Article ID Journal Published Year Pages File Type
8907633 Journal of South American Earth Sciences 2018 43 Pages PDF
Abstract
In the Gondwanan Paraná Basin, two fossil assemblages with affinity to the Eurydesma Fauna are well known in the Early Permian post-glacial deposits of the Rio Bonito Formation. Although the assemblages display similar invertebrate fossil content, the fossil concentrations were potentially accumulated in different paleo-bathymetric zones represented by the shallow marine and marginal marine settings. This paper provides a taphonomic analysis of the body-fossil concentration and the ichnological signatures of the fossiliferous deposits of the Rio Bonito Formation at the southern border of the Paraná Basin and also discusses their paleo-ecological and paleo-environmental significance. Three distinct taphofacies representing the fair-weather deposits, storm-wave deposits in the inner part of estuary, and time-averaged and storm-influenced deposits in the outer part of the estuary were recognized in the studied succession. They characterize the depositional processes that filled a shallow, marginal marine paleovalley formed during the Late Paleozoic Ice Age. The taphonomic signatures of the fossil concentrations suggest deposition under the transgressive and highstand phases of the paleo-valley infill. These new data reinforce the previous interpretation of the paleo-valley infill as estuarine depositional setting and further contribute to refining the stratigraphic framework of the post-glacial deposits at the southern margin of the Paraná Basin.
Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Earth and Planetary Sciences (General)
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