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Morphological diversity of mesas in Elbsandsteingebirge, on three representative examples. Models built from high-resolution LiDAR data.
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It is commonly assumed that geomorphic evolution of tablelands, where durable caprock overlies weaker formations, proceeds via escarpment retreat which leaves residual tabular hills (mesas) in front of the receding scarps. These in turn are reduced in extent towards buttes and then pinnacles in the final stage. In this paper we use empirical eviden...
Contexts in source publication
Context 1
... mesa of Quirl typifies a hill where dissection is negligible (Fig. 4A). The entirely planar top surface is 925 m long and up to 330 m wide, covering 17.38 ha. It is bounded by nearly continuous cliff lines developed in moderately bedded quartz sandstones of K Sr1+2 unit which overlie weaker sandstones of K P5 unit (Lobst, 1993). The height of cliffs varies from 5 to 25 m, with alternating spurs and minor ...
Context 2
... nearby tabular hill of Pfaffenstein, with K Sr3 thickly-bedded sandstone caprock as thick as 60 m overlying K Sr1+2 sandstone unit (Lobst, 1993), is the best example to show the role of joint-guided weathering in mesa fragmentation (Fig. 4B). The north-western and central part of the mesa in particular turned into rock mazes, dissected along a few box canyons and numerous ravines, clefts and impenetrable slots, all following two principal joint directions: WNW-ESE and NNE-SSW. These linear features isolate massive sandstone compartments, rectangular in plan and typically ...
Context 3
... represents a remnant of a plateau, where fragmentation is accomplished mainly by the development of minor valleys extending into the mesa (Fig. 4C). By contrast, the cap itself, built of thickly bedded quartz sandstone (K Sr3 ), remains poorly dissected along joint lines and deep penetrable clefts are few. The mesa of Papststein is a two-storey one, with the lower cliff line c. 10-24 m high in K Sr1+2 sandstone unit, an intermediate bench, and the upper cliff line in caprock, c. ...
Citations
... Our calculations of the total rock loss during the interval covered by cosmogenic ages of boulders showed that much more material has been removed from the mesa of Szczeliniec Wielki than is still present as either caprock or subcaprock. Simple extrapolation into the future would suggest that the complete disappearance of the mesa and its transformation into a large cluster of residual boulders, envisaged as one of evolutionary pathways in tablelands (Migoń et al., 2020), would occur in a few tens of thousands of years. However, any climate change towards colder/drier climate, consistent with the natural cyclicity within the Pleistocene, would probably result in decelerating the process of retreat in cold climate (see below). ...
... Young et al. (2009) made a strong argument that climatic differences and their effects on the disintegration rate of durable caprock are strongly-to-completely overshadowed by lithological and structural variations and our findings are generally consistent with that proposal. In an earlier study elsewhere in Central Europe (Elbsandsteingebirge, Germany) it was shown that diverging pathways of caprock disintegration on mesas are influenced by structural and lithological variability (Migoń et al., 2020). In the Stołowe Mountains the transition from mild periglacial (e.g., MIS3) to strong periglacial (such as MIS2) and subsequent climate warming in the Holocene did not change the overall pathway of escarpment retreat that was dominated by in situ caprock disintegration, aided by minor topples and falls. ...
... Loss of support due to sand removal caused more block collapses (including one leading to the death of a sand miner in 1918) and further disintegration of a residual hill. The site is thus of both geomorphological significance, illustrating a stage in the evolution of tabular hills towards their ultimate decay (see Migoń et al., 2020), as well as cultural one. Next to it, within the margin of the main mesa, another artificial cave of Lichterhöhle of similar origin occurs. ...
Cultural values may considerably enhance the significance of a geo(morpho)site, especially from the perspective of geotourism and geopark operations. Typically considered as one of 'additional values', they may in fact strongly influence the identity of a place and distinguish a landform from many others of similar kind. Cultural values may be intangible or associated with past landform modification to suit human needs. In sandstone areas of the Bohemian Cretaceous Basin (Czechia, Germany, Poland) multiple relationships between human activities and erosional scenery exist, leaving a diverse record of human uses and alterations of specific landforms. Seven major categories of added cultural values are recognized. They include the use of landforms to support defensive structures, spiritual (religious) associations, exploitation of stone resources and other industries, inspiration for art, modifications associated with tourism development, dwelling places and transport facilities. They also illustrate changing relationships of humans with geomorphological landscapes from prehistoric times until the present. Within each category specific examples are presented to show variety of uses and alterations. A possibility to include added cultural values in semi-quantitative geosite evaluations is discussed, but it is concluded that this is difficult to achieve satisfactorily. Following previous opinions of Czech researchers, it is suggested that sandstone landscapes offer the most striking and diverse linkages between rock scenery and culture at the global scale, at least in part facilitated by the relative ease of excavating, cutting and carving of the rock, which otherwise also tends to support spectacular erosional landforms of different size and shape.
... Continuing erosion of underlying strata, whether mechanical or chemical, results in further subsidence and disintegration of the former caprock, so that caprock blocks may take a position at significantly lower altitude than dictated by the regional geological structure. In an advanced phase of this long-term process, irregular boulder clusters or dispersed large boulders are the only vestiges of once existing mesas and buttes (Migoń et al. 2020;Migoń and Parzóch 2021). ...
... Thus, Jabal Al-Qarah emerges as an important locality that can help to validate the concepts developed in a different geographical setting (Central Europe), typified by much more humid climate, especially in contemporary conditions, but not so much different in terms of geological structure and geomorphic context (sedimentary tableland in a predominantly clastic succession). It demonstrates the role of subsurface runoff in the evolution of residual hills in sedimentary tablelands and adds to the diversity of evolutionary pathways experienced in such areas (Migoń et al. 2020(Migoń et al. , 2023Migoń and Duszyński 2022a). It also shows that significant geomorphic role of groundwater is not restricted to karst terrains, but may apply to other settings as well if there is adequate lithological and structural preconditioning such as the presence of a regular system of fractures and soft rocks, easy to erode even by limited subterranean flows, especially under more resistant cap that would slow down surface lowering (also Laity and Malin 1985;Higgins and Osterkamp 1990;Bruthans et al. 2012aBruthans et al. , 2012bDuszyński et al. 2016). ...
... In particular, a good view of two minor residual hills, the butte to the north and the pinnacle to the north-west, along with a more distant view of plateau edge to the west, offers a template to explain the evolution of residual hills by long-term dissection and scarp retreat, from plateau through mesa, butte, to the solitary pinnacle as a penultimate stage. Although such a scenario may be an oversimplification of the reality at a specific place (see Migoń et al. 2019Migoń et al. , 2020, it may still serve as a useful educational tool. ...
Jabal Al-Qarah in the eastern part of Saudi Arabia is a flat-topped residual hill (mesa) built of calcareous sandstones, mud-stones, and marls of Miocene age. It is located within the World Heritage property of Al-Ahsa Oasis, but geoheritage values were not considered in the nomination and remained overlooked. The locality is famous for its systems of maze caves developed along deep fractures by mainly mechanical erosion and wall/roof collapses. They illustrate the origin of non-karstic caves through the action of underground flows, redirected from the surface via sinkholes and open cracks. Hillsides of Jabal Al-Qarah show evidence of various types of mass movements, including spectacular collapses of harder overlying strata after denudation of weaker strata beneath caused loss of vertical support. Thus, the mesa may become a key locality to understand slope development in layered successions and the role of subsurface flows in the global context. The site also has considerable potential to develop geotourism, as an added value to the already recognized cultural assets of the oasis and scenic qualities.
... Until now, the evolution of residual tabular hills was usually interpreted in terms of mass movements and cliff retreat, leading to the gradual areal reduction of the hill along the 'classic' plateau ➔ mesa ➔ butte ➔ pinnacle trajectory. However, other pathways were hypothesized by Migoń et al. (2020), leading to the origin of apparently irregular ruiniform relief rather than buttes and pinnacles, but insights into the mechanisms at work were limited. ...
... Considering trails from the summit top and wadi, adventure activities on cuesta's slope and top cuesta, like hiking and bike driving, can be initiated. A walking trail with specific explanatory broad facilities, and simple explanation of the geomorphological and geological features (see Migoń et al. 2019Migoń et al. , 2020 will offer an immense opportunity to gather scientific knowledge to the visitors. Apart from the physical visit to the site, a digital story map on the web platform will also allow international tourists to see various viewpoints on a digital platform (Fassoulas et al. 2022). ...
Exploring new geosites and geoheritage opens opportunities for geotourism. One of the geomorphic features in central Saudi
Arabia is the Tuwaiq Mountain, extending from the southern margin of the Nafud Sand Sea to the northwest margin of Rub'
al Khali sand sea. Appraisal study in the Tuwaiq Mountain reveals the various geological and geomorphological features
like Escarpment, mesa, butte, pinnacle, wadi network, and fossil. The majestic view of the Escarpment comprises the clif,
talus, and a birds-eye view of the wadi (fuvial valley), one of the prime viewpoints. Initially, cuesta was formed due to the
tectonic movement associated with the opening of the Red Sea. Tectonic landforms like faults are continuously eroded and
form the scarp. Gulley network indicates the dominance of a fuvial environment that later transformed into an aeolian environment. Therefore, the landforms’ evolution and geomorphic processes in diferent geological periods enhance this place’s
geoheritage value. The Jurassic fossils remain in this area and are a unique geological attraction. Numerous dried-up gully
networks are another viewpoint of the Tuwaiq Mountain, which is essential for biodiversity. Each potential tourist attraction is
described in the context of protection, policy development, and enhanced additional attractions for geotourism development.
... The combined presence of these rock-related controls creates a very specific morphogenetic setting that involves a range of characteristic processes, which would have played a very minor role otherwise and are directly responsible for the distinctiveness of many sandstone-and conglomerate-dominated tablelands (Figs. 12, 13). These include subsurface processes of arenization (breakdown of quartz sandstone into sand due to dissolution of cementsee Martini, 1979;Young, 1986;Sauro, 2014), mechanical subterranean erosion and transport if rock fabric is less tight (Bruthans et al., 2012;Duszyński et al., 2016), widespread cavernous weathering, often associated with the evolution of surface crusts (Mustoe, 1983;Goudie et al., 2002;Bruthans et al., 2018;Guo et al., 2018), or long-distance gliding of large sandstone boulders on deformable substratum (Young, 1983;Migoń et al., 2020). Subsurface processes of arenization and mechanical erosion are very distinctive for the coarse clastic rocks (although cannot be claimed to occur everywhere) and account for a range of specific landforms that have hardly parallels in other rock types. ...
Coarse clastic sedimentary successions cover approximately-one fourth of the continental surface and give rise to distinctive landforms at a variety of scales. Rock-mass strength differences between members of layered successions account for the presence of escarpments, typically capped by thick sandstone or conglomerate beds, usually also with mid-slope cliffs and benches reflecting variable resistance of individual members of the succession. Depending on the dip of strata, two main types of regional landscapes are plateaus and plains, or homoclinal ridges (cuestas), but higher degree of deformation may occur in the vicinity of major faults, resulting in hogback morphology. Medium-scale landforms include residual hills of various types such as mesas and buttes, rock cities and assemblages of ruiniform relief, whereas canyons and slots are common valley forms. Escarpment retreat is usually considered as an overarching concept in geomorphology of layered successions, but it does not seem to be a universal pathway of landscape evolution and even retreat itself may occur in different ways. We propose that juxtaposition of strong and weak rocks in the vertical succession is the viable unifying theme, as it has profound geomorphological implications, influencing processes and patterns of evolution at a variety of spatial scales. However, depending on lithological characteristics, mechanical and hydrogeological properties, dominant processes may vary, explaining considerable landform diversity within tablelands, even though at the grand scale stepped topography becomes a repetitive theme. Synthetic graphical presentation of morphogenetic systems on coarse clastic successions is also presented.
... Two national parks have been established in this area: the Saxonian Switzerland National Park in 1990 and the Bohemian Switzerland National Park in 2000. Besides the Elbe River Canyon, the typical features include isolated table mountains (Migoń et al., 2020) and a network of valleys and ridges dissected by grikes and characterized by rock pillars and rock walls, arches, mushroom rocks, and a variety of small-scale weathering forms. Some symmetrical Opal-A is occasionally recrystallized to chalcedony or microquartz or combines with calcite laminae (Urbani, 1976;Aubrecht et al., 2008). ...
A variety of speleothems are present in crevice and boulder caves developed in Cretaceous sandstones of the Elbe River Canyon in northern Czech Republic. A set of complementary instrumental mineralogical methods was applied to characterize the speleothems and cave dripwaters, including X-ray powder diffraction, scanning electron microscopy and microanalysis, Raman spectroscopy and optical emission spectrometry. Four morphological types were distinguished and characterized in terms of their mineral and chemical composition: 1, rusty brown mud-dominated coatings with micro-gours, composed of a mixture of clay minerals; 2, white “chalky” coatings (moonmilk) composed of calcite with minor gypsum; 3, cauliflower-shaped coralloids composed of calcite and silica in a layered structure, with gypsum layers in apical parts; 4, knob coralloids, dark gray-brown with smooth surfaces and distinctly layered structures, composed of silica (quartz, opal-A) and Si–Al phases (kaolinite) and including phosphate-rich laminae (sasaite, vashegyite, taranakite). Only modest microbial mediation of silica precipitation was observed in cauliflower-shaped coralloids while no clear signs are present in knob coralloids despite organic enrichment in the topmost layer. White “chalky” coatings and cauliflower-shaped coralloids precipitated from weakly acidic Ca-, Mg- and sulphate-rich deeper sandstone percolates. These forms are probably still active, much like the micro-gours, produced by particulate clay deposition. Formation of knob coralloids combined clay deposition and the dominant silica precipitation from pore waters similar to the present shallow acidic percolates under changing climatic conditions, probably in the Pleistocene. It was favored by specific rock lithology (quartzose sandstone with kaolinite admixture), which explains the scarcity of similar forms in sandstone caves. Concentration of knob coralloids along protruding vertical edges and the presence of wind-guided forms suggests that silica precipitation was driven by evaporation under a constant air flow.
... These morphologies are characterised by an upper resistant caprock of sandstones and limestones, and a weaker talus lower rock that is segmented by minor structural steps (Duszinsky et al. 2019). These landforms progressively evolve to smaller landforms (from plateau to mesa, butte, and finally pinnacle) (Migoń et al. 2018(Migoń et al. , 2020 through slope retreat. In the final stages, these landforms lose their hard caprocks to form hills degraded by erosion and badlands (Boroda et al. 2011(Boroda et al. , 2014Migoń et al. 2018). ...
The polyphasic evolution of the testimonial buttes in the central area of the Ebro basin (Los Monegros) is analysed. This is a semiarid area that favours high erosion rates. An evolutionary model of the Jubierre hills is presented that shows the environmental cycles represented by aggradational and degradative processes on the slopes that resulted in the present arrangement of talus flatiron rings. In the four studied cases, talus relicts are composed of detritic material from a disappeared caprock pediment. Four slope stages (S4 to S1) that formed under stable climate conditions are identified. Older stages (S4 and S3) are estimated by comparison with other talus flatirons in the region. The S2 stage contains Bronze Age archaeological remains and the radiocarbon age obtained was 1608–1446 years cal BC (2σ), while S1 is younger. A palaeoenvironmental interpretation was made for these aggradational stages (S4 to S1). The active erosion of these hills led to a relief inversion, and talus flatirons remain as the only features revealing the presence of the relict hills and past human occupations.
... A fine example of regions, where geomorphological research, especially quantitative landform analysis, benefited from the use of LiDAR DEMs are structure-controlled sandstone landscapes of Central Europe (Migoń, 2021). Nevertheless, parallel field work conducted in these areas (e.g., Duszyński et al., 2017Duszyński et al., , 2018Jancewicz et al., 2019;Migoń et al., 2020) proved that LiDAR data are not flawless and may not represent such complex relief properly. DEM artefacts were usually revealed in areas covered by forests, which are a common land cover type in Central European medium-altitude mountain ranges. ...
... Realizing inherent limitations of LiDAR data one can become concerned whether the available LiDAR DEMs, even though branded as high-resolution and state-of-art, have the ability to represent the topography so rugged as sandstone erosional landscapes properly. Such concern seems to be especially justified in the context of contemporary studies conducted in Central Europe, which aim to develop a protocol for high-resolution geomorphometric research in complex sandstone landscapes (e.g., Migoń et al., 2018Migoń et al., , 2020Jancewicz et al., 2019). Considering such a regional environmental setting, specific problematic issues can be expressed as the following list of questions: ...
... While the knowledge of point density issues increases the awareness of whether a particular dataset is capable to represent certain microtopographic features or not, one should also consider possible classification errors, which may cause that LiDAR DEMs do not represent correctly local complex topography. Recent fieldwork Jancewicz et al., 2019;Migoń et al., 2018Migoń et al., , 2019Migoń et al., , 2020 has provided numerous examples of locations where the DEM products such as DMR5G, NMT or DGM1 suffer from oversimplification of ground surface due to Type I errors. Thus, it was justified to suppose that at least some (if not the majority) of these errors can be corrected by using the point cloud data. ...
Contemporary airborne Light Detection And Ranging (LiDAR) elevation data provide a high-resolution input to quantitative studies within various branches of geomorphological research. Availability of such data played an especially significant role in the recent developments of geomorphometric studies focused on extremely rugged terrains, such as dissected sandstone plateaus. These are the areas of very complex topography, featuring structurally-controlled landforms such as tabular hills, canyons, cleft-and-valley systems, numerous high and near-vertical rock walls, isolated tors and dense boulder slope covers. In this paper we focus on issues of LiDAR data handling for geomorphometric research in Central European sandstone areas in Czechia, Poland and Germany, where the extremely rugged terrains are usually located in the forest and, thus, usability of LiDAR DEM (Digital Elevation Model) products for morphometric studies can be constrained. The impact of forest density on local decrease of ground point density may be considerable, adversely affecting the quality of DEMs, which become unsuitable to represent properly terrain features. Therefore, the role of DEM pre-processing in geomorphometric workflow is emphasized. Using the original point cloud data one can provide a much more detailed terrain representation that includes numerous convex landforms (tors, boulders) which are erroneously filtered-out from ready-to-use DEMs. Results of such procedure are shown explicitly in the form of Elevation Difference maps, as well as on examples of selected morphometric indices such as Topographic Wetness Index, Terrain Ruggedness Index and Morphometric Protection Index. The awareness of qualities of particular LiDAR datasets should be considered crucial while assessing LiDAR data applicability for morphometric studies on rugged erosional landscapes, especially if the study areas are transboundary.
... Piikki and Söderström, 2019) would be tested in a range of irregular hillslope settings. This could include the quasi-horizontal ledges found in the Flint Hills, but also morphologically more complex hillslopes such as tablelands with slumping blocks (Migoń et al., 2020;Schoorl et al., 2014). If valuable across this range of environments, intra-slope geomorphometric variables should be considered in large-extent continental or global Digital Soil Mapping initiatives (e.g. ...
Landscape position co-determines soil formation, and hence soil properties are related to landscape position. In many landscapes, the importance of landscape position is large, and thus relations between soil properties and landscape position are strong. This is particularly true for agricultural landscapes, where tillage has smoothed over local variation in soils. It is less true for some forested landscapes, where local impacts of trees on soil formation have increased local variation. This raises the question whether soil-landscape relations are strong in natural grassland, with neither trees nor plowing. We answer this question for hillslopes in a natural grassland in the American Great Plains by quantifying soil-landscape relations and soil spatial autocorrelation based on a dataset of 100 soil observations. We find that soil-landscape relations are weak, even when accounting for topographic features specific for the study site, and that short-range variation in soil properties is about as large as long-range variation. We conclude that non-tree related natural processes disrupt the formation of clear catenas, and hypothesize that these include small burrowing mammals and infilling of parent-material fractures with finer material.
