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| Ottone,Eduardo G.; Mancuso,Adriana C.; Resano,Magdalena. |
| Lacustrine strata of the Los Rastros Formation (Middle to Upper Triassic) at Río Gualo section (La Rioja province), yield a distinctive palynological assemblage of miospores and chlorococcalean algae. The miospore association is characterized by a relative abundance of corystosperm pollen grains with subordinate inaperturates, diploxylonoid disaccates, spores, monocolpates, monosaccates and striate pollen grains. The phytoplankton are mostly represented by Botryococcus but also by Plaesiodictyon , a form probably related to the Hydrodictyaceae. Geological data and variations in phytoplankton content indicate that the lacustrine system probably evolved from a stretcht of freshwater with eutrophic conditions, into a body with oligotrophic conditions through... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Argentina; Triassic; Miospores and chlorococcalean algae; Systematics; Lacustrine environment. |
| Ano: 2005 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0002-70142005000200007 |
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| Horbe,Adriana M.C.; Behling,Hermann; Nogueira,Afonso C.R.; Mapes,Russell. |
| The sediments from the Coari lake, a terra firme lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rainforest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pb isotopes; Lacustrine environment; Paleovegetation; Flooding plain; Holocene. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300008 |
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