Differences between autogenic and allogenic expressions of the Glossifungites Ichnofacies in estuarine and shoreface deposits from the Permian of the Parana Basin, Brazil

The Glossifungites Ichnofacies is a substrate-controlled ichnofacies that occurs in omission surfaces and has been used in the identification and interpretation of stratigraphic discontinuities. The Early Permian Rio Bonito-Palermo sedimentary succession from the Parana Basin (southern Brazil) offers an opportunity to discuss the genesis of the omission surfaces demarked by the occurrence ofGlossifungitessuites. These suites are composed of sharp, unlined burrows with irregular boundaries and passive infill by generally medium- to coarse-grained sandstones.Thalassinoidesis the dominant component in theGlossifungitessuites in the studied deposits,with local occurrences ofDiplocraterion,Gyrolithes, andSkolithos. Based on the ichnological signatures of the distinctGlossifungitessuites observed in these deposits and the characteristics of the facies in which they occur, the associated discontinuity surfaces were interpreted as autogenic or allogenic. The morphological distinction between allogenic and autogenic expressions of the Glossifungites Ichnofacies is observed.Glossifungitessuites demarking autogenic surfaces are associated with dewatered muddy substrates from the estuarine settings.Glossifungitessuites demarking allogenic surfaces are characterized by large vertical burrows and occur in association with a sequence boundary and coplanar surfaces registered in lower shoreface settings.