Search results for "Bedrock"
showing 10 items of 50 documents
Storage and release of fossil organic carbon related to weathering of sedimentary rocks
2007
International audience; The biogeochemical carbon cycle, which plays an undeniable role in global climate change, is defined both by the size of carbon reservoirs (such as the atmosphere, biomass, soil and bedrock) and the exchange between them of various mineral and organic carbon forms. Among these carbon forms, fossil organic carbon (FOC) (i.e., the ancient organic matter stored in sedimentary rocks) is widely observed in modern environments but is not included in the supergene carbon budget. Using a digitized map of the world and an existing model of CO2 consumption associated with rock weathering, we establish the global distribution of FOC stored in the first meter of sedimentary rock…
Woodland key habitats in northern Europe: concepts, inventory and protection
2010
Abstract The woodland key habitat (WKH) concept has become an essential instrument in biodiversity-orientated forest management in northern Europe. The philosophy behind the concept is basically the same in all of the countries: to conserve the biodiversity of production landscapes by preserving small habitat patches that are supposed to be particularly valuable. This article reviews the definitions, inventories and implementation processes of WKHs in Sweden, Finland, Norway, Latvia, Estonia and Lithuania. Sweden and the Baltic countries have similar WKH models, while the models in Finland and Norway are clearly deviating. Depending on the country, the definitions emphasize different factor…
Taphonomical peculiarities and formation conditions of Baltic Devonian vertebrate fossil assemblages
2013
Devona mugurkaulnieku atrodņu tafonomiskais raksturojums un veidošanās apstākļi dienvidaustrumu Baltijā Pirmo reizi paleontoloģisko pētījumu vēsturē Baltijā ir veikta detalizēta Živetas, Franas un Famenas mugurkaulnieku atrodņu tafonomisko īpašību analīze, izmantojot mūsdienu metodiku. Savā starpā ir salīdzinātas vidējā un augšējā devona oriktocenozes Latvijas teritorijā, bet Baltijas (Galvenā devona lauka) fosiliju atrodnes ir salīdzinātas ar sakopojumiem Dienvidu Timanā. Ir secināts, ka, neskatoties uz tafonomisko pazīmju atšķirībām, Franas un Famenas klastiskās slāņkopas, kā arī vidus- un augšdevona mugurkaulnieku sakopojumu veidošanās mehānismi Baltijā ir bijuši visai līdzīgi. Ir noteik…
Geophysical and geotechnical investigations to support the restoration project of the Roman ‘Villa del Casale’, Piazza Armerina, Sicily, Italy
2011
A multidisciplinary geophysical and geotechnical study, including some non-invasive geophysical applications, was carried out during the restoration of the ‘Villa del Casale’, a Roman villa discovered near Piazza Armerina (Sicily, Italy) in 1929, famous for its Roman floor mosaics. The project aims were to characterize the geology of the subsoil and provide information for solving the main building structural problems including the subsidence of some parts of the floor and the detachment of the tesserae (i.e., the tiles) of the mosaics. Another goal was the detailed study of the underground structures of the Corridor of the Great Hunt, a part of the villa strongly affected by subsidence and…
Memory and Jesus’ Parables
2018
This article interacts with John P. Meier’s view concerning the parables that can be shown to be “authentic,” i.e., shown to have been uttered by the historical Jesus. His highly critical and largely negative result (only four parables remaining parables of Jesus) demonstrates once more that historical Jesus research that is intrinsically tied to questions of authenticity has run its course. Such an approach can only lead to minimalistic results and destroys the sources that we have. By contrast, the so-called memory approach tries to understand the process and result of remembering Jesus as a parable teller. Collective memory requires typification and repetition in order to bring the past …
Soil erosion susceptibility assessment and validation using a geostatistical multivariate approach: a test in southern Sicily
2008
A certain number of studies have been carried out in recent years that aim at developing and applying a model capable of assessing water erosion of soil. Some of these have tried to quantitatively evaluate the volumes of soil loss, while others have focused their efforts on the recognition of the areas most prone to water erosion processes. This article presents the results of a research whose objective was that of evaluating water erosion susceptibility in a Sicilian watershed: the Naro river basin. A geomorphological study was carried out to recognize the water erosion landforms and define a set of parameters expressing both the intensity of hydraulic forces and the resistance of rocks/so…
Analysis of soil surface component patterns affecting runoff generation. An example of methods applied to Mediterranean hillslopes in Alicante (Spain)
2008
Spatial patterns of soil surface components (vegetation, rock fragments, crusts, bedrock outcrops, etc.) are a key factor determining hydrological functioning of hillslopes. A methodological approach to analyse the patterns of soil surface components at a detailed scale is proposed in this paper. The methods proposed are applied to two contrasting semi-arid Mediterranean hillslopes, and the influence of soil surface component patterns on the runoff response of the slopes was analysed. A soil surface components map was derived from a high resolution photo-mosaic obtained in the field by means of a digital camera. Rainfall simulation experimental data were used to characterise the hydrologica…
Eolian and fluvial sedimentation in the southwestern Sinai Mountains, Egypt: a record of flash floods during the late Pleistocene
2012
Wadis emerging from the southwestern Sinai Mountains (Egypt) westwards to the Gulf of Suez are filled by >40 m thick late Pleistocene sediments, which have been subsequently incised to bedrock after the Last Glacial Maximum (LGM). Sedimentation and erosion resulted from changes in the basin's hydrological conditions caused by climate variations. Sediment characteristics indicate distinct processes ranging from high to low energy flow regimes. Airborne material is important as a sediment source. The fills are associated with alluvial fans at wadi mouths at the mountain fronts. Each alluvial fan is associated and physically correlated with the respective sediment fill in its contributi…
Overview of the Opportunity Mars Exploration Rover Mission to Meridiani Planum: Eagle Crater to Purgatory Ripple
2006
The Mars Exploration Rover Opportunity touched down at Meridiani Planum in January 2004 and since then has been conducting observations with the Athena science payload. The rover has traversed more than 5 km, carrying out the first outcrop-scale investigation of sedimentary rocks on Mars. The rocks of Meridiani Planum are sandstones formed by eolian and aqueous reworking of sand grains that are composed of mixed fine-grained siliciclastics and sulfates. The siliciclastic fraction was produced by chemical alteration of a precursor basalt. The sulfates are dominantly Mg-sulfates and also include Ca-sulfates and jarosite. The stratigraphic section observed to date is dominated by eolian bedfor…
Mineralogy and chemistry of cobbles at Meridiani Planum, Mars, investigated by the Mars Exploration Rover Opportunity
2010
Numerous loose rocks with dimensions of a few centimeters to tens of centimeters and with no obvious physical relationship to outcrop rocks have been observed along the traverse of the Mars Exploration Rover Opportunity. To date, about a dozen of these rocks have been analyzed with Opportunity’s contact instruments, providing information about elemental chemistry (Alpha Particle X‐ray Spectrometer), iron mineralogy and oxidation states (Mossbauer Spectrometer) and texture (Microscopic Imager). These "cobbles" appear to be impact related, and three distinct groups can be identified on the basis of chemistry and mineralogy. The first group comprises bright fragments of the sulfate‐rich bedroc…