The role of basement tectonic reactivation on the structural evolution of Campos Basin,offshore Brazil: Evidence from 3D seismic analysis and section restoration

The structural analysis of regional 3D seismic data shows evidence of long-term tectonic inheritance in Campos Basin, offshore Brazil. Main Lower Cretaceous rift structures controlled themselves by strike-slip deformation belts related to Proterozoic orogenic events, have been episodically reactivated during the divergent margin phase of Campos Basin, from the Albian to the Miocene. Balanced cross-sections of major salt structures indicate that such tectonic reactivations have been controlling thin-skinned salt tectonics, triggering pulses of gravitational gliding above the Aptian salt detachment. Additionally, major basin features like the Neogene progradation front and the salt tectonic domains are constrained by the main Proterozoic orogenic trends of the Ribeira Belt (NE–SW) and the Vitória-Colatina Belt (NNW–SSE). As the basement involved structures observed in Campos Basin can be attributed to general geodynamic processes, it is suggested that basement tectonic reactivation can be as relevant as isostatic adjustment and detached thin-skinned tectonics on the structural evolution of divergent margin settings.     

Integrating structural geology and petroleum systems modeling – A pilot project from Bolivia's fold and thrust belt

For the first time, a new approach to petroleum systems analysis is presented which allows full integration of tectonic and palinspastic restoration with three-dimensional (3D), PVT-controlled, multi-component, three-phase petroleum migration analysis through time. A systematic modeling study has been applied to a study area dominated by fold and thrust belts located in the Sub Andean orogeny near Tarija, Bolivia. The project has been performed with a special focus on the simulation technique and on the correct distribution of temperature, source-rock maturity and pressure development through time with reference to its input data. This is the first pilot project presenting a 3D numerical model in a compressional structural regime to which the basin modeling approach has been applied to explain the observed distribution of temperature, pressure, maturity and petroleum accumulations in general.     

乌鲁木齐地区中小地震震源机制解及构造应力场

主要对乌鲁木齐地区中小地震震源机制解及构造应力场进行分析。 结果表明, 乌鲁木齐地区中等地震震源断错性质主要以倾滑逆断层为主, 地震破裂面与其附近构造走向基本一致, 主压应力P轴方向为NE向或近NS向; 乌鲁木齐地区小地震的震源断错性质表现出一定的区域性, 破裂面以近EW向为主, 主压应力P轴方向近NS向, 兼有部分NE向或者NW向。 显示出小地震的发生既受局部地质构造的影响, 也受区域构造应力场的影响。     

三维随机波浪对桩柱的作用

试验研究了三维随机波浪作用于垂直圆柱上的作用力.采用二维波浪的方法计算三维波浪力,研究了各波力系数随ＫＣ数和波浪方向分布的变化规律,并对三维波力和二维波力进行了对比分析.     

青城子地区早元古宙辽吉岩套的构造演化

本文讨论了辽东青城子地区早元古宙辽吉岩套的构造变形作用与构造演化。作者提出了青城子推覆构造的三阶段演化模式。早期阶段,即第1变形幕形成了北西向转南西向的同斜倒转褶皱,构成了青城子推覆体的雏形;第2变形幕以剪切体制为主,辽吉花岗岩活化和底辟重就位形成了推覆体构造,并产生了逆冲型韧性剪切带;第3变形幕形成了叠加在推覆体构造上的北东向倾伏背斜、向斜构造,并使推覆体构造发生整体机械变位,最终奠定了青城子地区的宏观构造格局。     

高寒地区渠道防治冻害技术措施

依据黑龙江省水利科学研究院近20年来水工建筑物抗冻技术研究的主要成果,简述了高寒地区渠道防治冻害技术的主要内容,包括:抗冻胀设计参数的确定方法、渠道衬砌工程防治冻害技术措施的要点等,可供工程设计人员参考。     

Emplacement and deformation of the ca. 1.45 Ga Karlshamn granitoid pluton,southeastern Sweden,during ENE-WSW Danopolonian shortening

Anisotropy of magnetic susceptibility and structural geology of the ca. 1.45 Ga Karlshamn pluton (southern Sweden) are used to study its emplacement and structural evolution. The Karlshamn pluton is one of the largest metaluminous A-type granitoid intrusions in southern Sweden. It is a multiphase body made up of two suites that differ in composition but which have similar crystallization ages. The magmatic foliation, ductile shear zones and granite–pegmatite filled fractures were mapped as well as the metamorphic foliation and extension lineation in the metamorphic host rocks. The anisotropy of magnetic susceptibility was used to map the magnetite petrofabric of the pluton, providing a larger data set for both the magmatic foliations and lineations, which could not be mapped in the field. The fabrics within the pluton are continuous with the metamorphic fabrics in the country rocks. Both the pluton and the country rock fabrics were folded during ENE–WSW compression, while the pluton was still a magma mush. The stress field orientation during cooling of the pluton is determined on the basis of magmatic, ductile and brittle structures in the Karlshamn pluton that formed successively as the pluton cooled. The compressional event is referred to as the Danopolonian orogeny and therefore the Karlshamn granitoids, and other plutons of similar composition and age in central and southern Sweden, on the Danish Island of Bornholm, and in Lithuania, may be considered as syntectonic intrusions and not as anorogenic, as was previously thought.     

构造趋势法计算剥蚀量的计算机实现

剥蚀量的计算是盆地非连续沉降沉积模拟过程中一个非常重要的问题,通过量化模式分析,将构造趋势法计算剥蚀量在计算机上得以实现,并在实际应用中取得较好效果。     

重庆市南岸区土地利用变化及原因分析

利用重庆市南岸区1996—2004年土地利用现状年度变更调查数据，分析其土地利用变化的过程及引起土地利用变化的原因。分析结果显示：人口增长、经济发展、农业结构调整、政策等因素是南岸区土地利用变化的主要驱动因子。并提出土地可持续利用的建议。