Produção Nacional
Registro de mudanças ambientais Pleistocênicas e Holocênicas em depósitos de cabeceira de vale: Campo Alegre, planalto norte catarinense (SC)
2006; Sociedade Brasileira de Geologia; Volume: 36; Issue: 3 Linguagem: Inglês
10.5327/rbg.v36i3.1241
ISSN2317-4889
AutoresMarcelo Accioly Teixeira de Oliveira, Luiz Carlos Ruiz Pessenda, Hermann Behling, Gisele Leite de Lima, Glaucia Maria dos Santos Silva Ferreira,
Tópico(s)Hydrology and Sediment Transport Processes
ResumoLow resolution of continental sedimentary record is a common source of skepticism about the application of geomorphology and sedimentology to Quaternary studies. However, when supported by independent proxy data, geomorphology and sedimentology favor palaeoenvironmental interpretation. This paper presents results obtained from pedostratigraphic sequences, in valley head sites of southern Brazilian highlands, based on geomorphological, micromorphological, sedimentological, isotopical and palynological data. Results point to environmental changes, which ages coincide with Marine Isotopic Stages (MIS) 5b; 3; 2 and 1. During the late Pleistocene, in spite of temperatures and precipitation lower than today, the local valley head record points to wetter local environments, where shallow soil-water saturated zones contributed to erosion and sedimentation during periods of climatic change. During the mid Holocene, slope wash deposits suggest a climate drier than today, under the influence of seasonally contrasted precipitation regimes and torrential overland flow on hillslopes. The predominance of overland flow-related sedimentary deposits suggests an excess of precipitation over evaporation influencing local palaeohydrology. This palaeohydrological condition seems to be recurrent and explains how slope morphology had influenced pedogenesis and sedimentation in the study area, in response to environmental changes.
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