Evolution of the South Atlantic passive continental margin in southern Brazil derived from zircon and apatite (U-Th-Sm)/He and fission-track data

The area between São Paulo and Porto Alegre in southeastern Brazil plays a key area to understand and quantify the evolution of the South Atlantic passive continental margin (SAPCM) in Brazil. In this contribution, we present new thermochronological data attained by fission-track and (U-Th-Sm)/He analysis on apatites and zircons from metamorphic, sedimentary and intrusive rocks. The zircon fission-track ages range between 108.4 (15.0) and 539.9 (68.4). Ma, the zircon (U-Th-Sm)/He ages between 72.9 (5.8) and 525.1(2.4). Ma, whereas the apatite fission-track ages range between 40.0 (5.3) and 134.7 (8.0). Ma, and the apatite (U-Th-Sm)/He ages between 32.1 (1.5) and 93.0 (2.5). Ma. The spatial distribution of these ages shows three distinct blocks with a different evolution cut by old fracture zones. While the central block exhibits an old stable block, the Northern and especially the Southern block underwent complex post-rift exhumation. The sample of the Northern block shows two distinct cooling phases in the Upper Cretaceous and the Paleogene to Neogene. After sedimentation of the Permian sandstones the samples of the Central block were never heated up over 100. °C with a following moderate to fast cooling phase in Cretaceous to Eocene time and a fast cooling between Oligocene to Miocene. The five thermal models obtained in the Southern block indicate a complex evolution with three cooling phases. The exhumation events of the three blocks correspond with the Paraná-Etendekka event, the alkaline intrusions due to the Trinidad hotspot, and the evolution of the continental rift basins in SE Brazil and are, therefore, most likely to be the major force for the post-rift evolution of the passive continental margin in SE Brazil, which therefore corresponds to the three main phases of the Andean orogeny. © 2013 Elsevier B.V.

O teatro experimental do negro -: estudo da personagem negra em duas peças encenadas (1947-1951)

Pós-graduação em Artes - IA

Bolivia: estimacion de la mortalidad a partir de la distribucion por edades de las muertes, 1951. Metodo de William Brass

Incluye Bibliografía

Informe de Bolivia: la situacion reciente de la fecundidad y la mortalidad en Bolivia; una revision

Incluye Bibliografía

Mortalidad al comienzo de la vida: metodos de Sullivan, Feeney, Trussell y Brass

Se presentan las estimaciones efectuadas por el metodo de Brass y las variantes de Sullivan y de Trussell sobre la mortalidad en los primeros anos de vida. Se comparan los resultados de este ultimo con los obtenidos a traves del metodo de Feeney modificado. La tendencia de la mortalidad infantil se estimo por el metodo de Feeney, comparando sus resultados con las tasas obtenidas de las estadisticas vitales.