Basaltic Dyke with Specific Volcanogenic Structures and its geomorphic evolution: Unique Geoheritage of the Faroe Islands (North Atlantic Ocean)

Volcanic landforms resulting from Cenozoic volcanism represent the most peculiar features of global geodiversity and provide eminent narratives for geoeducation. Among them, however, relict volcanic forms and site-specific landforms in remote areas have received less attention. In this paper, we provide the first description of unique volcanogenic features (hereinafter referred to as pseudo-hieroglyphs) developed on a summit rock wall at the Sandfelli ridge near the village of Gjógv in the N Eysturoy Island (Faroe Islands). The geomorphic evolution of the ridge and rock wall during the Quaternary is described and detailed petrographic analyses of the volcanogenic features are provided. Based on observed petrographical features, we interpret the pseudo-hieroglyphs to probably represent unique examples of chaotic horizontal columnar jointing. Following the geomorphological and petrographic examination of the study site, we analyse current Faroese legislation aiming at nature conservation and use this case to discuss broader implications of geoheritage conservation and geotourism in distant regions.Vulkanická krajina vzniklá kenozoickým vulkanismem představuje nejpodivnější rysy globální geodiversity a poskytuje vynikající příběhy pro geovzdělávání. Méně pozornosti se však dostává reliktním vulkanickým formám a lokálním tvarům reliéfu v odlehlých oblastech. V tomto článku přinášíme první popis unikátních vulkanogenních tvarů (dále jen "pseudo-hieroglyfy"), které se vyvíjely na skalní stěně vrcholu na hřbetě Sandfelli u vesnice Gjógv v severní části ostrova Eysturoy (Faerské ostrovy). Je popsán geomorfologický vývoj hřbetu a skalní stěny během kvartéru a jsou uvedeny podrobné petrografické analýzy vulkanogenních vlastností. Na základě pozorovaných petrografických rysů interpretujeme pseudo-hieroglyfy, které pravděpodobně představují jedinečné příklady chaotické horizontální sloupcovité odlučnosti. Po geomorfologickém a petrografickém studiu zájmové lokality analyzujeme současnou faerskou legislativu zaměřenou na ochranu přírody a užíváme tohoto příkladu k diskusi širších důsledků zachování a geoturistiky geografického dědictví ve vzdálených regionech

Gneissic tors in the central European upland: Complex Late Pleistocene forms?

Bedrock outcrops punctuating regolith-covered surfaces in the summit/upper slope and hillside positions (torsand crags) have long been a subject of inquiry in geomorphology for their evolutionary trajectories and now alsoas valuable geoheritage sites. Methodological advances in research, such as DTM-based geomorphologicalanalysis and terrestrial cosmogenic nuclide inventories, create new perspectives to decipher the spatial andtemporal context of tor emergence and decay. The shape, structural controls, 10Be inventories and relation tosurrounding medium-scale landforms were studied at thirteen conspicuous bedrock outcrops developed inmetamorphic and sedimentary lithologies in the Bohemian-Moravian Highland, Czechia. The shapes of studiedbedrock outcrops indicate significant litho-structural controls. The general outline is mainly governed by (sub)vertical joints, whereas the inclination of foliation or bedding planes dictates summit and cliff morphology. Someof the tors described in this study developed in exceptionally densely foliated and jointed gneiss, which does notcomply with the generally accepted view of tors as massive rock compartments resisting weathering. A series ofrock hardness measurements performed at three gneissic tors using Schmidt hammer show statistically significant within-tor variability of R-values, indicating different exposure times to subaerial weathering. Thecomplexity of landform assemblages, within which studied tors/crags are developed, varies from isolatedbedrock outcrops surrounded by smooth slopes covered with debris-rich soils to outcrops accompanied by lowrock cliffs, debris-covered steps, slope benches, boulder fields and isolated large blocks. The 10Be inventoriesreveal ages mostly from the Late Pleistocene and rarely from the Holocene. Summit/upper slope tors and hillsidecrags show considerable variability in maximum denudation rates ranging from 6.4 ± 0.2 to 105.6 ± 4.8 m/Ma.Paired samples from the summits and cliffs of eight outcrops indicate three possible post-emergence evolutionaryscenarios with summit downwearing while keeping the outcrop outline, balanced cliff and summit degradationrate, and backwearing as the dominant degradation process

Landforms

Landforms are distinctive features of the land surface shaped by erosion, accumulation or deformational processes that involve the movement of mass (rock, sediment, water). Landforms are normally classified according to their genesis within three main fields of geomorphological investigation: Structural geomorphology, covering landforms controlled by geological factors; Climatic geomorphology, including landforms developed under specific climatic conditions); and Non-zonal geomorphology, comprising landforms shaped by geomophological processes that occur in most climatic zones. The study of landforms is crucial for (paleo)environmental reconstructions, prediction of the spatial distribution, magnitude and frequency of geomorphological processes (e.g., hazard assessments), and the analysis of local and global environmental impacts. A proper understanding of landforms' genesis and evolution is of paramount importance for the successful planning, design and implementation of engineering projects. Geomorphological mapping can be essential for identifying the suitable site for a project and understanding the processes occurring in the area, including those that may adversely affect the development or feasibility of the project itself. Landforms can be dated, monitored and modelled providing significant clues for the interpretation of past, present and future Earth surface processes, both subaerial and submarine. Since most engineering works are developed at the Earth’s surface, the study of landforms – produced by processes occurring at different temporal and spatial scales – is of special usefulness for engineering geologists. In this context, the analysis and assessment of the state of activity of landforms (active, dormant, inactive), especially in highly dynamic environments, provide important clues for hazard and risk assessments and related mitigation measures