Neogene palynology of the Solimões Basin, Brazilian Amazonia

Silva-Caminha, Silane A.F. da; Absy, Maria Lúcia

doi:10.1127/palb/284/2010/13

Cited by 52 publications

(85 citation statements)

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“…Paleontological analysis, based on ichthyolites (Pinto & Puper 1984) of several Coal Project wells (Maia et al 1977), shows that possibly the Iquitos Arch goes through the region of the lower Javari River drainage. Wells 1AS-32-AM, 1AS-4-AM, 1AS-4a-AM and 1AS-1-AM contain an older uplifted Miocene section (Repouso Formation), since the well 1AS-33-AM to the west studied by Leite (2006) and the wells to the east 1AS-19-AM and 1AS-27-AM studied by Silva (2004) and Silva-Caminha et al (2010), respectively, present a younger section (Late Miocene-Early Pliocene), known as the Solimões Formation. Cruz (1984), who zoned the Solimões Basin's Cenozoic section, based on sporomorphs found in several Coal Project wells, placed the herein discussed Repouso section in the Zone A (Miocene).…”

Section: Solimões and Acre Basinsmentioning

confidence: 99%

Eustatic and tectonic change effects in the reversion of the transcontinental Amazon River drainage system

Caputo

Soares

2016

Braz. J. Geol.

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The development of the transcontinental Amazon River System involved geological events in the Andes Chain; Vaupés, Purus and Gurupá arches; sedimentary basins of the region and sea level changes. The origin and age of this river have been discussed for decades, and many ideas have been proposed, including those pertaining to it having originated in the Holocene, Pleistocene, Pliocene, Late Miocene, or even earlier times. Under this context, the geology of the sedimentary basins of northern Brazil has been analyzed from the Mesozoic time on, and some clarifications are placed on its stratigraphy. Vaupés Arch, in Colombia, was uplifted together with the Andean Mountains in the Middle Miocene time. In the Cenozoic Era, the Purus Arch has not blocked this drainage system westward to marine basins of Western South America or eastward to the Atlantic Ocean. Also the Gurupá Arch remained high up to the end of Middle Miocene, directing this drainage system westward. With the late subsidence and breaching of the Gurupá Arch and a major fall in sea level, at the beginning of the Late Miocene, the Amazon River quickly opened its pathway to the west, from the Marajó Basin, through deep headward erosion, capturing a vast drainage network from cratonic and Andean areas, which had previously been diverted towards the Caribbean Sea. During this time, the large siliciclastic influx to the Amazon Mouth (Foz do Amazonas) Basin and its fan increased, due to erosion of large tracts of South America, linking the Amazon drainage network to that of the Marajó Basin. This extensive exposure originated the Late Miocene (Tortonian) unconformity, which marks the onset of the transcontinental Amazon River flowing into the Atlantic Ocean.

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Section: Solimões and Acre Basinsmentioning

confidence: 99%

Eustatic and tectonic change effects in the reversion of the transcontinental Amazon River drainage system

Caputo

Soares

2016

Braz. J. Geol.

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“…A consulta à literatura especializada auxiliou na identificação das espécies Lorente, 1986;Muller et al, 1987;Hoorn, 1993;Leite, 2006;Silva-Caminha et al, 2010;Jaramillo & Rueda, 2013). Posteriormente, fotomicrografias foram feitas na câmera Leica ICC50 HD acoplada ao microscópio Leica DM750.…”

Section: Methodsunclassified

“…Neomioceno/Plioceno para outros cinco poços da Formação Solimões (1AS-4a-AM, 1AS-32-AM, 1AS-33-AM 1AS-19-AM e 1AS-27-AM) (Hoorn, 1993;Leite, 2006;Silva, 2004;Silva-Caminha et al, 2010). Aqui se registra a presença de Echitricolporites mcneillyi pela primeira vez nesta unidade, indicando Plioceno para o topo da Formação Solimões.…”

Section: Comparações Entre Os Métodos Bioestratigráficos E Discussõesunclassified

“…Espécies e/ou pares de espécies característicos de cada Associação Unitária (UA) e/ou Zona. * Silva-Caminha et al (2010). Esta é a segunda vez que o método das Associações Unitárias é aplicado nos dados bioestratigráficos da Formação Solimões, sendo utilizado anteriormente por Silva-Caminha et al (2010) nos poços 1AS-27-AM e 1AS-19-AM.…”

Section: Comparações Entre Os Métodos Bioestratigráficos E Discussõesunclassified

“…As idades atribuídas para Formação Solimões variam entre Mioceno e início do Plioceno (Hoorn, 1993;Leite, 2006;Leite et al, 2016;Silva-Caminha et al, 2010) O ambiente de deposição da Formação Solimões é predominantemente lacustre e fluvial, com episódios de incursões marinhas registrados por alguns autores no Mioceno inferior e médio/superior (Maia et al, 1977;Hoorn, 1993;Hoorn et al, 1995Hoorn et al, , 2010Cozzuol, 2006;Lovejoy et al, 2006;Latrubesse et al, 2007Latrubesse et al, , 2010Silva-Caminha et al, 2010;Shephard et al, 2010;Linhares et al, 2011;Boonstra et al, 2015).…”

Section: Introductionunclassified

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Palinoestratigrafia da Formação Solimões: comparação entre bioestratigrafia tradicional e o método de Associações Unitárias

Kachniasz¹,

Silva-Caminha²

2017

Rev. bras. paleontol.

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-PALYNOSTRATIGRAPHY SOLIMÕESRESUMO -Análises palinológicas foram realizadas em 48 amostras coletadas nos poços 1AS-31-AM e 1AS-34-AM a fim de se estabelecer um quadro bioestratigráfico local usando métodos bioestratigráficos qualitativos e quantitativos. Os poços foram locados para a pesquisa do potencial linhítico da Formação Solimões, na década de 1970. Nossos resultados em palinoestratigrafia, pelo método tradicional, sugerem idades Neomioceno e Plioceno. As espécies-índice como Grimsdalea magnaclavata, grãos de pólen fenestrados, Ladakhipollenites? caribbiensis e Echitricolporites mcneillyi permitem incluir tais seções dentro das subzonas Psilatricolporites caribbiensis e Echitricolporites-Alnipollenites sensu Lorente. Usando o método de Associações Unitárias, sete associações unitárias e quatro zonas foram criadas indicando uma composição de espécies similares entre os poços. Comparações entre os dois métodos indicam que ambos os poços são contemporâneos.

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The Origin of the Modern Amazon Rainforest: Implications of the Palynological and Palaeobotanical Record

Hoorn

Silva

Leite

et al. 2009

Amazonia: Landscape and Species Evolution

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Northern South America harbours a highly diversifi ed forest vegetation. However, it is not clear when this remarkable diversity was attained and how it was produced. Is the high diversity the product of a positive speciation-extinction balance that accumulated species over long time periods, or is it the product of high origination rates over short time periods, or both? Middle Cretaceous fl oras, although very poorly studied, are dominated by non-angiosperm taxa. By the Paleocene, pollen and macrobotanical fossils suggest that the basic phylogenetic composition and fl oral physiognomy of Neotropical rainforests were already present. Hence there was a profound change in Amazonian fl ora during the Late Cretaceous, that still needs to be documented. Levels of Paleocene diversity are much lower than those of modern tropical rainforests. By the Early Eocene, however, pollen diversity was very high, exceeding values of modern rainforests. At the EoceneOligocene a major drop in diversity coincided with an episode of global cooling. The palynological and palaeobotanical records of Amazonia suggest that high levels of diversity existed during the Miocene, a period when the boundary conditions for sustaining a rainforest (e.g. low seasonality, high precipitation, edaphic heterogeneous substrate) were met. The predecessor of the present rainforest was formed during the Paleogene and Neogene when the western Amazon lowlands were affected by Andean tectonism, which radically changed drainage systems and promoted wetland development. An overall global cooling during the Neogene also may have affected the rainforest, decreasing its area and expanding adjacent savanna belts. Recent events like the Quaternary ice ages also played a role in the forest dynamics and composition, although it seems to have been minor. In this chapter we will review the main characteristics of the Neogene palynological and palaeobotanical records in Amazonia, and we will make some comparisons with pre-and post-Neogene records. The data indicate that the Amazonian rainforest is more likely to be a product of a dynamic geological history stretching back over the past 25 million years rather than the last few hundred thousand years.

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Neogene palynology of the Solimões Basin, Brazilian Amazonia

Cited by 52 publications

References 0 publications

Eustatic and tectonic change effects in the reversion of the transcontinental Amazon River drainage system

Eustatic and tectonic change effects in the reversion of the transcontinental Amazon River drainage system

Palinoestratigrafia da Formação Solimões: comparação entre bioestratigrafia tradicional e o método de Associações Unitárias

The Origin of the Modern Amazon Rainforest: Implications of the Palynological and Palaeobotanical Record

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