New age constraints on metamorphism,metasomatism and gold mineralisation at Plutonic Gold Mine,Marymia Inlier,Western Australia

The Plutonic Well Greenstone Belt (PWGB) is located in the Marymia Inlier between the Yilgarn and Pilbara cratons in Western Australia, and hosts a series of major Au deposits. The main episode of Au mineralisation in the PWGB was previously interpreted to have either accompanied, or shortly followed, peak metamorphism in the late Archean at ca 2650 Ma with a later, minor, event associated with the Capricorn Orogeny. Here we present new Pb isotope model ages for sulfides and Rb–Sr ages for mica, as well as a new ²⁰⁷Pb–²⁰⁶Pb age for titanite for samples from the Plutonic Gold Mine (Plutonic) at the southern end of the PWGB. The majority of the sulfides record Proterozoic Pb isotope model ages (2300–2100 Ma), constraining a significant Au mineralising event at Plutonic that occurred >300 Myr later than previously thought. A Rb–Sr age of 2296 ± 99 Ma from muscovite in an Au-bearing sample records resetting or closure of the Rb–Sr system in muscovite at about the same time. A younger Rb–Sr age of 1779 ± 46 Ma from biotite from the same sample may record further cooling, or resetting during a late-stage episode of metasomatism in the PWGB. This could have been associated with the 1820–1770 Ma Capricorn Orogeny, or a late-stage hydrothermal event potentially constrained by a new ²⁰⁷Pb–²⁰⁶Pb age of 1725 ± 26 Ma for titanite in a chlorite–carbonate vein. This titanite age correlates with a pre-existing age for a metasomatic event dated at 1719 ± 14 Ma by U–Pb ages of zircon overgrowths in a sample from the Marymia Deposit. Based on the Pb-isotope data presented here, Au mineralising events in the PWGB are inferred to have occurred at ca 2630, 2300–2100 Ma, during the Glenburgh and Capricorn orogenies, and 1730–1660 Ma. The 2300–2100 Ma event, which appears to have been significant based on the amount of sulfide of this age, correlates with the inferred age for rifting of the Marymia Inlier from the northern margin of the Yilgarn Craton. The texturally-later visible Au may have been deposited during the Glenburgh and Capricorn orogenies.     

Vegetational gradients around artificial watering points in the Kalahari Gemsbok National Park

Distance from artificial watering points was not significantly related to plant species composition in six habitats studied in the Kalahari Gemsbok National Park. Soil moisture had a significant effect on plant species composition of the riverbed habitat. Grazing intensity contributed significantly to trends in the vegetation composition of the river terrace and shrub savanna habitats, but grazing intensity was not associated with distance from artificial watering points. However, the analyses failed to show any significant influence of grazing intensity and distance from watering points on the plant species composition of the pan, savanna dune street and dune crest habitats. Therefore, although changes in plant species composition occurred in the six different habitats in the Kalahari Gemsbok National Park, they were not related to the presence of artificial watering points.     

Ability of a dual polarized X-band radar to estimate rainfall

The aim of this study is to assess rainfall estimates by a dual polarized X-band radar. This study was part of the European project FRAMEA (Flood forecasting using Radar in Alpine and Mediterranean Areas). Two radars were set up near the small town of Collobrières in South Eastern France. The first radar was a dual polarized X-band radar (Hydrix^®) associated with a ZPHI^® algorithm while the second one was an S-band radar (Météo France). We compared radar rainfall data with measurements obtained by two rain gauge networks (Météo France and Cemagref). During the experiments from February 2006 to June 2007, four significant rainfall events occurred. The accuracy of the rain rate obtained with both S-band and X-band radars decreased significantly beyond 60 km, in particular for the X-band radar. At closer ranges, such as 30–60 km from the radars, the X-band and the S-band radar retrievals showed similar performance with Nash criteria around 0.80 for the X-band radar and 0.75 for the S-band radar. Furthermore, the X-band radar did not require calibration on rainfall records, which tends to make it a useful method to assess rainfall in areas without a rain gauge network.     

The contribution of the ARIEL space mission to the study of planetary formation

The study of extrasolar planets and of the Solar System provides complementary pieces of the mosaic represented by the process of planetary formation. Exoplanets are essential to fully grasp the huge diversity of outcomes that planetary formation and the subsequent evolution of the planetary systems can produce. The orbital and basic physical data we currently possess for the bulk of the exoplanetary population, however, do not provide enough information to break the intrinsic degeneracy of their histories, as different evolutionary tracks can result in the same final configurations. The lessons learned from the Solar System indicate us that the solution to this problem lies in the information contained in the composition of planets. The goal of the Atmospheric Remote-Sensing Infrared Exoplanet Large-survey (ARIEL), one of the three candidates as ESA M4 space mission, is to observe a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres, which should show minimal condensation and sequestration of high-Z materials and thus reveal their bulk composition across all main cosmochemical elements. In this work we will review the most outstanding open questions concerning the way planets form and the mechanisms that contribute to create habitable environments that the compositional information gathered by ARIEL will allow to tackle.     

Is feeding behaviour related to glass eel propensity to migrate?

Several studies have shown that eel diadromy is facultative and that migratory divergences may appear during glass eel estuarine migration. The origin of the differences in migratory behaviour among glass eels remains unclear but initial evidence supports the role of individual energetic and thyroidal status. Even if starvation is usually associated with glass eel migration, feeding does seem to occur in some glass eels. The aim of the present study was to investigate feeding behaviour and glass eel growth in relation to the propensity to migrate. Feeding rate and weight gain were higher in fish having a high propensity to migrate (M⁺ fish) than in fish having a low propensity to migrate (M⁻ fish) in fed glass eels, whereas no clear difference in the variation in body weight was observed among unfed fish (controls). M⁻ fish initially had lower percent dry weight than M⁺ fish, which suggests a link between appetite, propensity to migrate, and energy content. We discuss the role played by endocrine signals on these processes. In fish, thyroid hormones contribute to the control of growth and development. In addition, they play a role in flatfish and leptocephalus metamorphosis and appear to be involved in smolt and glass eel migratory behaviour. As such, they represent a good candidate which would promote the propensity to migrate as well as digestive system development. Their role in the hormonal control of food intake however remains vague.     

西藏工布江达县亚贵拉铅锌、钼多金属矿床石英斑岩锆石SHRIMP定年及其地质意义

采用SHRIMP锆石微区U-Pb测年技术,对冈底斯成矿带东段工布江达县亚贵拉铅锌、钼矿区的容矿石英斑岩岩体进行年代学研究,通过对3件含矿石英斑岩样品中单颗粒锆石56个样品点的分析,其206Pb/238U 年龄范围在（110.2±6.8～140.9±1.9）Ma之间,三件样品206Pb/238U 年龄加权平均值分别为128±1.0Ma (n = 20 ,MSWD = 1.3),129.3±1.3Ma (n = 14 ,MSWD = 1.12),127.8±1.1Ma (n = 22 ,MSWD = 1.4)。结合前人研究以及本次测年结果认为：(1)含矿石英斑岩岩体侵位年龄在126.7～130.6Ma之间,属于燕山晚期。(2)辉钼矿成矿年龄约为60Ma左右,钼矿矿化发生在岩体侵位之后。(3)亚贵拉铅锌、钼矿矿床属于斑岩型钼矿夕卡岩型-热液脉型铅锌铜银多金属矿床,而非晚石炭世-早二叠世的海底喷流沉积成因矿床。(4)亚贵拉-沙让矿集区矿床的形成得益于燕山晚期和喜山早期的岩体侵位,并与碰撞前（180～65Ma ）及主碰撞期（65Ma-41Ma）的岩浆活动关系密切,属于碰撞前和主碰撞期早期成矿。这一认识对冈底斯的区域找矿具有极其重要的意义。     

Metabolic loss of mass in glass eels at different salinities according to their propensity to migrate

Eel facultative catadromy is not clearly understood. Initial work suggested a possible control by energy content and energy expense in young stages. The present work aimed to better understand the mechanisms involved, by studying the influence of the salinity rearing environment in the loss of mass and therefore on fish energy and migration. Glass eels (Anguilla anguilla L.) caught on the Atlantic coast were identified according to their rheotactic response to the dusk signal, and thus to their propensity to migrate which can be low (sedentary, M⁻ fish) or high (flow-wise catches in early night, M⁺ fish). M⁺ and M⁻ fish were individually placed at different salinities (0, 10 or 30) for 28 days in small containers equipped with shelters. Individual wet mass and pigmentary stage were determined on Day 1 and Day 28. In addition, dry mass and percent dry mass were measured on a sub-sample of 30 fish randomly chosen on Day 1, and on all fish on Day 28. There was no difference in the loss of mass linked to their adaptation to salinity between M⁻ and M⁺ fish, and so the results do not support the link between migratory behaviour and salinity tolérance (or to a larger extent osmoregulation). However, M⁻ fish lost more wet mass than M⁺ fish irrespective of the salinity, maybe because of a higher standard metabolism, which suggests that glass eels prone to loose more energy might choose to settle at sea or in estuary. In addition, the highest percent dry mass after 28 days in seawater associated to the highest loss of mass in 28 days in seawater does not support a higher energy cost of osmoregulation at sea.     

Interannual variability of the upper layer of the tropical Atlantic Ocean from in situ data between 1979 and 1999

Interannual variability of the upper layers of the tropical Atlantic is described based on in situ data. An objective analysis used all available temperature observations of the upper tropical Atlantic between 1979 and 1999 to construct a 4D database. Wind data are used to investigate potential mechanisms which might explain the observed variability. Four remarkable events are described: 1983–1984, 1988–1990, 1994–1995 and 1997–1998. Three of them are characterised as equatorial (1983–1984, 1994–1995, and 1997–1998). The 1988–1990 event is a basin-wide phenomenon which does not involve the same mechanisms as the other three. Results of statistical decomposition in empirical orthogonal functions (EOFs) are discussed. There is no evidence of an inter-hemispheric mode on the depth of the 20?°C-isotherm (D20) and heat content comparable to the observed mode for sea surface temperature (SST) fields. Most energetic patterns for D20 and heat content are dominated by the stronger variability in the northern part of the basin. Influences of other climate signals are investigated. Correlations between the winter NAO (North Atlantic Oscillation) index and our standard variables is marginally significant. A positive NAOW (North Atlantic Oscillation of Winter) is associated with SST cooling in a latitude band between 10°N and 20°N. When applied to the El-Niño index, correlations are much more significant. We found two scales of maximum correlation: at the four month lag after the El-Niño mature phase when the thermocline slope and zonal heat content gradient are maximum along the equator, and at the ten month lag after the mature phase of El-Niño when the thermocline slope weakens and the equatorial gradient of heat content vanished. The correlation with a zonal wind index (average between 30°W–35°W and 2°N–2°S) has been computed. Correlation is maximum at the six month lag when the thermocline slope and the zonal heat content gradient are maximum in the equatorial band. This “Atlantic Niño” mode is influenced by the Pacific Ocean's variability and reaches a maximum one year after a warm event in the eastern Pacific.     

海南抱板金矿田围岩蚀变带中绿泥石的特征及其意义

通过对海南抱板金矿田围岩蚀变带中绿泥石成分的分析，讨论了蚀变带中绿泥石的成分变化，并由此确定围岩蚀为形成于２９０～３００℃和氧逸度为１０＾－２６～１０＾－３４的条件下，结合含金石英脉的体包裹体研究，从蚀变到成矿物质沉淀，热液的温度和氧逸度是变化的。     

Probabilistic seasonal streamflow forecasts of the Citarum River,Indonesia, based on general circulation models

In this study we discuss probabilistic forecasts of Citarum River streamflow, which supplies 80 % of the water demands in Jakarta, Indonesia, based on general circulation model (GCM) output, for the September–November (SON) season. Retrospective forecasts of precipitation made over the period 1982–2010 with two coupled-ocean atmosphere GCMs, initialized in August, are used in conjunction historical streamflow records, with a cross-validated regression model. Pearson’s product moment correlation skill values of 0.58–0.67 are obtained, with relative operating characteristic scores of 0.67–0.84 and 0.74–0.92 for the lower and upper tercile categories of flows respectively. Both GCMs thus demonstrate promising ability to forecast below/above normal streamflow for the Citarum River flow during the SON season.