Late Quaternary colluvial deposits in the Bocaina Plateau, southeastern Brazil highlands: age and palaeoenvironmental consequences

Autor(es)

Hiruma, Silvio Takashi ^[1] ; Modenesi-Gauttieri, May Christine ^[1] ; Riccomini, Claudio ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Secretaria Estado Meio Ambiente Sao Paulo, Inst Geol, BR-04301903 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Geociencias, Dept Geol Sedimentar & Ambiental, BR-05508080 Sao Paulo - Brazil

^[3] CNPq, Brasilia, DF - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BOREAS; v. 42, n. 2, p. 306-316, APR 2013.
• Citações Web of Science: 8

Resumo

Hiruma, S. T., Modenesi-Gauttieri, M. C. \& Riccomini, C. 2013 (April): Late Quaternary colluvial deposits in the Bocaina Plateau, southeastern Brazil highlands: age and palaeoenvironmental consequences. Boreas, Vol. 42, pp. 306-316. 10.1111/j.1502-3885.2012.00272.x. ISSN 0300-9483. Despite the generalized occurrence of colluvial deposits in the humid tropical areas of southeastern Brazil, regional correlation is difficult because the deposits are discontinuous, and chronological data are very scarce and scattered. For the first time, colluvial deposits in the Bocaina Plateau are described, including 18 radiocarbon ages from 12 profiles. The plateau is located on the eastern flank of the Continental Rift of Southeastern Brazil and is the highest part of the Serra do Mar, with elevations up to 2000m above sea level. Because the Bocaina Plateau is part of the summit surfaces of southeastern Brazil, it was subjected to specific climatic conditions during the Quaternary. Colluvial deposits on the lower hillslopes and edges of amphitheatres can show complex sequences with up to three intercalated dark humic horizons, corresponding to Late Pleistocene and Holocene phases of morphodynamic activity and pedogenesis. Ages of palaeosols vary from 650 +/- 50 a BP to 36880 +/- 980 a BP. Landforms and colluvia on the Bocaina Plateau are very similar to those found on the opposite flank of the continental rift, on the Campos do JordAo Plateau. Ages of buried soils point to similar soil formation and colluviation episodes in the two plateaus. As in Campos do JordAo, the succession of erosive, depositional and pedogenetic processes on the altos campos hillslopes is probably related to late Quaternary climate changes. (AU)

• Processo FAPESP: 03/08031-0 - Morfotectônica e evolução cenozóica do Planalto de Bocaina
• Beneficiário: Claudio Riccomini
• Modalidade de apoio: Auxílio à Pesquisa - Regular