Genesis of the Ciemas Gold Deposit and Relationship with Epithermal Deposits in West Java,Indonesia:Constraints from Fluid Inclusions and Stable Isotopes

The Ciemas gold deposit is located in West Java of Indonesia, which is a Cenozoic magmatism belt resulting from the Indo-Australian plate subducting under the Eurasian plate. Two different volcanic rock belts and associated epithermal deposits are distributed in West Java： the younger late Miocene-Pliocene magmatic belt generated the Pliocene-Pleistocene epithermal deposits, while the older late Eocene-early Miocene magmatic belt generated the Miocene epithermal deposits. To constrain the physico-chemical conditions and the origin of the ore fluid in Ciemas, a detailed study of ore petrography, fluid inclusions, laser Raman spectroscopy, oxygen-hydrogen isotopes for quartz was conducted. The results show that hydrothermal pyrite and quartz are widespread, hydrothermal alteration is well developed, and that leaching structures such as vuggy rocks and extension structures such as comb quartz are common. Fluid inclusions in quartz are mainly liquid-rich two phase inclusions, with fluid compositions in the NaCI-H2O fluid system, and contain no or little CO2. Their homogenization temperatures cluster around 240℃-320℃, the salinities lie in the range of 14-17 wt.% NaCI equiv, and the calculated fluid densities are 0.65-1.00 g/cm^3. The values of δ18OH2O-VSMOW for quartz range from ＋5.5%0 to ＋7.7‰, the δDVSMOW of fluid inclusions in quartz ranges from -70‰ to -115‰. All of these data indicate that mixing of magmatic fluid with meteoric water resulted in the formation of the Ciemas deposit. A comparison among gold deposits of West Java suggests that Miocene epithermal ore deposits in the southernmost part of West Java were more affected by magmatic fluids and exhibit a higher degree of sulfidation than those of Pliocene-Pleistocene.

Double-difference tomography of P- and S-wave velocity structure beneath the western part of Java, Indonesia

West Java in the western part of the Sunda Arc has a relatively high seismicity due to subduction activity and faults.In this study,double-difference tomography was used to obtain the 3D velocity tomograms of P and S waves beneath the western part of Java.To infer the geometry of the structure beneath the study area,precise earthquake hypo・center determination was first performed before tomographic imaging.For this,earthquake waveform data were extracted from the regional Meteorological,Climatological,Geophysical Agency(BMKG)network of Indonesia from South Sumatra to Central Java.The P and S arrival times for about 1,000 events in the period April 2009 to July 2016 were selected,the key features being events of magnitude>3,azimuthal gap<210°and number of phases>8.A nonlinear method using the oct-tree sampling algorithm from the NonLinLoc program was employed to determine the earthquake hypocenters.The hypocenter locations were then relocated using double-difference tomography(tomoDD).A significant reduction of travel-time(root mean square basis)and a better clustering of earthquakes were achieved which correlated well with the geological structure in West Java.Double-difference tomography was found to give a clear velocity structure,especially beneath the volcanic arc area,i.e.,under Mt Anak Krakatau,Mt Salak and the mountains complex in the southern part of West Java.Low velocity anomalies for the P and S waves as well as the vp/vs ratio below the volcanoes indicated possible partial melting of the upper mantle which ascended from the subducted slab beneath the volcanic arc.

Survey on gastrointestinal parasites and detection of Cryptosporidium spp. on cattle in West Java,Indonesia

Objective:To evaluate the presence of gastrointestinal parasites on cattle in Indonesia because the prevalence of parasites varies between counlries depending on the terrain surrounding livestock farms and investigations in Indonesia have never been performed.Methods:Fecal samples from cattle at 35 farms in 7 districts in West Java,Indonesia,has been examined using the floatation or sedimentation methods,and a immunofluorescence assay and experimentally inoculation to mice for Cryptosporidium or Giardia spp.Results:153 of 394 examined cattle(38.8%)were infected with gastrointestinal parasites.The prevalence of Eimeria spp.,Nematoda spp.(including Oesophagustomum and Bunostomum-like),Fasciola gigantica and Paramphistomum spp.was 22.4%,11.2%,12.5%and 3.8%,respectively.Cryptosporidium andersoni(C.andersoni)was also found in two samples.One isolate of this parasite was confirmed to be transmitted to mice,in contrast to the isolates from other countries.Conclusions:although this survey is preliminary,the results shows that the infection of gastrointestinal parasites in Indonesia was not high,but these infected cattle could be as a potential source leading to economic losses in livestock production.

Vulnerability assessment: A comparison of three different city sizes in the coastal area of Central Java, Indonesia

Considering the importance of connecting urbanization phenomena and vulnerability assessments, this paper aims to explore vulnerability assessment in three different city sizes in the northern coast of Central Java province of Indonesia. It compares the vulnerability levels of the three cities based on their sizes (that is, levels of urbanization). It uses the most current secondary data from the lowest administrative levels,called as kelurahan (urban village), for its assessment. There are two indexes used to indicate their vulnerability levels, namely exposure and sensitivity index (ESI) and adaptive capacity index (ACI). By combining the ESI and ACI, the study found that the kelurahans in Tegal (the medium sized city) have similar vulnerability levels. The kelurahans in Semarang (as the big city) have more combination of vulnerability levelsdindicating that the city has various sensitivity, exposure, as well as adaptive capacity among its kelurahans. In Lasem (the small sized city), due to limitations imposed by adaptationdmostly because of lack of public services and high dependency on primary economic sectorsdall of its kelurahans were found to be vulnerable. The study therefore concluded that the bigger a city is, the more the different areas of that city will have varying levels of vulnerability, leading to a high propensity of vulnerability among its inhabitants. On the other hand, the smaller a city is, the less capacity it will have in reducing its emerging vulnerability challenges.

Earthquake vulnerability disaster in the Lembang district of West Bandung Regency, Indonesia

This research is concerned with an analysis of the level of vulnerability for an earthquake disaster in Lembang district,an area in West Java that includes the Bandung basin and has a high potential for earthquake disaster.The Lembang district is close to the active Lembang fault whose movement can cause earthquakes of magnitude 7 on the Richter scale(Tempo Interaktif,May 11,2010).The research method used to assess the level of vulnerability is essentially a descriptive approach.The data analysis is based on calculating an earthquake disaster risk index(EDRI),which is in turn based on assessment of the region's social,physical and economic vulnerabilities.The vulnerability level for earthquake disaster in the Lembang is ranked as medium category.The social vulnerability of the population is the major contributing factor given the high population density and growth rate for the region.The physical characteristics of the district,which includes mild temperatures and attractive scenery,make many people want to stay in and visit Lembang.The construction quality of buildings is so bad that they are not designed to withstand earthquakes,so improvement of building infrastructure is an alternative to reducing the various physical vulnerabilities.

KARANGBOLONG KARSTIC LIMESTONE AND ITS ENVIRONMENTAL DEVELOPMENT (JAVA, INDONESIA)

The distribution of limestone in Java are dominantly located in the south coast and most of them had been suffered by karstie processes. The one that its environment has been studied is the Karangbolong karstic limestone in Kebumen, Central Java. The other karstic limestones were found in Merakurak (?), East Java, with different topography and morphology, All that

Relationship of Biometrical Aspect of Turritellidae with Geochronological Aspect in West Java

Mollusk paleontology research in Indonesia so far has not been widely utilized in various kinds of applications, especially in the geology. Although mollusk in Java is very rich, the study of correlation between mollusk appearances with geological condition is rare. This study aimed to determine Turritellidae base on morphological observations (qualitative) and quantitative (biometric method). The ultimate goal is to find out the relationship between of biometrical aspect of Turritellidae with geological development especially of chronological conditions. Stratigraphic analysis and sampling have done at five location of field survey. Site selection was based on the type locality of mollusk biostratigraphic unit arrange by Martin (1919) [1] and Oostingh (1938) [2]. The scattered analysis shows two large distribution of consistent groups based on shell size and geochronological aspect. Biometrical aspect of Turritellidae is reflection of the chronological aspect in West Java. Small size was appearance in Upper Miocene to Lower Pliocene and large shell in Pliocene to Pleistocene.

Influence of the Indonesian Throughflow on the upwelling off the east coast of South Java

A wave–tide–circulation coupled model is used to simulate upwelling off the south coast of Java, Indonesia. The results show that the vertical velocity off East Java is stronger than other parts in this area. The strongest vertical velocity is located approximately at 80 m depth.The annual averaged values of upwelling are 2.3 9 10-6and 1.06 9 10-5m/s for south of West Java and south of East Java, respectively. The vertical velocity from the model shows that upwelling off West Java has seasonal variability, while it is quite steady and strong off East Java.Additional numerical experiments show that the wind is not the dominant factor for the steady upwelling off the southern part of East Java. It is then hypothesized that the Indonesian Throughflow(ITF) may be responsible for the upwelling. To test this hypothesis, two scenarios are implemented, both of which block the outflow of the ITF.Sensitive study shows that the ITF plays a key role in the formation of East Java upwelling. The effect of the ITF can account for about 55 %–65 % of the upwelling.

Redox conditions in sediments and during sedimentation in the Ontong Java Plateau,west equatorial Pacific

Redox-sensitive elements in sediments, such as manganese （Mn）, vanadium （V）, molybdenum （Mo）, and uranium （U）, are promising indicators of past redox conditions during sedimentation and early diagenesis. However, in the Ontong Java Plateau, west equatorial Pacific, there are sparse datasets of redox-sensitive elements in sediment cores. Here, we present a 250 ka record of redox sensitive elements from a 460 cm gravity core at site WP7 （3~56＇S, 156^.E, water depth 1 800 m）, which was recovered from the southwest Ontong Java Plateau during the 1993 cruise of R/V Science I of the Institute of Oceanology, Chinese Academy of Sciences （IOCAS）. Relative to the Post-Archean Australian Shale （PAAS）, authigenic Mn, cobalt （Co）, nickel （Ni）, Mo, V, U, and cadmium （Cd） were found at constantly low levels except when peaks occurred at several depth intervals. Manganese, Co, Ni, and Mo concentrations were elevated at 25-35 cm due to Mn redox cycling. The core was divided into three distinct sections, the top 0-25 cm being oxic, a suboxic section at 25-35 cm and from 35-460 cm which was anoxic. Differential authigenic enrichments of Co, Ni, Mo, V, U, and Cd at the same depth intervals were observed indicating that the enrichments happened during sedimentation or diagenesis and suffered no post settlement redox changes. Therefore, no significant changes in redox conditions during sedimentation must have happened. The water at depth on the Ontong Java Plateau during past 250 ka must have been well oxygenated, possibly resulted from the more or less continuous presence of oxygen-rich deep water like the modem Antarctic Intermediate Water （AAIW） and Antarctic Circumpolar Water （ACW）; while it＇s slightly less oxygenated in glacial intervals, possibly due to ventilation weakening and/or the surface productivity increase.

Landslide Hazard and Community-based Risk Reduction Effort in Karanganyar and the Surrounding Area,Central Java,Indonesia

Karanganyar and the surrounding area are situated in a dynamic volcanic arc region, where landslide frequently occurs during the rainy season. The rain-induced landslide disasters have been resulting in 65 fatalities and a substantial socioeconomical loss in last December 2007. Again, in early February 2009, 6 more people died, hundreds of people temporary evacuated and tens of houses damaged due to the rain-induced landslide. Accordingly, inter-disciplinary approach for geological, geotechnical and social investigations were undertaken with the goal for improving community resilience in the landslide vulnerable villages. Landslide hazard mapping and communitybased landslide mitigation were conducted to reduce the risk of landslides. The hazard mapping was carried out based on the susceptibility assessment with respect to the conditions of slope inclination, types and engineering properties of lithology/soil as well as the types of landuse. All of those parameters were analyzed by applying weighing and scoring system which were calculated by semi qualitative approach (Analytical Hierarchical Process). It was found that the weathered andesitic-steep slope (steeper than 30o) was identified as the highest susceptible slope for rapid landslide, whilst the gentle colluvial slope with inter-stratification of tuffaceous clay-silt was found to be the susceptible slope for creeping. Finally, a programme for landslide risk reduction and control were developed with special emphasize on community-based landslide mitigation and early warning system. It should be highlighted that the social approach needs to be properly addressed in order to guarantee the effectiveness of landslide risk reduction.

印度尼西亚爪哇岛去印度化的历史进程

公元初,印度已经形成了较有影响力的城市国家,并且影响着印度次大陆以外的国际关系,以印度教为代表的印度文化开始传入爪哇岛,爪哇岛开启了“印度化”的过程。16世纪,西方殖民者的入侵和淡目王国的建立,改变了以爪哇岛为中心的地区国际关系,伊斯兰教在爪哇岛的传播速度加快,并逐渐取代过去占主导地位的印度教和佛教,爪哇岛正式开始了“去印度化”的过程。爪哇岛“去印度化”过程也是东南亚国际关系转变的过程,在宗教文化上表现为两方面:一方面在于岛内印度教不断衰落;另一方面在于伊斯兰教通过海上贸易、武力征服、苏菲派传教等各种方式得到广泛传播。而且,在抵制西方殖民者入侵的过程中,当地权贵强化和推广了爪哇岛的伊斯兰教,也加快了爪哇岛的“去印度化”进程。“印度化”和“去印度化”深入爪哇岛的宗教信仰、价值习俗以及政权更替中,二者融合形成兼收并蓄的爪哇特色文化。“印度化”与“去印度化”贯穿了爪哇岛整个历史发展进程,从宗教文化方面反映了古代东南亚地区国际关系发展的基本历史进程。

分离主义运动中的国际干预——以印尼西巴布亚分离主义运动为例

在分离主义冲突中母国与分离主义势力力量悬殊的情况下,作为区别于母国和分离族群的外部国家行为体,第三方国家的干预对分离主义运动的走向具有至关重要的作用。过去,学者们往往围绕单一驱动因素对第三方国家的干预进行解释,组态视角与多变量、复杂因果的思维方式尚未得到足够的关注。本文基于印尼西巴布亚的案例,以情感性驱动力和工具性驱动力为理论框架对第三方国家干预的动因进行质性比较分析(QCA),以把握多重驱动因素共存时相互之间的复杂互动关系。本文指出,情感性和工具性驱动力共同作用于第三方国家的立场选择。族群纽带是第三方国家支持西巴布亚分离主义的必要非充分条件和最重要的情感性驱动因素,但是工具性驱动力对于国家立场选择的影响具有优先性。无论是否受到情感性驱动力的影响,第三方国家由于受到维护地缘安全稳定、保护自身免受分离主义威胁等现实需求的驱动而倾向于支持印尼政府,而人权以及经贸因素并不是国家立场选择的重要考量。

内卷化与后殖民——以爪哇稻作农业为核心的讨论

20世纪50年代,根据印度尼西亚的实地考察,格尔茨提出的“内卷化”主要指稻作农业的劳动边际报酬极度下降时,仍旧过多地投入劳动力。印尼内岛和外岛的生态系统、经济状况以及政治统治存在巨大张力、紧密的依存关系和二元发展。内卷化有着复杂的生成机制,从格尔茨的文化生态学观点、水利社会研究、殖民与现代世界体系等视角有助于综合理解“内卷化”的内涵以及概念形成的社会历史过程。结合李伯重江南人口史和农业生产的研究,指明束缚于“人口压力”说的黄宗智对于“内卷化”的误用和对城市系统与乡村系统依存关系的忽视。韦伯对于城乡依存关系的讨论为格尔茨的讨论奠定了比较研究的基础和走向。

印尼爪哇岛印度教神庙研究

印度教在东南亚的古代史中扮演了非常重要的角色,国内学术界对这个问题的研究主要集中在宏观层面,对微观的文化现象的研究一直不够深入。在实地考察的基础上,本文以爪哇岛的印度教神庙作为研究对象,通过对比中爪哇的普兰班南神庙和东爪哇的加维神庙在建筑风格上的异同点,阐述爪哇岛印度教神庙的建筑特点。

印度尼西亚西岸温盐锋时空变化特征

通过WOA13多年季节气候态数据分析了印度尼西亚5°S锋面与15°S锋面的季节变化特征及水平方向垂直方向上变化特点:两处海洋锋均在表层以下,其中5°S附近仅有温度锋,主要存在于1—6月份,1—3月份为锋强度最大时期,集中在30—100 m水层内。15°S处既存在温度锋又存在盐度锋,全年均有锋现象,但其强度存在季节差异。对比声速剖面,发现声速在从南到北穿越5°S(15°S)锋面时逐渐声速减小(增大)。

肯尼迪政府与印(尼)荷西伊里安领土争端的和平解决(1961-1962)

西伊里安争端,是荷兰与印尼因西伊里安地区的主权移交问题而引发的一场长达10余年的领土争端,争端在1960年代初发展为危机事态,双方一度将形势推到战争的边缘。美国作为印(尼)荷之间的主要平衡力量,长期以来奉行亲荷的消极中立政策。肯尼迪政府上台后,经过曲折的转变,最终改变了美国以往在该问题上的消极政策,通过积极的外交斡旋和联合国的干预,使这场区域领土危机得以和平解决。探讨肯尼迪政府对西伊里安问题的决策转变过程对研究冷战与反殖民主义的关系,以及分析美国处理他国领土问题的外交政策具有重要意义。

印度尼西亚西爪哇低品位金矿柱浸试验

在较佳入浸粒度(-20mm)及适宜的喷淋制度条件下,经5天浸出周期柱浸后,可获得金浸出率91.31%、NaCN耗量142.3g/t的技术经济指标,表明该金矿适合用本堆浸工艺提金。

亶洲再探

据《三国志》载 ,秦代徐福渡海所到达的地方 ,名叫“洲”。从孙权寻求洲的时间和动机、洲的方位和距离、地名对音和含义、中国与印尼的交往、生活方式与风俗习惯等五个方面的情况来分析 。

浅析美国在印度尼西亚收回西伊里安问题上的角色转变

收复西伊里安是战后印度尼西亚(下称印尼)外交斗争中最为重要的内容。从沉默的平衡者到积极的斡旋者,美国政府对于印尼收回西伊里安的态度转变源于两任政府对印尼的不同认识。西伊里安问题的和平解决对美国与印尼关系的改善具有重要意义,它扫除了美印关系中一个最主要的障碍。从某种程度来说,肯尼迪政府因此修复了艾森豪威尔政府与苏加诺政府之间因外岛危机而产生的裂痕。

物探航空磁法在印尼爪哇省斯乌兰海滨钒钛磁铁砂矿勘查中的应用

印度尼西亚爪哇省斯乌兰海滨钒钛磁铁矿,为基性岩浆岩经过风化剥蚀及海浪的冲刷淘洗所形成的次生富集砂矿,矿体具有磁性。为了节约勘探成本,利用轻便航磁方法对印尼爪哇省斯乌兰海滨钒钛磁铁矿区进行测量,发现磁异常、圈定异常范围,共圈定5个钒钛磁铁砂矿体,分布面积约182.6 km^(2)。通过磁异常正反演计算,结合矿区成矿地质条件并依据钒钛磁铁砂矿磁化率与TFe百分含量之间的相关关系,估算钒钛磁铁砂矿总资源量51.28亿吨。该项勘查工作说明,利用轻便航磁方法可快速发现、圈定钒钛磁铁砂矿体,为进一步的勘查和利用提供依据。