@Article{RossettiZaniCoheCrem:2012:LaPlWe,
               author = "Rossetti, Dilce de F{\'a}tima and Zani, Hiran and Cohen, Marcelo 
                         and Cremon, {\'E}dipo Henrique",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "A Late Pleistocene-Holocene wetland megafan in the Brazilian 
                         Amazonia",
              journal = "Sedimentary Geology",
                 year = "2012",
               volume = "282",
                pages = "276--293",
             keywords = "tropical wetland megafan, late Pleistocene–Holocene, facies model, 
                         residual morphology, monsoonal climate, tectonic subsidence.",
             abstract = "Despite the growing interest in megafans, definitions provided for 
                         this type of environmental setting have not yet been widely agreed 
                         upon. A record of sedimentary facies distribution in both space 
                         and time including a larger number of analogs is particularly 
                         needed for improving megafan facies models. This work focuses on a 
                         large fan-like feature from an Amazonian wetland in northern 
                         Brazil. Morphological data based on remote sensing, as well as 
                         sedimentary facies and radiocarbon analyses, were integrated to 
                         propose that this feature is related to a megafan system active 
                         during the Late Pleistocene to Holocene. The megafan displays a 
                         divergent drainage network, gently-dipping slope, and concave-up 
                         and convex-up longitudinal and transverse profiles, respectively. 
                         Near surface deposits correspond to fining and coarsening upward 
                         sands related to active channels and overbank sand sheets/terminal 
                         fan lobes. Sediments are interbedded with abandoned 
                         channel/floodplain and lake/pond muds. Morphostructural analyses 
                         and drainage anomalies revealed a geological setting affected by 
                         reactivation of pre-existing faults contemporaneous with sediment 
                         accumulation. Establishment of a megafan system in this wetland 
                         most likely occurred within a slightly tectonically subsiding 
                         basin under favorable climatic conditions. During wet seasons, 
                         high water discharge would have favored sediment transport from 
                         highlands into this depositional site. High summer temperatures 
                         and drought under a monsoonal regime kept the water levels low. 
                         The described megafan could serve as an analog for contemporary 
                         tropical wetland megafans formed under a monsoonal climate 
                         regime.",
                  doi = "10.1016/j.sedgeo.2012.09.015",
                  url = "http://dx.doi.org/10.1016/j.sedgeo.2012.09.015",
                 issn = "0037-0738",
                label = "lattes: 0307721738107549 1 RossettiZanCohCohCre:2012:LaPlWe",
             language = "en",
           targetfile = "1-s2.0-S0037073812002758-main.pdf",
        urlaccessdate = "04 maio 2024"
}