The responses of different ethnic groups in the Sudan to rural-urban migration

The ethnic identities of the various population groups in the Sudan are a product of their specific natural and social environments. The migration of these groups to the towns, especially to Greater Khartoum, involves a drastic change of cultural norms and values. However, the capability of change and the subsequent results are strongly conditioned by the specific background of each ethnic group and by the conditions in its area of origin. This is being proved by a comparative study on three ethnic groups in the Sudan: the Nuba, the Zaghawa and the Hadandawa.     

Identification of the interstellar cyanomethyl radical (CH2CN) in the molecular clouds TMC-1 and Sagittarius B2

We report the astronomical identification of the cyanomethyl radical, CH2CN, the heaviest nonlinear molecular radical to be identified in interstellar clouds. The complex fine and hyperfine structures of the lowest rotational transitions at about 20.12 and 40.24 GHz are resolved in TMC-1, where the abundance appears to be about 5 x 10(-9) relative to that of H2. This is significantly greater than the observed abundance of CH3CN (methyl cyanide) in TMC-1. In Sgr B2 the hyperfine structure is blended in the higher frequency transitions at 40, 80, and 100 GHz, although the spin-rotation doubling is clearly evident. Preliminary searches in other sources indicate that the distribution of CH2CN is similar to that for such carbon chain species as HC3N or C4H.     

南极威尔克斯地SGR钻孔处雪冰转化过程中的密度变化特征

本文着重描述了SGR钻孔处冰盖上的积雪在密实化过程中的特征变化,并对该过程进行了分段的和全面的回归分析.结果表明,冰盖密度随深度增大,但增长幅度随深度减小.作者提出密度变化减小度的概念.计算得出的所研究冰芯钻取点的密度变化减小度为-0.15kg/m~3·m~2,粒雪成冰前的密实速率平均值为4.08kg/m~3·a.本文得到的冰盖密度变化“临界点”与以往报道的有所不同.分析这一现象时,作者强调当积雪还在活动层时冰盖温度的影响,并以此解释密度剖面的异常变化以及离差的回升.特别指出,积雪的密度变化具有气候学意义,它在一定程度上能够反映出积雪形成及变化过程中气候变化的某些信息.本文由密度变化确定的钻孔点雪冰转化深度为50米.     

青海南部熔积岩的发现:对寻找VMS型矿床的重要启示

熔积岩指的是侵入、混合到未固结或弱固结的湿沉积物中的熔浆分解、原位形成的一类特殊岩石。正确地认识该类岩石,有利于增进人们对岩浆-水(沉积物)相互作用过程的理解,恢复古环境。在青海南部沱沱河地区发现了一套角砾为撕片状、锯齿状及浑圆状的安山岩,胶结物为铁硅质组合的特殊熔积岩。研究表明,该熔积岩的角砾为岩浆遇水后快速淬火、裂解的产物,铁硅质组合为海底喷气沉积形成的含铁建造;且安山岩与含铁建造发生混合时,含铁建造尚未固结。该套熔积岩的发现,改变了长期以来对开心岭铁矿为火山热液交代安山岩而形成的认识,对于在矿区寻找VMS型矿床、区域内寻找海底热水喷流沉积型矿床具有重要的启示意义。     

The Nordic geological surveys： Geology for society in practice

Since the mid-nineteenth century., when the first of the Nordic Geological Surveys were established, they have generated a substantial amount of information on the Earth＇s crust, its natural resources, its processes, and on the geological history of Nordic areas. The collective mission of the geological surveys is to carry out ＂Geology for Society＂, by doing research and providing services, and by making geological information and data easily accessible to all the varied end users in industry, government agencies, government institutes, public administrations, technical offices, academia and research institutes, as well as for private individuals. The present paper gives a brief overview of a few, selected, research areas and projects currently undertaken by the Nordic geological surveys. These serve as practical examples of how the Nordic geological surveys address important societal problems and challenges that require geological input for their solution.     

Geological research at the Natural History Museum of Moscow University, 1759-1930 （in Russian）

In 2006, the Moscow publishing house Nauka （Science） published a 246-page book by Zoya A. Bessudnova entitled Geological Research at the Natural History. Museum of Moscow University, 1759-1930 as No. 32 in its series ＂Sketches on the History of Geological Knowledge＇. The author is a geologist and Senior Researcher in the Department for the History of Geology of the Vernadsky State Geological Museum of the Russian Academy of Sciences, and a member of the International Commission on the History of Geological Sci- ences （INHIGEO）.     

气候变化对塔里木河来自天山的地表径流影响

塔里木河水资源主要来自天山南坡两条源流,选择西段阿克苏河和中段开都河-孔雀河作为研究区.1956-2003年研究河源山区气温呈持续升温且降水波动增加的趋势,其中1995-2003年升温强劲,升温速率高出48 a期间平均的3倍以上;降水自1986年后持续增加,20世纪90年代较80年代增幅达18%,并显示出河源山区湿岛向塔里木盆地扩展.因高山缺少气象观测,出山径流过程变化可以综合反映中高山带的气候变化.塔里木河来自天山的地表径流在1986-2003年间持续增长,以冰川融水补给为主的库玛拉克河,1994年以来年径流量增加已在前期平均值基础上提升了一个台阶;开都河以降水径流补给为主,1986-2002年出现了观测记录以来的丰水期,并使1986年后博斯腾湖水位快速上升,恢复到1958年记录的最高水位以上.两河年径流变化趋势基本相似,但也显示有西、中段的气候变化局部差异,出现丰枯水期的不一致;然而,在近16 a升温过程中,年径流增长幅度和快慢相近.     

江苏潮滩沉积物激光粒度仪与移液管-筛析分析结果的对比

激光粒度仪的广泛应用带来了与历史数据的对比问题,因此需要建立激光粒度仪与早期分析结果之间的关系。根据江苏海岸潮滩沉积物样品的激光粒度仪和移液管-筛析法分析,对粒度参数、粒度组分等进行了对比,对两种方法的差异进行了分析。结果表明,对于江苏潮滩沉积物粒度参数中平均粒径的激光粒度仪与移液管-筛析分析结果之间有良好的线性关系;筛分法测得的粗颗粒物质较激光法偏少,而移液管法法测得的细颗粒物质较激光法偏多;将样品分类之后再进行两种方法所获粒度参数的回归分析,相关性得以提高,说明不同粒度组成的沉积物对分析结果的对比有不同的影响。两种方法之间的换算关系不仅与研究区域有关,而且与沉积物本身的粒度组成有关。     

冈底斯新近纪钾质火山作用:消减沉积物折返的地球化学与Sr-Nd-Pb同位素证据

在冈底斯岩浆岩带的羊八井地区,林子宗火山岩系上部出现小规模的粗面质火山岩.岩石学与地球化学研究表明粗面岩与时空密切相关的大体积安山质-英安质-流纹质火山岩属于不同的火山岩系:碱性钾质系列与钙碱性系列.详细的地球化学研究证明林子宗晚期小体积钾质岩具有独立的岩浆源区,而非早期钙碱性系统低压岩浆过程演化的产物.粗面质熔岩SiO2含量为62.91%～64.63%,具有高K2O(7.52%～8.05%)、Al2O3(16.64%-17.35%)、低TiO2(0.59%～0.68%)与MsO(0.15%～0.77%).钾质熔岩富集LILE与LREE,亏损HFSE,具有高Rb/Sr(1.1～2.3)、Th/La(0.59～0.80)、Th/U(6.3～10.9)和低Ce/Pb(4.1～6.2)与Ba/Th(4.3～14.5)比值,其同位素组成变化范围分别是87Sr/86Sr(I)=0.7068～0.7075、143Nd/144Nd(I)=0.51241～0.51252、206Pb/204Pb=18.87～18.95、207Pb/204Pb=15.63～15.70和208Pb/204Pb=39.24～39.68.粗面岩的地球化学与同位素特征表明冈底斯新近纪钾质火山岩来源于角闪岩相的消减沉积物熔融.因此,羊八井新近纪钾质火山熔岩提供了印度-亚洲大陆碰撞早期消减沉积物折返的证据.     

河南洛宁段河金矿流体包裹体研究和矿床成因

河南省洛宁县段河石英脉型金矿主要包括石寨沟和岭东两个矿区,分别由3～4条含金石英脉构成。矿化过程从早到晚包括石英-黄铁矿、石英-多金属硫化物和石英-碳酸盐等3个阶段．其中中阶段金矿化最强,次为早阶段。各阶段石英中流体包裹体以气液两相包裹体为主．次为纯液体包裹体。激光拉曼测试表明,气液两相包裹体的液相为H2O,气相主要为Ho和CO2混合、纯H2O,次为纯CO2;纯液体包裹体为纯H2O。石寨沟矿区包裹体均一温度从早到晚依次为240．9～315．9℃．188．7～304．5℃,137．3～259．3℃：流体盐度变化依次为（6．74～12．85）wt%NaCl．eq,（2．41～8．68）wt％NaCl．eq,（2．24-7．86）wt%NaCl．eq。岭东矿区均一温度从早到晚依次为303．7-343．1℃,251．8-325．4℃,305．7～355．0℃：流体盐度变化依次为（5．11～11．70）wt％NaCl．eq,（2．74-10．11）wt％NaCl．eq,（0．53-6．74）wt％NaCl．eq。两矿区主成矿期流体均为中温、低盐度,早阶段流体为改造热液和变质热液的混合体,含一定量CO2,且流体CO2含量和盐度从早到晚逐渐降低。石寨沟矿区包裹体均一温度逐渐降低,而岭东矿区包裹体均一温度先降后升,加之岭东矿区各阶段成矿温度均高于石寨沟矿区．表明成矿流体系统主要受岩浆热驱动,岭东矿区更靠近岩体,且在晚阶段又有脉动性的岩浆加热．段河金矿区南部存在隐伏岩体。