地学数据产品的开发、发布与共享

数据是科学研究的基础,数据共享可以最大程度地发挥数据的使用价值,数据是实现数据共享最基本的要素。地学数据具有空间性、综合性、时间性、海量性、多源性等特点。属性数据、遥感数据、矢量数据是加工生产地学数据产品的重要数据源,属性数据空间化是加工、生产地学数据产品的重要技术手段。地学数据共享发布平台应当具备用户管理、数据目录查询、元数据管理、数据查询与浏览、数据下载等基本功能。推进科学数据共享,必须要有相应的政策措施保证,必须建立公正、合理的数据工作评价体系。     

海南岛含杜内早期腕足动物群层的发现

白沙县金波附近的 Spirifer subgrandis Rotai,Unispirifer extensus Tan,Fusella tornacensis (Koninck) ,Punctospirifer insculptus (Phillips) ,Marginatia huaqiaoensis Tan,Palaeochoristites sp.,Megachonetes sp.,Plicochonetes sp.,Schuchertella sp.,Pustula sp.,Sentisia sp.,Crurithyris sp.,Rhipidomella spp.等是海南岛首次发现的最丰富的杜内早期腕足动物群。据此 ,该地区含化石的南好组第四段确定为下石炭统岩关阶 ,似可与湖南马栏边组、黔南汤耙沟组等层位对比。以石燕贝类最繁盛、长身贝类数量少为特征的该动物群与华南其他地区同期腕足动物群存在诸多相同属种但又有明显差异。     

姬塬地区长8油层组浅水三角洲沉积特征

姬塬地区位于鄂尔多斯盆地中偏西部地区,晚三叠世主要受北东、北西及南部三个方向的物源控制。通过岩心观察、薄片鉴定、测井曲线等资料的综合分析,对研究区上三叠统长8油层组岩石类型、沉积构造、物源方向、古生物和沉积相特征进行了详细研究,发现长8沉积时期姬塬地区地形平缓,河流作用较弱,主要发育一套浅水三角洲沉积体系,其沉积作用和砂体展布受湖平面升、降和物源方向控制明显,对油气成藏有着重要的意义,表现为:①湖平面上升期,湖岸线快速向物源方向迁移,以发育长条状和鸟足状水上—水下分流河道砂体为主;②下降期以发育三角洲平原为主,来自不同物源方向的前缘砂体在研究区中部交汇;③湖平面上升期水下分流河道砂体呈席状发育以及岩性遮挡条件更好,因而比湖平面下降期发育的砂体更有利于形成岩性油藏。     

酒泉盆地青西凹陷下沟组湖相热水沉积岩锶同位素地球化学特征

以地质背景、物质组分和岩石组构分析为基础,对酒泉盆地青西凹陷下沟组湖相热水沉积钠长石—铁白云石岩进行了Sr同位素地球化学研究。结果表明,热水沉积岩87Sr／86Sr比值变化范围为0.712 25～0.717 81,平均值0.715 61,远高于同期海水和下沟组玄武岩,略高于代表早白垩世湖水锶同位素组成的藻灰岩,但低于基底壳源硅铝质岩,反映热流体不可能为单纯的湖水或幔源岩浆水;其中直接化学结晶沉淀的纹层状泥微晶热水沉积岩锶同位素比值变化范围较小,可代表均一化的热卤水池流体锶同位素组成特征;指示不同喷流口位置的“水爆角砾岩”锶同位素组成变化较大,但同一位置的热水角砾与胶结物锶同位素组成基本一致,说明两者应属于具相同成因意义的同期热水喷流沉积产物;综合青西凹陷下沟组湖相热水沉积岩锶同位素地球化学特征,初步推测早白垩世湖底热流体可能为富集硅铝质基底岩石高放射成因Sr的深循环下渗湖水与少量上升幔源岩浆水构成的混合热流体,可为青西凹陷早白垩世湖底热流体性质的确定以及热流体循环动力学模型和热水沉积模式的建立奠定基础。     

Co‐seismic Faults and Geological Hazards and Incidence of Active Fault of Wenchuan Ms 8.0 Earthquake,Sichuan, China

Abstract: There are two co-seismic faults which developed when the Wenchuan earthquake happened. One occurred along the active fault zone in the central Longmen Mts. and the other in the front of Longmen Mts. The length of which is more than 270 km and about 80 km respectively. The co-seismic fault shows a reverse flexure belt with strike of N45°–60°E in the ground, which caused uplift at its northwest side and subsidence at the southeast. The fault face dips to the northwest with a dip angle ranging from 50° to 60°. The vertical offset of the co-seismic fault ranges 2.5–3.0 m along the Yingxiu-Beichuan co-seismic fault, and 1.5–1.1 m along the Doujiangyan-Hanwang fault. Movement of the co-seismic fault presents obvious segmented features along the active fault zone in central Longmen Mts. For instance, in the section from Yingxiu to Leigu town, thrust without evident slip occurred; while from Beichuan to Qingchuan, thrust and dextral strike-slip take place. Main movement along the front Longmen Mts. shows thrust without slip and segmented features. The area of earthquake intensity more than IX degree and the distribution of secondary geological hazards occurred along the hanging wall of co-seismic faults, and were consistent with the area of aftershock, and its width is less than 40km from co-seismic faults in the hanging wall. The secondary geological hazards, collapses, landslides, debris flows et al., concentrated in the hanging wall of co-seismic fault within 0–20 km from co-seismic fault.     

Dextral‐Slip Thrust Faulting and Seismic Events of the Ms 8.0 Wenchuan Earthquake,Longmenshan Mountains,Eastern Margin of the Tibetan Plateau

Abstract: Dextral-slip thrust movement of the Songpan-Garzê terrain over the Sichuan block caused the Ms 8.0 Wenchuan earthquake of May 12, 2008 and offset the Central Longmenshan Fault (CLF) along a distance of ~250 km. Displacement along the CLF changes from Yingxiu to Qingchuan. The total oblique slip of up to 7.6 m in Yingxiu near the epicenter of the earthquake, decreases northeastward to 5.3 m, 6.6 m, 4.4 m, 2.5 m and 1.1 m in Hongkou, Beichuan, Pingtong, Nanba and Qingchuan, respectively. This offset apparently occurred during a sequence of four reported seismic events, EQ1–EQ4, which were identified by seismic inversion of the source mechanism. These events occurred in rapid succession as the fault break propagated northeastward during the earthquake. Variations in the plunge of slickensides along the CLF appear to match these events. The Mw 7.5 EQ1 event occurred during the first 0–10 s along the Yingxiu-Hongkou section of the CLF and is characterized by 1.7 m vertical slip and vertical slickensides. The Mw 8.0 EQ2 event, which occurred during the next 10–42 s along the Yingxiu-Yanziyan section of the CLF, is marked by major dextral-slip with minor thrust and slickensides plunging 25°–35° southwestward. The Mw 7.5 EQ3 event occurred during the following 42–60 s and resulted in dextral-slip and slickensides plunging 10° southwestward in Beichuan and plunging 73° southwestward in Hongkou. The Mw 7.7 EQ4 event, which occurred during the final 60–95 s along the Beichuan-Qingchuan section of the CLF, is characterized by nearly equal values of dextral and vertical slips with slickensides plunging 45°–50° southwestward. These seismic events match and evidently controlled the concentrations of landslide dams caused by the Wenchuan earthquake in Longmenshan Mountains.     

开敞式滩海油田保滩促淤工程研究

分析了飞雁滩油田海区的海洋环境条件,试验研究了不同结构型式潜堤的稳定性和保滩促淤效果,对潜堤的保滩促淤效果和淤积速率进行了预测,对工程布置、潜堤结构方案、基础冲刷防护措施和潜堤顶高程提出了建议．     

东亚地区夏季大气环流季节循环进程及其在区域持续性降水异常形成中的作用

利用32年(1968～1999年)月平均NCAR/NCEP再分析资料,分析了东亚地区夏季大气环流的季节循环进程, 并以1991/1994年为例,探讨了东亚地区夏季7～8月对流层上层环流的季节循环提前和延迟与气候平均的季节循环的差异,以及在江淮流域持续性降水异常过程中的作用,证实东亚地区季节循环的变异对形成我国东部地区持续性降水异常,特别是7月旱涝起着重要作用,江淮流域旱涝一般是和东亚地区大气环流季节循环的提早或推迟一个月左右相对应.通过波作用量的动力学诊断分析,研究了欧亚大陆沿副热带西风急流传播的异常准静止波的传播特征,并从以副热带西风急流为波导的准静止波(或者遥相关)角度对东亚地区夏季7～8月环流季节循环进程提前和延迟的可能机制作了分析.     

茅尾海夏季海水与表层沉积物叶绿素a空间分布研究

根据2011年6月茅尾海生态环境调查资料,对该海域海水和表层沉积物中叶绿素a的空间分布进行了分析。结果表明,海水叶绿素a变化范围1.384~4.060 mg/m3,平均值为2.143 mg/m3,表层沉积物叶绿素a范围为0.006~0.740 mg/kg(湿重),均值为0.124 mg/kg;海水与表层沉积物叶绿素a均呈现自河口向南逐渐降低的空间分布特征。单位面积表层沉积物叶绿素a平均含量为上方水柱叶绿素a平均含量的129.44%,沉积物对该海域初级生产力有显著的潜在贡献。相关分析表明,海水和沉积物叶绿素a均与无机氮及底栖动物栖息密度呈显著或极显著的正相关关系(P0.05或P0.01)。     

LDPC码及其研究进展

对低密度奇偶校验码(LDPC)的结构、编译码原理进行了介绍，并与turbo码进行了简单的比较，最后对目前LDPC码的几个研究方向及其进展作了较详细的论述，指出LDPC码具有很大的发展前景。