...Mark J. Johnsson; Robert H. Meade Abstract Modification of sediment composition by chemical weathering depends both on the overall intensity of weathering and on its duration. At Macuapanim Island, Solimboes River (Amazon main channel), Brazil, a number of alluvial deposits have been exposed...

... including Fourier transform infrared spectroscopy (FT-IR), electron paramagnetic resonance (EPR) and potentiometric measurements. Particulate and colloidal matter are organo-mineral and organic, respectively. Signatures of the particulate fractions distinguish Rio Amazonas/Rio Solimoes rivers...

... are proposed. The samples from the Solimões Formation contain the following taxa: Mediaverrunites elsikii , Mediaverrunites mulleri , Monoporisporites sp., Fusiformisporites crabbii , and Multicellites cingulatus . The presence of these suggests river channel margins colonized by freshwater vegetation, where...

... by sediment- and nutrient-rich white-water rivers (e.g. the Solimões River). These floodplains include lakes formed between bars, in abandoned river meanders, in depressions, and in old tributary valleys (Junk et al. 2012 ), all formed by fluvial processes (Latrubesse 2012 ). In the extant Amazon Basin...

.... We studied two cores from the Solimões Formation ( Figures 1, 2 ) that were drilled by the Brazilian Geological Survey (CPRM). Core 1-AS-33-AM (hereafter 33AM) was drilled along the Curuça River, Amazonas State [5°15’S, 71°33’W; elevation 100 m above sea level (asl)] and reached a depth of 404.15 m...

... two of the most prolific fossiliferous bonebeds of the Solimões Formation, the Niteroi and Talismã sites ( Fig. 1 , Table 1 ). The Niterói site (19L 629983E/8879539S, datum WGS84) is on the right bank of the Acre River, near Senador Guiomard municipality, in southeastern Acre State ( Negri 2004...

... Formations in Coari ( Figure 3 ; Nogueira et al. 2013 ; Silveira and Souza 2015 ). Figure 3. Correlation of sections discussed in the text. From left to right: (a) Solimões Formation cores in the upper Solimões River (Hoorn et al. 1993 ; Silva Caminha et al. 2010 ; Kachniasz & Silva-Caminha et al...

... Be nuclide concentration of all Andean tributaries of the upper Solimões, Ucayali, Napo, Beni, and Mamoré rivers (see Table 3 ) translates to a flux-weighted mean denudation rate of 0.37 ± 0.06 mm/yr. This average value compares to 0.24 ± 0.02 mm/yr ( Fig. 4B ) for central Amazonian river samples, excluding...

... of the Amazon and therefore its biogeography and possibly biodiversity. Herein we present palynological and lithostratigraphical results from the Solimões Formation in the well 1AS-33-AM. It was drilled in the Solimões Basin, Amazonas State, Brazil, reaching 405 m in depth. We identified 152 palynomorphs, in 32...

... that Pliocene sedimentation is also recorded in the Western Amazonia of Peru, and provides new palynological information compared with the Mio–Pliocene Solimões, Acre, and eastern Amazonas basins. CONTACT Francisco Javier Parra fjparran@unal.edu.co Géosciences Environnement Toulouse (GET), Université de...

... has been hampered by limited outcrop exposure. Also, ichnological data largely have been ignored. This study focuses on ichnological and sedimentological relationships observed in outcropping strata of the Solimoes Formation (Middle Miocene) along the Acre River in western Brazil and northern Bolivia...

... tributaries draining the basic and metamorphic rocks from the southeastern Guiana Shield, and strongest influence of the upstream Amazon and Solimoes areas. These source signals are damped by transitional storage and intense lateral sediment exchange between channel and floodplain. The Brazilian Shield...

... (∼700 m from the banks). This lower transference of sediments into the water-saturated area of the IPF in reach 1 was also detected in our SSSC mapping ( Fig. 1 ). It happens because the well-developed CDF in the Solimões River constrains flooding and provides limited channel-floodplain connectivity...

... River. Here, we provide some clarifications and show that a late Miocene origin of the Amazon River is underpinned by a very robust data set. Firstly, Campbell comments that the absolute ages of the base and top of biozone NN9 differ from Lourens et al. (2004) . The presented biostratigraphic zonation...

... ). The examples reported here illustrate how the provenance, with the help of TST, is of paramount importance, yielding data that enhance the strength of taphonomic and paleoenvironmental analyzes. It should also be noted that most Solimões Formation outcrops are river banks, exposed only in drier months...

...J. Figueiredo; C. Hoorn; P. van der Ven; E. Soares Abstract New biostratigraphic, isotopic, and well log data from exploration wells on the outer continental shelf and uppermost Amazon deep-sea fan, Brazil, reveal that the Amazon River was initiated as a transcontinental river between 11.8 and 11.3...