Sequence of facies at a Holocene storm-dominated regressive barrier at Praia de Leste, southern Brazil

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dc.contributor.authorde Souza, Maria Cristina
dc.contributor.authorAngulo, Rodolfo José
dc.contributor.authorAssine, Mario Luis [UNESP]
dc.contributor.authorde Castro, David Lopes
dc.contributor.institutionUniversidade Federal do Paraná (UFPR)
dc.contributor.institutionUniversidade Estadual Paulista (UNESP)
dc.contributor.institutionUniversidade Federal de Rio Grande do Norte
dc.date.accessioned2022-04-29T08:48:47Z
dc.date.available2022-04-29T08:48:47Z
dc.date.issued2012-01-01
dc.description.abstractAlong the coast at Praia de Leste, southern Brazil (25° 41' S latitude), a positive sedimentary budget and a lowering of the sea level following the postglacial maximum has given rise to a progradational strandplain barrier that is 3-5. km wide. Sand quarries that lie 3.5. km from the present-day coastline have provided material from exceptional outcrops of 75% of the sequence of Holocene barrier facies. Five facies associations have been identified, which correspond to the inner shelf, the lower, middle and upper shorefaces, and the foreshore. The architecture of the facies shows a regressive sequence that overlies an erosional surface and downlapping Pleistocene sediments. At Praia de Leste, the facies association has a thickness of 14. m and is deposited between 2. m above and 12. m below mean paleo sea level. The barrier corresponds to a coastal environment that is characterised by medium to low wave energy under the additional influence of episodic storm events. The sequence at the Praia de Leste barrier differs from the sequence of clastic shoreline facies found elsewhere in two main ways. The first difference is the high content of fine sediment and plant debris, released at around the same time as the formation of the barrier from large estuarine systems, and the second is the predominance on the middle and lower shorefaces of swaley cross-stratified sand facies with abundant plant debris. We also describe two further characteristics of the barrier at Praia de Leste. First, the swaley cross-stratified sand represents a component of onshore transport that resulted in the accumulation of sediment transported from the shelf. Second, the beach step has been well preserved, thereby allowing the continuous tracing of seaward-dipping, low-angle cross-stratification to a sigmoidal cross-stratified beach-step sandy facies. Finally, we have herein been able to improve the precision of the sequence of formation of the depth of the facies, by making reference to paleo sea level during the formation of the barrier, rather than to present-day mean sea level. © 2011 Elsevier B.V..en
dc.description.affiliationLaboratório de Estudos Costeiros Departamento de Geologia, Universidade Federal do Paraná Centro Politécnico, Caixa Postal 19001
dc.description.affiliationDepartamento de Geologia Aplicada Universidade Estadual de São Paulo
dc.description.affiliationDepartamento de Geologia Universidade Federal de Rio Grande do Norte
dc.description.affiliationUnespDepartamento de Geologia Aplicada Universidade Estadual de São Paulo
dc.format.extent49-62
dc.identifierhttp://dx.doi.org/10.1016/j.margeo.2011.10.009
dc.identifier.citationMarine Geology, v. 291-294, p. 49-62.
dc.identifier.doi10.1016/j.margeo.2011.10.009
dc.identifier.issn0025-3227
dc.identifier.scopus2-s2.0-82255173845
dc.identifier.urihttp://hdl.handle.net/11449/232039
dc.language.isoeng
dc.relation.ispartofMarine Geology
dc.sourceScopus
dc.subjectBeach step
dc.subjectClastic strandplain
dc.subjectPaleo-bathymetry
dc.subjectSubtropical barrier
dc.subjectSwaley cross stratification
dc.subjectWave dominated environments
dc.titleSequence of facies at a Holocene storm-dominated regressive barrier at Praia de Leste, southern Brazilen
dc.typeArtigo

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