Doors and fences: Controlling Indonesia's porous borders and policing asylum seekers

Although the partial outsourcing of state border control to non‐state actors is not a new phenomenon, Indonesia is an interesting case study. Border control in an archipelago consisting of more than 17 000 islands is particularly challenging for state authorities. In addition to contending with the exceptional geography, Indonesia's state authorities are also challenged by the political constellation with Australia in regard to irregular cross‐border movements of asylum seekers that has become a controversial issue in recent history. As an important transit country for asylum seekers and refugees en route to Australia, Indonesia's porous borders have rendered it possible to enter and exit the country relatively easily. Given Australia's political pressure and the financial incentives offered to Indonesia to act as a ‘final bulwark’ and control irregular migration flows more effectively, border control nowadays has gained more significance in Indonesia than in the past. Yet, financial constraints and, more importantly, a lack of political will to host asylum seekers in its own territories for the long term remain as obstacles. Fieldwork observations show that due to ongoing funding restrictions for state‐led border control, state‐society cooperation for border surveillance has increased. Civilians in many hotspots for irregular border crossings have been encouraged to report on ‘suspicious foreigners’. State‐society cooperation for border control, however, offers new opportunities for people smugglers to pay off civilian spies or corrupt border authorities.     

Rainfall and streamflow response to El Niño Southern Oscillation: a case study in a semiarid catchment,Australia

Abstract

This paper aims to compare the shift in frequency distribution and skill of seasonal climate forecasting of both streamflow and rainfall in eastern Australia based on the Southern Oscillation Index (SOI) Phase system. Recent advances in seasonal forecasting of climate variables have highlighted opportunities for improving decision making in natural resources management. Forecasting of rainfall probabilities for different regions in Australia is available, but the use of similar forecasts for water resource supply has not been developed. The use of streamflow forecasts may provide better information for decision-making in irrigation supply and flow management for improved ecological outcomes. To examine the relative efficacy of seasonal forecasting of streamflow and rainfall, the shift in probability distributions and the forecast skill were evaluated using the Wilcoxon rank-sum test and the linear error in probability space (LEPS) skill score, respectively, at three river gauging stations in the Border Rivers Catchment of the Murray-Darling Basin in eastern Australia. A comparison of rainfall and streamflow distributions confirms higher statistical significance in the shift of streamflow distribution than that in rainfall distribution. Moreover, streamflow distribution showed greater skill of forecasting with 0–3 month lead time, compared to rainfall distribution.     

Were Ediacaran siliciclastics of South Australia coastal or deep marine?

The Late Neoproterozoic Ediacara Member of the Rawnsley Quartzite in South Australia has been considered aeolian, fluvial, intertidal and deep marine by various authors. Palaeosols would not be expected for the deep marine interpretation, but some palaeosols should be evident for the aeolian–fluvial–intertidal interpretations, and this is the first study to examine the Ediacara Member at a petrographic and geochemical scale appropriate to recognize potential palaeosols. Recognition of palaeosols and floodplain facies in Neoproterozoic rocks is a challenge because such rocks are too ancient for diagnostic non‐marine fossils such as root traces. The varied thickness of Ediacara Member red siltstones and white sandstones is distinct from laterally persistent overlying and underlying grey shales and limestones with acritarchs, stromatolites and other marine fossils. The sandstones are trough cross‐bedded and fill palaeovalleys. The red siltstones have poorly sorted, highly angular, silt‐size grains characteristic of loess. Particular sandy and silty beds were sampled for detailed petrographic and geochemical studies, because they include desiccation cracks, sand crystals, ice cracks, carbonate nodules and soft‐sediment deformation like those of palaeosols. Chemical and grain‐size variations within these beds reveal surficial clay formation and oxidation from feldspar as in soils. Petrographic studies also revealed surficial disruption of these palaeosols by filamentous structures comparable with microbial ropes of biological soil crusts. This array of palaeosol features may be of use for recognizing palaeosols in other Neoproterozoic siliciclastic sequences.     

河西走廊带与澳大利亚的亲缘性 ——来自牛首山中寒武统碎屑锆石U-Pb年龄和Hf同位素的证据

在河西走廊带东端牛首山地区中寒武统的沉积岩中开展碎屑锆石原位LA-ICP-MS U-Pb定年和Hf同位素研究。结果表明,所采样品U-Pb年龄谱存在3个峰值：0.6~0.8Ga(峰值为669Ma)、1.0~1.3Ga(峰值为1173Ma)、1.6~1.8Ga(峰值为1710Ma),明显区别于河西走廊带寒武系之上地层中的碎屑锆石U-Pb年龄谱。碎屑锆石U-Pb年龄谱和Hf同位素特征表明, 典型的格林威尔期的物质和峰值为1710Ma的碎屑物质可能源于澳大利亚西南部,与现有的古生物学和古地磁学研究结果相吻合;中奥陶世随着北祁连洋的进一步扩张及其古地理位置的变化,碎屑物质的源区也随之变化,河西走廊带开始出现0.8~1.0Ga晋宁期的碎屑物质;晚奥陶世后由于祁连山的造山隆起、剥蚀、风化,河西走廊带记录了该地区0.4~0.5Ga的碎屑物质。     

澳大利亚铀矿的成矿区划、矿床类型及找矿前景

澳大利亚蕴藏了丰富的铀矿资源,目前铀矿储量位居世界第二。在大地构造上,澳大利亚可划分为中西部前寒武纪克拉通和东部显生宙造山带。在区域地质构造背景和成矿条件研究的基础上,总结了铀矿在北澳、南澳、西澳、中澳和东澳五大成矿区带中的分布情况,勾勒了北澳的派恩克里克、南澳的奥林匹克坝、西澳的伊利列等15个矿集区中的34个类型迥异的矿区的总体地质环境与矿床特征。根据成矿地质作用、成因类型、矿物特征等因素,结合该国铀矿床的具体情况,归纳出8种典型的矿床类型。选取代表性铀矿进行地质环境、矿床地质的分析与总结,认为澳大利亚铀矿的成矿地质条件优越,矿床类型丰富,资源潜力巨大,并指出这些类型可作为今后找铀的靶向类型。     

Four new species of the lanternfish genus Diaphus (Myctophidae) from the Indo‐Pacific

Four new species of the genus Diaphus are described. Three of these are in the subgeneric group with a suborbital luminous organ and are members of the D. fulgens species group with a raised AOa₁ photophore. D. impostor sp. nov. from the Indo‐West Pacific is most similar to D. aliciae, differing in lower gill raker count and smaller size. D. wisneri sp. nov. from north of Hawaii and south Pacific lacks a luminous scale at the PLO and has a lower gill raker count than similar species. D. kora sp. nov. from north‐east of New Zealand has a large luminous scale at the PLO, and a longer Vn and lower gill raker counts than similar species. D. kapalae sp. nov. from the south‐western Pacific is most similar to D. splendidus and D. antonbruuni, from which it differs by the presence of an Ant, higher gill raker counts, and position of the VLO photophore.     

New records and invasive potential of the poeciliid fish Phalloceros caudimaculatus

Many species from the family Poeciliidae have been transported around the world by the aquarium trade, often establishing populations in areas far outside their natural range. The one‐spot livebearer, Phalloceros caudimaculatus is one such poeciliid species. In March 2002, a nonindigenous population of P. caudimaculatus was discovered at Collaroy, in the Sydney metropolitan area, the first record of this species in eastern Australia. Following this discovery, electrofishing and light‐trap surveys were conducted at the site, and dip‐netting and visual surveys were conducted in surrounding water bodies. P. caudimaculatus was widespread and abundant at the Collaroy site, but no further populations were discovered. Another pest poeciliid species, Gambusia holbrooki, originally present at the site, was absent and, although the mechanism remains unclear, may have been displaced by P. caudimaculatus. Both P. caudimaculatus and G. holbrooki share the characteristics of successful invasive species, with extremely broad physical tolerances and high reproductive outputs. Given the well‐documented negative ecological effects of poeciliids, especially G. holbrooki, we recommend that a precautionary approach should be adopted for the management of P. caudimaculatus and its eradication from the site be attempted.     

Criteria for the recognition of acid-precipitated halite

Modern acid and neutral saline lakes in Western Australia are an excellent natural laboratory for testing how pH affects halite, and for developing criteria for distinguishing past acid saline waters from past neutral saline waters in the rock record. This study characterizes and compares physical, chemical and biological features in halite precipitated from acid (pH 1·7 to 4·2) and neutral (pH 6·8 to 7·3) saline lakes in southern Western Australia. Supplemental data include synthetic halite grown from acid and neutral saline solutions, as well as halite deposited in Permian acid lakes. Although physical processes of halite growth are not affected by pH, there are differences in the colour, accessory minerals, fluid inclusions and microfossils between acid and neutral halites. Acid lake halite commonly is yellow or orange in colour; neutral lake halites examined in this study are always snow white. Acid halites tend to contain abundant sulphate and iron oxide minerals, both as solid inclusions and as solids within fluid inclusions; neutral halites contain little, if any, sulphates and no iron oxides. Acid fluid inclusion freezing/melting behaviours include characteristics that differ from neutral fluid inclusion behaviours, such as lower eutectic temperatures, higher and wider temperature range of hydrohalite rims with a definable fuzzy border and more complex metastable phases. Acid halite contains 'hairy blobs', clusters of bacterial/archaeal/fungal remains and sulphate crystals, which are not found in halite from neutral lakes. This distinct assemblage of features characteristic of modern acid lake halites may serve as informal criteria for the recognition of past acid lake evaporites in the rock record.     

澳大利亚煤层气开发工艺技术

参考当前国内外在煤层气开发方面的相关研究成果,对澳大利亚现今主要的煤层气开发工艺技术,包括钻采工艺技术和煤层气开采技术进行了重点重点调研,以期能够给予我国煤层气产业发展起到启示作用。研究表明:澳大利亚目前最主要的钻井类型是中等半径钻井,普遍运用欠平衡钻井工艺,其煤层气开采技术因地制宜,采用有针对性的工艺方法。对于与我国煤层气地质条件相似的区域,其煤层气开发技术值得我们借鉴。     

东澳大利亚南悉尼盆地二叠系与地震沉积有关的软沉积变形构造

悉尼盆地位于澳大利亚东部,Lachlan褶皱带和New England褶皱带之间。悉尼盆地从晚石炭世末到中三叠世经历了弧后扩张到前陆盆地的不同阶段:弧后扩张阶段(石炭纪)、被动热沉降阶段(早、中二叠世Berry组)和挤压挠曲负载阶段(中二叠世Broughton组—三叠纪)。此时位于悉尼盆地东侧的New England褶皱带为岛弧背景。因此,二叠纪处于弧后盆地的南悉尼盆地受弧后扩张和东侧弧前海沟俯冲的影响地震活动强烈,发育一系列与地震有关的震积岩,形成多种类型的与地震活动有关的软沉积物变形构造。南悉尼盆地二叠系的软沉积物变形包括地裂缝、震褶层、液化脉、沙火山、负荷构造、火焰构造、枕状构造、球状构造、枕状层、滑塌构造、角砾岩化等。其中地裂缝、震褶层是地震颤动直接引起的断裂和褶皱;枕状层是地震颤动引起的砂层脱水、下沉形成的;液化脉、沙火山为液化的砂层穿入地震形成的裂隙形成的;负荷构造、火焰构造、枕状构造、球状构造是受地震颤动在砂、泥岩界面上由于砂层下沉、泥层上穿形成的;滑塌构造和角砾岩化是地震引起的重力滑塌或泥石流形成的。地裂缝、震褶层、液化脉、沙火山、负荷构造、火焰构造、枕状构造、球状构造、枕状层相当于原地震积岩,而滑塌构造和角砾岩化属于异地震积岩。