期刊名称：Annales Universitatis Mariae Curie-Skodowska. Sectio B, Geographia, Geologia, Mineralogia et Petrographia
印刷版ISSN：0137-2025
出版年度：2003
卷号：LVIII
出版社：Maria Curie-Sklodowska University, Lublin
摘要：The main features, origin and stratigraphic distribution of cryogenic structures occurring in loesses of three last glacial cycles in Poland, western Ukraine and south-western Russia are presented on the basis of literature review and the author's own studies.
Distinct ice wedge casts occurring in polygons were found in SE Poland (Kol. Zadębce) within the loesses from the Odranian Glacial. They indicate the occurrence of discontinuous permafrost (Dolecki 1993, 1995).
The described above structures can be correlated with ice wedge casts occurring in the Morshansk loess in Russia, included in the Dnieperian cryogenic phase "a". Corresponding structures were found in western Ukraine within the upper part of the lower bed of the Middle Pleistocene loesses (according to the scheme by Bogutskiy 1987). Fissure casts with primary mineral infilling were found in Poland in the pedocomplex from the Lublin (= Odincovo = Korshov = Ohe) Interglacial and the Early Wartanian. They occur in two generations. They were probably formed as a result of occurrence of seasonally frozen ground. Structures which can be defined as cryohydrolaccoliths occur in some places.
The Cryogenic structures found in the Korshov pedocomplex in western Ukraine are of the same age. The corresponding cryogenic unit in Russia contains structural deformations of spotted-medallion-like tundra, and also ice wedge casts with secondary seasonal infilling, and involutions disturbing the top of the Tambov I paleosol and other soils with the same stratigraphic position.
Ice wedge casts within the Wartanian (= Moscovian) loesses have vertical dimensions of 2-4 m and widths about 0.6 m; they form polygons up to a dozen metres in diameter. These structures were formed in conditions of sporadic and discontinuous permafrost (Dolecki 1985, 1991).
In Russia the Moscovian loesses correspond to the Cnin and Moskva loesses covering the Oka and Don interfluve. Two generations of ice wedge casts 2.5-3.0 m thick occur within the Cnin loesses. They are included in the Dnieperian cryogenic phase "b" or to the Moscovian unit (Velichko 1980). Casts of the lower generation have smaller dimensions; in the Michajlov profile near Riazan their vertical dimension is 23 m, and they form polygons 89 m in diameter (Velichko et al. 1984).
The upper older (Wartanian) loesses are correlated with the upper bed of the Middle Pleistocene loesses in Ukraine (according to the scheme by Bogutskiy et al. 1994). These authors distinguished three cryogenic units of different age within these loesses in the Volhynia, and similarly in Podolia.
In Poland two or three generations of cryogenic structures of different age with primary mineral infilling occur within the pedocomplex from the Eemian and Early Vistiulian. They were formed while there was strongly developed seasonally frozen ground.
The oldest cryogenic structures of the Early Vistulian correspond to the Smolensk cryogenic phase "a" found in the Russian Plain within the interglacial pedocomplex defined as the Mikulino soil. It is represented by the deformations of different type. The younger Smolensk cryogenic phase "b" was connected with the end of the Krutick Interstadial which corresponded probably to the Odderade Interstadial known from the Polish profiles. The discussed above pedocomplexes from the Eemian and Early Vistulian correspond to the Horochow pedocomplex occurring in the western Ukraine (Bogutskiy, Velichko, Nechaev 1975). Wedge-like structures found in this pedocomplex are connected with the Smolensk cryogenic phase "a". Phase "b" left similar structures running down from the A1 horizon to a depth of 1.3-1.5 m and occurring in polygons 24 m in diameter.
In Poland the deposits from the lower pleniglacial of the Vistulian, i. e. the lower younger loesses contain ice wedge casts with secondary mineral infilling. They were formed when there was a sporadic or discontinuous permafrost.
The lower younger loesses correspond to the thin (2 m) Khotylev (Valdaian I) loess distinguished in the stratigraphic division of Russian loesses. Cryogenic structures are present in the lower part of this loess, just above the Mikulino pedocomplex. They are connected with the Smoleńsk cryogenic phase "b". Casts of that age are defined in Ukraine as the structures of the Torchyn cryogenic phase "b". They have an epigenetic character and are found in the middle part of the lower level of the Upper Pleistocene loesses (LMd according to the Polish stratigraphic scheme).
In the interpleniglacial of the Vistulian, during the accumulation of the middle younger loess in Poland, wedges were formed in the conditions of sporadic and discontinuous permafrost occurrence. They can be correlated with the Volodimir cryogenic phase "a" distinguished in the stratigraphic schemes of East European loesses (Gerasimov, Velichko 1982) in the upper pleniglacial of the Valdaian, and also with bottom of the Desna loess. Cryogenic deformations in the Briansk soil below Desna loess reveal distinct regional differentiation. In the Volhynia this cryogenic unit is connected with the lower part of the Upper Pleistocene loesses where structureless deformation of solifluction and involution type occur.
Two generations of ice wedge casts were found in the upper younger loesses which had been accumulated in Poland during the upper pleniglacial of the Vistulian. The older one is known as "final wedges" with vertical dimensions up to 45 m and widths up to 1 m. They were formed on continuous permafrost. In the opinion of Velichko et al. (1987) these structures correspond to the Jaroslav cryogenic phase "a" found in the Russian Plain (Gerasimov, Velichko 1982; Nechaev 1994), and they were formed during the period 2018 ka BP. Structures of this age occur in the upper part of the Altynovo loess which is younger than the Trubachevsk soil which developed on the Desna loess. In the Volhynia loesses the Jaroslav cryogenic phase "a" is connected with a fossil active layer from the pleniglacial of the Valdaian.
Cryogenic structures of the successive generation occurring in the upper part of the upper younger loess cover are rather rare in Poland. They are probably casts with primary mineral infilling strongly transformed by the Holocene pedogenesis. Stratigraphically corresponding unit in the middle part of the Russian Plain is probably the Jaroslav cryogenic phase "b" from the Late Dryas. It is represented by ice wedge casts and structureless deformations. In western Ukraine this unit is represented by ice wedge casts whose upper parts occur usually within the Holocene soil
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