Walter Luzio L.1

The pedogenesis of two soils (Lo Vásquez and Las Rosas Soil Series) was studied. Chemical, granulometric, mineralogical and micromorphological analysis were carried out. The last ones were diseussed in a preeedent paper.
From the chemical and mineralogieal (sand and cIay fraetion) analysis it is possible to conclude that both soils would originate from diHerent parent materials. Micromorphological studies support this hypothesis and also evidenee the different degree of evolution of both soils.
Consequently, the presenee of two different sourees of parent materials would be involved in the pedogenesis of Lo Vásquez and Las Rosas Soil Series.
The zonal soil, aeeording to the Supplement to Soil Classification System (7th. Approximation), is classified as Ultic Haploxeralfs and the azonal soil as Typic Xerofluvents.

1Ing. Agr., M. S. Departamento de Producción Agrícola, Facultad de Agronomía, Universidad de Chile. Casilla 1004, Santiago, Chile.