HILLSLOPE DEPOSITS AND THE QUATERNARY EVOLUTION OF THE ALTOS CAMPOS - SERRA DA MANTIQUEIRA, FROM CAMPOS DO JORDÃO TO THE. ITATIAIA MASSIF.

MAY CHRISTINE MODENESI-GAUTTIERI

Resumo


This contribution is an attempt to integrate results of 20 years of geomorphological investigation with new morphotectonic data and 14C ages of colluvia and peat-rich sediments. The Quaternary evolution of the altos campos landscape, in the highest summits of the Serra da Mantiqueira, between the crystalline plateau of Campos do Jordão and the alkaline massif of Itatiaia, has a cyclic character, characterized by intensive episodes of hillslope degradation, by mass movements, and by stability intervals. Mass movement processes differ in each plateau according to environmental conditions. In Itatiaia, 500m higher than the Campos do Jordão Plateau, interference of geocryogenic activities was stronger. Since approximately 37,000 years BP, erosive and depositional events took place in the altos campos hillslopes, at Campos do Jordão (three colluvia with intercalated soils) and Itatiaia (two colluvia over older scree deposits). The last and widespread colluviation episode is Holocene, with similar ages in both plateaus. The new data confirm the interference of Quaternary neotectonics in the landscape evolution of the altos campos, but the triggering of instability phases, whether tectonic or climatic, still remains to be clarified.

Palavras-chave


Quaternary; Hillslope evolution; Weathering; Colluvium; Mass movements; Geocryogenic processes; 14C.

Texto completo:

PDF (English)

Apontamentos

  • Não há apontamentos.