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Reconstructing cold climate paleoenvironments from micromorphological analysis of relict slope deposits (Serra da Estrela, Central Portugal)

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cris.lastimport.scopus2024-02-12T20:34:22Z
dc.abstract.enThe paper focuses on analysis of macro- and micromorphological characteristics of relict slope deposits in Serra da Estrela (Portugal) to understand the significance of different slope processes and paleoenvironmental settings. Micromorphology is a useful sedimentology technique allowing significant advances compared to macro- scopic techniques. Results show that different processes are involved in the develop- ment of the slope deposits, reflecting different environmental conditions. The main processes responsible for the emplacement of the relict slope deposits are solifluc- tion, debris-flow and runoff, but postdepositional changes are also present. Solifluc- tion was identified in slope deposits between 650 and 1500 m a.s.l. The common microfeatures identified are circular arrangement of grains with a core grain, rounded vesicles, vertical grains, matrix deformations and fine-grained deposits. Slope deposits above 1300 m a.s.l have a platy microstructure and coincide with the altitu- dinal range of the relict rock glaciers, indicating the elevation limit of permafrost. Below this altitude platy microstructures are less frequent. Slope deposits in north- facing slopes were affected by frost-induced processes in a seasonal frost regime, followed by a postdeposition illuvial phase. Debris-flow and runoff were identified in slope deposits between 680 and 1260 m a.s.l. The common microfeatures are oblique grains, grain dumps, and coarse and fine grain lineations, and banded micro- structures were identified in runoff processes. Debris-flow deposits have a circular arrangement of grains without a core grain, identified in sediments in paraglacial and periglacial environments. The slope deposits show evidence of past periods of enhanced periglacial activity since the last glaciation until the Younger Dryas.
dc.affiliationUniwersytet Warszawski
dc.contributor.authorVieira, Gonçalo
dc.contributor.authorJohansson, Margareta
dc.contributor.authorSchaefer, Carlos
dc.contributor.authorNieuwendam, Alexandre
dc.contributor.authorWoronko, Barbara
dc.date.accessioned2024-01-25T18:58:00Z
dc.date.available2024-01-25T18:58:00Z
dc.date.issued2020
dc.description.financePublikacja bezkosztowa
dc.identifier.doi10.1002/PPP.2054
dc.identifier.issn1045-6740
dc.identifier.urihttps://repozytorium.uw.edu.pl//handle/item/118040
dc.identifier.weblinkhttps://doi.org/10.1002/ppp.2054
dc.languageeng
dc.pbn.affiliationearth and related environmental sciences
dc.relation.ispartofPermafrost and Periglacial Processes
dc.relation.pages1-20
dc.rightsClosedAccess
dc.sciencecloudnosend
dc.subject.enmicromorphology
dc.subject.enpaleoenvironments
dc.subject.enperiglacial processes
dc.subject.ensedimentology
dc.subject.enslope deposits
dc.subject.enslope processes
dc.titleReconstructing cold climate paleoenvironments from micromorphological analysis of relict slope deposits (Serra da Estrela, Central Portugal)
dc.typeJournalArticle
dspace.entity.typePublication