Preservation of aeolian dunes by pahoehoe lava: An example from the Botucatu Formation (Early Cretaceous) in Mato Grosso do Sul state (Brazil), western margin of the Paraná Basin in South America

This paper reports on a contact between Botucatu and Serra Geral Formations in Mato Grosso do Sul state (southwestern border of the Paraná Basin), where this kind of sediment–lava interaction has never been described before. The palaeodune registers mean palaeocurrent towards southwest, and the main volcano-sedimentary features are preserved ripples, striations, chevron and crescentic marks, empty or sand-filled tubes and cooling cracks. These features indicate that when lava flows covered the dune, the Botucatu erg was active in the study area, hence consolidating the concept of the non-existence of a hiatus between the Botucatu and Serra Geral Formations.