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EN
This study covers the western part of Poland’s loess Nałęczów Plateau (Kazimierz Dolny, Zbędowice). Mass movements in the Lublin Upland occur during periods of increased precipitation or after a snowy and cold winter. To date, there are no comprehensive studies on active (precipitation, hydrology, vegetation, land use, anthropogenic factors) or passive factors (lithology, slope angle) causing such geohazards in this region. This area’s formations are characterised by high sensitivity to even small changes in moisture content; thus, their geotechnical parameters deteriorate as a result of precipitation or rising groundwater levels. The calculations in this study were chosen to determine the time necessary for ground response to external factors, in addition to determining the impact of these factors on decreases in the factor of safety (FS). Based on calculations in GeoStudio software, the impacts of rainfall totals and duration on slope failure, interpreted as an event where the FS falls below 1.0, were analysed. Accordingly, the threshold rainfall value was determined as the total rainfall at the time of slope failure. The study’s results indicate that loess covers are characterised by average water permeability, relatively high internal friction angles and low cohesion, which, combined with high slope inclination, favour landslide formation even when the slope is only partially saturated. The most unfavourable stability conditions occur at the beginning of spring, indicating that loess stability is significantly affected by snowmelt and precipitation at the beginning of the vegetation season, as well as the occurrence of episodic intense precipitation during the summer.
Raport
|
2019
|
vol. 14
121-124
EN
Excavation photos of the earthwork of Altheim from 1914 show a fully-developed Luvisol (para-brown earth). In 2012, fieldwork recommenced at the site and revealed a second ditched enclosure as well as the serious impact of soil erosion: In the course of a century about 0.4 m of the ditch feature has been lost. In comparison with the total amount of erosion since the creation of the earthwork in the 37th/36th century BC the loss of soil material has dramatically accelerated during the past century.
PL
Artykuł prezentuje porównanie składu geochemicznego i stopnia zwietrzenia chemicznego dwóch późnoplejstoceńskich sekwencji lessowo-glebowych, zlokalizowanych w SE i SW Polsce. Analiza chemiczna w zakresie pierwiastków głównych (Si, Al, Fe, Mn, Mg, Ca, Na, K, Ti, P) oraz wyliczonych na ich podstawie wskaźników (CIA, Ti/Al, K/Al, Mg/Ca, K/Ca, Na/K oraz Si/Al) wykazała, że obie sekwencje są zróżnicowane zarówno w ujęciu stratygraficznym, jak i przestrzennym. Zmienność stratygraficzna związana jest ze zmianami paleoklimatu warunkującymi natężenie zarówno procesów lito-, jak i pedogenezy. Zmienność przestrzenna może wynikać m.in. z odmiennych warunków klimatycznych w trakcie tworzenia się sekwencji lessowo-glebowych, recyklingu lessów lub nawet odmiennego źródła materiału. Istotna może być też dysproporcja miąższości sekwencji, skutkująca zróżnicowanym wpływem infiltracji wód opadowych.
EN
The article presents the comparison of the geochemical composition and the degree of chemical weathering between two Late Pleistocene loess-palaeosol sequences of SE and SW Poland. The results of major element (Si, Al, Fe, Mn, Mg, Ca, Na, K, Ti, P) and geochemical index (CIA, Ti/Al, K/Al, Mg/Ca, K/Ca, Na/K oraz Si/Al) analyses indicate stratigraphical and spatial differentiation between sequences. The stratigraphic differentiation is connected with palaeoclimatic conditions which control the intensity of pedogenesis. The spatial variability may be attributed to different climatic conditions during the deposition of loess, the loess recycling process, or even to different source areas. The disproportion between the thicknesses of the loess covers can also be important. It can affect the rainwater infiltration effect.
Organon
|
2017
|
vol. 49
265-280
EN
The first research on Prehistory in Alsace took place in 1865 in Haut–Rhin, in the foothold of a naturalistic society founded in 1859 in Colmar. Collections of stone tools and fossil bones attributed to prehistoric times, were built from this period, in a way inspired by the discoveries made in France and Belgium. After these early beginnings, the four changes of nationality that took place in Alsace between 1870 and 1945 led to deep changes in the life of scientific societies and museums. Nevertheless, prehistoric research has continued in this region despite these constraints. Researchers like Paul Wernert took advantage of this situation by establishing the link in their work between the French and German traditions.
PL
Zagłębienia bezodpływowe stanowią typowe formy rzeźby obszarów lessowych Europy, a ich geneza jest szeroko dyskutowana w literaturze. Artykuł prezentuje stan dotychczasowych badań, dotyczących zagłębień bezodpływowych obszarów lessowych Polski, istniejące hipotezy genetyczne oraz kierunki przyszłych badań. Dotychczas w literaturze opisane zostały cechy morfometryczne, rozmieszczenie i warunki geologiczne występowania tych form. W wybranych zagłębieniach zbadano gleby kopalne i osady koluwialne wypełniające formy. Zróżnicowane procesy (pierwotne i wtórne): deflacja, nierównomierna akumulacja lessu, sufozja, wyciskanie poziomów kurzawkowych, termokras były opisywane jako możliwe procesy morfogenetyczne. Zagłębienia bezodpływowe pełnią funkcję sedymentologicznych archiwów, umożliwiających rekonstrukcję naturalnych i antropogenicznych procesów zachodzących w przeszłości. Niezbędne są dalsze badania genezy i ewolucji zagłębień bezodpływowych. Pozwoli to na lepsze zrozumienie znaczenia okresu późnego glacjału i holocenu dla morfogenezy obszarów lessowych Europy.
EN
Closed depressions (CDs) are typical geomorphological features of the loess belts in Europe and their origin is highly debated in literature. This paper presents the current state of research on CDs in the loess belts in Poland. A review was conducted of several studies describing CDs. The existing genetic hypothesis and the scope of future research are described. Morphometric features of CDs, distribution and geological conditions were described in several publications so far. In the selected CDs, colluvial sediments and fossil soils were studied. Various processes (primary and secondary): deflation, uneven loess deposition, suffosion, extrusion of strongly saturated layers, thermokarst were reported as probable genetic processes. CDs act as important archives allowing a reconstruction of natural and anthropogenic processes operating in the past. More research is needed for a better understanding of the origin and evolution of CDs. This will help better understand the importance of the Late Glacial and Holocene stages for the morphogenesis of the loess belts in Europe.
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