新近系全球界线层型剖面及点位(GSSP)简介

新近系全球界线层型剖面及点位(GSSP)位于意大利北部阿莱桑德利亚省卡洛西奥村的勒梅-卡洛西奥剖面,点位在距剖面之顶35m处。根据国际地层委员会的决议,作为界线定义的标志事件是:C6Cn.2n地磁极性时间带的底、浮游有孔虫Paragloborotalia kugleri的最低发生面及钙质超微化石Reticulofenstra bisecta的灭绝面(NN1带的底)附近。     

Effects of Overpressured Fluid Flow on Petroleum Accumulationin the Yinggehai Basin

The Yinggehai Basin is a strongly overpressured Cenozoic basin developed in the northern continental shelf of the South China Sea. The flow of overpressured fluids in this basin has given rise to strong effects on petroleum accumulation. (1) The overpressured fluid flow has enhanced the maturation of shallow-buried source rocks, which has caused the source rocks that would have remained immature under the conduction background to be mature for hydrocarbon generation. As a result, the overpressured fluid flow has increased the volume and interval of mature source rocks. (2) The overpressured fluid flow has strong extraction effects on the immature or low-mature source rocks in the shallow parts. This has increased, to some extent, the expulsion efficiency of the source rocks. More importantly, the extraction effects have strongly limited the effectiveness of biomarker parameters from oil and condensate in reflecting the source and maturity of the oil and gas. (3) The flow has caused the sandstones in the     

Seismic characterization of basalt flows from the Faroes margin and the Faroe-Shetland basin

High‐quality seismic profiles across the Faroes volcanic continental margin and the adjacent continental shelf show contrasting styles of basalt emplacement across two major structural boundaries. At the rifted continental margin, the basalts form prominent seaward dipping reflector sequences up to 5 km thick. The same basalts, after they had travelled in a landward direction across the elevated, subaerial Faroes shelf, produced prominent landward dipping foresets, where they flowed across the paleo‐coastline into the deep water of the Faroe‐Shetland Basin. In both cases we are able to image details of the internal structure of the basalts as a result of using a low‐frequency airgun source capable of penetrating through the basalt sequence, together with long‐offset recordings from ocean bottom seismometers and a 12 km long, deep‐towed, hydrophone streamer.     

综合致矿地质异常信息提取与集成

矿床及其周围局部和区域的地质、地球物理和地球化学以及遥感地质等勘查信息构成认识成矿规律和资源潜力评价的基础.矿产资源综合定量评价首先涉及到以建立地质成矿概念模型为基础的地质、地球化学、地球物理以及遥感地质等单学科异常信息的提取与集成, 然后是对多学科异常信息的综合提取与集成, 最后应用综合致矿信息定量圈定找矿靶区, 评价资源潜力.阐述了综合地质异常数字找矿过程中综合致矿地质异常信息提取、信息关联、信息转换和信息集成的基本概念.强调实现“由地质异常体特征到空间地质异常信息模型, 再根据空间异常信息模型推断地质异常体特征”这一信息双向转换的重要意义.结果表明: (1) 综合致矿地质异常概念模型是选择资源评价变量和建立综合地质异常数字找矿模型的基础; (2) 非线性方法技术是提取隐蔽矿化信息的有效手段; (3) 综合致矿地质异常概念模型与数字找矿数学模型的有机结合是实现数字找矿突破的关键; (4) 应用综合致矿异常信息模拟矿产资源潜力的过程实质上是一个信息逐渐提取与集成的过程, 亦是一个空间数据→空间信息→知识决策的过程.      

基于遥感技术的黑龙江上中游河道特征研究

以2000年Landsat-7 ETM+影像、地形图、数字高程数据等为数据源,从河道平面形态及河流纵剖面形态对黑龙江上中游河道特征进行分析。从河流动力特征、流域自然环境条件及人类活动方面探讨其对河道形态特征形成的影响。研究发现:黑龙江上中游河道曲折系数均值为1.20,属于微弯顺直型河道,整体相对稳定,但局部河段河道形态复杂,河流纵剖面形态为下凹型曲线;河流形态的形成遵循一定的河流动力学规律,是水流和河床在自然因素与人类活动影响下相互作用结果。     

Ground motion parameters of Shillong plateau: One of the most seismically active zones of northeastern India

Strong ground motion parameters for Shillong plateau of northeastern India are examined. Empirical relations are obtained for main parameters of ground motions as a function of earthquake magnitude, fault type, source depth, velocity characterization of medium and distance. Correlation between ground motion parameters and characteristics of seismogenic zones are established. A new attenuation relation for peak ground acceleration is developed, which predicts higher expected PGA in the region. Parameters of ...     

Numerical modeling of the development of southeastern Red Sea continental margin

The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolution of Red Sea rift. This margin is characterized by occurrence of thin sediments, significant onshore uplift, tectonic subsidence of the offshore sedimentary basin, active faulting and seismicity. Studies indicate that sedimentary sequences of the margin are deformed by faults and folds resulti...     

Monitor : transiting planets and brown dwarfs in star forming regions and young open clusters

The Monitor project

1 www.ast.cam.ac.uk/∼suz/monitor/monitor.php

is a large scale photometric monitoring survey of ten star forming regions and open clusters aged between 1 and 200 Myr using wide‐field optical cameras on 2–4 m telescopes worldwide. The primary goal of the project is to search for close‐in planets and brown dwarfs at young ages through the detection of transit events. Such detections would provide unprecedented constraints on planet formation and migration time‐scales, as well as on evolutionary models of planets and brown dwarfs in an age range where such constraints are very scarce. Additional science goals include rotation period measurements and the analysis of flares and accretion‐related variability. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

1999年山西大同-阳高5.6级地震灾害损失评估

１９９９年１１月１日在山西省大同县和阳高县间发生Ｍｓ５．６地震,通过野外调查,对这次地震灾害损失进行了评估。评估结果表明,这次地震受灾面积达３２４ｋｍ＾２,主要受灾村５６个,重伤１０人,轻伤６０人,总经济损失为１４０２３万元。指出灾区所有房屋经历了１９８９年、１９９１年１次或２次中强地震的破坏,抗震能力明显降低是这次震害较生的主要原因。并针对这次震害的特征,提出防御与减轻震害的经验、教训及有关建议