Evolutionary interpretation of Holocene landscapes in eastern Brazil by optimally stimulated luminescence: Surface coverings and climatic pulsations

Abstract

The research seeks to explain the use of Optically Stimulated Luminescence (OSL) and highlight the importance of this method for the evolutionary interpretation of tropical quaternary landscapes through systematic geochronological reconstitutions of a pedogeomorphological nature. To this end, studies that used OSL and corroborated the geochronological evolution of tropical landscapes were evidenced. Emphasis was given to Brazilian studies conducted in the state of São Paulo, in the Western Plateau and Peripheral Depression, that addressed the relationship between fluvial and planation surfaces (geomorphological systems) and their surface coverings, in addition to Holocene climatic pulsations, associating them with landforms and deposition processes of surface coverings. Such surveys showed recent erosive/depositional events, responsible for imposing new dynamics on pedogeomorphological systems. At the same time, they were able to establish regional morphoclimatic scenarios to review former geomorphological proposals based on relative dating and relatively subjective hypotheses. OSL was important and has undeniably contributed to the enhancement of evolutionary theories; the identification of Holocene climatic pulsations that lead to hot and wet periods (5.300–6.200, 4.200–4.600, 2.000–2.400, 800–1.200 and 0–400 years B·P.), interrupted by hot and dry periods (7.900–10.000, 6.200–6.600, 4.600–5.300, 2.400–4.200, 1.200–2.000, 400–800 years B·P.), resulting from global cooling events; the building of a geochronological database (ages); and the innovation of geomorphological knowledge regarding surface coverings of geomorphological surfaces in tropical climates.