Seismites as a tool in the palaeoenvironmental reconstruction of fluvial deposits: The Cambrian Guarda Velha Formation, southern Brazil

Autor(es)

Santos, Mauricio G. M. ^{[1, 2]} ; Almeida, Renato P. ^[1] ; Mountney, Nigel P. ^[2] ; Fragoso-Cesar, Antonio R. S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geosci, BR-05508080 Sao Paulo - Brazil

^[2] Univ Leeds, Sch Earth & Environm, Fluvial Res Grp, Leeds LS2 9JT, W Yorkshire - England

• Tipo de documento: Artigo Científico
• Fonte: SEDIMENTARY GEOLOGY; v. 277, p. 52-60, NOV 15 2012.
• Citações Web of Science: 13

Resumo

Soft-sediment deformation (SSD) is widely described in the literature, but there is no clear consensus regarding its origin and significance. Existing models for SSD in fluvial sediments do not clearly demonstrate a relationship between the structures, preserved facies expression, and larger-scale depositional architecture. In this study several types of SSD structures are recorded in Cambrian fluvial deposits and these occur interbedded with undeformed strata throughout the entire stratigraphic interval. The random distribution of these features in relation to primary facies types and fluvial forms indicates that they have neither a direct nor indirect relationship with any depositional processes or bedform type. We propose that the relationship of SSD at the bed-set-scale to larger-scale depositional architecture, combined with tectono-stratigraphic analysis allows the determination of both short-term fluvial hydraulic conditions in ancient stream systems, such as the nature of the flow regime responsible for depositing ancient fluvial stream successions, and the long-term subsidence rates, in the form of mean recurrence interval of the seismic events responsible for triggering the generation of SSD in tectonically active basins. (c) 2012 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 10/50902-2 - Arquitetura deposicional e analise de facies dos sistemas fluviais pre-vegetacao da bacia do camaqua
• Beneficiário: Maurício Guerreiro Martinho dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 09/53362-1 - Evolução e controles alogênicos de sistemas aluviais pré-vegetação da Bacia do Camaquã (Neoproterozóico - Cambriano, RS)
• Beneficiário: Renato Paes de Almeida
• Modalidade de apoio: Auxílio à Pesquisa - Regular