Field photographs from the Butte Iouton quarry. A) Stratal succession from U1 to U3 cycles showing the thick and horizontally layered oolitic-peloidal grainstone beds. B) Close view on stratal succession from U1 and U2 cycles C) Erosional contact between Priabonian lacustrine oolitic grainstones and overlying Burdigalian bioclastic limeston.es. Priabonian limestone clasts are reworked within the Burdigalian deposits (black arrows).