Genesis of some selected soils in the Valdés Península, NE Patagonia, Argentina

BOUZA,P. J., M. SIMÓN TORRES, J. AGUILAR RUIZ, M. ROSTAGNO AND H. DEL VALLE.

Advances in Geoecology 36 Sustainable Use and Management of Soils of Arid and Semiarid Regions

CATENA VERLAG

Lugar: Reiskirchen; Año: 2005; p. 1 - 12

Four soil profiles from two regions in the Valdés Peninsula (NE Patagonia, Argentina) were studied. The detailed field and laboratory studies indicated that these soils were formed from tl;1ree different successive erosional-depositional episodes altemating with pedogenic episodes and seven successive stages of soil formation. During the first pedogenic episode, the primary soil-forming processes were leaching of carbonates and day illuviation from which only the remains of the ca1cic horizon and the transformation of smectite to palygorskite were preserved. This was followed by an erosion process, and. from the second pedogenic episode the ca1cic and argillic horizons were preserved. Clay coatings were partially disturbed and illite was transformed to smectite. Between 19,000 and 15,000 yrs the day illuviation was promoted by the presence of high Na+ content in the exchangeable site, forming a natric horizon. Finally, an aeolian sand deposit covered these soils and at present the soil materials are redistributed by the wind, accentuating the current mound-intermound morphology.