Search results for "Bedrock"
showing 10 items of 50 documents
Bedrock Characterisation of Four Candidate Repository Sites in Finland As Determined by He-Gas Methods
1999
AbstractAt the end of the year 2000, one of four sites will be chosen as the final repository site in Finland. Therefore accurate and comprehensive statistics of the bedrock characteristics such as porosity [% ] and effective diffusion coefficient [m2/s ] of these sites are of importance. Altogether 115 rock samples from the four sites were measured by different He-gas methods to achieve this goal.The results obtained indicate that the average bedrock properties at these sites are quite similar. Variations among individual samples and different rock types within one repository site were larger than variations among the averaged values of the four sites. Some indication of increased microfra…
Anthropogenic units fingerprinted by REE in archaeological stratigraphy: Mas d'Is (Spain) case
2013
Abstract On occasions, archaeologists have to deal with serious difficulties to differentiate between processes that ultimately are responsible for the formation of stratigraphic units. Sometimes we face problems related with depositional units in multilayered deposits and other times, we ask for the character of some dark surface soils, very similar to natural paleosols and usually associated with archaeological findings. In both cases, the problems we must address concern the relative impact of human activities. The imbalance between anthropic and natural processes in the formation of archaeological deposits is crucial for a correct interpretation of the processes involved in the formatio…
Long term seismic noise acquisition and analysis in the Homestake Mine with tunable monolithic sensors
2009
In this paper we describe the scientific data recorded along one month of data taking of two mechanical monolithic horizontal sensor prototypes located in a blind-ended (side) tunnel 2000 ft deep in the Homestake (South Dakota, USA) mine chosen to host the Deep Underground Science and Engineering Laboratory (DUSEL). The two mechanical monolithic sensors, developed at the University of Salerno, are placed, in thermally insulating enclosures, onto concrete slabs connected to the bedrock, and behind a sound-proofing wall. The main goal of this experiment is to characterize the Homestake site in the frequency band 10-4 ÷ 30 H z and to estimate the level of Newtonian noise, providing also the ne…
The cork oak in the Mountains of Palermo (Italy): ecological insights from the south-eastern edge of its distribution range
2020
Abstract: The uneven presence of the cork oak (Quercus suber L.) within its distribution range is not only determined by its climatic requirements but also by specific edaphic needs. Although most of the natural populations thrive in acidic soils deriving from metamorphic or volcanic rock outcrops, some cork oak populations are found growing in soils deriving from calcareous bedrock, which are considered less suitable. We carried out a multidisciplinary investigation at the south eastern edge of the Q. suber distribution range (Mountains of Palermo, NW Sicily), including soil, floristic, and vegetation surveys, aimed at: (i) assessing the native or introduced origin of some peculiar cork oa…
An exceptional rocky shore preserved during Oligocene (Late Rupelian) transgression in the Upper Rhine Graben (Mainz Basin, Germany)
2012
The Early Oligocene (Late Rupelian) Alzey Formation (Mainz Basin, Upper Rhine Graben, Germany) records the development of a rocky coast depositional system during transgression. The formation unconformably overlies Permian bedrock across a composite transgressive ravinement surface. Exposure of the surface shows a succession of subplanar bedrock terraces, separated by near-vertical risers. Terraces show a broad staircase geometry and display wave-erosional features (notches, sea stacks, furrows). Detailed sedimentological and palaeoecological investigations reveal prograding beachface and shoreface depositional units that overlie terraces and are adjacent to risers. Terraces are interpreted…
Sulfuric acid speleogenesis (SAS) close to the water table: Examples from southern France, Austria, and Sicily
2016
Caves formed by rising sulfuric waters have been described from all over the world in a wide variety of climate settings, from arid regions to mid-latitude and alpine areas. H2S is generally formed at depth by reduction of sulfates in the presence of hydrocarbons and is transported in solution through the deep aquifers. In tectonically disturbed areas major fractures eventually allow these H2S-bearing fluids to rise to the surface where oxidation processes can become active producing sulfuric acid. This extremely strong acid reacts with the carbonate bedrock creating caves, some of which are among the largest and most spectacular in the world. Production of sulfuric acid mostly occurs at or…
Gis-analysis to assess landslide susceptibility in a fluvial basin of NW Sicily (Italy).
2008
Abstract Landslide hazard assessment, effected by means of geostatistical methods, is based on the analysis of the relationships between landslides and the spatial distributions of some instability factors. Frequently such analyses are based on landslide inventories in which each record represents the entire unstable area and is managed as a single instability landform. In this research, landslide susceptibility is evaluated through the study of a variety of instability landforms: landslides, scarps and areas uphill from crown . The instability factors selected were: bedrock lithology, steepness, topographic wetness index and stream power index. The instability landform densities computed f…
The Role of Wastewater in Controlling Fluvial Erosion Processes on Clayey Bedrock
2023
In recent decades, fluvial erosion processes in highly anthropized areas are mainly associated with in-stream gravel mining activities or with the presence of artificial reservoirs which have increased the erosive capacity of the river as a consequence of the reduced sediment transport or the modification of the longitudinal profile of the channel. On the other hand, the role of pollutants in the degradation processes of soils with a predominantly clayey component is little known. The present study, through chemical analyses of water and mineralogical–geotechnical analyses of clayey soil samples taken along some river channels in central Italy in correspondence with water treatment pl…
Geophysical investigations in the Flumendosa River Delta, Sardinia (Italy) — Seismic reflection imaging
2006
A geophysical investigation that included seismic-reflection surveying and time-domain electromagnetics (EM) was carried out in the Flumendosa River Delta plain in southeastern Sardinia, Italy. The objective was to improve knowledge of geologic and hydrogeologic controls on a highly productive aquifer hosted in thick Quaternary deposits and known to be affected by an extensive saltwater intrusion. The seismic reflection survey, whose results are reported here, aimed to image the Paleozoic bedrock topography and to obtain detailed structural and stratigraphic information on the sequence of largely fluvial sediments extending from the surface down to bedrock. The survey consisted of two inli…
Morphology, internal structure and genesis of the Burtnieks drumlin field, Northern Vidzeme, Latvia
1997
Abstract The Burtnieks drumlin field is one of the largest in the Baltic countries. It occupies a broad and uneven bedrock macrodepression. The uneven distribution of drumlins is related to the relief of the bedrock surface. Needle-shaped drumlinoids occur in the proximal part of the drumlin field, and they gradually merge into typical drumlin forms downglacier. This morphologic change reflects the differences in their genesis as suggested by internal structure. The cores of drumlins consist mainly of glaciotectonically deformed Pleistocene sediment and, in some places, also weakly cemented, dislocated Middle Devonian sandstone. All of them are folded into linear anticlines trending paralle…