Cave studies enable us to unravel valuable information on landscape evolution. In glacial settings, the glacial cycles induced fluctuations in the underground hydraulic regime, sediment availability ...and base level in adjacent caves. Here, we present our work on the Grønli-Seter cave system in Northern Norway, which comprises >8 km of passage length at an elevation between 250 m and present sea level. By linking cave morphology and deposits to shifting glacier configurations and external base level changes during the last deglaciation and the Early Holocene, we establish how the hydraulic conditions in the cave system shifted in pace with glacier fluctuations. Maze sections and phreatic loops appear in a hydraulic confined setting close to the interface between the calcite marble and the overlying mica schist. Scallops in the cave walls demonstrate slow, ascending water flow, evidence of subglacial speleogenesis under wet-based, topographically constrained glaciers with a gentle surface slope. Moreover, cave morphology and clastic deposits indicate various hydrological phases of descending water flow, stagnant conditions, and excessive flow rates. Our work establishes that the last glaciation and deglaciation had an insignificant effect on the cave system's solutional development. In contrast, the cave sediments reveal diverse hydraulic conditions that may be related to shifting glacier configurations. This research offers valuable insights into glacier ice-contact speleogenesis and landscape development in glacial terrains.
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•Reveal the relationship between cave morphology, deposits and glacier fluctuations.•Relate ice-contact speleogenesis to the glacial valley development.•Identify shifting hydrological conditions in the caves during the last deglaciation.
In this study, the evolution, the development and the development environment of solution dolines of glaciokarst (the Alps and the Dinarides) are studied. Based on morphological observations (partly ...with the help of literary data), the dolines of sample sites were put into doline types (giant solution doline, small-sized solution doline and schachtdoline). The various features of the dolines belonging to different doline types were analysed and compared: their size, shape, elongated nature and the slope angle of their side slope. Giant solution dolines are much more similar to the dolines of the temperate belt rather than to small-sized solution dolines or schachtdolines. At temperate climate, giant solution dolines developed under the tree line similarly to dolines of the temperate belt, and not above the tree line. Below the tree line, the dolines grew horizontally to the effect of horizontal dissolution. Later, in the glacials, they developed laterally mainly along their longer axis by glacial erosion. They got into their periglacial environment during the uplifting of the bearing area. In mountains where they are absent, the circumstances of their environment were not present either because the uplifting of the mountain was fast or it was covered by non-karstic rock. The shapes of small-sized solution dolines and schachtdolines prove that their increase happened by deepening. Their deepening was caused by the meltwater of the snow patches of snow drifts which water does not move laterally because of the rock debris of the floor and thus, solution works downwards in the features. Deepening and snow accumulation strengthen each other. These karstic depressions are connected to the periglacial zone because treeless environment favours snow drifts. If the depression is completely filled with snow in most part of the year, the snow patch is wide thus, dissolution affects the total width of the doline. A doline (schachtdoline) with vertical sides and plain floor develops. If snow-fill is only partial in most part of the year, the snow patch and thus, dissolution will have a smaller area and a small-sized solution doline with funnel shape develops.
The Carpathian island-type glaciokarst has a great potential of preserving signals of past environments, archived in cave deposits like speleothems and clastic infills. We present here the ...geomorphology and structural control of several relict alpine caves and the surrounding glaciated marble karst in the Făgăraș Mountains. Four truncated and partially unroofed caves remained on the ridge-top of Mușeteica Mountain, above the glacial cirque, while a ponor cave that developed on the cirque bottom could be related to the Last Glacial Period. Structural measurements and cave morphology showed that the conduits formed at the intersection of foliation planes and tectonic fractures on the NE-SW and NW-SE directions. Cave development reflects three speleogenetic stages: 1) texture- and fabric-controlled dissolution and distension; 2) structurally-controlled breakdown; and 3) truncation, unroofing, and cave infilling with sediments. Slow diffuse dissolution was typical for the ridge-top caves, whereas M1 Cave developed by pressure flow.
Further, we report the first UTh speleothem ages, related to the evolution of alpine caves and island glaciokarst in the South Carpathians during the Middle and Late Pleistocene. Dating results show a minimum estimated age of ~560 ka for the ridge-top caves, and that speleothem deposition met optimal conditions only during warmer periods, largely corresponding to interglacials. Stable carbon isotope values in speleothems range between −9.96‰ and −4.11‰, indicating the presence of plant and soil organic activity at the time of deposition. In total, five speleothem growth phases were distinguished during the last ~560 ka.
We excavated the sediment infill of a ridge-top doline down to a 2-m depth. Radiocarbon dating revealed that it was deposited during the Late Holocene, and preliminary pollen analysis identified a plant assemblage dominated by grasses.
Using the relationships between karst development, glaciation, and cave sedimentary archives, we present a time slice chronology of alpine landscape evolution at >560 ka, ~400 ka, ~330 ka, the Last Glacial Period (70–12 ka), and the Late Holocene. Our geomorphological, isotopic, and geochronological results also support the existing hypothesis that the South Carpathians may have experienced at least two glacial phases during the Pleistocene. Glacial erosion rate during the Last Glacial Period, and most likely during the penultimate glaciation, averages around 0.6 mm yr−1.
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•We investigated glaciokarst morphology in the Făgăraș Mountains, Romania.•We provide the first speleothem ages of alpine caves in the South Carpathians.•The minimum estimated age of ridge-top caves is ~560 ka.•Speleothem growth was limited only to warm periods.•Sedimentary infill of dolines unravels Late Holocene environmental conditions.
The present article is focused on high mountain relief in marble, which combines glacial, periglacial and karstic morphology. High mountain karst is found in Northern Pirin (Vihren and Sinanitsa ...area) and central Pirin (Orelek area), the latter lacking traces of glaciation due to its low altitude. In the most representative area, Vihren part, several vast and deep cirques-uvalas were formed, which comprise a large diversity of landforms. Main factor for the specifics of relief in marble is the structure of the rock, which combines carbonate mineral content and crystalline properties; they favour both the occurrence of karstification and frost weathering. The high elevation of Northern Pirin (up to 2914 m a.s.l.), and the resulting extensive former glaciation enhanced the karst processes by weathering of the morphological surface. At present, surface karst is most developed on elevated sections of cirque bottoms, which were ice free before the beginning of the Holocene and are away from rockfall creep accumulation. A special element of glaciokarstic relief in Pirin are the summer lasting snow/ice features (glacierets and snow patches), two of which are considered centuries old, and still survive despite the temperature warming. In general, karst processes in the high mountain areas of Pirin are less developed than in the western part of the Balkan Peninsula (the Dinarides), due to the greater susceptibility of marble to physical weathering compared to limestone, which leads to a more intensive formation of regolith on the surface, and in result of the generally colder and dryer climate.
The karren formation and karren features of bare slopes is studied. The occurrence of various karren features was measured on slopes with different inclination. The occurrence of various karren ...features on slopes has been presented according to slope inclination values. The slopes were put into slope categories and their karren features were given. Thus, the karren formation of the bare slopes of various karst types and karst features (glaciokarst, coastal karst, tropical karst, mediterranean karst, collapse dolines, gorges, caves etc.) can be described. It can be stated that on limestone with the increase of the inclination of the bearing slope, the diversity of karren features decreases and those of flow origin will be increasingly dominant. However, with the increase of slope inclination, features of flow origin will be increasingly simpler. On limestone, on slopes with a smaller dip and on slopes of less soluble rocks, the distribution of karren features of seepage origin increases. On glaciokarst, where bare slopes are widespread and of various inclination, karren are diverse and the distribution of various types is also considerable. In other karst areas, small-inclined slopes (coastal karst, tropical karst) or very large-inclined slopes (tropical karst, collapse dolines) are predominant and thus, the distribution of some karren features (e.g. rinnenkarren) is limited. The change of slope inclination may result in the change of karren formation. On glaciokarst, bare and subsoil karren formation are separated from each other, on mediterranean and tropical karst, they are less separated from each other and the latter prepares the former. On halite, the effect of slope inclination on karren formation may be modified by intensive dissolution. The karren formations of halite and tropical karst are partly similar which can be explained by intensive dissolution in both cases.
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