Search results for "rock"
showing 10 items of 1160 documents
Effects of the 6th September 2002 earthquake: damage amplification in the south-eastern sector of Palermo explained by GIS technology
2009
During the 6th September 2002 earthquake the highest damage level in Palermo was observed in the SE sector. This is a recent urbanization area where reinforced concrete structures predominate. A detailed analysis of soil properties in Palermo was carried out by City-GIS to investigate a possible role of nearsurface geology on earthquake effects. City-GIS is a tool dedicated to natural hazard evaluation in urban areas. The availability of high density of well log data (stratigraphic and geotechnical) allowed a realistic modeling of surface geology and physical-mechanical properties that control the seismic response. In wide zones of the above mentioned sector of…
Emergence of blueschists on Earth linked to secular changes in oceanic crust composition
2015
The oldest blueschists—metamorphic rocks formed during subduction—are of Neoproterozoic age1, and 0.7–0.8 billion years old. Yet, subduction of oceanic crust to mantle depths is thought to have occurred since the Hadean, over 4 billion years ago2. Blueschists typically form under cold geothermal gradients of less than 400 °C GPa−1, so their absence in the ancient rock record is typically attributed to hotter pre-Neoproterozoic mantle prohibiting such low-temperature metamorphism; however, modern analogues of Archaean subduction suggest that blueschist-facies metamorphic conditions are attainable at the slab surface3. Here we show that the absence of blueschists in the ancient geological rec…
Sedimentary features reveal transport paths for Holocene sediments on the Kristianstad coastal plain, SE Sweden.
2017
AbstractWe have investigated coastal and aeolian deposits on the Kristianstad plain in southernmost Sweden by a combination of methods that has yielded data on sedimentary features such as grain-size variations, shape and character of quartz grain surfaces (determined in light microscope and scanning electron microscope), and mineralogical composition. Such sedimentary techniques have been not applied to coastal deposits in this part of the Baltic Sea region before. The littoral, foredune and parabolic dune sands are sedimentologically similar, only a slight grain-size transformation by aeolian processes in the foredune was observed. Sand in straight-crested dunes, on the other hand, origin…
Advances and challenges for experiment and theory for multi-electron multi-proton transfer at electrified solid-liquid interfaces.
2020
Multi-electron, multi-proton transfer is important in a wide spectrum of processes spanning biological, chemical and physical systems. These reactions have attracted significant interest due to both fundamental curiosity and potential applications in energy technology. In this Perspective Review, we shed light on modern aspects of electrode processes in the 21st century, in particular on the recent advances and challenges in multistep electron/proton transfers at solid–liquid interfaces. Ongoing developments of analytical techniques and operando spectrometry at electrode/electrolyte interfaces and reliable computational approaches to simulate complicated interfacial electrochemical reaction…
Habitat Discontinuities Separate Genetically Divergent Populations of a Rocky Shore Marine Fish.
2016
Habitat fragmentation has been suggested to be responsible for major genetic differentiations in a range of marine organisms. In this study, we combined genetic data and environmental information to unravel the relative role of geography and habitat heterogeneity on patterns of genetic population structure of corkwing wrasse (Symphodus melops), a rocky shore species at the northern limit of its distribution range in Scandinavia. Our results revealed a major genetic break separating populations inhabiting the western and southern coasts of Norway. This genetic break coincides with the longest stretch of sand in the whole study area, suggesting habitat fragmentation as a major driver of genet…
Tertiary Ultrapotassic Volcanism in Serbia: Constraints on Petrogenesis and Mantle Source Characteristics
2005
The Serbian province of Tertiary ultrapotassic volcanism is related to a post-collisional tectonic regime that followed the closure of the Tethyan Vardar Ocean by Late Cretaceous subduction beneath the southern European continental margin. Rocks of this province form two ultrapotassic groups; one with affinities to lamproites, which is concentrated mostly in the central parts of the Vardar ophiolitic suture zone, and the other with affinities to kamafugites, which crops out in volcanoes restricted to the western part of Serbia. The lamproitic group is characterized by a wide range of Sr/Sri (0 70735–0 71299) and Nd/Ndi (0 51251–0 51216), whereas the kamafugitic group is isotopically more ho…
Finnish fandom of Japanese popular culture : what are the Finns doing for anime, manga, and J-rock?
2010
Beaches in Valencian Coast
2018
The main factors that determined the Valencian beaches characteristics are the configuration of relief structures; fluvial sediment supply; low tidal range; the predominance of low energy waves; scarcity of big storms; longshore littoral drift; and human action. There is a significant prevalence of sandy beaches. Nevertheless, both at the northern part of the Gulf of Valencia and in the structural segment, between the Cape Sant Antoni and Alicante city, pebble and gravel beaches are predominant. Most of the Valencian beaches have experienced significant morphological changes during the last decades due to the human interventions -voluntary or involuntary- in the coastal system. The implemen…
Landscape reconstruction and major flood events of the River Main (Hesse, Germany) in the environs of the Roman fort at Groβkrotzenburg
2020
Abstract Detailed geoarchaeological studies were conducted at the Groβkrotzenburg floodplain (Southern Hesse, Germany) in order to reconstruct the fluvial palaeogeography and search for Roman harbour installations. Another objective was to reconstruct the local flood history based on stratigraphic and geochronological data. Prospection based on electrical resistivity tomography, vibracoring and direct push electrical conductivity logging were carried out to detect and analyze subsurface stratigraphies. Altogether, 6 sediment cores, up to 7 m long, were drilled along transects along and perpendicular to the present course of the River Main. Based on sedimentological and geochemical data, we …