Miocene siliciclastic deposits of Naxos Island: Geodynamic and environmental implications for the evolution of the southern Aegean Sea (Greece)

An interdisciplinary study has been carried out on Naxos Island, located in the southern Aegean Sea (Greece), which shows Miocene geodynamic and environmental changes in a classic example of a collapsing orogen. Early to Mid-Miocene siliciclastic deposits on Naxos have been shed from an uplifting mountainous realm in the south, which included a patchwork of at least four source terrains of different thermal histories.Petrography of pebbles suggests that the source units formed part of a passivecontinental margin succession (external Pelagonian unit), and an ophiolite succession mainly of deep-water cherts and limestones deposited on basalt substratum (Pindos unit). The continental margin source contributed rounded zircon crystals of Late Jurassic to Early Cretaceous age and broadly scattering Paleozoic zircon fission-track cooling ages. A distal pebble assemblage of Paleogene shallow-water carbonates passing into flysch-like, mixed calcarenitic and siliciclastic components with volcanic arc components is subordinately present. High-grade metamorphic components from the nearby metamorphic core complex are not present. The depositional evolution reflects increasing relief and, in some parts, a fluvial succession with rhythmic channel deposition, possibly due to runoff variability forced by orbital cyclicity. Upsection, the depositional trend indicates increasing seasonality and decreasing humidity in the source region. The Miocene sedimentary succession has been deposited on an ophiolite nappe. Juxtaposition of this ophiolite nappe occurred as an extensional allochthon during large-scale extension in the Aegean region at the margins of an exhuming metamorphic core complex

Linking the northern Alps with their foreland: The latest exhumation history resolved by low-temperature thermochronology

The evolution of the Central Alpine deformation front (Subalpine Molasse) and its undeformed foreland is recently debated because of their role for deciphering the late orogenic evolution of the Alps. Its latest exhumation history is poorly understood due to the lack of late Miocene to Pliocene sediments. We constrain the late Miocene to Pliocene history of this transitional zone with apatite fission track and (U-Th)/He data. We used laser ablation inductively coupled mass spectrometry for apatite fission track dating and compare this method with previously published and unpublished external detector method fission track data. Two investigated sections across tectonic slices show that the Subalpine Molasse was tectonically active after the onset of folding of the Jura Mountains. This is much younger than hitherto assumed. Thrusting occurred at 10, 8, 6–5 Ma and potentially thereafter. This is contemporaneous with reported exhumation of the External Crystalline Massifs in the central Alps. The Jura Mountains and the Subalpine Molasse used the same detachments as the External Crystalline Massifs and are therefore kinematically coupled. Estimates on the amount of shortening and thrust displacement corroborate this idea. We argue that the tectonic signal is related to active shortening during the late stage of orogenesis

Der Wandel der Wissensformen: Zur Vielfalt und Rationalität der Wissenschaftsgeschichte

Carrier M. Der Wandel der Wissensformen: Zur Vielfalt und Rationalität der Wissenschaftsgeschichte. In: Büschenfeld J, Franz H, Kuhlemann F-M, eds. Wissenschaftsgeschichte heute: Festschrift für Peter Lundgreen. Bielefeld: Verl. für Regionalgeschichte; 2001: 211-231

Nonenhanced ECG-gated quiescent-interval single-shot MRA (QISS-MRA) of the lower extremities: Comparison with contrast-enhanced MRA

Aim To evaluate electrocardiogram (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) for nonenhanced assessment of peripheral artery occlusive disease (PAOD) using contrast-enhanced MRA (CE-MRA) as the reference standard. Materials and methods Twenty-seven patients (mean age 66.6 ± 10.8 years) with PAOD were included in the study. QISS-MRA and CE-MRA of the lower extremity were performed using a 1.5 T MR scanner. In each patient, subjective image quality and the degree of stenosis were evaluated on a four-point scale for 15 predefined arterial segments. Results Twenty-five of the 27 patients were considered for analysis. Subjective image quality of QISS-MRA was significantly lower for the distal aorta, pelvic arteries, and femoral arteries as compared to CE-MRA (p < 0.01), while no significant difference was found for other vascular segments. The degree of stenosis was overestimated with QISS-MRA in 23 of 365 (6.3%) segments and underestimated in two of 365 (0.5%) segments. As compared to CE-MRA, QISS-MRA had a high sensitivity (98.6%), specificity (96%) as well as positive and negative predictive value (88.7 and 99.6%, respectively) for the detection of significant stenosis (≥50%). Conclusion ECG-gated QISS-MRA is a promising imaging technique for reliable assessment of PAOD without the use of contrast material

Nonenhanced ECG-gated quiescent-interval single-shot MRA (QISS-MRA) of the lower extremities: Comparison with contrast-enhanced MRA

Aim To evaluate electrocardiogram (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) for nonenhanced assessment of peripheral artery occlusive disease (PAOD) using contrast-enhanced MRA (CE-MRA) as the reference standard. Materials and methods Twenty-seven patients (mean age 66.6 ± 10.8 years) with PAOD were included in the study. QISS-MRA and CE-MRA of the lower extremity were performed using a 1.5 T MR scanner. In each patient, subjective image quality and the degree of stenosis were evaluated on a four-point scale for 15 predefined arterial segments. Results Twenty-five of the 27 patients were considered for analysis. Subjective image quality of QISS-MRA was significantly lower for the distal aorta, pelvic arteries, and femoral arteries as compared to CE-MRA (p < 0.01), while no significant difference was found for other vascular segments. The degree of stenosis was overestimated with QISS-MRA in 23 of 365 (6.3%) segments and underestimated in two of 365 (0.5%) segments. As compared to CE-MRA, QISS-MRA had a high sensitivity (98.6%), specificity (96%) as well as positive and negative predictive value (88.7 and 99.6%, respectively) for the detection of significant stenosis (≥50%). Conclusion ECG-gated QISS-MRA is a promising imaging technique for reliable assessment of PAOD without the use of contrast material

Author manuscript, published in &quot;22nd EARSeL Annual Symposium &quot;Geoinformation for European-wide integration&quot;, Prague: Tchèque, République (2002)&quot; A new generation of satellite based solar irradiance calculation schemes

ABSTRACT: A successful integration of solar energy into the existing energy structure highly depends on a detailed knowledge of the solar resource. HELIOSAT-3 will supply high-quality solar radiation data gained from the exploitation of existing Earth observation technologies and will take advantage of the enhanced capabilities of the new Meteosat Second Generation (MSG) satellites. The expected quality represents a substantial improvement with respect to the available methods and will better match the needs of companies and other customers of the resulting products. These goals will be achieved by an improvement of the current semi-empirical Heliosat calculation schemes (see section 2) as well as by the development and establishment of a new type of calculation scheme. This new type will be based on radiative transfer models (RTM) using the information of atmospheric parameters retrieved from the MSG satellite (clouds, ozone, water vapor) and the GOME/ATSR-2 satellites (aerosols). Within this paper, the new type of the solar irradiance calculation scheme, including the functional treatment of the diurnal variation of the solar irradiance, is described.