Three-dimensional magnetotelluric model along seismic profile 2T: An improved view on crustal structure in central Slovakia (Western Carpathians)

We present the crustal-scale geophysical model based on the magnetotelluric method focused on 3-D model¬ling of the seismic 2T profile crossing the major Western Carpathian tectonic units in central Slovakia. The results of the 3-D modelling show substantial improvement in previous 2-D models of deep crustal structure in central Slovakia, mainly of the physically distinct tectonic segments and major geo-electrical regional structures like the zone of the Carpathian Conductivity Anomaly, which indicates the occurrence of the large-scale shear zone in the contact zone of the European platform and Inner Western Carpathians. High detail geo-electrical data in 3-D magnetotelluric (MT) cross section also allowed a better interpretation of other conductive anomalies. In the final integ-rated interpretation (combination of 3-D geo-electrical model, gravity data and seismic reflectors), it is shown that frontal part of the Inner Western Carpathians plate exhibits the transpressional tectonic style of the back-thrust Outer Western Carpathians (Flysch Belt) and Pieniny Klippen Belt units over the progressing Inner Western Carpathian thrust wedge. These back-thrusts form the southern branch of the accretionary structural fan – a large-scale transpressional flower structure typical mainly but not only for oblique con-vergent regimes. The southernmost segment of the profile with high whole-crust conductivity due to a higher heat flow caused by young volcanic activity indicates partial melting in the middle and lower crust.

Legacy of Human Impact on Geomorphic Processes in Mountain Headwater Streams in the Perspective of European Cultural Landscapes

Mountain headwater streams are still somewhat on the boundary of interest regarding possible human impact on their morphology or geomorphic processes, which may be caused by our perception of mountains as islands of relatively preserved natural conditions. This paper summarizes the past and present human pressure on the headwater streams that drain the highest mountain ranges of the Outer Western Carpathians in Czechia. Anthropogenic pressure began in this region in the 16th century during a colonization of the mountains and continued by timber harvesting, timber floating, and construction of torrent control works until present. Each of these interventions produced a morphological response of the channels in relation to altered sediment or water fluxes at the whole catchment scale or within longitudinal stream profiles. Because it is highly unlikely to reach pre-settlement conditions of the channels, the management effort should be concentrated to achieve realistic restoration targets under the present socioeconomic circumstances by taking into consideration the morphodynamical specifics of mountain headwater streams.

Tracing Pre-Mesozoic Tectonic Sutures in the Crystalline Basement of the Protocarpathians: Evidence from the Exotic Blocks from Subsilesian Nappe, Outer Western Carpathians, Poland

Pre-Mesozoic exotic crystalline blocks within the Outer Carpathian flysch have potential to unravel the nature of their eroded basement source(s) and to reconstruct the Paleozoic–Precambrian history of the Protocarpathians. Strongly tectonized Campanian–Maastrichtian grey marls in the Subsilesian Nappe of the Outer Western Carpathians in Poland contain a variety of different lithology types, including granitoids and andesites. Petrological investigations coupled with zircon and apatite U-Pb dating were performed on crystalline (subvolcanic) exotic blocks from a locality in the Subsilesian Nappe. U-Pb zircon dating yields magmatic crystallization ages of c. 293 Ma for the microgranitoid and c. 310 Ma for the andesite block, with inherited zircon cores yielding Archean, Paleoproterozoic, Mesoproterozoic and Cadomian ages. Whole rock trace element and Nd isotope data imply that the melt source was composed of a significant Neoproterozoic crustal component in both the microgranite and andesite. The Late Carboniferous–Permian magmatic activity likely continues outside the Carpathian Belt and can be linked to a Late Paleozoic transtensional zone, which is a continuation of the Lubliniec–Kraków Zone that extends under the Carpathians to Moesia. This Late Paleozoic transtensional zone was probably reactivated during the Late Cretaceous under a transpressional regime within the Żegocina tectonic zone, which caused the uplift of the Subsilesian Ridge and intensive erosion.

Holocene environmental reconstructions based on organic and mineral deposits of Mt Śnieżnica landslide, Outer Western Carpathians, Poland

<p><span><span>The Outer Western Carpathians is a region in Poland with an exceptionally high number of landslides. Besides geohazard issues, these landslides are frequently an archive of the past environmental changes thanks to organic and mineral material accumulated in numerous landlocked pits where small peat bogs formed. We investigated a large landslide body developed on the northside part of Mt Śnieżnica. No historical information exists related to the instability of this region. After finding and examining 20 pits, we selected three for detailed analyses. We extracted three cores with the use of a peat sampler. The cores were 10 cm in diameter and up to 4,2 m deep. Compared to other landslides in this region, the depth of peat bogs is substantial and suggests that the landslide is a minimum of several thousand years old. Laboratory analyses included: bulk density measurement,</span></span><span> </span><span><span>geochemical analyses (organic matter, SiO2ter, SiO2biog, CaCO3, TOC, TIC, C, N, S, Na, K, Mg, Ca, Fe, Mn, Cu, Zn, and Pb contents) of biogenic deposits (405 samples), AMC radiocarbon dating of plant tissue (20 pieces), macroscopic charcoal (420 samples each representing 1 cm slice of the core). The aim of the present study is 1) to reconstruct environmental conditions in the area, 2) dating of the landslide formation in relation to climate change during the Holocene, and the main events after its triggering: changes in vegetation cover, hillslope instability, e.g., soil erosion, hydroclimate fluctuations, and human impact. Our results fill the gap in environmental reconstruction encountered by other authors investigating this part of the Outer Western Carpathians and push forward the ongoing discussion on the environmental conditions during the Holocene in this region.</span></span></p>