Search results for "BASIN"
showing 10 items of 872 documents
Geochemical and sedimentological evidence of productivity cycles recorded in Toarcian black shales from the Belluno Basin, Southern Alps, northern It…
1999
ABSTRACT Organic-carbon-rich black shales cyclically alternating with bioturbated limestones and gray marlstones, which crop out in the Belluno Trough (Southern Alps, Italy), are expression of the early Toarcian anoxic event in the Tethys basin. Sedimentological and geochemical features such as well-developed lamination, common very small ( A negative 13C excursion at the middle part of the studied interval is correlative to maxima in TOC, V/Rb, and Ba/Rb values, identifying, within the Toarcian anoxic event, a stage of more intense bottom-water anoxia coupled with high surface fertility.
Síntesis de los estudios sobre moluscos continentales neógenos del sector septentrional de la Depresión de Teruel: período 1775-1998
2006
Se recopila y analiza la información que se considera más relevante y se encuentra contenida en los estudios realizados sobre el registro fósil de los moluscos neógenos del sector septentrional de la Depresión de Teruel en el período comprendido entre los años 1775 y 1998. Se contabilizan, por una parte, el número total de taxones diferentes mencionados en cada trabajo y, por otra, sólo el número de citas efectuadas a nivel de especie en cada uno de ellos. Estas últimas se organizan en tres categorías que reciben el nombre de citas nuevas, especies nuevas y citas repetidas. Se propone, a partir de la información contenida en cada trabajo, el número de taxones contemplados, y la tipología de…
The N Variscan margin of the Ruhr coal district (Western Germany): structural style of a buried thrust front?
1988
The Ruhr coal district represents part of an external fold and thrust belt of the Variscan orogen in central Europe. Extensive mining exposed molasse-type, coal-bearing clastic sequences of Upper Carboniferous age, deformed by folding and thrusting. Thrusts range in scale from decameters to 40 kilometers along strike but displacements are below 2.5 km. They are distributed in various stratigraphic levels and no regional detachment horizon is exposed. Displacement is mainly towards NW (towards the foreland) but also towards SE. The thrusts are bound to stockwerk-tectonics and die out towards depth frequently antithetic to the exposed strata. Folds vary in wavelength from decameters to more t…
Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora
2010
9 páginas, 1 figura, 4 tablas.
Parameter Uncertainty in Shallow Rainfall-triggered Landslide Modeling at Basin Scale: A Probabilistic Approach
2014
Abstract This study proposes a methodology to account for the uncertainty of hydrological and mechanical parameters in coupled distributed hydrological-stability models for shallow landslide assessment. A probabilistic approach was implemented in an existing eco-hydrological and landslide model by randomizing soil cohesion, friction angle and soil retention parameters. The model estimates the probability of failure through an assumed theoretical Factor of Safety (FS) distribution, conditioned on soil moisture content. The time-dependent and spatially distributed FS statistics are approximated by the First Order Second Moment (FOSM) method. The model was applied to the Rio Mameyes Basin, loc…
Annual runoff assessment in arid and semiarid Mediterranean watersheds under the Budyko's framework
2017
The solution of many practical water problems is strictly connected to the availability of reliable and widespread information about runoff. The estimation of mean annual runoff and its interannual variability for any basin over a wide region, even if ungauged, would be fundamental for both water resources assessment and planning and for water quality analysis. Starting from these premises, the main aim of this work is to show a new approach, based on the Budyko's framework, for mapping the mean annual surface runoff and deriving the probability distribution of the annual runoff in arid and semiarid watersheds. As a case study, the entire island of Sicily, Italy, is here proposed. First, ti…
Pleistocene age paleo-groundwater inferred from water-stable isotope values in the central part of the Baltic Artesian Basin.
2016
A new data set of δ(2)H and δ(18)O in the groundwater from the central part of the Baltic Artesian Basin is presented. The hydrogeological section is subdivided into stagnation, slow exchange and active exchange zones. Na-Ca-Cl brine found at the deepest part - the stagnation zone - is characterized by δ(18)O values above -5 ‰ and δ(2)H values approaching -40 ‰ with respect to Vienna Standard Mean Ocean Water. The slow exchange zone where waters of mostly intermediate salinity reside is characterized by δ(18)O values around -11.7 ‰ and δ(2)H values around -85.3 ‰. Mean δ(18)O and δ(2)H values of the fresh groundwater in the active water exchange zone are -11.1 and -79.9 ‰, respectively. Cha…
Flash floods in Mediterranean ephemeral streams in Valencia Region (Spain)
2016
Summary Ephemeral streams are typical Mediterranean fluvial systems with high risk of flash flooding, and few data are available about these systems in most locales. However, the SAIH network (Automatic Hydrological Information Systems) of the Jucar River Water Authority has been providing detailed information about ephemeral streams in Spain every 5 min since 1988. Using these data, we evaluated the processes of rainfall–runoff conversion and flood generation in five Mediterranean ephemeral streams ranging in size from 25 to 450 km 2 . To provide a general framework for hydrological analysis, the study included 142 flash flood events registered between 1989 and 2007. A more detailed analys…
Particularities of Grey Alder (Alnus incana) Stands in Riparian Galleries Along Streams of the Southern Transylvanian Tableland (Romania)
2019
Abstract Grey Alder (Alnus incana (L.) Moench.) stands are distributed in the Carpathian area on alluvial deposits with sediments of different grain size as galleries along rivers and streams of the sub-montane to the middle montane level. The geological structure (Tertiary sedimentary deposits) in relation to the hydromorphological processes is the base for the structure of the stream valleys, which are in part very deep. Under the special microclimate of these deeper stream stretches with lower temperatures there are favourable conditions for the development of grey alder stands.
The formation of alluvial fans and young floodplain deposits in the Lieser catchment, Eifel Mountains, western German Uplands: A study of soil erosio…
2011
This study deals with the exploration and spatiotemporal quantification of the young Holocene, nearly skeleton-free floodplain sediments of the Lieser River, a tributary of the Mosel River in the Eifel Mts. The deposits are primarily a consequence of anthropogenic-triggered soil erosion in the catchment. To observe the phenomenon of corresponding soil erosion on multiple levels two small alluvial fans of tributary catchments were investigated. For comparison, one location in the neighboring Salm valley was described. The results were compared with those of other streams. With extensive fieldwork more than 100 drillings and pits were made at 12 locations. For dating the sediments OSL dating…