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1.
The hydrogeological effectiveness of fracture sets is determined and evaluated by the fuzzy c-mean and hierarchical clustering.
These cluster analyses combine the geological spatial attributes and the hydraulic relevant attributes of fractures. Based
on the results of the clustering the fracture set volumes are estimated. 相似文献
2.
The Austrian blackfly fauna were analysed with regard to spatial (ecoregions, bioregions), vertical (altitude classes) and longitudinal zonation characteristics [stream order, biocoenotic (= fish) regions] on the basis of 2600 investigation sites. Of a total of 45 species recorded, Simulium ornatum, S. variegatum, S. argyreatum and S. reptans are the most common and most frequently distributed species, occurring in 60% of the investigated sites. Although the Austrian blackfly fauna seem to be quite well documented (on average one investigation site per 32 km2) the jackknife analyses indicates that there are still some fauna deficits. Whereas the species diversity of the main ecoregions is quite similar, the number of species differs clearly between the bioregions. Within the typological context of the Water Framework Directive, the Austrian Simuliidae confirm the bioregions as the most useful spatial units for river typology. A further optimisation in predicting a target list of blackfly species of a site can be achieved by subdividing the bioregions into either catchment area and altitude classes or into longitudinal zonation types (biocoenotic regions). 相似文献
3.
Summary Intimate intergrowths of ferrotantalite and ferrotapiolite occur in a pegmatite in Spittal a.d. Drau, Carinthia. They are associated with muscovite, albite, smoky quartz, cassiterite, and microscopic uranmicrolite, zircon and uraninite. An assemblage of secondary uranium minerals is also present, generated by extensive alteration and leaching of the uranmicrolite and zircon. Textures of the ferrotantalite-ferrotapiolite intergrowths suggest considerable recrystallization that obliterated most of their primary features; neither coprecipitation nor exsolution can be recognized with certainty. Despite intersecting tielines indicating disequilibrium, the ferrotantalite and ferrotapiolite compositions show very restricted ranges (Mn/(Mn + Fe) 0.08–0.11, Ta/(Ta + Nb) 0.53–0.57 for ferrotantalite, and 0.01–0.04, 0.84–0.89 for ferrotapiolite, respectively), particularly in comparison with compositions from other localities featuring primary textures. A degree of compositional equilibration could have been attained during recrystallization. This process may also explain the high level of structural order characterizing both minerals; they are considerably disordered in other localities. Extensive deformation typical of pegmatites in the southern Ostalpen in general, and specifically of the Spittal pegmatite, is probably responsible for the recrystallization phenomena in the Ta, Nb, Sn-bearing mineral assemblage.
Eine Ferrotantalit-Ferrotapiolit Verwachsung von Spittal a.d. Drau, Kärnten, österreich
Zusammenfassung In einem Pegmatit von Spittal a.d. Drau, Kärnten, treten enge Verwachsungen von Ferrotantalit und Ferrotapiolit auf. Diese werden von Muskovit, Albit, Rauchquarz, Zinnstein sowie-in mikroskopischem Masstab-von Uranmikrolith und Zirkon begleitet. Die Textur der Verwachsungen lässt Rekristallisation erheblichen Ausmasses erkennen, die die primären Merkmale weitgehend auslöscht. Weder eine gemeinsame Auskristallisation der beiden Mineralphasen noch eine Bildung durch Entmischung kann mit Sicherheit erkannt werden. Trotz einander kreuzender Verbindungslinien, die einen Hinweis auf Ungleichgewicht darstellen, zeigen die Zusammensetzungen des Ferrotantalits und des Ferrotapiolits lediglich geringe Schwankungsbreiten: Mn/(Mn + Fe) 0,08–0,11, Ta/(Ta + Nb) 0,53–0,57 für den Ferrotantalit beziehungsweise 0,01–0,04 und 0,84–0,89 für den Ferrotapiolit. Dies gilt insbesondere für den Vergleich mit Zusammensetzungen solcher Mineralphasen mit jenen von Fundarten, die primäre Verwachsungstrukturen aufweisen. Bis zu einem gewissen Ausmass ist diese homogene Zusammensetzung möglicherweise auf die Rekristallisation zurück zuführen. Diese Rekristallisation könnte auch den hohen strukturellen Ordnungsgrad der beiden Mineralphasen erklären. An anderen Fundorten zeigen diese Minerale strukturell merklich geringeren Ordnungsgrad. Intensive metamorphe überprägung, wie sie für die Pegmatite in den südlichen Ostalpen und insbesondere für jenen von Spittal typisch sind, kann wahrscheinlich als Ursache der Rekristallisationsphänomene der Ta-Nb-Sn Mineralparagenese angenommen werden.相似文献
4.
After several decades of little work, a revised tornado climatology for Austria is presented. Tornadoes seldom form in the alpine areas, however, near the eastern flanks of the Alps, favourable conditions for tornado genesis are found. Whereas in the alpine regions less than 0.3 tornadoes per 10,000 km2 a year touch down (averaged for provinces or major parts of a province), we can count 0.9 in the greater Graz area, 1.0 in the greater Linz area and 1.2 tornadoes per 10,000 km2 a year in the greater Vienna area, suggesting the existence of so-called tornado alleys. As these regions are the most populated areas of Austria, there is a possible population bias in the dataset. The overall average for Austria is 0.3 tornadoes per 10,000 km2 a year.The database consists of 89 tornadoes, one landspout and six waterspouts, with a total of 96 events. The seasonal peak is in July with a maximum probability of tornadoes in the late afternoon and early evening hours. Every fifth tornado occurs in the hour after 5 p.m. The maximum intensity determined for a tornado in Austria was T7 on the TORRO-Scale (F3 on the Fujita-Scale), the most common intensity is T2 on the TORRO-Scale (F1 on the Fujita-Scale). 相似文献
5.
A fine‐grained slope that exhibits slow movement rates was investigated to understand how geohydrological processes contribute to a consecutive development of mass movements in the Vorarlberg Alps, Austria. For that purpose intensive hydrometeorological, hydrogeological and geotechnical observations as well as surveying of surface movement rates were conducted during 1998–2001. Subsurface water dynamics at the creeping slope turned out to be dominated by a three‐dimensional pressure system. The pressure reaction is triggered by fast infiltration of surface water and subsequent lateral water flow in the south‐western part of the hillslope. The related pressure signal was shown to propagate further downhill, causing fast reactions of the piezometric head at 5·5 m depth on a daily time scale. The observed pressure reactions might belong to a temporary hillslope water body that extends further downhill. The related buoyancy forces could be one of the driving forces for the mass movement. A physically based hydrological model was adopted to model simultaneously surface and subsurface water dynamics including evapotranspiration and runoff production. It was possible to reproduce surface runoff and observed pressure reactions in principle. However, as soil hydraulic functions were only estimated on pedotransfer functions, a quantitative comparison between observed and simulated subsurface dynamics is not feasible. Nevertheless, the results suggest that it is possible to reconstruct important spatial structures based on sparse observations in the field which allow reasonable simulations with a physically based hydrological model. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
Christoph Spötl Yuri Dublyansky Michael Meyer Augusto Mangini 《International Journal of Earth Sciences》2009,98(3):665-676
The area south of the prominent east–west trending Salzach Valley at the northern rim of the Central Alps of Austria has long
been known to host anomalously warm springs emerging from a highly deformed calcite marble (Klammkalk). This unit also hosts
cavities whose shapes suggest a hydrothermal karst origin and which are lined by calcite spar. We report here petrographic
and isotopic evidence suggesting that dissolution by ascending low-temperature thermal waters also played an important role
in the origin of a large cave in this region, Entrische Kirche. A paleo cave wall, preserved behind a thick flowstone in the
interior of this cave, revealed a brownish bleaching zone which contrasts to the medium grey colour of the unaltered marble
beneath. Across this zone the C and O isotope values gradually decrease by 3 and 11‰, respectively. These compositions are
very different from those of the speleothem above but are similar to phreatic calcite spar from hydrothermal karst cavities
in other outcrops in the area, where the absence of two-phase fluid inclusions suggests a low-temperature (less than ca. 50°C)
hydrothermal origin. U/Th dating of the flowstone capping the alteration zone yielded a minimum age of the thermal water invasion
in Entrische Kirche of ca. 240 kyr. There is no evidence in Entrische Kirche that these palaeowaters reached the point of
calcite precipitation, but it is physically conceivable that higher and as yet unexplored parts of this deep (ca. 900 m) cave
contain cavities lined by phreatic cave spar. 相似文献
7.
Abstract The apprehension and elaboration of hydrological maps in parallel with the development of hydrogeological maps render inevitable at first a clarification of terminology, besides an examination of the whole problem concerning the mapping of the data relating to water. It states theoretical (limits and validity of mapping in this property) and practical problems (methods, cooperation and distribution of work between using specialists and organizations). 相似文献
8.
Schmidsippl剖面位于奥地利北钙质阿尔卑斯构造带内Gosau群典型地区。剖面出露的Bibereck组记录了一个海侵和沉积区海水变深过程。Bibereck 组之下是Santonian 晚期Hochmoos 组(Sandkalkbank段),主要为砂质、粉砂质灰色生物扰动构造发育的泥灰岩,含少量双壳类碎片。Hochmoos组之上为灰色泥灰岩和泥灰质灰岩。Bibereck组下部显示变深到近滨-远滨过渡带区域;向上,泥灰岩指示细粒泥质远滨沉积,水深大致50~150 m;之上出现浮游有孔虫含量超过90%的泥灰质灰岩,代表着半深海沉积环境。生物地层数据显示采样层位整体位于浮游有孔虫asymetrica elevata 带,由Globotruncanita elevata 和Dicarinellaasymetrica 的共同出现来界定。钙质超微化石Calculites obscurus、Lucianorhabdus cayeuxii、Arkhangelsk iella cymbiformis 的出现指示属于钙质超微化石带CC17b/UC12,相当于Campanian初期。地层深度剖面上,Ca/Al比值和Catot含量显示海水来源的Ca在0~5 m地层内几近于零,向上快速增加;(Fe/Al)/碳酸盐显示两个峰值,代表更还原条件,分别位于4 m和10 m位置;K/Al比值的下降被解释为更潮湿气候条件;剖面上部Ba含量的增加显示向更低原始生产条件的变化;陆源矿物在剖面7 m以下保持稳定,之上一直到剖面顶部不断下降。生物地层 相似文献
9.
Evolution of Moldanubian rocks in Austria: review and synthesis 总被引：7，自引：1，他引：7
K. PETRAKAKIS 《Journal of Metamorphic Geology》1997,15(2):203-222
The Moldanubian zone in Austria comprises three major lithological units. Despite general agreement that nappe tectonics contributed to its current structure, the number and position of tectonic boundaries, or continental pieces that were involved in its evolution, as well as the age, extent and position of oceanic sutures are disputed. Recent models ascribe the Moldanubian tectonostratigraphic structure to its oblique, N- to NE-directed collision with Moravia only. The rocks of the Moldanubian Bunte series and Gföhl unit experienced a common, intensive overprint in the range 700–800 °C and 8–11 kbar. Textural evidence suggests that this overprint was attained during nearly isothermal decompression, so the rocks experienced higher pressures prior to this overprint. These conditions constrain a continent–continent collision environment that contributed to the formation of the Moldanubian granulites. The estimated metamorphic temperatures are close to Tmax. During this Hercynian, high-T overprint, the minerals underwent extensive diffusion-controlled homogenization of elements. The early stages of retrogression of these units were characterized by isobaric cooling at c. 6 kbar in the range 650–500 °C that is related to the oblique collision of the Moldanubian and Moravian zones. Cooling to c. 400 °C is demonstrated by unstrained, diasporized corundum inclusions in garnet of common Moldanubian granulites. The available age data (including cooling ages) from metamorphic rocks show a very wide variation between 490 and 280 Ma that depends on sample characteristics and the dating method used. They demonstrate clearly, however, that the metamorphic overprint is Hercynian. The possibility that the large variation in ages reflects homogenization, resetting and closure of the isotopic systems attained at different, sample- and method-specific times is discussed. Age data varying between c. 370 and c. 346 Ma tentatively date different stages during the Hercynian, high-T decompression. The majority of zircon and monazite U/Pb ages as well as the hornblende and muscovite Ar/Ar cooling ages cluster between c. 345 and c. 326 Ma and date the effective closure conditions and the onset of rapid, nearly isobaric cooling. The continent–continent collision that formed the granulites pre-dates c. 370 Ma. The intra-Moldanubian nappe-stacking pre-dates thrusting of the Moldanubian zone over the Moravian zone. The range c. 340–335 Ma is the lower limit for completion of tectonic activity in the Moldanubian zone. The Moldanubian series are post-tectonically intruded by granitoids of the Southern Bohemian Pluton. Recent age determinations and geochemical evidence suggest that the formation of the early granitoid types took place in the lower crust in connection with the Hercynian high-grade overprint. The Moldanubian Monotone series in Austria is separated from the other Moldanubian units by a conspicuous tectonic horizon. It also differs from them by its characteristic high-T , low-P overprint, which is best demonstrated by a widespread cordierite gneiss. 相似文献
10.
J. G. Zötl 《Environmental Geology》1995,26(4):240-245
The Badgastein spa shows almost all the special geological and hydrological features existing in the northeastern central Alps. Situated within the Tauern window, the open joint system enables the infiltration of surface water to great depths. There it becomes heated and loaded with radon and trace elements such as fluor. The water discharges as thermal water springs at the steep right flank of the cascade of the Gastein-Ache. This hydraulic process occurs during a span of 3600–3800 years. The springs are captured in galleries, and the largest discharge is in gallery IX (2518 m3/d–1). The spa became known worldwide in the 19th century by visiting aristocrats from Central and Eastern Europe. The most important event in the 20th century was the discovery of the heat joint in the Böckstein gallery. In 1940 an effort to reactivate gold mining in the Radhausberg near Böckstein south of Badgastein failed. However, the miners had the unexpected experience of being cured of rheumatism. A connection between the great depth and high temperature in the gallery was made by the discovery of the joint set with heat and radon emanation. In the medical stations of the Böckstein gallery treatment of polyarthritis has become especially successful. 相似文献