震前深井电磁短临前兆信息的观测和研究

本文应用大量震例研究了地震前深井电磁波短临前兆信息。研究结果表明，在１．９和２７ｋＨｚ信道上，地震前２－４个月和１０－６Ｏ天，可观测到短临型、短期型和临震型三种电磁波信号。电磁信号增强时段与孕震区小震频度增强同步，表明这些信号可能与孕震区微破裂有关。本文还利用信息包源偶全体模型定量计算了组成变化的电磁场的准静场、感应场、辐射场随观测距离及方位的变化，据此对观测结果进行了初步解释。     

Recognition of the hydrogeological potential using electrical sounding in the Khemisset-Tiflet region,Morocco

The low recharge of reservoirs and the increasing demand for water limit the potential of mobilized resources, especially in arid to semi-arid areas like Morocco. Integrated management is essential to safeguard this resource. In respect with this perspective, this work provides the analysis of hydrogeological potential of Khemisset-Tiflet region, which falls within the action area of the Sebou Hydraulic Basin Agency. The basis of our studies was as follows:(1) The interpretation of the existing geoelectric data;(2) application of geophysical methods for non-destructive reconnaissance and their integration into a Geographic Information System(GIS). The analysis demonstrates that: The map of the isohypses and the geoelectric cross-section of the substratum of the superficial roof aquifer show clearly a plunge associated with development of the Paleozoic roof in the South and the direction of flow of the surface water is from south to north, from the upper zone to the north of the El Kansera dam. These conclusions constitute very useful contribution for any resource management projects in this area.     

Effective Community Engagement for Sustainability: Wombat Community Forest Management Case Study

The first significant government sponsored community‐based forest management project in Australia was initiated in Central Victoria in 2002. This paper analyses the initial stage of the Wombat Community Forest Management Pilot Project. The paper develops a functional concept of ‘effective community’ for structuring community engagement in these kinds of natural resource management projects. The effective community has characteristics in common with a community of interest, adopts a bioregional perspective, embodies the values of environmental stewardship and interacts in a fully informed way as a ‘discursive community’ (Meppam 2000 Meppam, T. 2000. ‘The discursive community: evolving institutional structures for planning sustainability’, Ecological Economics, 34: 47–61.  [Google Scholar]). The paper offers general advice for organising effective community engagement in such projects and 12 recommendations for governments developing similar initiatives elsewhere.     

Les monchiquites de Tchircotché, vallée de la haute Bénoué (Nord du Cameroun)

Dykes of monchiquites of Cainozoic age (37.5±2.3 Ma) are intrusive in Cretaceous sandstones in the Tchircotché area, Upper Benue valley (northern Cameroon). The differentiation of the monchiquites is explained by crystal fractionation of olivine, clinopyroxene, magnetite, ilmenite and apatite. A studied rock has low Sr-isotope ratio $\text{(0.703}\text{69±10)}$, which is similar to those of the alkali basalts of the Cameroon Line. Therefore the continental crust appears to have no significant role in the genesis of the monchiquites.     

2003年7月28日晋东南及豫北区域暴雨天气分析

利用MICAPS系统提供的资料，对2003年7月28日发生在晋东南和豫北区域暴雨过程的大尺度环流背景和物理量场进行了分析。得出：本次暴雨过程是在中纬度西风槽与中低空切变线的相互作用下产生的，前期不稳定能量的高度积累为暴雨提供了充沛的水汽和能量，近地面层的微弱扰动触发了不稳定能量的释放，为暴雨的发生提供了动力条件。     

Crystal Structure of Natural Non-metamict Ti- and Fe~(2+)-rich Chevkinite-(Ce)

1 Introduction Chevkinite groups can be assigned to the chevkinite-(Ce) subgroup and perrierite-(Ce) subgroup in accord with the angle β : β ≈ 100o for the chevkinite subgroup and β ≈ 113o for the perrierite subgroup. Chevkinite-(Ce), polykovite-(Ce) and Maoniupingite (new mineral No. 017 of 2003) belong to the former subgroup, while renjeite and matsubaraite belong to the latter group. As strontio-chevkinite is a Sr-analogue of perrierite, usually the natural chevkinite-(Ce) group min…     

Un réseau fluviatile d'âge Burdigalien terminal dans le Sud-Est de la France : remplissage,extension, âge,implications

An integrated study combining facies analysis, multiple group biostratigraphy, identification of depositional sequences and mapping has been conducted on the Miocene Molasse Basin of the external Alps (southeastern France). The filling of the basin is described as resulting from a succession of fluvial incisions subsequently filled during marine transgressions. The major incision is dated as Latest Burdigalian and the major transgression as Langhian. This revised interpretation of the Miocene physiographic evolution of the Molasse Basin implies a re-examination of previous stratigraphic correlations within the basin. To cite this article: D. Besson et al., C. R. Geoscience 337 (2005).     

Subsurface structure of the volcanic centre of the České Středohoří Mountains, North Bohemia, determined by geophysical surveys

Former geophysical surveys performed in the region of the volcanic centre of the České Stř edohoří Mts. in North Bohemia (the Ohře Rift zone) showed that anomalous volcanic bodies and features can be effectively identified within sedimentary environment. For this reason we carried out new geophysical measurements in the area of the main mafic intrusion of essexitic character. The target was the exact location and geometry of the intrusion and its relation to other components of the volcanic centre. We used gravity, magnetic, shallow seismic and electromagnetic techniques. The new gravity and magnetic data were tied to the old databases so that we could investigate the area as a whole complex. Electromagnetic measurements were applied in the area of the expected extent of the intrusion, and the seismic measurements in the central part of the intrusion. Based on all the data, mainly on gravity modelling, we delineated not only the surface and subsurface extent of the intrusion, but we also defined the hidden relief of the intrusion. It was found that the intrusion is formed by a single body that has a few protrusions, and not by a set of separate individual intrusions, as indicated by surface outcrops. However, the body of the intrusion is affected by a major fault that caused lithological differences on both sides (essexite/monzodiorite). In detail we show the depth of the debris cover and the thickness of the weathered zone in the central part of the essexite body. We also derived indications of tectonic elements in the area of the intrusion in the main structural/tectonic direction in the region. The results will be utilized to establish a 3D geological model of the whole volcanic centre. This investigation may serve as an example of non-seismic geophysical exploration applied to the study of volcanic centres surrounded by sedimentary rocks.     

The geology of Mount Hasan stratovolcano, central Anatolia, Turkey

Mount Hasan is a double-peaked stratovolcano, located in Central Anatolia, Turkey. The magmas erupted from this multi-caldera complex range from basalt to rhyolite, but are dominated by andesite and dacite. Two terminal cones (Big Mt. Hasan and Small Mt. Hasan) culminate at 3253 m and 3069 m respectively. There are four evolutionary stages in the history of the volcanic complex (stage 1: Kecikalesi volcano, 13 Ma, stage 2: Palaeovolcano, 7 Ma, stage 3: Mesovolcano and stage 4: Neovolcano). The eruptive products consist of lava flows, lava domes, and pyroclastic rocks. The later include ignimbrites, phreatomagmatic intrusive breccias and nuées ardentes, sometimes reworked as lahars. The total volume is estimated to be 354 km³, the area extent 760 km². Textural and mineralogical data suggest that both magma mixing and fractional crystallization were involved in the generation of the andesites and dacites. The magmas erupted from the central volcanoes show a transition with time from tholeite to calc-alkaline. Three generations of basaltic strombolian cones and lava flows were emplaced contemporaneously with the central volcanoes. The corresponding lavas are alkaline with a sodic tendency.