities have led to conflicts between various stakeholder groups. Marked by unequal power relationships, the conflicts place subsistence fishers as the weakest stakeholders. Fishers also have the lowest rates of knowledge of and participation in conservation activities. The study concludes that in order for conservation programs to be effectively transitioned onto the social and legal fabric of Mabini–Tingloy, resource use conflicts need immediate attention.     

Human mobility intentions in response to heat in urban South East Asia

Climate change and associated weather extremes and natural hazards have large impacts on the urban population of the Global South where population growth will rapidly increase the already large number of people who will be affected. Using Protection Motivation Theory (PMT), we investigate how hot temperatures, manifested as heat stress, is affecting the intentions of moving among the urban population in three Asian countries (Indonesia, Malaysia, Philippines). We conducted an online survey with 2219 respondents. Almost all respondents (98%) had experienced heat stress, albeit at different levels. When asked whether respondents would be likely to move away from their current locations because of heat, nearly a quarter (23%) reported that they were very likely to do so, and 50% that they probably would. Stronger moving intentions because of heat were associated with women and older people. Concerns about increases from damage from heat (threat appraisal) were more strongly associated with moving intentions than an understanding of the costs and benefits (coping appraisal). Among the threat appraisal, heat stress levels and risk perception were the strongest predictors of moving intentions because of heat. The results contrast with the findings of migration studies in response to sudden onset hazards and underpin the differences in adaptation behaviour in response to different climate change impacts. Moving away to cooler places as an adaptation strategy to heat may be challenging to foresee in terms of timing, capabilities, destination and potential costs because it may not happen soon. We strongly recommend further research on climate change migration of the urban population, including within urban and urban-to-urban movements. While many people move back after sudden onset disasters, heat potentially leads to permanent movements given it is likely to be better planned, and as the habitability of some places is increasingly compromised. Overall the effects of slow onset environmental hazards such as pollution and heat on migration warrant more research attention given the rapidity of urban population growth, particularly in the global south.     

Benthic status of near-shore fishing grounds in the central Philippines and associated seahorse densities

Benthic status of 28 near-shore, artisanal, coral reef fishing grounds in the central Philippines was assessed (2000-2002) together with surveys of the seahorse, Hippocampus comes. Our measures of benthic quality and seahorse densities reveal some of the most degraded coral reefs in the world. Abiotic structure dominated the fishing grounds: 69% of the benthos comprised rubble (32%), sand/silt (28%) and dead coral (9%). Predominant biotic structure included live coral (12%) and Sargassum (11%). Rubble cover increased with increasing distance from municipal enforcement centers and coincided with substantial blast fishing in this region of the Philippines. Over 2 years, we measured a significant decrease in benthic 'heterogeneity' and a 16% increase in rubble cover. Poor benthic quality was concomitant with extremely low seahorse densities (524 fish per km(2)). Spatial management, such as marine reserves, may help to minimize habitat damage and to rebuild depleted populations of seahorses and other reef fauna.     

与印度洋偶极子模态有关的西太平洋海温异常型及其对东亚冬季气候的影响

利用NOAA（National Oceanic and Atmospheric Administration）海温、GPCP（Global Precipitation Climatology Project）降水和ERA-20C（ECMWF's first atmospheric reanalysis of the 20th century）再分析大气环流资料,结合大气环流模式ECHAM5敏感性试验,研究了与秋季印度洋海温偶极子模态（IOD）相联系的冬季热带西太平洋海温异常型及其对东亚冬季气候的影响。发现在秋季发生IOD背景下,冬季西太平洋存在两类海温异常的变化型:一类是西太平洋区域一致偏暖/冷的模态,另一类是区域西冷东暖/西暖东冷的模态。尽管西太平洋海温一致偏暖和西冷东暖这两类海温变化型均有利于华南冬季少降水,但影响的范围有所不同。一致偏暖型引起的少降水范围较大,从华南扩展到长江中下游地区。西冷东暖型引起少降水范围主要限于华南,而在长江中下游到华北则降水偏多。相应地,在大气环流上,尽管两类海温异常型均有利于在西北太平洋菲律宾海附近出现气旋式环流异常,但气旋的强度和中心位置有差异。一致偏暖型引起的气旋偏强,中心位置偏西,其后部异常东北风控制的范围更大,导致少降水范围更大,而西冷东暖型引起的气旋偏弱,中心位置偏东,其后部异常东北风控制的范围小,导致少降水区域主要在华南沿海。本文结果对认识IOD调制随后冬季东亚降水异常的机理有重要意义。     

1950—2009年夏季菲律宾低空越赤道气流的变化特征

利用1950—2009年NECP/NCAR的月平均经向风再分析资料,根据夏季(6—8月)菲律宾低空越赤道气流的特征,定义了该支气流的强度指数IS和位置偏移指数IL,并根据这两个指数分析了菲律宾越赤道气流的时间变化特征及对应的环流特征,以及其与亚洲夏季降水的关系。结果表明,IS主要呈现弱、强、弱、强的年代际变化特征,IL主要呈现振荡、稳定、径直转向的年代际变化特征。IS与由低层澳大利亚高压北侧冷空气活跃和西太平洋副热带高压减弱所造成的经向气压梯度的变化有关,IL与澳大利亚地区和赤道低槽区高、低层的南北气压梯度有关。IS与印度尼西亚、孟加拉湾南部、热带西太平洋和澳大利亚东部的降水关系密切,IL与孟加拉湾和中国南海南部的降水关系密切。此外,IL与澳大利亚上空的垂直运动具有密切联系。     

土壤地球化学测量在菲律宾红土型镍矿勘查中的应用

通过在菲律宾迪纳加特岛红土型镍矿勘查区开展土壤地球化学测量工作,发现了一批有价值的地球化学异常。根据红土型镍矿的成矿地质条件与特征,评价了异常区的找矿潜力,圈定了红土型镍矿的找矿靶区,并在靶区的工程查证中取得了较好的找矿效果。工作效果证明,土壤地球化学测量方法对于红土型镍矿的找矿具有高效、快速和低成本的优势。     

Improved Wildcat Modelling of Mineral Prospectivity

Wildcat modelling of mineral prospectivity has been proposed for greenfields geologically-permissive terranes where mineral targets have not yet been discovered but a geological map is available as a source of spatial data of predictors of mineral prospectivity. This paper (i) revisits the initial way of assigning wildcat scores (S_c) to predictors of mineral prospectivity and (ii) proposes an improvement by transforming S_c into improved wildcat scores (IS_c) by using a logistic function. This was shown in wildcat modelling of prospectivity for low-sulphidation epithermal-Au (LSEG) deposits in Aroroy district (Philippines). Based on knowledge of characteristics of and controls on LSEG mineralization in the Philippines, the spatial predictors of LSEG prospectivity used in the study are proximity to porphyry plutonic stocks, faults/fractures and fault/fracture intersections. The S_c and IS_c of spatial predictors are input separately to principal components analysis to extract a favourability function that can be interpreted as a wildcat model of LSEG prospectivity. The predictive capacity of the wildcat model of LSEG prospectivity based on the IS_c of geological predictors is roughly 70% higher than that of the wildcat model of LSEG prospectivity based on the S_c of geological predictors. A slight increase of predictive capacity of wildcat modelling of LSEG prospectivity is also achieved when the IS_c of geological predictors are integrated with the IS_c of geochemical anomalies, but not with the S_c of geochemical anomalies. The proposed improvement is significant because if the study district were a greenfields exploration area, then a wildcat model of LSEG prospectivity based on the old wildcat methodology would have caused several LSEG targets to be missed.     

Generation and Evolution of Ore Fluids for Porphyry Cu-Au Mineralization of the Santo Tomas II (Philex) Deposit, Philippines

Abstract: The Santo Tomas II (Philex) deposit is a porphyry Cu‐Au deposit, located in the southern part of the Baguio mineral district, Benguet Province, northern Luzon, Philippines. The Santo Tomas II deposit is associated with an intrusive complex consisting of four rock types that are distinguished based on petrography. They are 1) post‐ore clinopyroxene‐bearing hornblende andesite porphyry, 2) ore‐generating hornblende andesite porphyry, 3) hornblende quartz diorite porphyry and 4) porphyritic hornblende quartz diorite. K‐Ar age of hydrothermal biotitization was estimated to be 1.5±0.4 Ma. A number of intrusive bodies having broadly similar petrography and K‐Ar age occur in the vicinity of the Santo Tomas II deposit, such as at Clifton, Ligay (Binang), Bumolo (Waterhole) and Philex Main Camp areas. The intrusions at the Santo Tomas II deposit and in the vicinity are characterized by high X_Mg (Mg/[Mg+Fe] atomic ratio, about 0.7 or higher) of mafic silicate phenocrysts such as hornblende, and high sulfur contents (> 0.2 wt% as SO₃) in accessory microphenocrystic apatite, suggesting a highly oxidizing condition. Sulfur is accommodated dominantly as oxidized species since the crystallization of phe‐nocrysts. Sub‐dendritic rim of tremolitic amphibole on hornblende phenocryst in the ore‐generating andesite porphyry at the Santo Tomas II deposit suggests interaction of magma and aqueous fluid(s) exsolved due to decompression during intrusion. Dissemination of magnetite is associated with hydrothermal biotitization and is followed by sheeted and stockwork quartz veinlets having silician magnetite and rare titanohematite instead of Cu‐Fe sulfides. The silician magnetite‐rich quartz veinlet was formed at f_O2 near the hematite‐magnetite buffer at nearly magmatic temperature, where sulfur dominantly existed as oxidized species such as SO₂. Chalcopyrite and bornite, which commonly exhibit micrographic texture often accompanying Pd telluride and native gold/Au‐rich electrum, are associated with subsequent anhydrite (‐quartz) veinlets and stringers. Both intermediate solid solution (iss) and bornite solid solution (bnss) are thought to have coprecipitated primarily at above 500°C based on fluid inclusion microthermometry and sulfur isotope thermometry applied for anhydrite and associated chal‐copyrite and bornite. The initial iss is considered to have converted to chalcopyrite partly replacing bnss during cooling. The hypersaline polyphase fluid inclusions abundantly found in the sheeted and stockwork quartz as well as anhydrite veinlets with scarce gaseous inclusions suggest that they have been trapped in the two aqueous fluid immiscible region. The western Luzon arc associated with porphyry Cu mineralization is characterized by oxidized hydrous magmatism and shallow emplacement, and by the source of sulfur enriched in ³⁴S.     

菲律宾大马尼拉地区海水入侵研究分析

本文阐述了菲律宾大马尼拉地区的地貌、气候、水文、地质等背景情况；介绍区内的地下水质水介质类型及含水层发育情况、富水性和导水性、地下水水力性质、水化学特征和补排条件以及地下水的开采情况和需求量，从而分析了大马尼拉地区海水的机理。