Intelligence-Aided Seismic Zonation System IASHES

In this paper,the structure of the intelligence-aided seismic zonation system IASHES and its validation are briefly introduced.Emphasis is placed on the two rank scheme of potential seismic source areas; an expert subsystem for estimating the seismicity trends of rank A source areas; an expert subsystem for delineation of rank B source areas; an expert subsystem for judgment of upper limit of magnitude of rank B source areas,and an improved procedure for determination of weighting factors of rank B source areas,which is specially suitable to ES(Expert systems).     

新疆阿舍勒块状硫化物矿床成矿特征及形成环境

阿舍勒块状硫化物矿床位于阿尔泰华力西地槽系南缘。容矿岩石为中、下泥盆统富钠的火山岩系，为双峰式火山岩组合，系弧后扩张背景下的产物。矿床具双层结构，并具明显的垂向分带和侧向分带。矿体下盘火山岩发生了强烈地蚀变作用，形成由石英＋绢云母＋绿泥石±黄铁矿组成的半整合蚀变带。同位素研究表明，硫由海水硫酸盐和岩石中硫化物所提供，铅具深源的特征。通过对比，认为阿舍勒矿床与矿区阿尔泰的块状硫化物矿床相似     

长江三峡工程坝区及外围地壳稳定性评价与分区研究

本文分长江三峡工程坝区及外围（约３１对万ｋｍ２）和长江三峡工程库首区（约３万ｋｍ２）两个层次和范围进行区域地壳稳定性评价与分区研究，在构造分区及现今地应力地场研究的基础上，运用模糊数学进行地壳稳定性量化综合评价，然后结合地质分析，进行地壳稳定性分区。长江三峡工程坝区及外围地壳稳定性评价与分区结果为：库首区地壳稳定性总体系属相对较稳定一稳定状态，三斗坪坝址区属于相对稳定地块；长江三峡工程库首区地壳稳定性评价与分区结果为：三斗坪坝址位于古老的花岗岩完整块体之上，属于相对稳定（Ⅰ）地块。从区域地壳稳定性评价看，     

Regional distribution of Al-silicates and metamorphic zonation in the low-grade Verrucano metasediments from the Northern Apennines, Italy

Abstract Mineralogical and petrological studies of Triassic Verrucano metasediments of the Northern Apennines are reported. The widespread occurrence of Al-silicates allows the delineation of four metamorphic zones with increasing metamorphic grade: (1) kaolinite zone (well Perugia 2, Umbria); (2) kaolinite-pyro-phyllite zone (Monte Argentario and part of the Verrucano of the Monticiano-Roccastrada area and Monti Leoni); (3) pyrophyllite zone (Monti Pisani, Iano, Monti Leoni, the Monticiano-Roccastrada area and some wells in the Larderello region); (4) kyanite zone (Massa area and some wells in the Larderello area).
The four metamorphic zones correspond to temperatures ranging from 300°C to about 450°C. On the basis of the Si content of muscovite and geological arguments, pressures of between 3 and 5 kbar are estimated. The metamorphic zones are located more or less parallel to the bent north-west-south-east trending structural zonation of the Northern Apennines, with the concave side towards the Tyhrrenian Sea.
During the Alpine orogeny, the Verrucano metasediments underwent three folding phases each of which has produced an axial plane schistosity (S₁, S₂, S₃). During the first folding phase the Verrucano sediments were buried increasingly deeply within the crust from east to west. The climax of Alpine metamorphism was attained prior to the second folding phase with crystallization of porphyroblasts of kyanite and chloritoid in a central area located between Massa and Larderello. The inferred paleo-temperature distribution pattern resembles an asymmetric thermal high defined by the kyanite zone, and surrounded by the pyrophyllite zone. A similar pattern is still present in the Tuscan crust, as indicated by a series of geothermal anomalies passing through the Northern Apennines.     

Weathering and biokarst development on marine terraces,northwest Morocco

Weathering features are described from an arid coastal area in northern Morocco which are indicative of invasive chasmolithic and endolithic microbial communities. Active weathering of marine terraces and karst development is associated with endolithic and epilithic algae responsible for boring, disintegration of matrix and mineral fabrics, solution and biomineralization that undermines the marine carbonate platform. Evidence of a range of biological weathering agents remains preserved, speci?cally calci?ed ?laments and sporangial material. An abundance of ?laments and spores representative of a consortium of algae, fungi, cyanobacteria and lichens is associated with the most denuded outcrops. The array of microbes contributes to the formation of the stromatolites to depths of 0·5 m within the limestone substrate. The preservation of stromatolites is supported by calci?cation of spores and ?laments, with trapping and binding of carbonate held in suspension by vadose waters. The pervasive weathering on this sector of coastline has important practical implications for coastal planning and development authorities in Morocco. Copyright © 2003 John Wiley & Sons, Ltd.     

冀中地区的侏罗系

冀中地区侏罗系为一套杂色含煤碎屑岩层系 ,自下而上发育有 Osmundacidites- Cyathidites- Gleicheniidites-Protoconiferus、L eiotriletes- Cycadopites- Quadraeculina- Classopollis及 Granulatisporites- L eiotriletes- Cyathidites- Cy-cadopites等 3个孢粉化石组合。冀中地区侏罗系岩性组成及化石组合特征与周边地区具有一定可对比性 ,但因其岩性具有明显的特殊性 ,故自下而上新建葛渔城组、杨村组和苏桥组。同时对冀中地区侏罗纪岩石地层系统的区域对比关系和地质时代进行了初步讨论。     

Seismic hazard in Northern Algeria using spatially smoothed seismicity. Results for peak ground acceleration

Seismic hazard in terms of peak ground acceleration (PGA) has been evaluated in northern Algeria using spatially smoothed seismicity data. We present here a preliminary seismic zoning in northern Algeria as derived from the obtained results.Initially, we have compiled an earthquake catalog of the region taking data from several agencies. Afterwards, we have delimited seismic areas where the b and m_max parameters are different. Finally, by applying the methodology proposed by Frankel [Seismol. Res. Lett. 66 (1995) 8], and using four complete and Poissonian seismicity models, we are able to compute the seismic hazard maps in terms of PGA with 39.3% and 10% probability of exceedance in 50 years.A significant result of this work is the observation of mean PGA values of the order of 0.20 and 0.45 g, for return periods of 100 and 475 years, respectively, in the central area of the Tell Atlas.     

改进的模糊模式识别方法在测井曲线分层中的应用

应用改进的基于数域上的模糊模式识别方法，综合多条测井曲线进行自动分层。首先，找出各条曲线总的上升沿（或下降沿），然后，在对上升沿（或下降沿）中各采样点构造模糊集时采用测井曲线的斜率，而不是采用测井曲线值。在求取各点隶属度时，采用各条曲线中的最大斜率值，反映了地层分层点在测井曲线拐点这一客观规律。最后，应用贴近度准则分层。该方法给出了更合理的分层点。