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@Article{RossettiGrReCoMoCoRo:2017:LaHoTe,
               author = "Rossetti, Dilce de F{\'a}tima and Gribel, Rog{\'e}rio and 
                         Renn{\'o}, Camilo Daleles and Cohen, Marcelo C. L. and Moulatlet, 
                         Gabriel M. and Cordeiro, Carlos Leandro de Oliveira and Rodrigues, 
                         Erika do Socorro Ferreira",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas da Amaz{\^o}nia (INPA)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Federal 
                         do Par{\'a} (UFPA)} and {University of Turku} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Federal 
                         do Par{\'a} (UFPA)}",
                title = "Late Holocene tectonic influence on hydrology and vegetation 
                         patterns in a northern Amazonian megafan",
              journal = "Catena",
                 year = "2017",
               volume = "158",
                pages = "121--130",
                month = "Nov.",
             keywords = "Forest canopy, Landscape evolution, Mid/late Holocene, Tectonics, 
                         Northern Amazonia.",
             abstract = "The factors that control the heterogeneous canopy of the Amazonian 
                         rainforest have long been a topic of interest for research. Among 
                         all hypotheses, changes in landscape due to geological processes 
                         have been increasingly defended. Large areas of open vegetation in 
                         the northern Amazonian lowlands are confined to paleolandforms 
                         created by the abandoning of megafan depositional systems. 
                         Previous investigations related the megafan sedimentation in this 
                         region to Late Pleistocene-Holocene tectonic reactivations. 
                         However, the influence of neotectonics on both the Amazonian 
                         megafans and associated vegetation cover remains to be further 
                         investigated. We studied a depression preliminarily noticed in the 
                         south-central sector of one Amazonian megafan (i.e., Viru{\'a} 
                         megafan) aiming to determine if its genesis was due to recent 
                         tectonic subsidence after the megafan abandoning. The 
                         investigation combined morphostructural, hydrological and remote 
                         sensing reflectance analyses, as well as characterization of 
                         floristic communities in the modern and ancient environments based 
                         respectively on field inventories and palynological data. The 
                         results indicated a nearly 10-km long and rectangular-shaped area 
                         having straight margins paralleling NNE/SSW-trending regional 
                         structural lineaments. Hydrological analysis suggests that this 
                         area experiences the largest floods during wet seasons, a 
                         condition compatible with the topographic data that revealed a 
                         smoother gradient of ~ 3 m comparing this area with others from 
                         the megafan plain. In the studied depression, numerous forest 
                         patches are arranged as sets of parallel straight lines trending 
                         consistently in the NE/SW direction. The patches have spectral 
                         values that differ significantly from other forest patches over 
                         the megafan surface, being compared to those of seazonally-flooded 
                         forests, such as igap{\'o}s and v{\'a}rzeas, that surround the 
                         megafan paleolandform. In addition, a forest patch within the 
                         depression revealed trees physiologically adapted to tolerate 
                         submersion 6 to 7 months per year, which is also a characteristic 
                         of the inundated forests external to the megafan. These data 
                         altogether led us to conclude that the studied depression consists 
                         of a shallow subsiding basin formed by tectonic reactivations in 
                         the mid/late Holocene. Tectonic instability at around 2 cal kyr BP 
                         further disturbed this system by creating NE/SW-trending lakes and 
                         leading to the replacement of seazonally-flooded forests by 
                         grasslands. Thus, tectonic activity in a relatively recent 
                         geological time must be accounted when analyzing plant 
                         distribution in the Amazonian wetlands.",
                  doi = "10.1016/j.catena.2017.06.022",
                  url = "http://dx.doi.org/10.1016/j.catena.2017.06.022",
                 issn = "0341-8162",
             language = "en",
           targetfile = "rossetti_late.pdf",
        urlaccessdate = "30 nov. 2020"
}


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