西昆仑山北缘盆山构造转换解析

根据新藏公路南段、穿越玉龙喀什河谷至和田以北的剖面考察解析及山前钻井和物探解释,结合杜瓦及皮阿曼等地综合考察分析,西昆仑山北缘向塔里木盆地的盆山过渡,是以帕米尔-西昆仑逆冲断裂系的构造形式向塔里木西南前陆盆地(简称前陆盆地)渐变,表现为一系列褶皱冲断组合的构造样式.研究表明,帕米尔-西昆仑前缘逆冲断裂系的形成发育,是控制帕米尔-西昆仑造山带(简称造山带)和前陆盆地发育的重要变形机制,逆冲断裂系的扩展大致可分4个时段.     

鄂尔多斯盆地东缘海陆过渡相页岩气储层孔隙特征及影响因素

为了研究鄂尔多斯盆地石炭—二叠系海陆过渡相页岩气储层孔隙特征,选取页4井、页1井和DT803井海陆过渡相泥页岩样品进行了扫描电镜、低温液氮吸附实验以及相关的地球化学实验,分析了海陆过渡相页岩气储层的孔隙类型、特征及其影响因素。实验结果表明:研究区页岩孔隙以粒间孔和有机质孔最为发育;页岩孔形态以狭窄的平行板状为主,孔隙微观孔径分布范围为1~60 nm,主孔径分布介于1~6 nm和40~60 nm,介孔为孔体积和比表面积的主要贡献者,但微孔对比表面积的贡献不容忽视;有机碳和黏土矿物含量是海陆过渡相页岩孔隙发育的主要影响因素,脆性矿物对孔隙发育影响不明显。     

壳幔过渡带的复杂性特征及其动力学意义

不同构造单元的地震测深资料Pm波形的复杂性有明显的差异,这种差异与深部构造特征有密切的联系。利用波的瞬时特性和波列长度,给出一种地震波形复杂性系数的计算方法。古老稳定的地块的Moho复杂性系数小,反映一级间断面的特征;反之对于活动性强烈地块,Moho复杂性系数大,反映壳幔过渡带的特征。处理了穿过青藏高原东北缘的一条地震测深剖面,并对结果进行了动力学意义的解释。     

转型时期广州城市户籍人口新贫困的地域类型和分异机制

本文把新城市贫困度量指标从经济领域拓展到社会文化等领域,利用广州市2005年最低保障统计和五普数据,采用因子分析法计算街道层面贫困主因子和综合贫困得分,并对得分大于全市平均水平的街道进行聚类,划分出"外围工人相对集中的贫困区、邻近核心就业不理想的贫困区和内城核心住房设施匮乏的贫困区"三种类型。结合三类代表社区的问卷访谈、综合调研和社区发展分析,发现计划和转型两个时期,体制和市场的双重因素共同作用,深刻改变或影响了社区的物质和社会特征,最终导致贫困地域产生明显的特征分异。     

转型时期中国城市贫困地理的实证研究——以广州市为例

研究辨析了综合贫困(Multiple Deprivation)与贫困概念、总结综合贫困的指标体系和研究方法,评述国外地理学对综合贫困空间的研究内容.再利用广州市最低保障数据和五普数据构建综合贫困的指标体系,采用因子分析法总结贫困主因子,并求得各街道综合贫困得分.发现广州市内城区和外围局部地区存在综合贫困累积型分布的状况,呈现"圈层 局部放射"的综合贫困空间总体形态,内外城贫困特征有一定差异,是历史、政策和市场等多种力量长期综合作用的结果.研究对拓展中国转型期贫困地理研究视角和指标体系有一定的裨益.     

南海北部海陆过渡带地壳结构的研究现状及展望

首先总结了前人在南海北部海陆过渡带获得的研究成果：由重磁异常、水深及卫星影像等资料推测滨海断裂带存在于南海北部海陆过渡地区：介绍了最近在南海北部海陆过渡地区开展的海陆地震联测试验,其结果显示有一个穿透整个地壳的低速破碎带发育于海陆过渡地区,推测它为滨海断裂带在速度上的表现,另外广泛分布于华南大陆的中地壳低速层在海陆过渡处也有较好发育;总结了天然地震层析成像在南海北部海陆过渡带的研究成果。最后结合目前的研究现状,指出了今后我们的研究方向：在逐步完善目前海陆地震联测试验的基础上,同时开展海陆过渡带的多道地震数据采集及地球化学研究：加强海陆过渡带的地震监测。进行震源机制解和人工地震与天然地震联合成像的研究。     

塔里木盆地南缘铁克里克断隆结晶基底特征

依据在原划埃连卡特群花岗片麻岩中获得(1 970±47)M a(锆石U-Pb法)同位素年龄数据,结合岩石学、岩石地球化学及区域地层对比,从中解体出喀啦喀什岩群。通过岩石学、岩石地球化学、构造特征和变形变质特征、同位素年龄及成矿专属性研究,认为铁克里克断隆构造基底具双重构造基底特征,喀啦喀什岩群组成结晶基底,埃连卡特岩群、塞拉加兹塔格岩群组成过渡基底;蓟县纪的博查特塔格组、苏玛兰组及青白口纪的苏库勒克组及震旦系组成沉积盖层。喀啦喀什岩群对铁、铜、金多金属矿成矿有利。该成果对铁克里克断隆结晶基底的组成、发展和演化研究具有重要意义。     

Distribution patterns of SOC/TN content and their relationship with topography,vegetation and climatic factors in China’s north-south transitional zone

Journal of Geographical Sciences - The spatial distributions and variation mechanism of key soil indices in the Qinling-Daba Mountains are important indicators for the identification of the...     

Probabilistic assessment of one‐step‐ahead rainfall variation by Split Markov Process

In this paper, Split Markov Process (SMP) is developed to assess one‐step‐ahead variation of daily rainfall at a rain gauge station. SMP is an advancement of general Markov Process and specially developed for probabilistic assessment of change in daily rainfall magnitude. The approach is based on a first‐order Markov chain to simulate daily rainfall variation at a point through state/sub‐state transitional probability matrix (TPM). The state/sub‐state TPM is based on the historical transitions from a particular state to a particular sub‐state, which is the basic difference between SMP and general Markov Process. The cumulative state/sub‐state TPM is represented in a contour plot at different probability levels. The developed cumulative state/sub‐state TPM is used to assess the possible range of rainfall in next time step, in a probabilistic sense. Application of SMP is investigated for daily rainfall at four rain gauge stations – Khandwa, Jabalpur, Sambalpur, and Puri, located at various parts in India. There are 99 years of record available out of which approximately 80% of data are used for calibration, and 20% of data are used to assess the performance. Thus, 80 years of daily monsoon rainfall is used to develop the state/sub‐state TPM, and 19 years data are used to investigate its performance. Model performance is assessed in terms of hit rate (HR), false alarm rate (FAR), and percentage captured. It is found that percentage captured is maximum for Khandwa (70%) and minimum for Sambalpur (44%) whereas hit rate is maximum for Sambalpur and minimum for Khandwa (73%). FAR is around 30% or below for Jabalpur, Sambalpur, and Puri. FAR is maximum for Khandwa (37%). Overall, the assessed range, particularly the upper limit, provides a quantification possible extreme value in the next time step, which is a very useful information to tackle the extreme events, such as flooding, water logging and so on. Copyright © 2011 John Wiley & Sons, Ltd.     

Field Meeting to the Bawdsey Peninsula, Suffolk, England, 22nd May 2010, to examine London Clay, Coralline Crag and Red Crag deposits: Leaders: Roger Dixon and Bob Markham

A one-day Geologists’ Association field excursion to the Bawdsey Peninsula in coastal Suffolk is described, with a guided tour of ‘The Pliocene Island’ at Sutton Knoll and visits to examine coastal erosion, the London Clay and Red Crag at Bawdsey East Lane, and the Red Crag at Alderton and Ramsholt. The depositional environments indicated by the Crag sediments and faunas are discussed, and non-derived Red Crag mollusc faunas at Sutton and sand-wave mollusc assemblages from Ramsholt are described.