Modelo alternativo para el desarrollo de calcretas: Un ejemplo del Plio-Cuaternario de la cuenca de Madrid

Abstract

Plio-Quaternary calcrete profiles from the Mesa de Ocaha, South of Madrid Basin, have developed by vertical accretionary processes and differ from the classical model of calcrete development based on studies in the United States and Australia. The profiles have laminar or chalky horizons, with the former reaching thicknesses of 2 m. Unlike previously described types, these laminar forms did not develop on hardpan horizons but appear to have formed as thin indurated layers within the soil. Internally the laminar horizons exhibit complex textures wich may reflect polyphase histories of multiple climatic changes and landscape instability. This style of calcrete formation, while differing from that seen in the classical model, may be more widespread than has been appreciated and is similar to that seen in the tepetate soils of Mexico