LITOESTRATIGRAFÍA Y PEDOESTRATIGRAFÍA DE LOS DEPÓSITOS RECIENTES EN EL ALTIPLANO DE SANTA ROSA DE OSOS (ASRO)

Different deposits separated by two regional erosive discontinuities, as well as different kind of pedogenesis that superimposes these deposits, have been identified in the Santa Rosa de Osos Altiplano. In relation with the discontinuities, the deposits are from bottom to top: early deposits, middle age deposits and recent deposits. Several large­scale pedogenetic patterns allow the correlation and the elucidation of environmental conditions from which these patterns might have originated. These large­scale pedogenetic patterns developed in the recent deposits, are part of the the paleo­environmental record and can be used as guide horizons defined as pedostratigraphic mantles. Such patterns were identified thorugh litostratigraphic and pedostratigraphic characterization of the material overlaying the discontinuity, which is a regional marker, associated with the "stone line" on other sectors of the Antioquia department. Thus, the litostratigraphy was carried out by means of field descriptions and mineralogical and granulometrical analysis. The pedostratigrahy was based on morphological profile description and physical and chemical analyses, allowing the identification of the profile genesis. This stratigraphic record allows elucidate environmental changes from cooler and dry phases to more humid and fresher with respect to recent climate.