Search results for "Go"
showing 10 items of 57859 documents
Phanerozoic geological evolution of Northern and Central Africa: An overview.
2005
61 pages; International audience; The principal paleogeographic characteristics of North and Central Africa during the Paleozoic were the permanency of large exposed lands over central Africa, surrounded by northerly and northwesterly dipping pediplanes episodically flooded by epicontinental seas related to the Paleotethys Ocean. The intra-continental Congo–Zaire Basin was also a long-lived feature, as well as the Somali Basin from Late Carboniferous times, in conjunction with the development of the Karoo basins of southern Africa. This configuration, in combination with eustatic sea-level fluctuations, had a strong influence on facies distributions. Significant transgressions occurred duri…
Single zircon U–Pb ages and geochemistry of granitoid gneisses from SW Poland: evidence for an Avalonian affinity of the Brunian microcontinent
2010
AbstractSeven granitoid gneisses from the contact zone between the eastern margin of the Variscan belt and the Brunian microcontinent in SW Poland have been dated by ion-microprobe and207Pb/206Pb single zircon evaporation methods. The zircons define two age groups for the gneiss protoliths: (1) late Neoproterozoicc.576–560 Ma and (2) early Palaeozoicc.488–503 Ma granites. The granitoid gneisses belonging to the basement of the Brunian microcontinent contain abundant Mesoproterozoic to latest Palaeoproterozoic inherited material in the range of 1200–1750 Ma. The gneisses of the Variscan crustal domain lack Mesoproterozoic inherited zircon cores. Trace element geochemistry of Proterozoic gnei…
The (de)politicisation of nuclear power: The Finnish discussion after Fukushima
2017
When the Fukushima accident occurred in March 2011, Finland was at the height of a nuclear renaissance, with the Government’s decision-in-principle in 2010 to allow construction of two new nuclear reactors. This article examines the nuclear power debate in Finland after Fukushima. We deploy the concepts of (de)politicisation and hyperpoliticisation in the analysis of articles in the country’s main newspaper. Our analysis indicates that Finnish nuclear exceptionalism manifested in the safety-related depoliticising and the nation’s prosperity-related hyperpoliticisation arguments of the pro-nuclear camp. The anti-nuclear camp used politicisation strategies, such as economic arguments, to sho…
Steroid Biomarkers Revisited - Improved Source Identification of Faecal Remains in Archaeological Soil Material.
2017
Steroids are used as faecal markers in environmental and in archaeological studies, because they provide insights into ancient agricultural practices and the former presence of animals. Up to now, steroid analyses could only identify and distinguish between herbivore, pig, and human faecal matter and their residues in soils and sediments. We hypothesized that a finer differentiation between faeces of different livestock animals could be achieved when the analyses of several steroids is combined (Δ5-sterols, 5α-stanols, 5β-stanols, epi-5β-stanols, stanones, and bile acids). We therefore reviewed the existing literature on various faecal steroids from livestock and humans and analysed faeces …
Active tectonics along the south east offshore margin of Mt. Etna: New insights from high-resolution seismic profiles
2018
The offshore margin of Mt. Etna has been shaped by Middle Pleistocene to Holocene shortening and extension and, more recently, by gravity-related sliding of the volcanic edifice. These processes have acted contemporaneously although the gravitational component largely prevails over the tectonic one. In order to investigate this issue, we focused on the main role of active tectonics along the south-eastern offshore of Mt. Etna by means of marine high-resolution seismic data. Seismic profiles revealed post-220 ka sedimentary deposits unconformably overlaying the Lower-Middle Pleistocene Etnean clayey substratum and volcanics of the Basal Tholeiitic phase and the Timpe phase. Offshore Aci Trez…
Secondary minerals from salt caves in the Atacama Desert (Chile): a hyperarid and hypersaline environment with potential analogies to the Martian sub…
2017
Over the past 15 years several expeditions by French, American and especially Italian cavers have unveiled over 50 caves in the Cordillera de la Sal (Atacama Desert, Northern Chile). Many of these caves contain a variety of speleothems and minerals, some of which have rarely been observed within karst systems. Most of the secondary deposits in these caves are composed of halite, but also other halide, carbonate, sulphate, nitrate, phosphate, and silicate minerals have been found. Among the sixteen cave mineral species recognized, atacamite, darapskite, blödite, leonite, anhydrite, and especially antarcticite are worth mentioning. In one of the samples an unknown Ca-Sr-bearing chloride miner…
Hydrological drivers of wetland vegetation community distribution within Everglades National Park, Florida
2010
The influence of hydrological dynamics on vegetation distribution and the structuring of wetland environments is of growing interest as wetlands are modified by human action and the increasing threat from climate change. Hydrological properties have long been considered a driving force in structuring wetland communities. We link hydrological dynamics with vegetation distribution across Everglades National Park (ENP) using two publicly available datasets to study the probability structure of the frequency, duration, and depth of inundation events along with their relationship to vegetation distribution. This study is among the first to show hydrologic structuring of vegetation communities at…
Evaluation of deep learning algorithms for national scale landslide susceptibility mapping of Iran
2021
The identification of landslide-prone areas is an essential step in landslide hazard assessment and mitigation of landslide-related losses. In this study, we applied two novel deep learning algorithms, the recurrent neural network (RNN) and convolutional neural network (CNN), for national-scale landslide susceptibility mapping of Iran. We prepared a dataset comprising 4069 historical landslide locations and 11 conditioning factors (altitude, slope degree, profile curvature, distance to river, aspect, plan curvature, distance to road, distance to fault, rainfall, geology and land-sue) to construct a geospatial database and divided the data into the training and the testing dataset. We then d…
Remote sensing algorithms for estimation of fractional vegetation cover using pure vegetation index values: A review
2020
Abstract Green fractional vegetation cover ( f c ) is an important phenotypic factor in the fields of agriculture, forestry, and ecology. Spatially explicit monitoring of f c via relative vegetation abundance (RA) algorithms, especially those based on scaled maximum/minimum vegetation index (VI) values, has been widely investigated in remote sensing research. Although many studies have explored the effectiveness of RA algorithms over the past 30 years, a literature review summarizing the corresponding theoretical background, issues, current state-of-the-art techniques, challenges, and prospects has not yet been published. The overall objective of the present study was to accomplish a compre…
Validation of a novel Multi-Gas sensor for volcanic HCl alongside H2S and SO2 at Mt. Etna
2017
Erratum to: Bull Volcanol (2017) 79: 36DOI 10.1007/s00445-017-1114-zDuring the steps of corrections, the publisher inadvertently changed the author affiliations so that they were no longer correct. The correct information is given below. The publisher regrets this mistake.; International audience; Volcanic gas emission measurements inform predictions of hazard and atmospheric impacts. For these measurements, Multi-Gas sensors provide low-cost in situ monitoring of gas composition but to date have lacked the ability to detect halogens. Here, two Multi-Gas instruments characterized passive outgassing emissions from Mt. Etna’s (Italy) three summit craters, Voragine (VOR), North-east Crater (NE…