Distinction of the fluvial, aeolian and lacustrine elements of Morr o Pelado Member, Late Permian of Paraná Basin
The Late Permian Morro Pelado Member is the upper part of the Rio do Rasto Formation of Paraná Basin and is composed of an association of fluvial, eolian and lacustrine deposits. In order to depict its facies associations and depositional elements as well as to characterize the fluvial style, a faci...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Universidade de São Paulo
2014-09-01
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| Series: | Geologia USP. Série Científica |
| Subjects: | |
| Online Access: | http://ppegeo.igc.usp.br/pdf/guspsc/v14n3/03.pdf |
| Summary: | The Late Permian Morro Pelado Member is the upper part of the Rio do Rasto Formation of Paraná Basin and is composed of an association of fluvial, eolian and lacustrine deposits. In order to depict its facies associations and depositional elements as well as to characterize the fluvial style, a facies and architectural element analysis was carried out in the eastern outcrop belt in Santa Catarina and Paraná States, southern Brazil. Four facies associations (FA) were recognized: FA-A is interpreted as mixed-load meandering fluvial systems, with conspicuous laterally accreted macroforms, levees and floodplain fines; FA-B was deposited as terminal splays in the distal parts of the fluvial system, where sheet floods prevailed; FA-C defines a fluvial-dominated lacustrine delta formed in response to episodes of extreme flooding and rising water table in the terminal splay zone; FA-D comprises eolian dunes, wet and damp interdunes and eolian sand sheets that occur interbedded with the fluvial and lacustrine deposits marking periods of aridization in the alluvial
plain. The vertical stacking pattern shows an upward increase in frequency and thickness of eolian deposits recording
progressive expansion of the erg systems towards basin margins in response to progressive drying combined with high
rates of accommodation and sediment supply. |
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| ISSN: | 1519-874X 2316-9095 |