Retroceso e inundación de una rampa carbonatada en una cuenca de antepaísla Caliza de la Cervatina (Pensilvaniense, Cuenca Carbonífera Central, NO de España)

Zusammenfassung

The aim of this work is to study the sedimentology and stratigraphic architecture of a carbonate ramp (Cervatina Limestone), developed in the distal parts of a foreland basin during the lower Moscovian (Pennsylvanian) in the Piedrafita-Lillo sector (Central Coalfield, Cantabrian Zone, NW Spain). The Cervatina Limestone is mostly composed of dark grey bioclastic limestones with abundant fusulinids, Chaetetes sp. and colonial rugose corals, alternating with micritic, massive and moundshaped boundstones. According to the vertical and lateral facies relationships, and the stratigraphic architecture of the ramp margin, it is interpreted that the limestone represents the transgressive phase of a regional cyclothem with a probable tectonic and/or glacioeustatic origin. During the middle and late Kashirian transgression, the relative sea level rise and the high amount of accommodation generated, caused an eastward backstepping of the carbonate ramp, moving the carbonate factory to the shallower and distal areas of the basin, far away from the siliciclastic input. Continuous sea level rise and subsequently eastward progradation of deltaic siliciclastics, caused the replacement of carbonates by deep marls and mudrocks, and thus the shut down of the carbonate factory and the drowning of the platform.