1976
DOI: 10.1590/1809-43921976063293
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Abstract: Palynological investigations on sediment cores from three localities in Rondonia in the southern part of the Amazon Basin, indicate that marked vegetational changes have ocurred there. The series of samples from Katira represents the late Cenozoic, probably Quaternary. The sediments from Capoeira might be partly of Holocene age (and possibly Upper Pleistocene as well). Apparently the climatic changes during several intervals of the Late Cenozoic (Quaternary) caused the development of savannas in this region wh… Show more

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Cited by 78 publications
(28 citation statements)
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“…The more recent savanna period, at and after 18,500 yr B.P., seems to have had the more extremely dry climate, judging from the thick colluvia deposited in the valley. We have no data from this site on when the rain forest invaded the area again but, on the basis of data from other sites in Rondonia (Absy and Van der Hammen, 1976) and from Carajas (Absy et al, 1991), this probably happened at the beginning of the late glacial or Holocene.…”
Section: Rondonia (Brazil)mentioning
confidence: 93%
See 1 more Smart Citation
“…The more recent savanna period, at and after 18,500 yr B.P., seems to have had the more extremely dry climate, judging from the thick colluvia deposited in the valley. We have no data from this site on when the rain forest invaded the area again but, on the basis of data from other sites in Rondonia (Absy and Van der Hammen, 1976) and from Carajas (Absy et al, 1991), this probably happened at the beginning of the late glacial or Holocene.…”
Section: Rondonia (Brazil)mentioning
confidence: 93%
“…In this section, palynological and sedimentological information (Van der Hammen, 1972;Absy and Van der Hammen, 1976) and additional recently obtained •13C data and AMS dates from Katira (Rondonia; approximately 9°S, 63°W) will be reviewed. The palynological data (Fig.…”
Section: Rondonia (Brazil)mentioning
confidence: 99%
“…Katira (Rodonia, Brasil, ca. 93S, 633W;Van der Hammen, 1972;Absy and Van der Hammen, 1976;Van der Hammen and Absy, 1994) The sequence analyzed consists of 13 m of a valley in"ll in an area covered with rain forest and annual rainfall between 2000 and 2500 mm. The lowermost humic layer dominated by Mauritia and other trees (Didymopanax, Hedyosmum, Weinmannia-type', Curatella, Ouratea, Podocarpus, and Ilex) has ages of 41,000 and 49,000 BP and delta C values of !29%, and represents (rain) forest with Mauritia.…”
Section: Re-evaluation Of Available Pollen Recordsmentioning
confidence: 99%
“…Independentemente o geólogo Jürgen Haffer no final de 1969 chegou ao mesmo modelo de especiação em aves amazônicas nos refúgios florestados por entre áreas mais abertas (Haffer, 1969). A paleobotânica Maria Lucia Absy tem encontrado várias evidências de áreas abertas e fechadas amazônicas, com evidências de ciclos paleoclimáticos onde ocorreram fragmentações da floresta, através da análise de polens fósseis (Absy e Van Der Hammen, 1976). Outra forma para reconhecermos a presença de áreas abertas onde hoje é mata, é através de métodos radioativos que analisam as relações entre os isótopos de carbono C13 e C14 (Pessenda et al, 2004).…”
Section: Domínios Morfoclimáticos Brasileiros: a Floresta Atlânticaunclassified