Changes in the development of frost wedges in the Middle Warta valley deposits (Central Poland)
2011; Lithuanian Academy of Sciences; Volume: 53; Issue: 1 Linguagem: Inglês
10.6001/geologija.v53i1.1614
ISSN2029-056X
Autores Tópico(s)Geology and Environmental Impact Studies
ResumoIn the alluvia of the middle Warta River valley, different kinds of frost wedges and fissures such as syngenetic ice wedge pseudomorphs, epigenetic ice wedge pseudomorphs and wedges, and fissures with primary mineral infilling were documented. The formation of ice wedges of the older generation is dated to the transition from the Middle Plenivistulian to the Upper Plenivistulian, and ice wedges of the younger generation and sand wedges date to the coldest period of the Upper Plenivistulian. The thawing of some ice wedges preceded the degradation of permafrost and was due to thermokrast processes in the Upper Plenivistulian. Keywords: ice-wedge pseudomorphs, sand wedges, thermokrast, Vistulian, middle Warta River valley, Central Poland
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