Spectral analysis and modeling of microcyclostratigraphy in late Paleozoic glaciogenic rhythmites, Parana Basin, Brazil

Autor(es)

Franco, Daniel R. ^[1] ; Hinnov, Linda A. ^[2] ; Ernesto, Marcia ^[3]

Afiliação do(s) autor(es)

^[1] Natl Observ, Dept Geophys, BR-20921400 Rio De Janeiro - Brazil

^[2] Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 - USA

^[3] Univ Sao Paulo, Dept Geophys, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS; v. 12, SEP 8 2011.
• Citações Web of Science: 6

Resumo

We investigate the depositional time scale of lithological couplets (fine sandstone/siltstone-siltstone/mudstone) from two distinctive outcrops of Permo-Carboniferous glacial rhythmites in the Itarare Group (Parana Basin, Brazil). Resolving the fundamental issue of time scale for these rhythmites is important in light of recent evidence for paleosecular variation measured in these sequences. Spectral analysis and tuning of high-resolution gray scale scans of sediment core microstratigraphy, which comprises pervasive laminations, reveal a comparable spectral content at both localities, with a frequency suite interpreted as that of short-term climate variability of Recent and modern times. This evidence for decadal- to centennial-scale deposition of these lithological couplets is discussed in light of the `varvic' character, i.e., annual time scale that was previously assumed for the rhythmites. (AU)

• Processo FAPESP: 02/06480-0 - Investigação acerca do caráter anual dos ritmitos permocarboníferos da bacia do Paraná através da magnetoestratigrafia e magnetismo de rochas
• Beneficiário: Daniel Ribeiro Franco
• Modalidade de apoio: Bolsas no Brasil - Doutorado