Paleogene Carbonate Buildups in the South Pyrenean Foreland Basin

H. Eichenseer, C. Betzler, H. P. Luterbacher

Lower Paleogene carbonates in the South Pyrenean foreland basin formed on southward-moving thrust folds. Different platform types and facies association can be distinguished according to the position on the thrust and the overall geometry of the thrusts. (1) Small carbonate banks with coralgal reefs and low-amplitude nummulite bars formed on the fore limbs of minor overthrusts and on thrust slices. (2) The back limb of major overthrusts and western parts of thrust anticlines were occupied by linear carbonate banks with an extensive system of nummulitic nearshore bars, sand flats, grain flats, and patch reefs. (3) Eastward-plunging tectonic ramp anticlines were characterized by low to medium-energy carbonate ramps with tidal flats, lagoons, barrier bars, and nummulitic-gra n flats merging into semirestricted basinal shales. Carbonate deposition ended with the final detachment of the foreland basin and evolution into a thrust-sheet top basin.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.