中国南方海相含油气保存单元的层次划分与综合评价   总被引：1，自引：0，他引：1  

梁兴  叶舟  马力  吴少华  张廷山  刘家铎  徐克定 《海相油气地质》2004,(Z1)

以最近十年中国南方的海相新区油气勘探评价成果为依托 ,以油气成藏和整体封闭保存体系评价为核心 ,在渝东—湘鄂西、中下扬子和滇黔桂三大区域划分出 9个有利区块 5 1个含油气保存单元 ,并将其归纳为四个层次。综合评价认为 ,方西和石柱保存单元具有较好的整体封存体系 ,属持续性含油气保存单元 ,为首选勘探目标 ;江汉盆地南部、句容—海安区块、南鄱阳坳陷、楚雄盆地东北部具备或基本具备整体封存条件 ,属于沉积重建型含油气保存单元 ,通过精细勘探可望获得商业性油气流 ;楚雄盆地西北部、南盘江坳陷、十万大山盆地和渝东—湘鄂西地区利川复向斜由于晚期强烈构造改造而仅存在部分封存体系 ,需要攻关探索 ;思茅、渝东—湘鄂西地区的花果坪和桑植—石门地区已失去整体封闭保存条件 ,仅局部存在封存体系 ,地质条件高度复杂 ,勘探风险甚高。  相似文献   

沉积学的发展历程与未来展望   总被引：6，自引：0，他引：6  

于兴河  郑秀娟 《地球科学进展》2004,19(2):173-182

沉积学的概念自提出以来，其发展经历了：萌芽、初步形成、专业研究、总结提高、理论升华及学科渗透与综合 7个发展阶段，每一阶段都充分表现出，一方面受科学技术进步的影响，另一方面对全球经济的发展与进步又起到了不可忽视的推动作用，尤其是在各种沉积矿床和油气的寻找方面。随着地质勘探与开发实践的不断进行，已陆续在沉积体中发现了油气、煤、黄金、铀、金刚石、钾、水晶、铂、铝、锰、膏盐及天然气水合物等多种重要矿产，为全球经济的发展做出了不可磨灭的贡献。沉积学未来的发展在 7个方面表现出明显的规律性：层次上，由宏观向微观；方法上，由定性向定量；目的上，由理论向应用；形式上，由静态向动态；学科上，由单学科向多学科；手段上，由手工向计算机；领域上，由地区向全球发展的总体趋势。  相似文献   

A coherency function model of ground motion at base rock corresponding to strike-slip fault   总被引：2，自引：0，他引：2  

丁海平  刘启方  金星  袁一凡 《地震学报(英文版)》2004,17(1):64-69

IntroductionEarthquakedamagesurveyandresearchresultshavedemonstratedthatspatialdistributiondifferenceofgroundmotionisoneoftheimportantreasonswhichcausedlongstructure(eglongspanbridge,undergroundpipe)destroy.Thathowtoprovideareasonableinputofgroundmotionfieldforaseismicdesignoflongstructureisaurgentprobleminearthquakeengineeringfield.Atpresent,themethodtostudyspatialvariationofgroundmotionsisadoptingstatisticanalysisbasedondensearrayrecordssuchasSMART-1array,etc,togetcoherencyfunctionofground…  相似文献   

Pedogenic factors affecting magnetic susceptibility of the last interglacial palaeosol S1 in the Chinese Loess Plateau     

Z.‐D. Feng  H. B. Wang  C. G. Olson 《地球表面变化过程与地形》2004,29(11):1389-1402

The magnetic susceptibility has been used as a quantitative or semi‐quantitative proxy for reconstructing the summer monsoon intensity in the Chinese Loess Plateau based on extensive studies on climatic or/and environmental mechanisms producing the magnetic susceptibility signatures. However, the precise nature of the link between past climates and the susceptibility signatures has remained uncertain primarily due to lack of our understanding in the ?nalizing and preserving processes of the signatures. This paper attempts to examine the reliability or acceptability of this summer monsoon proxy from non‐magnetic perspectives of soil‐forming processes. We chose nine sections along two transects: one across the western part of the Chinese Loess Plateau and another across the eastern part. Several conclusions can be drawn from our analytical data. First, clay translocation within the S1 palaeosol pro?les, as indicated by ?eld‐observed clay coatings on ped faces in Bt and Bk horizons and demonstrated by laboratory‐analysed clay contents, must have moved some of the magnetic minerals downward so that the susceptibility re?ects only the post‐translocation distribution of the magnetic‐susceptibility‐producing minerals. Second, the best‐developed palaeosol S1S3 at most of the sections studied is not expressed by the magnetic susceptibility because this palaeosol developed in underlying coarse loess (L2) and coarse textures tend to lower the susceptibility. Third, carbonate concentration is normally negatively correlated with the magnetic susceptibility or simply suppresses the magnetic susceptibility peak when the susceptibility enhancement exceeds the carbonate dilution effect. To conclude, extreme caution must be observed when using magnetic susceptibility signatures to retrieve high‐resolution records of the last interglacial palaeoclimate in the Chinese Loess Plateau. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Optimal design of viscoelastic dampers using eigenvalue assignment   总被引：1，自引：0，他引：1  

Sang‐Hyun Lee  Dong‐In Son  Jinkoo Kim  Kyung‐Won Min 《地震工程与结构动力学》2004,33(4):521-542

In this study a procedure for determining the optimum size and location of viscoelastic dampers is proposed using the eigenvalue assignment technique. Natural frequencies and modal damping ratios, required to realize a given target response, are determined first by the convex model. Then the desired dynamic structural properties are realized by optimally distributing the damping and stiffness coefficients of viscoelastic dampers using non‐linear programming based on the gradient of eigenvalues. This optimization method provides information on the optimal location as well as the magnitude of the damper parameters. The proposed procedure is applied to the retrofit of a 10‐story shear frame, and to a three‐dimensional structure with an asymmetric plan. The analysis results confirm that the responses of model structures retrofitted by the proposed method correspond well with the given target response. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Seismic structural control using an electric servomotor active mass driver system     

Chien‐Liang Lee  Yen‐Po Wang 《地震工程与结构动力学》2004,33(6):737-754

This study investigates an electric‐type active mass driver (AMD) system for structural vibration control. Composed primarily of an electric servomotor and a ball screw, the electrical AMD system is free from noise problems, oil leakage, and labor‐intensive maintenance that commonly are associated with hydraulic AMD systems. The desired stroke amplification of the mass and the power demand of the servomotor can be adjusted via the ball screw pitch, which in turn affects the effectiveness and efficiency of the system. Meanwhile, an instantaneous optimal direct output feedback control algorithm is adopted. Numerical simulation is performed using a five‐story steel frame as the object structure under the conditions of the 1940 El Centro earthquake. The AMD system proves to be effective and efficient within a certain range of the ball screw pitch. The reductions of the peak responses can reach as high as 70% if properly designed. Requiring only the velocity measurement of the top floor for on‐line feedback control, the proposed control algorithm is recommended for practical implementation. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

地面风对瓦里关山大气CH₄本底浓度的影响分析   总被引：6，自引：1，他引：6       下载免费PDF全文

周凌晞温玉璞  李金龙汤洁　张晓春 《应用气象学报》2004,15(3):257-265

使用1994年7月至1996年12月大气CH₄和地面风现场连续观测资料，分析了瓦里关全球大气本底基准站（36°17′N, 100°54′E，海拔3816 m）地面风变化对大气CH₄本底浓度的影响。结果表明，水平风向、风速和垂直风向、风速的变化对大气CH₄观测值的影响在春、夏、秋、冬季有明显不同，水平风向NE—ENE—E为CH₄测量最主要的局地影响非本底扇区，静风及水平风速大于10 m/s、垂直风速大于±1 m/s对观测结果都有较大影响；由的统计平均还给出了此段期间瓦里关大气CH₄在不同季节的浓度分布范围和日变化类型，并分析了可能成因；将地面风数据作为大气CH₄本底资料的过滤因子之一，提出了适用于不同使用目的和要求的我国内陆高原大气CH₄本底数据筛选方法，本底数据留存率约为原始资料量的50%。  相似文献   

内蒙古大青山地区构造新样式初探     

杜菊民张庆龙  杜松金李洪喜赵世龙  解国爱 《江苏地质》2004,28(2):65-68

内蒙古大青山地区侏罗纪盆地中发育有断层相关褶皱，有十分清晰的断层传播褶皱，断层转折褶皱等构造样式。断层相关褶皱轴向呈东西向展布，形成褶皱的地层是早侏罗世右拐群煤系地层，表明该褶皱至少在煤层形成后，受南北向挤压应力作用形成。研究这一构造样式，对这一地区的推覆构造、盆山耦合研究具有重要地质意义。  相似文献   

Bio-climatic imprints on a Holocene loess palaeosol from China     

He Xiubin  Tian Junliang  Tang Keli  Sun Jianzhong  John A Matthews 《Journal of Asian Earth Sciences》2004,22(5):455

Micromorphology, heavy minerals, pollen and soil properties were examined in a typical Holocene loess profile in the north of the Loess Plateau, consisting of a palaeosol (locally known as the Ansai palaeosol) underlain by the Malan loess and overlain by modern loess. The palaeosol consists of an upper humus-rich (AB) horizon over a clay-rich (Bt) horizon. The humus-rich horizon is intensely weathered, contains precipitated calcitic material derived from the overlying modern loess, and has both high pollen content and diversity. Clay coatings in the clay-rich horizon indicate formation by eluviation–illuviation of clay. Pedogenetic characteristics and pollen analysis imply that the vegetation during the time of most intensive soil development is likely to have been a warm-temperate forest. A complex interpretation of the loess–palaeosol sequence recognizes several development stages. The phase of soil development, maximum and minimum limiting ages for which are ca. 8800 and 4400 ¹⁴C years BP, involved continuing but reduced loess deposition, and successive Holocene bio-climatic environment overprinted new features on the palaeosol.  相似文献   

Origin of Natural Gas in Kekeya Field, Tarim Basin, China     

HouDujie XiaoZhongyao TangYoujun ZhuJunzhang LiXianqing 《中国地质大学学报(英文版)》2004,15(1):91-98

This paper is mainly concentrated on the geochemical characteristics and origin of gas of Kekeya field in the Tarim basin, NW China. This study shows that Permian mudstone is the main source rock of oil and gas. Based on the carbon isotopes of C1--C4, the carbon isotope of gas in Kekeya field is a little heavier than that in the typical marine-derived gas. The relationship between carbon isotopes of methane and ethane is coincident with Faber equation of gas derived from organic matter Ⅰ/Ⅱ. The majority of gas maturity is estimated, based on the formula, at 1.8%-2.2% besides K2 and K18 wells. In addition, the gas derived from 0.9%-1.2% Ro source rocks may also bemixture. ^40Ar/^36Ar and ^3He/^4He ratios from the gas samples also support the mixing process. Moreover, the gas in this region is mainly generated from more mature source rocks although the low mature gas exists.  相似文献