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Late Quaternary evolution of the Czyżynka river valley, Wałbrzych Upland, Middle Sudetes Mts, southwestern Poland

100%

Krzyszkowski D.

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tom Vol. 31, nr 2

259-288

EN

The lower part of the Czyżynka river valley (Wałbrzych Upland, Sudetes) was formed entirely after the early Saalian (Odranian) stage. The subsequent, 60-80 m deep, valley was incised into the mountain plateau. The valley is generally narrow with an alternating wide and narrow segments, and characterized by steep slopes, including common subvertical rock walls. Three terraces, formed most probably during the Wartanian/Eemian, Middle Weichselian and Late Weichselian represent the main stages of fluvial activity. Fluvial sequences show that sinuous to meandering rivers were active throughout the late Quaternary. Two phases of loess deposition are inferred (Wartanian and Middle Weichselian), as the deposits of the older terraces contain large admixtures of loess-like deposits. Moreover, two phases of large angular debris production and formation of extensive slope covers and fans have been recognized. The older occurred during the Upper Pleniglacial of the Weichselian stage. A continuum of slope colluvium was formed at that time, from fine-grained sheet wash deposits (including redeposited loess) to coarse grained deposits formed by cohesive debris flows, noncohesive debris flows and grain flows, and open-work loose material formed by debris avalanches. Frost activity and permanently moist conditions have been reported for that time, most probably with permafrost. Also, all these slope deposits contain an admixture of loess, suggesting loess deposition that time, too. The second phase of coarse debris production occurred, most probably, during the the Younger Dryas forming less extensive slope covers.

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Pleistocene evolution of fault-line scarps in the northern margin of the Krzeszowice Graben, south Poland

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Pawelec H.

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2007

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tom Vol. 24

29-35

EN

The paper aims at reconstructing Pleistocene slope processes and transformation of tectonic relief in two sections across the northern margin of the Krzeszowice Graben. The investigations are based on the analysis of deposits present on the slopes of fault-line scarps. The lithology and stratigraphy of these deposits was reconstructed based on analysis of outcrops and boreholes. Detailed lithological logs were prepared, along with grain size analyses, and determination of CaCO3, Fe2O3 and Corg contents in fine-grained sediments. The studied fault-line scarps were transformed by Pleistocene denudation. The type and intensity of these processes were different in the sections studied. In the Będkowice area, accumulation prevailed; the fault-line scarp became covered with sediments. In the Karniowice area, in turn, periglacial processes caused degradation of the fault-controlled slope. In the lower part of the fault-line scarp, the intensity of degradation processes was limited by repeated presence of sediment cover which preserved the substratum. Differences in the intensity and type of Pleistocene denudation can be explained by different heights of fault-line scarps, controlled by tectonic structure and neotectonic movements.

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Pleistocene evolution of fault-line scarps in the northern margin of the Krzeszowice Graben, south Poland

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Pawelec H. , Pawelec H.

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tom 24

4

Geneza skałek wierzchowinowych Płaskowyżu Ojcowskiego na podstawie badań osadów stokowych

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Pawelec H.

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tom Vol. 14, No. 2

163--176

PL

Artykuł podejmuje dyskusję dotyczącą genezy skałek wierzchowinowych na Płaskowyżu Ojcowskim. W odróżnieniu od najczęściej obecnie stosowanej w badaniach skałek metody, opartej wyłącznie na analizie geomorfologicznej, podstawą badań jest szczegółowa analiza osadów stokowych - powstałych równocześnie z niszczeniem skałek. Badania przeprowadzono w rejonie Jerzmanowic, pomiędzy górnymi odcinkami dolin Będkowskiej i Szklarki, na obszarze falistej wierzchowiny ze skałkami. Opracowano szczegółowe profile litologiczne osadów stokowych. Wykonano badania uziarnienia oraz zawartości CaC03, Fe203 i Corg. Dla frakcji iłowej wykonano analizy mineralogiczne. Badania wykazały, że występujące na stokach obszaru osady powstały w środowisku peryglacjalnym, w rezultacie wietrzenia mrozowego, sedymentacji lessu oraz redepozycji materiału gruzowego i lessowego przez procesy stokowe. Analiza sukcesji tych osadów oraz analiza procesów glebowych wskazują, że są to osady górnovistuliańskie. Na podstawie analizy rozmieszczenia poszczególnych typów osadów wnioskowano o zależnościach pomiędzy procesami peryglacjalnymi a rzeźbą stoków. Głównym kierunkiem przeobrażania ścian skałek było boczne cofanie w rezultacie wietrzenia mrozowego i odpadania wapieni. W obrębie falistej wierzchowiny, wypukły profil górnych części stoków jest rezultatem współdziałania wietrzenia mrozowego i soliflukcji. Dolne, wklęsłe części stoków zostały uformowane w wyniku depozycji osadów soliflukcyjnych i deluwialnych oraz okresowej redepozycji tych osadów, głównie przez spłukiwanie. Podczas plejstocenu obszar Płaskowyżu Ojcowskiego ulegał intensywnej denudacji, uwarunkowanej cyklicznymi zmianami klimatu. W środowisku peryglacjalnym działało głównie wietrzenie mrozowe i procesy stokowe. Podczas interglacjałów oraz interstadiałów działały procesy wietrzenia krasowego. Rezultatem plejstoceńskich procesów denudacyjnych, które rozwijały się na podłożu przeobrażonym przez kras, są współczesne formy skałek oraz rzeźba falistej wierzchowiny. Wyniki badań wskazują, że dotychczasowe teorie, dotyczące wieku i genezy skałek, nie doceniały znaczenia plejstoceńskiej morfogenezy dla rozwoju rzeźby Płaskowyżu Ojcowskiego.

EN

The origin of the monadnocks on the Ojców Plateau has been analysed not only on the basis of morphology but also by sedimentological analysis of the slope deposits that cover the slopes around the monadnocks. The investigations were carried out in the area of Jerzmanowice, between the upper courses of the Będkowska and Szklarka valleys within the undulated plateau where the monadnocks form the highest parts. Detailed lithological profiles were prepared, the granulometry was determined, and the CaC03, Fe203 and Corg content was estimated. Within the Clay fraction, mineralogical analyses were carried out. It is shown that the deposits covering the slopes developed in a periglacial environment as a result of frost weathering, loess sedimentation and reworking of scree and loess by slope processes. Both lithology of these deposits and the traces that soil processes left indicate an upper Vistulian age. The distribution of the individual lithofacies points to a distinct influence of periglacial processes on the slope relief. The main process was lateral retreat of rock walls as a result of frost weathering and rock fall. A convex profile of the upper parts of the slopes resulted due to the joint action of frost weathering and solifluction. The lower parts of the slopes, in contrast, developed a concave surface as a result of solifluction and surface wash, i.e. periodical redeposition of sediments. During the Pleistocene, the area of the Ojców Plateau underwent intensive denudation conditioned by cyclic climate changes. Frost weathering and slope processes were the most important under periglacial conditions. During interstadials, chemical weathering occurred in the active layer of the permafrost. Outcropping Jurassic limestones and the slope cover underwent karst processes. It is concluded that the present-day relief of the undulating plateau with monadnocks in the Cracow Upland results from the Pleistocene denudation processes. Surface degradation was stimulated during the Pleistocene by differential resistance of the rock units transformed by subsurface karst. Earlier studies concerning the age and origin of the monadnocks in this region underestimated the Pleistocene denudation.

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Zróżnicowanie pokryw deluwialnych i aluwialnych w Sudetach Wschodnich w świetle analiz sedymentologicznych i datowań radiowęglowych

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Latocha A.

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tom Vol. 55, nr 1

38-38, 45

EN

Textural and structural diversity of slope covers and alluvial deposits in the upper parts of mid-mountain valleys in the Eastern Sudetes allows for assessing human impact on their formation. Sandy-silty colluvial deposits in the lower parts of slopes or within local flats and slope depressions originate due to enhanced surface wash from arable grounds, in contrast to underlying coarser material with solifluctional features. Similarly, fine-grained overbank alluvial deposits can be also connected with human activity, as the slope material, washed down from arable fields, was transported to the channels and deposited within the floodplains during high-water stages. Their linkages with human activity have been confirmed by radiocarbon dating of charcoal found at the bottom of these sediments. The dates show a strong correlation with the dates of foundation of villages in the study area. The development of agriculture and deforestation of slopes resulted in increasing surface wash and transportation of slope material to footslopes and river channels. The extent of deposits, which can be correlated with human activity, is much more widespread than it was suggested before and they are found as high as 800 m a.s.l. Their thickness, however, is visibly smaller in comparison to colluvial or alluvial sediments deposited in the Sudetes foreland and it is strongly influenced by the local morphology. According to the 14C dating, these sediments are also much younger than those in the foreland, which corresponds to a substantial delay in human settlement expansion into the mountain areas.