Valanginian–Early Aptian Carbonate Platforms from Provence, Southeastern France
Name: Urgonian limestones
Author: Jean-Pierre Masse
Location: From 43° to 44° north latitude and at 5° east longitude, Provence, southeastern France
Geologic time interval: Early Cretaceous, Valanginian-early Aptian
Tectonic-sedimentary setting: Passive trailing margin stage of the Alpine basin
Basin type: Epeiric shelf margin to oceanic basin
Paleoclimate: Generally humid, semitropical, possibly arid phases during the Barremian
Platform type: Isolated (epicontinental), flat, gently sloping toward the basin
Platform geometry: 200 to 400 m thick; up to 100 km wide and total length more than 1000 km (from Spain to Switzerland)
Facies and fossils: Littoral: stromatolites and mudstones to pelleted and oolitic grainstone. Inner platform: rudist assemblages in packstone–wackestone or fine-grained pelleted grainstone. Outer platfom: well-sorted cross-bedded sandstone and coral beds. Outer shelf: bivalve-echinoid argillaceous carbonates and calcisponge–bryozoan packstone and wackestone.
Systems tracts: Inter- to supratidal marginal-littoral; fine-grained subtidal carbonates with isolated rudist inner platfoms; coarse-grained subtidal carbonate sandstones and coral bed outer platforms; argillaceous carbonate outer shelf systems.
Stacking pattern: Three main stages of platform growth and progradation interrupted by drowning of the platform.