Caracterización de Ultisoles en la cuenca del río Capaz, Mérida-Venezuela

Abstract

espanolCatorce Ultisoles desarrollados sobre lutitas fueron caracte­rizados en la cuenca del rio Capaz, Merida-Venezuela. La textura fina, reaccion acida, dominancia de minerales resistentes a la alteracion y coexistencia en la fraccion arcilla de caolinita bien cristalizada e ilitas degradadas con interestratificados desorganizados y vermiculitas bien crista­lizadas se asocia a la herencia de la roca madre (lutitas cretacicas acidas que han sufrido varios ciclos de transfor­macion) y a una alteracion moderada. El desarrollo de Ultisoles en la zona estudiada esta fundamentalmente aso­ciado a la presencia de un material parental de origen sedimentario con textura fina y baja reserva de minerales alterables (lutitas), independientemente de las condiciones bio-climaticas. EnglishFourteen mudstone-formed Ultisols located in Capaz River basin (Merida, Venezuela) were characterized. Aspects such as fine texture, acid reaction, abundance of resistant materials, and coexistence of well-crystallized clay fraction kaolinite, degraded illite through interstratified minerals under disorder arrangement, and well-crystallized vermiculite are associated with inheritance from parent rock (cretaceous and acid mudstone having undergone various transformation cycles) and moderate alteration. Ultisols development in the region of this study is mainly related to parent material of sedimentary origin, being characterized by fine texture and low deposits of unstable minerals (lutite or mudstone), independent of the bioclimatic conditions.