The recent expansion of an avian invasive species (the Cattle Egret Ardea ibis) in Algeria

This study identifies new information on the recent distribution of an invasive bird species, the Cattle Egret Ardea ibis, in Algeria. Breeding and wintering distributions as well as breeding numbers were obtained from large-scale surveys in 1999 and 2007, and from historical data. Between 1999 and 2007, the total number of colonies found increased from 51 to 87, and most were located in the northern part of the country. The breeding distribution area, confined to the coastal areas in the 1970s, has shifted further south, and reached the northern part of the Sahara since the 2000s. Most colonies were established during the period 1980-1995. The oldest colonies were generally larger than the recent ones. The number of colonies increased by 83% between 1999 and 2007 in the 12 administrative units (wilayas) surveyed. The number of breeding pairs increased from 7765 in 1999 to 28544 in 2007, corresponding to an annual population growth rate of 17.7%. The changes in distribution and population dynamics since the 1970s and the potential factors affecting these changes are discussed.     

Non-metamorphosed autochthonous Kuncha-Naudanda-Heklang Formations and their differences from those of the Kuncha nappe: A multichronological approach

Non-metamorphosed, autochthonous Lesser Himalayan sediments (LHS), which are correlated to the Kuncha and Naudanda Formations, were found in a narrow belt between the Main Boundary Thrust and the Lesser Himalayan Thrust at the base of the Kuncha nappe in southeastern Nepal. The autochthonous Naudanda Formation is comprised of cross-bedded and rippled orthoquartzite and yielded a maximum depositional age of 1795.1 Ma ±5.1 Ma using detrital zircons. Low-grade metamorphosed quartzite in the Kuncha nappe yielded a maximum depositional age of 1867.4 Ma ±3.4 Ma, although it is totally recrystallized. These ages and age distribution patterns of detrital zircon grains indicate that the meta-quartzite of the nappe is originally Naudanda Formation. A zircon fission-track age of the autochthonous Naudanda Formation shows partially annealed age of 864 Ma ±56 Ma, in contrast, that of the Kuncha nappe shows a totally annealed age of 11.9 Ma ±1.6 Ma. These results suggest that the autochthonous LHS have never undergone metamorphism during the Himalayan orogeny. We also discovered a non-metamorphosed Heklang Formation that rests on the Naudanda Formation, and designated it as a sub-type section on the basis of detailed lithostratigraphic study. It is characterized by black and light green slate with dolerite sills and ill-sorted quartzose sandstone, and correlated to the metamorphosed Dandagaon Phyllites in the Kathmandu area. Non-metamorphosed autochthonous formations distributed to the south of the nappe front suggest that they escaped from thermal metamorphism by hot nappe.     

一种匹配滤波结合ChirpScalingSAR数字成像处理方法

合成孔径雷达（ＳＡＲ）是一种重要的微波遥感工具。其关键技术是成像处理,即把接收到的雷达信号转换成雷达图像。事实上,合成孔径就是通过成像处理来实现的。该文在总结目前星载ＳＡＲ各种成像处理算法的基础上,提出一种匹配滤波与ＣｈｉｒｐＳｃａｌｉｎｇ相结合的处理方法。处理过程无需插值便可进行距离迁移校正,还可获得好的聚焦与相位保持性能。所得图像质量超过现有的其它ＳＡＲ成像处理方法所得图像质量。     

The use of ablation‐dominated medial moraines as samplers for 10Be‐derived erosion rates of glacier valley walls,Kichatna Mountains,AK

We use cosmogenic ¹⁰Be concentrations in amalgamated rock samples from active, ice‐cored medial moraines to constrain glacial valley sidewall backwearing rates in the Kichatna Mountains, Alaska Range, Alaska. This dramatic landscape is carved into a small ～65 Ma granitic pluton about 100 km west of Denali, where kilometer‐tall rock walls and ‘cathedral’ spires tower over a radial array of over a dozen valley glaciers. These supraglacial landforms erode primarily by rockfall, but erosion rates are difficult to determine. We use cosmogenic ¹⁰Be to measure rockwall backwearing rates on timescales of 10³–10⁴ years, with a straightforward sampling strategy that exploits ablation‐dominated medial moraines. A medial moraine and its associated englacial debris serve as a conveyor system, bringing supraglacial rockfall debris from accumulation‐zone valley walls to the moraine crest in the ablation zone. We discuss quantitatively several factors that complicate interpretation of cosmogenic concentrations in this material, including the complex scaling of production rates in very steep terrain, the stochastic nature of the rockfall erosion process, the unmixed nature of the moraine sediment, and additional cosmogenic accumulation during transport of the sediment. We sampled medial moraines on each of three glaciers of different sizes and topographic aspects. All three moraines are sourced in areas with identical rock and similar sidewall relief of ～1 km. Each sample was amalgamated from 25 to 35 clasts collected over a 1‐km longitudinal transect of each moraine. Two of the glaciers yield similar ¹⁰Be concentrations (～1·6–2·2 × 10⁴ at/g) and minimum sidewall slope‐normal erosion rates (～0·5–0·7 mm/yr). The lowest ¹⁰Be concentrations (8 × 10³ at/g) and the highest erosion rates (1·3 mm/yr) come from the largest glacier in the range with the lowest late‐summer snowline. These rates are reasonable in an alpine glacial setting, and are much faster than long‐term exhumation rates of the western Alaska Range as determined by thermochronometric studies. Copyright © 2010 John Wiley & Sons, Ltd.     

大兴安岭北段哈多河地区骆驼脖子岩体地球化学和锆石U-Pb年代学

骆驼脖子岩体位于大兴安岭哈多河地区东南部,大地构造上位于兴蒙造山带东段,其岩性由正长花岗岩、花岗闪长岩(其中含石英闪长岩包体)、二长花岗岩组成.其中锆石呈自形晶,发育细微振荡生长环带,具有较高的Th/U值,表明锆石的岩浆成因.LA-ICP-MS锆石U-Pb测年结果显示,加权平均年龄和岩性分别为127±1 Ma的正长花岗岩、126±1 Ma的花岗闪长岩、131±1 Ma的石英闪长岩、130±1 Ma的二长花岗岩,集中在早白垩世.除闪长岩包体外,岩体具有高硅(SiO2=71.11％～76.89％)、富碱(Na2O+K2O=8.04％～9.17％)、较低的Al2O3(12.9％～14.99％)、贫钛(TiO2=0.08％～0.22％),属于高钾钙碱性系列.A/CNK值为0.97～1.10,属于准铝质到弱过铝质,分异指数(DI)为86.1～97.46,固结指数(SI)为0.1～5.59,岩体经历了较强的分异演化作用,δEu为0.26～2.51,正、负异常皆有,LREE/HREE为6.35～32.16,(La/Yb)N比值为4.59～43.04,轻稀土相对富集,重稀土相对亏损.微量元素亏损Ti、Ta、Nb等元素;富集Th、U、Hf、Zr、La、Rb等元素,TFeO/MgO比值较低,为2.37～6.41,Zr+Nb+Ce+Y=106.48×10-6～162.74×10-6,均低于A型花岗岩的下限值,同时锆石饱和温度也较低(723.43～760.48℃),结合岩相学、年代学、地球化学及区域地质资料,骆驼脖子岩体具有高分异的高钾钙碱性Ⅰ型花岗岩的特点,其成因可能为东北地区中生代古太平洋板块斜向俯冲后,大陆岩石圈拉张减薄的产物.     

Quartz-topaz-loellingite rocks near Eldorado,Victoria

Two small dykes consisting of a quartz-topaz-loellingite rock type have recently been discovered within the aplitic phase of the Pilot Range granite, near Eldorado, in NE Victoria. Minor biotite, muscovite, chlorite, kaolinite, anatase and pharmacosiderite are associated. Apart from the loellingite, the dykes are similar mineralogically to the ‘topazites’ from New England, NSW. These were considered to be magmatic in origin, based on field relationships and high homogenization temperatures for fluid inclusions in topaz (Eadington & Nashar 1978, Contrib. Mineral. Petrol. 67, 433–438). Although experimental evidence on F-enriched ‘granitic’ systems is inconclusive, the emplacement of the Eldorado topazite dykes most likely involved both magmatic and hydrothermal components operating essentially simultaneously. The topazite melt represented a F-rich residual granitic magma, from which aqueous alkali halide-rich solutions separated during high level intrusion. Separation of these aqueous solutions was responsible for miarolitic cavities into which topaz crystals grew. F-OH equilibration calculations for coexisting topaz-biotite pairs suggest the minerals equilibrated in the presence of hydrothermal solutions of variable composition (in terms of the HF/H₂O fugacity ratio), at temperatures around 550°C. Alteration of topaz to muscovite, the precipitation of loellingite and the formation of clay and fluorite in the cavities occurred at progressively lower temperatures. The widespread alluvial topaz in the Beechworth-Eldorado area may be derived from similar quartz-topaz dykes.     

Relationship between physical and chemical soil attributes and plant species diversity in tropical mountain ecosystems from Brazil

Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado （savanna）. Different habitats occur according to soil characteristics （e.g., presence of rocks, sand, fertility, hydrology, etc.）. These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us： rocky outcrops, peat bogs, sandy bogs, quartz gravelfields, and ＂cerrado＂ （savanna）. A floristic survey indicated that four families are found at greater frequency： Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus （Poaceae） was the most dominant species in the rocky outcrops, Axonopus siccus （Poaceae） in the peat bogs, Lagenocarpus rigidus （Cyperaceae） in the sandy bogs, Schizachyrium tenerum （Poaceae） in the cerrado, while Vellozia sp. 8 （Velloziaceae） dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.     

A Gibbs sampling disaggregation model for orographic precipitation

Hydrological applications in complex topographic areas need high spatial resolution precipitation data. Some daily high-resolution products are now available for recent past data, even in complex terrain. While the spatial resolution of Regional Climate Models (RCMs) and operational meteorological models are becoming increasingly fine, there still exists a mismatch between the spatial resolutions of observed or estimated recent past data and simulated or forecasted precipitation.Statistical disaggregation models can generate precipitation on a high-resolution grid using as input a mesoscale precipitation grid (e.g., RCM or meteorological grid). In this paper, a Gibbs sampling disaggregation model previously developed for flat areas is adapted to account for topography. Only one variable, the topographic anomaly, is added to the original model. The model is applied on a 300 km × 300 km area in the northwestern United States, covering the Olympic Mountains and the Cascade Range. Daily high-resolution precipitation data for the 2002–2005 period are used to estimate the model parameters. Using 750 days taken from the 2006–2008 period, 36, 52-km grid boxes are disaggregated on 4.3-, 8.7-, 13-, 17.3- and 26-km grids; each day being simulated nine times. Thank to the Gibbs sampling algorithm, the original model, which does not account for topography, is able to capture the mesoscale topographic structure of the daily precipitation, while the adapted model accounting for topography is better suited to recreate the local impact of topography on interannual means, interday standard deviation, and maximum values. The model outputs could be used by hydrological modelers who need high-resolution precipitation data in complex topographic area application.     

基于网络的航天靶场大地测量管理系统研究

针对航天靶场大地测量各环节数据链脱节、成果数据和资料档案管理基于人工模式这一现状,提出构建基于网络的航天靶场大地测量成果数据与资料档案关联存取、数据生产与服务结合的一体化管理系统,阐述了系统研制的主要目标和内容。结合实际作业流程,详细设计了成果数据和资料档案管理功能,论述了系统开发的关键技术,解决了各类数据的在线共享,实现了航天靶场大地测量的信息化管理。