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31.
TherelationshipbetwentheearthquakesofNingboareaandtheNeotectonicmovementJIAGENGCHEN1)(陈家庚)CUNGUOCHEN2)(陈存国)LIWANG2)(王里)BO...  相似文献   
32.
A priori, the recorded relative sea-level changes during the Cretaceous must be the combined effect of tectono-eustasy, geoidal-eustasy and various crustal level changes. To this we must add the human factor of differences and errors in interpretations.A posteriori, it is claimed that geoidal-eustasy dominated during the Hauterivian, Barremian, Turonian, Santonian and Maastrichtian, that tectono-eustasy dominated during the Albian, Cenomanian, Campanian and at the Maastrichtian/Danian boundary, and that local influences of sea-floor spreading are identified from the Albian/Cenomanian boundary onwards. To this we must add the local differential crustal movements modulating the global and regional ocean level changes. Geoidal-eustasy is mainly expressed as a latitudinal differentiation of the sea-level with out-of-phase changes between the hemispheres or the both high latitude regions. Furthermore, sedimentological records seem to record short-period geoidal-eustatic cycles.  相似文献   
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34.
Three species of Arietellidae are described from the south‐west Pacific: a new species of Paraugaptilus, a species which can not be separated from P. buchani, and Arietellus aculeatus. The identity of A. aculeatus is clarified by comparison of type material and material from the U.S. National Museum of Natural History, and an unidentified Atlantic species of Arietellus, evident from the comparison, is described.  相似文献   
35.
Landform analysis of basement rocks has been undertaken with the aid of digital elevation data, aerial photographs and field observations in central West Greenland (69°15′N–66°00′N). Palaeosurfaces have been identified, dated relatively to each other, used to quantify uplift and fault movements and also used to estimate differential erosion. Two types of palaeosurfaces were mapped across the Precambrian basement: a surface at low elevation with distinct hills (hilly relief), and two planation surfaces formed across different types of basement rocks. The hilly relief surface emerges as an inclined surface from Cretaceous cover rocks in Disko Bugt and is interpreted as a stripped late Mesozoic etch surface. This surface is cut off towards the south by a less inclined planation surface, which is younger and thus of Cenozoic age. It is similar to the post-Eocene (Miocene?) planation surfaces identified on Disko and Nuussuaq in other studies. The planation surface splits in two southwards towards high areas around Nordre Isortoq and Sukkertoppen Ice Cap. The upper planation surface forms near-summit areas of tectonic blocks dipping in different directions and with different tilts. The uplift centres define the crests of two mega blocks, separated by the ‘Sisimiut Line’ which coincides with the Precambrian Ikertôq thrust zone. A partially developed lower planation surface indicates a first uplift of maximum 500 m followed by a second uplift of maximum 1000 m. We infer that these uplift events occurred during the late Neogene based on correlation with similar surfaces on Nuussuaq and the timing of exhumational events estimated from apatite fission track analyses of samples from a deep borehole on Nuussuaq (reported elsewhere). The difference between a reconstruction of the upper planation surface across the entire area and the present topography was used as an estimate of erosion of basement rock since the formation of the upper planation surface. The erosion is unevenly distributed and varies from almost none on the well-preserved planation surfaces to 800–1300 m along valleys, and even more in the fjords. Erosion is less within areas of gneiss in granulite facies, than in areas of gneiss in amphibolite facies.  相似文献   
36.
As demand for energy is growing and resources become scarcer, energy increasingly becomes the site of heated controversies. In Latour’s terms, energy turns from a “matter of fact” into a “matter of concern”. In these energy controversies, environmental movements frequently play a central role, highlighting what is at stake in these developments. While these movements have often been studied, these studies rarely focus on the interaction between controversies, environmental movements, and place-making. In this article, we not only argue that energy is frequently turned from matter of fact into a matter of concern, but that this argument also extends to the notion of place. As such, energy controversies turn villages, cities, or regions themselves into “places of concern”. The article delves deeper into the production of places of concern through two case studies of energy controversies around power plants: a proposed coal plant in Bo Nok, Thailand, and HidroAysen, a hydropower project in Chilean Patagonia. We specifically focus on the issues that were opened up for debate in both countries, and on the role of environmental movements in the production of these places. Our examples are based on fieldwork and interviews in these two areas, as well as media and document analysis. While the two cases are from two different countries, we nonetheless find surprising parallels between them. These insights are instrumental to link theoretical debates on controversies and place-making. Moreover, they provide empirical insights into the transformative and lasting effects of energy controversies on people and places.  相似文献   
37.
The river Varde Å discharges into the bay of Ho Bugt on the western coast of Jutland forming a small, bar-built estuary. This paper deals with tidal fluxes of water and sediment in the Varde Å estuary.The inflowing water at flood tide is part of a turbidity maximum in the northern part of the bay. At high tide slack water the suspended material deposits inside the estuary. During ebb-tide it is resuspended, and the estuary bottom is washed clean coinciding with the influx of relatively pure freshwater from the drainage area.From one station in the estuary mouth, current velocities and concentrations of suspended material have been measured during 10 tidal periods covering all four seasons. It is shown how these data can be used in a quantitative calculation of the transport of water and suspended material through the cross-section of study.A model has been formulated which—based on half-tidal periods—quantifies the transport of water and suspended material through the estuary mouth.The model is calibrated on the basis of measurements made during the above-mentioned 10 tidal periods. The rather small number of measurements is to some extent compensated for by a carefully pre-arranged selection of tidal periods.The model is discussed in relation to the prediction of net suspended transport through the estuary mouth in different weather and tidal situations.  相似文献   
38.
Spis Castle, a monument included in the UNESCO World Heritage Site list (Eastern Slovakia) is built on a travertine mound overlying soft Paleogene rocks. Lateral spreading resulting from the subsidence of strong upper travertine into soft claystone strata has fractured and separated the castle rock into several cliffs. The differential movement of individual cliff faces is the primary influence on the stability of the monument. In order to monitor and quantify the movement, two techniques were adopted: a mechanical-optical TM-71 crack gauge and a demec gauge (demountable mechanical—SOMET type crack gauge). This paper presents the results and interpretation of medium and short-term monitoring at the site.  相似文献   
39.
The widening empirical and theoretical scope of political ecology has been accompanied by discussions on the coherence and content of the field. While these evaluations necessarily focus on what is included in the conceptual boundaries of political ecology, little is said about what is left out. This paper considers the struggle for land rights by Anjuman Muzareen Punjab, a movement of tenant farmers in Pakistan, to illustrate how changing research priorities, difficulties in crossing theoretical and conceptual boundaries, and geopolitics and research access can hinder the visibility of particular forms of socioenvironmental events in mainstream political ecology scholarship.  相似文献   
40.
The NW corner of the Little Hungarian Plain, which lies at the junction of the Eastern Alps, the Pannonian Basin and the Western Carpathians, is a neotectonically active region linking the extrusional tectonics of the Eastern Alps with the partly subsiding Little Hungarian Plain. The on-going deformation is verified by the earthquake activity in the region. An extremely flat part of the area, east of Neusiedlersee, the so-called Seewinkel, has been investigated with Airborne Laser Scanning (ALS, also known as airborne LiDAR) techniques, resulting in a digital terrain model (DTM) with a 1 m grid resolution and vertical precision of better than 10 cm. The DTM has been compared with known and inferred neotectonic features.Potential neotectonic structures of the DTM have been evaluated, together with geological maps, regional tectono-geomorphic studies, geophysical data, earthquake foci, as well as geomorphological features and the Quaternary sediment thickness values of the Seewinkel and the adjacent Parndorfer plateau. A combined evaluation of these data allows several tectonic features with a relief of < 2 m to be recognized in the DTM. The length of these linear geomorphological structures ranges from several hundred meters up to several kilometers. The most prominent feature forms a 15 km long, linear, 2 m high NE–SW trending ridge with gravel occurrences having an average grain size of ca. 5 cm on its top. We conclude this feature to represent the surface expression of the previously recognized Mönchhof Fault. In general, this multi-disciplinary case study shows that ALS DTMs are extremely important for tectono-geomorphic investigations, as they can detect and accurately locate neotectonic structures, especially in low-relief areas.  相似文献   
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