Pedology and relative chronology of the cuaternary deposits in three basins in the Venezuelan Central Andes (Estado Merida)

In order to establish relative chronological differences among the different geomorphological units, the pedological characteristics of 15 profiles of soils originated on glacial, fluvioglacial and aluvio torrential deposits of different ages, were analyzed in the Venezuelan Central Andes. In addition, some pedogenetic characteristics such as granulometry, texture and morphometry of the sediments were determined, as well as some chemical properties such as pH, pH of abrasion, CIC, percentange of saturation of bases of aluminum and organic carbon. In the same way, the mineralogy of the clay fraction was determined through X-rays analysis. The results of physical and chemical analyses showed no significant differences among the different soil units. At the same time, the mineralogical analysis of the clay fraction revealed the presence of illite, kaolinite and chlorite as principal components. Therefore, it seems that these clays represent a stage of early or incipient weathering, whose origin is intimately related to the parental material of these soils. In this particular case, the pedological analyses were not useful to elaborate a relative chronology by means of which the geomorphological units in deposits of different ages could be separated as a function of the evaluated soil properties.