Home Itens selecionados Provedores de dados OAI Créditos Sobre Ajuda

			Busca avançada
	Provedor de dados Anais da ABC (AABC) (2) Autor Ernesto,Marcia (1) HARTMANN,LÉO A. (1) MCNAUGHTON,NEAL J. (1) PINTO,VITER M. (1) SANTOS,JOÃO O.S. (1) Tamrat,Endale (1) Mais... Palavra-chave Botucatu Formation (2) Brazil (1) Late Jurassic (1) Magnetic anisotropy (1) Magnetostratigraphy (1) Neoarchean to Palaeozoic ages (1) Paleomagnetism (1) Provenance (1) Sand extrudite (1) Zircon U-Pb ages (1) Mais... Tipo do documento Info:eu-repo/semantics/article (2) Ano 2015 (1) 2006 (1) País Brazil (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última Zircon ages delimit the provenance of a sand extrudite from the Botucatu Formation in the Paraná volcanic province, Iraí, Brazil Anais da ABC (AABC) PINTO,VITER M.; HARTMANN,LÉO A.; SANTOS,JOÃO O.S.; MCNAUGHTON,NEAL J.. Ion microprobe age determinations of 102 detrital zircon crystals from a sand extrudite, Cretaceous Paraná volcanic province, set limits on the origin of the numerous sand layers present in this major flood basalt province. The zircon U-Pb ages reflect four main orogenic cycles: Mesoproterozoic (1155-962 Ma), latest Proterozoic-early Cambrian (808-500 Ma) and two Palaeozoic (Ordovician- 480 to 450 Ma, and Permian to Lower Triassic- 296 to 250 Ma). Two additional small concentrations are present in the Neoarchean (2.8 to 2.6 Ga) and Paleoproterozoic (2.0 to 1.7 Ga). Zircon age peaks closely match the several pulses of igneous activity in the Precambrian Brazilian Shield and active orogeny in Argentina. A main delimitation of the origin of the sand is the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Botucatu Formation; Brazil; Neoarchean to Palaeozoic ages; Provenance; Sand extrudite; Zircon U-Pb ages. Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000401611 Paleomagnetic constraints on the age of the Botucatu Formation in Rio Grande do Sul, southern Brazil Anais da ABC (AABC) Tamrat,Endale; Ernesto,Marcia. Paleomagnetic and rockmagnetic data are reported for the aeolian Botucatu Formation, in the southern Brazilian State of Rio Grande do Sul. Oriented samples were taken from a section located between the cities of Jaguari and Santiago. After thermal and alternating field demagnetization, both normal and reversed characteristic remanent magnetizations were found. These results yielded 13 reversed and 5 normal polarity sites, composing a magnetostratigraphic column displaying a sequence of reversed-normal-reversed polarity events. The paleomagnetic pole calculated for 18 sites is located at 114.7ºE, 78.5ºS (dp=8.1º; dm=1.2º), after restoring the strata to the paleohorizontal. This paleomagnetic pole indicates a Late Jurassic-Early Cretaceous age to the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Paleomagnetism; Botucatu Formation; Magnetostratigraphy; Magnetic anisotropy; Late Jurassic. Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652006000300016 Registros recuperados: 2 Primeira ... 1 ... Última

Empresa Brasileira de Pesquisa Agropecuária - Embrapa Todos os direitos reservados, conforme Lei n° 9.610 Política de Privacidade Área restrita		Embrapa Parque Estação Biológica - PqEB s/n° Brasília, DF - Brasil - CEP 70770-901 Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco