Neotectonics in the northern equatorial Brazilian margin

The role of tectonics in the late Quaternary evolution of Brazil's Amazonian landscape

“…Furthermore, Marajó Island records high sedimentation rates, i.e., up to 1.8 mm yr -1 , during the last 50 ka (Rossetti et al, 2012a). Considering the flat topography in this area (i.e., 4−12 m in average), only tectonics could justify this high sedimentation rates and the creation of space to accommodate several tens of meters of sediment.…”

“…9C). Morphostructural evidence in support of tectonic control in this area includes the modern juvenile drainage still undergoing organization, and which displays many structural anomalies (i.e., multibasin to trellis pattern with occurrence of trellis to sub−dendritic, trellis and subparallel to rectangular patterns; rapid changes in these patterns; straight channels with subtle orthogonal to nearly orthogonal changes in course; subtle changes from highly sinuous to straight channels; local meandering in mainly straight channels; highly asymmetric basins; subtle channel enlargements; and flow inversions over time) (see Souza and Rossetti, 2011;Rossetti et al, 2012a for more detailed descriptions). The latter authors also demonstrated the continuity of faults in the subsurface using geophysical investigations, such as ground penetrating radar ( Fig.…”

A multi-proxy evidence for the transition from estuarine mangroves to deltaic freshwater marshes, Southeastern Brazil, due to climatic and sea-level changes during the late Holocene

“…Several paleoenvironmental indicators, such as sedimentological features (Suguio et al, 1985;Giannini et al, 2007;Rossetti et al, 2012), isotopes and geochemical data (Freitas et al, 2003;Pessenda et al, 2010), pollen (Behling et al, , 2004Cohen et al, 2005aCohen et al, ,b, 2008Cohen et al, , 2012França et al, 2012) and diatoms (Round et al, 1990;Bennion, 1995;Hillebrand and Sommer, 2000;Rivera and Diaz, 2004;Hassan et al, 2006;Korhola, 2007;Zong and Horton, 1998;Zong et al, 2010;Castro et al, 2013) have been used individually to investigate the past climate and the sea level fluctuations, as well as local environmental changes.…”

Relative sea-level and climatic changes in the Amazon littoral during the last 500 years

“…Recent works focusing the evolution of Amazonian mangroves have documented an expansion during the early and middle Holocene, followed by their replacement by freshwater vegetation along the Marajó Island coast in areas in the Amazon River mouth Rossetti et al, 2012). Mangroves and salt-marsh vegetation persisted in areas with marine-influenced littoral, where brackish water vegetation is recorded over tidal mud flats throughout the Holocene.…”