http://www.sciencedirect.com/science/article/pii/S1674987111000570

Mid-Cretaceous strata within the Tintina Trench.3 km west of the community of Ross River, contain evidence of deposition in two distinct,alternating,fluvial settings.Coal-bearing,mud-dominated strata are commonly associated with high-constructive sandy channel systems,with extensive overbank. levee and splay deposits.Channels are between 3 and 30 m wide and 0.4-7 m thick.They show repetitive development of side and in-channel bar-forms,as well as up-channel widening of the rivers by selective erosion of associated overbank and levee deposits.Levees extended for several hundred metres away from the channels.In this setting low-angle inclined stratification and epsilon cross stratification may reflect lateral migration of crevasse channels or small streams.The paucity of exposure prevents recognition of the channels as products of multiple channel anastomosed systems or single channel high-constructive systems. Gravel-dominated strata,inter-bedded with,and overlying coal-bearing units,are interpreted as deposits of wandering gravel-bed rivers,with sinuosity approaching 1.4.In most exposures they appear to be dominated by massive and thin planar-bedded granule to small pebble conglomerates,which would traditionally be interpreted as sheet-flood or longitudinal bar deposits of a high-gradient braided stream or alluvial fan.Architectural analysis of exposures in an open-pit shows that the predominance of flat bedding is an artefact of the geometry of the roadside exposures.In the pit the conglomerates are dominated by large scale cross stratification on a scale of 1-5.5 m.These appear to have developed as downstream and lateral accretion elements on side-bars and on in-channel bars in water depths of 2-12 m.Stacking of strata on domed 3rd order surfaces suggests development of longitudinal in-channel bar complexes similar to those observed in parts of the modern Rhone River system.Mudstone preserved in some of the channels reflects intervals of channel abandonment or avulsion.Minimum channel width is from 70 to 450 m.     

吉林南部地区老岭群变质作用特征研究

吉林南部地区老岭群变质矿物较为发育,本文通过对其中发育的变质矿物进行详细鉴定和大量探针分析,将老岭群下亚群主要变质矿物划分为两个世代,分别代表两期变质作用M1和M2.结合研究区老岭群变质矿物组合、分布特征以及变质相带的研究,认为M1为中-低温区域动力热流变质作用,可以划分为低绿片岩相和高绿片岩相,而M2为局部热变质作用...     

国家尺度社会经济数据格网化原理和方法

空间信息获取和处理技术,可将传统关系型社会经济数据转变为空间化的矢量或者格网数据.首先,分析了传统关系型社会经济数据库的不足,并对社会经济数据格网化理论研究及格网数据库建设的历史做了回顾;在明确社会经济数据格网化基本概念的基础上,提出了社会经济数据格网化的3个基本要求,即时间可比、空间一致和逻辑自洽;同时提出了一个包括...     

基于岸线配准的海岛礁遥感影像几何纠正方法

由于缺少可靠的控制点,很难对遥远海岛进行几何精校正.在假定海岛岸线相对稳定的情况下,提出一种基于海岸线配准的几何校正方法.首先,基于波谱分析从卫星影像提取海岸线;接着,根据海图上陆地特定的颜色提取海岸线;最后,通过将两种岸线进行配准实现了几何精校正.试验表明这个方法可行,校正结果也令人满意.     

Long-term response of an arctic fiord system to lead-zinc mining and submarine disposal of mine waste (Maarmorilik, West Greenland)

Contamination by lead (Pb) and zinc (Zn) was studied in seawater, sediments, seaweeds and blue mussels near the former Black Angel Pb-Zn Mine in Maarmorilik, West Greenland. The mine operated during the period 1973-90 when mine waste (tailings and later waste rock) was discharged directly into the sea. Metal concentrations peaked during the mining period and Pb and Zn in seawater within the discharge area were measured up to 440 and 790 μg L?1, respectively. Pb in fiord sediments, seaweeds and blue mussels just outside the discharge area were measured in concentrations up to 190, 84 and 2650 and Zn up to 300, 360 and 1190 μg g?1 dry wt., respectively. Within the discharge area, seawater metal concentrations (especially Pb) decreased abruptly after mine closure. Metals concentrations in sediments and biota, however, decreased more slowly and two decades after mine closure seaweeds and blue mussels were still contaminated 12 km from the mine.     

Phenotypic and genetic differentiation in young-of-the-year common sole (Solea solea) at differentially contaminated nursery grounds

Growth-related characters, condition factor, and genetic differentiation were investigated for a single cohort of young-of-the-year (YOY) sole within and among nurseries with differing levels of heavy metals (Cd, Cu and Zn) contamination in the two Charentais Straits, Bay of Biscay, France. Analyses were performed when individuals recruited (May), then after a full summer spent in each nursery (October). Levels of phenotypic and genetic diversity were compared, together with genetic differentiation at a candidate metallothionein (MT) locus and three putatively neutral microsatellite loci. No phenotypic or genetic differentiation was detected among nurseries in May, but significant variation at each phenotypic trait and at the multilocus level in October (P < 0.001). Single locus analysis demonstrated that only the MT locus was significantly differentiated among nurseries, whether corrected for null alleles or not (θ=0.0401 and θ(corr.FreeNA)=0.0326, respectively; P < 0.001). Results indicate that phenotypic differences among YOY sole nurseries present a molecular correlate acting at identical spatio-temporal scales among nurseries, potentially reflecting differential selective pressure among nurseries in response to contamination.     

Tree Population Dynamics of Three Altitudinal Vegetation Communities on Mount Cameroon(1989-2004)

Changes in permanent sample plots in the lowland,submontane and montane forests on Mount Cameroon(4,095 m above sea level),an active volcano,are described for 15 years from 1989 to 2004.Throughout the study period,the stocking level of trees with a diameter at breast height(DBH) ≥ 10 cm in the three forests were lower than in pan-tropical stands suggesting a significant impact of volcanic and human-related activities on the vegetation communities on the mountain.Annual mortality rates in the submontane and ...     

Integrated Futures for Europe’s Mountain Regions: Reconciling Biodiversity Conservation and Human Livelihoods

Introduction Europe's mountains cover nearly half of the continent's area (Price et al. 2004) and land cover varies significantly (European Commission 2004). In most massifs, except for Sicily, southern Greece, and the British Isles, forest cover is dominant. In northern Europe, grassland is proportionately more important, and much of the mountains of the British Isles is covered by moorland. In central and southern Europe, arable land is of far greater importance than grassland, with Med…     

The Multi-Wavelength Quasar Survey Ⅲ. Quasars in Field 836

This is the third paper in a series connected with our Multiwavelength Quasar Survey. The survey is aimed to provide a quasar sample more complete than any previous survey by using a combined selection technique to reduce selection effects. We present the observational results for the X-ray candidates in field f836. We found 15 X-ray AGNs in this field of which eight are new discoveries. The X-ray data and optical spectra of these AGNs are given. We give the X-ray candidate selection criteria, which proved to be highly efficient in isolating X-ray AGNs.