@Article{RossettiCTSCMBMTYM:2015:MiPlOS,
author = "Rossetti, Dilce de F{\'a}tima and Cohen, M. C. L. and Tatumi, S.
H. and Sawakuchi, A . O. and Cremon, {\'E}dipo Henrique and
Mittani, J. C. R. and Bertani, Thiago Castilho and Munita, C. J.
A. S. and Tudela, D. R. G. and Yee, M. and Moya, G.",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Universidade Federal do Par{\'a} (UFPA)} and {Universidade
Federal de S{\~a}o Paulo (UNIFESP)} and {Universidade de S{\~a}o
Paulo (USP)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {Universidade Federal de S{\~a}o Paulo (UNIFESP)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
de Pesquisas Nucleares} and {Universidade de S{\~a}o Paulo (USP)}
and {Universidade Federal de S{\~a}o Paulo (UNIFESP)} and
{Universidade Federal de S{\~a}o Paulo (UNIFESP)}",
title = "Mid-Late Pleistocene OSL chronology in western Amazonia and
implications for the transcontinental Amazon pathway",
journal = "Sedimentary Geology",
year = "2015",
volume = "330",
pages = "1--15",
month = "Dec.",
keywords = "Amazon reversal, Fluvial systems, Mid-Late Pleistocene, OSL ages,
Paleoenvironment.",
abstract = "The origin of the transcontinental Amazon drainage system remains
unrevealed. Sedimentary deposits formed from the Neogene in the
Amazonas and Solim{\~o}es Basins constitute natural archives for
reconstructing this event in space and time. However,
paleoenvironmental and chronological analyses focusing on these
deposits, or even their basic mapping, are still scarce to allow
such investigation. In this context, primary interests are fluvial
strata related to the lithostratigraphic I{\c{c}}{\'a}
Formation, mapped over a widespread area in western Amazonian
lowlands. Although long regarded as Plio-Pleistocene in age, this
unit has not yet been dated and its overall depositional setting
remains largely undescribed. The main goal of the present work is
to contribute for improving facies analysis and chronology of
these deposits, approaching an area in southwestern Amazonia and
another in northern Amazonia, which are located more than 1000. km
apart. Despite this great distance, the sedimentological and
chronological characteristics of deposits from these two areas are
analogous. Hence, facies analysis revealed paleoenvironments
including active channel, abandoned channel, point bar, crevasse
splay and floodplain, which are altogether compatible with
meandering fluvial systems. Similarly, optically stimulated
luminescence (OSL) dating revealed thirty three ages ranging from
65.4. ±. 16.9 to 219.6. ±. 25.1. ky (in addition to three
outliners of 54.0. ±. 7.6, 337.3. ±. 36.9 and 346.6. ±. 48.6. ky),
and nine 97.1. ±. 9.9 to 254.8. ±. 23.8. ky for the areas in
southwestern and northern Amazonia, respectively. These data lead
to establish that deposits mapped as I{\c{c}}{\'a} Formation
over a vast area of western Brazilian Amazonia have a Mid-Late
Pleistocene age, rather than the previously inferred
Plio-Pleistocene age. It follows that if Plio-Pleistocene deposits
exist in this region they remain to be dated and must be
restricted to a narrow belt in western Amazonia, as well as
isolated occurrences underlying the Mid-Late Pleistocene strata
characterized herein. The combination of data from this work with
previously published provenance studies supports main Andean
sediment sources only in the Mid-Late Pleistocene. It is proposed
that before this time, the Amazon River was restricted to eastern
Amazonia, being separated from western Amazonian drainage basins
due to the presence of the Purus Arch. Erosion and/or subsidence
of this geological feature would have promoted the connection of
these drainage systems, ultimately with the expressive record of
the transcontinental Amazon pathway into the Atlantic Ocean in the
Mid-Late Pleistocene.",
doi = "10.1016/j.sedgeo.2015.10.001",
url = "http://dx.doi.org/10.1016/j.sedgeo.2015.10.001",
issn = "0037-0738",
language = "en",
targetfile = "2015_rossetti.pdf",
urlaccessdate = "27 abr. 2024"
}