九州-帕劳海脊南段铁锰结壳物质组成特征及成因机制

铁锰结壳（又称富钴结壳、多金属结壳）富含Co、Cu、Mn、Ni、Ti、V、REE、Y和Zn等人类日常生活和高新技术产业亟需的关键金属,是一种重要的战略性矿产资源。本文对九州-帕劳海脊南段水深1900～2600 m处获得的9个站位铁锰结壳样品进行了矿物学和地球化学研究,分析了铁锰结壳的矿物组成、主微量元素和稀土元素含量,并进一步探讨了铁锰结壳的成因类型。结果表明,研究区铁锰结壳的矿物组成以水羟锰矿为主,同时含有大量非晶态铁氧/氢氧化物;Mn、Fe、Co、Ni、Cu平均含量分别为16.15%、15.38%、0.32%、0.33%、0.10%;CaO/P2O5均值为5.93,表明九州-帕劳海脊南段铁锰结壳样品均未发生磷酸盐化作用;铁锰结壳明显富集稀土元素（含Y,REYs）,平均含量为1194 μg/g,轻稀土显著富集,稀土元素经后太古代澳大利亚页岩（PAAS）标准化后配分模式整体相对平坦,呈现Ce正异常而Eu无异常,与海水呈现镜像关系,说明铁锰结壳稀土元素主要来源于海水。铁锰结壳的矿物组成和元素判别图均表明九州-帕劳海脊南段铁锰结壳属于水成型,未受明显的成岩作用影响。     

西南印度洋中脊表层沉积物非碳酸盐组分的粒度特征及其地质意义

The carbonate-free fraction of 20 surface sediments collected from the ultraslow-spreading Southwest Indian Ridge(SWIR) was studied by grain size analysis and mineralogical analysis with X-ray powder diffraction(XRD),stereo microscopy and scanning electron microscopy(SEM). The characteristics of the carbonate-free fraction of the sediments were obtained, and related influential factors were discussed. The results show that the mean grain size of this fraction is in 1.96Φ–8.19Φ, with poorly sorting and unimodal, bimodal or irregular bimodal distribution patterns. Four grain size end members of the fraction are derived with the End Member Model method. The finest end member EM1 shows a significant contribution of terrigenous materials of the aeolian input and sediment carried by the bottom current. End member EM2 with medium size mainly reflects sediment of a siliceous bioclast origin. EM3 and EM4 are interpreted as representing the coarser volcanic materials related to bedrock weathering or volcanic activities. Multi-provenance is the dominant factor controlling the grain size pattern of the carbonate-free fraction of the sediments in that area. In addition, sediment transport processes such as the bottom current and wind are the minor factors that influence the grain size distribution of the carbonate-free fraction sediments.     

塔里木盆地古近纪岩相古地理

古近纪是塔里木盆地由海向陆转化的时期。当时该区的海侵来自研究区西侧的古地中海分支,物源则主要是盆地北部的南天山以及南部的昆仑山,沉积中心在库车坳陷西部以及塔西南坳陷带的西部。古新世-始新世早期（库姆格列木群沉积期）在盆地北部库车坳陷发育砾岩、砂岩、碳酸盐岩及膏盐岩,沉积环境有滨岸、漏湖、潮坪及扇三角洲等,塔西南坳陷以碳酸盐岩和膏岩为特征,从东到西发育开阔台地、近岸局限台地、蒸发盐台地、辫状河三角洲环境等,二者之间即在塔北隆起及北部坳陷带位置为宽阔的古隆起区。始新世晚期-渐新世（苏维依组沉积期）整个盆地以滨浅湖为主,发育粉砂岩与泥岩互层沉积,塔西南坳陷虽然仍发育多个海相层,但海水的影响明显比始新世早期弱,当时主要古地理单元有海湾渴湖、滨浅湖、扇三角洲和辫状河三角洲。总体上,塔里木盆地在古近纪经历了早期以扇三角洲为主的浅水环境到晚期的滨浅湖及海湾溻湖环境,古近纪研究区的古气候以热带-亚热带的干旱气候为主。     

云南双沟变质橄榄岩中蛇纹石的稀土元素空间分布

本文探讨变质橄榄岩的ＬＲＥＥ富集型及Ｕ型分布的ＲＥＥ球粒陨石模型,是橄榄石固有的还是后期蚀变形成的。并寻求复原蚀变前橄榄石的ＲＥＥ丰度及型式。我们用蛇纹石颗粒代表蚀变后的橄榄石,用分选法和化学分层剥离法对样品进行予处理。用中子活化分析（ＮＡＡ）手段进行了测试。结果表明：分选法确定了ＬＲＥＥ的主要赋存载体是蛇纹石。分层剥离最后内核的ＲＥＥ丰度及模型,可近似地作为原来（未蚀变前）橄榄石的ＲＥＥ丰度及模型。     

A new approach for vegetation change detection in urban areas

IntroductionVegetation distribution and change is regardedas ani mportant sign of urban environment . Withcity expanding and population increasing, herecomes a series of problems on environment ,andmoreover ,greening ratio is regarded as a stand-ard of ci…     

西湖凹陷平北地区泥岩地球化学特征及其地质意义

为了研究西湖凹陷平北地区泥岩微量及稀土元素的分布特征及其地质意义,采用ICP—MS对研究区25个泥岩样品进行了稀土元素和微量元素分析,研究表明：（1）研究区泥岩稀土元素主要来自陆源碎屑矿物,源岩主要为沉积岩及碱性玄武岩;（2）始新世末构造运动揭示的构造沉积界线在研究区留下了证据,微量元素比值、稀土总量等参数在此界面上存在明显的突变,界线十分明显,并且此界线亦是研究区平湖组与花港组的沉积界面,界面以下以三角洲沉积为主,界面之上主要为河流相沉积,这一沉积相转换面在研究区P1井尤为明显;（3）利用Sr／Cu比值推测平北地区始新世中晚期．早渐新世经历了较为明显的气候变化,总体上有逐渐变温湿趋势,并且研究区北部要温湿于南部。     

An analytical solution for rainfall infiltration into an unsaturated infinite slope and its application to slope stability analysis

Surficial slope failures in residual soils are common in tropical and subtropical regions as a result of rainfall infiltration. This study develops an analytical solution for simulating rainfall infiltration into an infinite unsaturated soil slope. The analytical solution is based on the general partial differential equation for water flow through unsaturated soils. It can accept soil–water characteristic curve and unsaturated permeability function of the exponential form into account. Numerical simulations are conducted to verify the assumptions of the analytical solution and demonstrate that the proposed analytical solution is acceptable for the coarse soils with low air entry values. The pore‐water pressure (pwp) distributions obtained from the analytical solution can be incorporated into a limit equilibrium method to do infinite slope stability analysis for a rain‐induced shallow slip. The analysis method takes into account the influence of the water content change on unit weight and hence on factor of safety. A series of analytical parametric analyses have been performed using the developed model. The analyses indicate that when the residual soil slope, consisting of a completely decomposed granite layer underlain by a less permeable layer, is subjected to a continuous heavy rainfall, the loss of negative pwp and the reduction in factor of safety were found to be most significant for the shallow soil layer and during the first 12 h. The antecedent and subsequent rainfall intensity, depth of a less permeable layer and slope angle all have a significant influence on the pwp response and hence the slope stability. Copyright © 2012 John Wiley & Sons, Ltd.     

Archaeal community structure in sediments from a seamount in the Mariana Volcanic Arc

Seamounts are subsurface mountains in the ocean. Examination of the abundance and distribution of Archaea in seamount ecosystems may provide a better understanding of their ecological functions. Most studies of marine archaeal assemblages in seamount area have focused on hydrothermal vents or ferromanganese crusts. We investigated the archaeal communities from a seamount of the Mariana Volcanic Arc, in the tropical western Pacific Ocean by using high-throughput sequencing. Thaumarchaeota was dominant in the sediments of all sample stations. Community diversity and species richness were greatest at stations near the top of the seamount, and lowest at the deepest station. One sample station on the steep southeast slope that faced the Yap-Mariana trench had a unique composition of Archaea. In summary, depth has an important influence on archaeal community structure, and the geographic properties and sediment characteristics may explain the unique distribution patterns of Archaea in this seamount. This study provides a foundation for future research on Archaea in seamounts.     

某隔震结构动力特性的理论分析与脉动测试

本文针对国内最大单体隔震建筑建立了SAP2000三维分析模型,并进行了动力特性的理论分析;现场对实际建筑进行了平移振动、扭转振动、垂直振动和平面内弯曲4个方面的脉动测试。利用工程振动反演理论分析了该结构的固有频率、振型、阻尼等动力特性,将实测结构动力特性与理论分析结果进行比较,详细分析实测结果与理论结果差别的原因,并据此对理论模型进行修正,为今后类似结构的设计积累了资料。     

利用云南水管仪观测资料检测地球自由振荡

利用云南省数字化水管仪的观测资料,采用功率谱密度估计方法,在没有对资料进行去固体潮处理的情况下,准确获得了2004年12月26日苏门答腊大地震激发的0S4～0S30基频球型自由振荡,并与前人的观测结果进行比较,同时对照了PREM模型的理论计算周期,发现水管仪观测与这三者符合得非常好,除0S4振型的观测周期和周期1、周期2、周期3的相对误差均大于0.3%外,其余的差别在3‰以下。研究表明,利用数字化水管仪观测资料的确可以提取到苏门答腊大地震激发的地球球型振荡,这就为地球自由振荡的研究提供了一种新的观测手段。