湘东北临湘地区钾质煌斑岩~(40)Ar-~(39)Ar定年及其地球化学特征

对出露于湘东北临湘地区的煌斑岩脉群进行了同位素年龄测定及岩石地球化学分析。研究表明,煌斑岩的全岩40Ar-39Ar年龄为(119.5±2.2)Ma,形成于早白垩世。岩石地球化学方面,岩石属碱性系列、钾质—超钾质煌斑岩;富集大离子亲石元素(LILE)和高场强元素(HFSE);稀土元素分配模式为相似的右倾轻稀土富集型;具有较小的TDMⅡ值(1.5Ga)和较低的εNd(t)(-7.3)。上述特征暗示煌斑岩物质来源于异常(交代富集)地幔,形成于后造山陆内拉张减薄的构造环境。     

Hydrothermal Alteration Related to Silver Mineralization at the Iwami Silver Deposit,Shimane Prefecture,Japan

The Iwami epithermal silver deposit consists of Ag-Cu veins in a dacitic intrusive body at the deep portion of the Eikyu area, and veinlets with disseminated Ag mineralization in dacitic tuff breccia at a shallow portion of the Fukuishi area. Hydrothermal alteration associated with the silver mineralization is characterized by intense potassium metasomatism with oxidizing conditions. An illite zone occurs around the pathways of uprising fluids in both the Eikyu and Fukuishi areas. It grades laterally into the illite/smectite zone, which is surrounded by a broad smectite zone. Because of boiling, abundant adularia associated with silver mineralization overlaps on the altered tuff breccia in the Fukuishi area. The alteration zoning suggests that the western Eikyu area and the eastern Fukuishi area belong to a single hydrothermal system. The data of fluid inclusion microthermometry indicate that the temperatures range 220–270°C, and salinities range 5–7 wt percent NaCl equivalent for the silver mineralization at the upper portion in the Eikyu area and the lower portion in the Fukuishi area. Radiometric ages for volcanic rocks in the area range from 2.19 to 1.64 Ma, and the dacitic intrusion formed at approximately 1.6 Ma. The silver-dominant mineralizing hydrothermal fluids system was active around 1.44 to 1.07 Ma, which formed the Eikyu Ag-Cu veins at depth, and the Fukuishi Ag ores at the shallower portion.     

青藏高原西北缘郭扎错断裂~(40)Ar/~(39)Ar年代学研究——阿尔金断裂西延的新证据

采自阿尔金断裂西南端、沿郭扎错—龙木错—空喀山口一线展布的郭扎错断裂内的糜棱岩样品中同构造黑云母~(40)Ar/~(39)Ar同位素测年的坪年龄分别为105.9Ma±0.5Ma、121.5Ma±0.6Ma、150.4Ma±0.9Ma,表明其早期韧性变形事件发生在晚侏罗世和早白垩世晚期,与阿尔金断裂带主期活动的时期基本一致,为阿尔金断裂带西延提供了新的证据。研究表明,郭扎错断裂与阿尔金断裂带具有一致的变形年代学特征、构造特征等属性,前者是后者的西延部分,二者为同一构造带,均是拉萨地块整体向北运动的动力环境下所产生的脉冲式构造活动的产物。     

E.U. migrant criminal activity: Exploring spatial diversity and volume of criminal activity attributed to inter EU migrants in England

European Union expansion over the last decade has generated many studies, surpassed in number only by governmental comment and media headlines following this general theme. Issues and knowledge explored and expressed have been many, one being a hard to evidence crime-migration nexus leading to constructive empirical studies focussing on the accession to the EU of predominantly East European nations and ensuing migratory patterns. Appertaining to this study is geographic focus on crime committed by inter-EU migrants in England, resulting from holistic research of a contemporary EU statute concerning inter-state sharing of bio-informatics, seeking contextual knowledge to the benefit of policy makers. The geography of inter-EU crime in England identifies spatial dispersion and regional areas of activity on a meso scale. The activity of individual nationalities is examined in a spatial manner displaying distinct differences in movements on a regional (meso) scale. Results improve on current knowledge of the criminality of inter-EU migrants but also identify and call for further research in a conceptual development as localised criminal activity draws an international investigatory perspective.     

Ethnic Place Identity Within A Parisian Neighborhood

The Goutte d'Or neighborhood of Paris has long been seen as an impoverished yet colorful quarter of the city. In recent years, it has also developed a reputation as a center for immigrants. Three populations now share the neighborhood: the European French, the Maghrebi immigrant population and their children, and the newest population of migrants from former Francophone colonies. This paper examines how the Goutte d'Or's social and ethnic identity is revealed in the built environment and in its social and economic activity. This neighborhood demonstrates how different communities and place identities coexist. It also shows how global networks of migration, exchange, and visits infuse local places. The Goutte d'Or distills many aspects of French immigrant identities, providing an example for increasing numbers of immigrant neighborhoods in France and across the world.     

基于Ripley’s K函数浙江城市空间格局及其影响分析

以Ripley′s K函数为核心,通过城市区位与规模联立估计、地理权重引入、全局函数分解等手段,研究2001~2010年浙江省已有县级及以上城市空间分布的总体及局部估计问题,探讨城市空间格局与特征,以期揭示边界效应和市场潜力对浙江城市空间格局的影响机理。结果表明:1浙江省城市区位与规模的空间格局不一致,即前者是分散分布而后者是集聚分布,且随着空间尺度的增加,其分散或集聚程度逐步加强。2无论是行政边界还是海岸线,对浙江省城市区位与规模的空间分布演化有一定的负向作用。空间尺度越大,边界负效应越强。3在城市化发展过程中,浙江形成了3个各具产业特色的块状组团式城市聚集区,但边界负效应会抑制它们的发展,此时杭州、宁波将承担起服务全省经济的重要职责。4浙江城市规模因受市场潜力因素的影响会出现空间分布不均衡性。城市规模与市场潜力显著正相关,其程度却随着空间尺度的增加而减小。     

绵阳市度日数特征及其变化趋势分析

从20世纪50年代以来,度日数一直作为气候变化与供暖关系的一个综合评价指标。基于全球变暖可能对我国供暖天数和温度产生深刻的影响,本文采用绵阳市1946~2005年共49年的日最低、最高气温资料,分析了绵阳市度日数年变化特征,并对其进行了趋势分析。结果表明:绵阳市历年供暖度日数最小值处于1998年,比1976年最大值低93.5%,10a年均供暖度日数变化趋势为二次曲线;制冷度日数波动性很大,1960~1979年在1500℃·d左右波动,1979~1990年在1400℃·d左右波动,1990年以后基本处于1500℃·d以上,10a年均制冷度日数拟合趋势曲线为三次曲线。基于Mann-Kendall(M-K)检验法,在α=0.05水平下,对绵阳市供暖和制冷度日数进行检验,研究发现:供暖度日数明显减少,1992年为突变起始年份;制冷度日数波动增长,且自1997年起突变。     

Interannual variability in the biochemical composition of newly hatched larvae of the spider crab Maja brachydactyla (Decapoda,Majidae)

The spider crab Maja brachydactyla is an important commercial species in Europe and supports intensive fisheries in the NE Atlantic. A field survey was performed to assess long‐term and consecutive interannual (2005–2010) variation of the biochemical composition of newly hatched larvae of M. brachydactyla. Larval biochemical profiles differed significantly among years, with pronounced differences being recorded in 2010. Differences among batches of newly hatched larvae were mainly explained by the contribution of triacylglycerols and, to a lesser degree, by protein and lipid content. The use of different nutrition indices is discussed. The biochemical composition of newly hatched larvae from M. brachydactyla was highly variable, even though surveyed broodstock was obtained from the same local population and was always sampled during the same season. The unpredictable biochemical profiles of newly hatched larvae may condition their survival and recruitment. This largely overlooked aspect of larval variability should be considered in future fisheries management strategies and captive production of marine organisms that still rely on wild seeds.     

Effects of the oophagous bivalve Acesta oophaga on the morphology and fecundity of its deep‐sea tubeworm host,Lamellibrachia luymesi

The deep‐sea bivalve Acesta oophaga lives attached to the anterior end of the vestimentiferan tubeworm, Lamellibrachia luymesi, at cold methane seeps. The bivalve is found almost exclusively on female tubeworms, where it consumes the lipid‐rich eggs of L. luymesi that are spawned year round (Biological Bulletin, 209, 2005, 87). It is apparent that A. oophaga benefits directly from this close association, but the consequences for the tubeworm host may be more complicated than just a simple predator–prey interaction. Since A. oophaga completely surrounds the tube opening and plume of the worm, it is likely that its presence would limit oxygen uptake by L. luymesi, thereby inhibiting worm growth and reproduction. We hypothesized that occupied tubeworms would compensate for this by growing larger plumes for oxygen uptake. To explore the effects of bivalve presence/absence on female tubeworms, several morphological features, including body size, plume length, tube diameter, and tube segment length, as well as instantaneous fecundity, were compared. Results suggest that the mere presence of A. oophaga has a significant impact on the morphology of its host worm, as all measures of worm size, except for tube segment length, were significantly greater with clams present. Additionally, instantaneous fecundity was 3.5 times higher in occupied worms, implying that tubeworms are not oxygen‐deprived or energy limited as a result of bivalve presence. Our findings suggest that the association between these two deep‐sea organisms may be a more complex form of symbiosis than the simple predator–prey relationship, as previously thought.     

Size‐frequency distributions of Joania cordata and Argyrotheca cuneata (Brachiopoda: Megathyrididae) from the Central Tyrrhenian Sea

Size‐frequency distributions can support reliable inferences concerning population dynamics of brachiopods, but only a few data are available so far. In this study, length and width frequency distributions of dead specimens of the Recent brachiopods Joania cordata and Argyrotheca cuneata from the Marine Protected Area ‘Secche di Tor Paterno’, Central Tyrrhenian Sea, Italy (41°35′ N, 12°20′ E), are reported in order to add new data about size‐frequency distributions of brachiopods. The studied specimens came from death assemblages in the coralligenous substrate, in the Posidonia oceanica meadows, and in the sand channels. The observed patterns vary from left‐skewed (J. cordata) to right‐skewed (A. cuneata), indicating respectively a low and high mortality of smaller individuals. Significant differences between the coralligenous substrate and the P. oceanica meadow were observed for both species, revealing a variation among different habitats. All length and width distributions are clearly polymodal, but the biological meaning of the peaks is difficult to interpret, as the two species seem to have a 2‐year life span. A biometric analysis of shell sizes revealed that length and width are the most variable parameters during the growth of the animal.