Architecture, growth patterns, and early diagenetic modifications of a greenhouse ramp to rimmed shelf system: Danian of the Urbasa–Andia plateau, western Pyrenees, North Spain

Abstract

The Danian carbonates exposed in the Urbasa–Andia plateau (western Pyrenees, North Spain) provide the opportunity to examine at different scales the facies types and architecture of a greenhouse ramp to rimmed shelf from the slope to coralgal reefal margin through to the highly restricted evaporitic inner shelf areas, integrated with a range of porosity-forming, early diagenetic phases associated with third-order highstands and lowstands. The detailed nature of the stratal architecture of this greenhouse system provides an understanding of potential reservoir layering, lateral facies and facies cycle changes, and widespread early dolomitization but significantly allows a whole paleokarst macroporosity system related to a third-order lowstand to be accessed, illustrating how eogenetic karstic porosity can vary drastically from margins to shelf interiors. The outcrops serve as potential analogs for fields in Paleocene carbonates in North Africa and the Middle East and also offer valuable depositional and digenetic models for greenhouse platforms of other ages.