Late Quaternary surface deformation and rupture behavior of strong earthquake on the segment north of Mianning of the Anninghe fault

The Anninghe fault is an important active fault along the eastern boundary of Sichuan-Yunnan active tectonic block, and the study of its surface deformation and rupture behavior during strong earthquake in the late Quaternary is of fundamental importance for understanding the future seismic risk of the fault zone or even the entire western Sichuan region. Using the methods of detailed geomorphic and geological survey, digital image analysis, total station instrument survey, excavation of combined trench and dating, we analyze the geomorphologic sequences of the offset strata at several sites where the late Quaternary deformation remnants are fairly well preserved and obtain some new results as follows: Strong earthquake events with left-lateral displacements of about 3 m occurred at the two sites of Zimakua and Yejitong at 1634-1811, 1030-1050 and 280-550 a BP, respectively, and the recurrence interval is 520-660 a; The youngest event in the area of Dahaizi-Ganhaizi should be the earthquake of 1536, other events are at 1768-1826, 2755-4108 and 4108-6593 a BP, respectively, with a recurrence interval of 1300-1900 a. The strong earthquake activity shows a clustering character. The possibility of occurrence of a strong earthquake exists on the north segment of the Anninghe fault sometime in the future.     

Coupling relationships between brachiopods and Girvanella during the Late Devonian F-F transition in Guilin, South China

The abundance curves derived from area proportions of brachiopods and Girvanella in the thin sections from the Yangdi section, South China, exhibits complex relationships during the Late Devonian Frasnian-Famennian transition. The living activity of brachiopods such as grazing and borrowing did great damage to the growth of Girvanella. However, there was more to just a mere a survival competing relationship between them, Girvanella actually improved marine environments by oxygenating the dysoxic ambient sea-water through photosynthesis in the lower Kellwasser Horizon. Profited from this improvement brachiopods’ abundance increased subsequently and suppressed Girvanella again. Nonetheless, without Girvanella’s photosynthesis, brachiopods were wiped out by the farther anoxic environments in the upper Kellwasser Horizon. The complex relationships between Girvanella and brachiopods may be a key to unlocking the relationships between geomicrobes and metazoans in the geological overturn periods. Supported by NSFC Innovation Research Group Program (Grant No. 40621002), MOE Innovative Research Team Program (Grant No. IRT0546), the National Natural Science Foundation of China (Grant Nos. 40472020, 40730209, 40802005 and 40872001) and SINOPEC Project (Grant No. G0800-06-ZS-319)     

Episodic Fluid Injections in Overpressured Basins:A Case Study from Yinggehai Basin

INTRODUCTIoNTheprocessesandratesoffluidflowsinsedimentarybasinsareakeyforunderstandingdiagenesis,thermalconvec-tionandpetroleumaccumu1ationanddistribution.Therearemorethan18ooverpressuredbasinsintheworld(Hunt,l996,l99o).Episodicexpulsionisbelievedbymanyinvesti-gatorstobethemainprocessesforprimaryhydrocarbonmi-grationinoverpressuredsourcerocks.However,littlehasbeenknownaboutthenatureoffluidinjectionandpetroleumaccumulationinoverpressuredbasins.TheYinggehaibasinisoneofthefourmajorTertiaryb…     

Dijkstra 最短路径算法的一种高效率实现

在已存在的一些最短路径算法测试总结的基础上,根据ＧＩＳ中网络计算的实际情况,从网络结构的拓扑表示以及Ｄｉｊｋｓｔｒａ 算法中快速搜索技术的实现入手,提出了一种Ｄｉｊｋｓｔｒａ 最短路径算法的高效率实现方法。     

基于DEM及GIS的最佳位置的自动确定

阐述了用数字高程模型的理论去解决自动确定最佳观察位置的思想及算法。考虑到实际问题的复杂性,提出了从ＧＩＳ数据库中获取知识,以解求更为复杂的最佳位置的定位问题。实例验证了基于ＧＩＳ的最佳位置的自动确定算法的正确性。     

参数线性规划及应用讨论

本文介绍了测绘运筹学参数线性规划的实用意义,并就如何应用参数线性规划为测绘生产管理提供量化决策依据进行了讨论。     

广西五圩锑矿床的水锑铅矿及其物种归属

Bindheimite is a secondary antimony oxide minera l and a weathering product of jamesonite. It is reported that bindheimite occurr in an antimony deposit at the surface of the earth′s crust in Wuxu,Guangxi, China.     

An efficient solution for building polygonal objects

Polygonal object is a fundamental type of geometric data in vector GIS. The key step of cleaning topological relationship after data collection of polygonal layer is to build polygonal objects from digital arcs. The raw digital arcs may intersect with each other. The algorithm for building polygonal objects after the raw arcs have been split at all intersections is presented. The build-up of polygonal objects in this paper is designed to be implemented by two steps. The first step is to extract all the polygons needed for build-up of polygonal objects from arcs. The second step is to organize polygonal objects from these polygons. For the first step, a tracing algorithm is proposed. The algorithm merely extracts the polygons needed for the build-up of polygonal objects, which is a subset of all the possible polygons that can be induced from the arcs. For the second step, an algorithm based on a specially designed order of polygons is advanced. All the topological relationships among the polygons are sho     

城市环境下的水土作用对土强度的影响

在对南宁市水化学场进行历史分析的基础上,对南宁市天然水化学场进行模拟,以模拟溶液作为土体的浸渍液,研究变异后的水化学场对土体强度的影响。     

我国与火山作用有关的宝玉石资源研究

本文将我国已发现的与火山作用有关的宝石资源划分为5种类型,① 幔源成矿类型;② 壳幔成矿类型;③ 火山作用直接成矿类型;④ 火山期后热液成矿类型;⑤ 相关类型。讨论了各种成矿类型的宝石资源的地质学及宝石学特征,介绍了它们开发的情况和对地方经济的意义。通过归纳对比,认为我国目前对与火山作用有关的宝玉石资源形成机理及找矿勘探方面的研究工作是薄弱的。