Una sucesión de paleosuelos superpuestos del pleistoceno medio - tardio, holoceno: Zona sur de La Plata, Provincia de Buenos Aires

a 11-m deep pedological sedimentary succession (middle-late pleistocene and holocene) has been studied in a quarry exposure located on a flat interfluve, in the vicinity of la plata airport, argentina (34o55′00′′s y 57o57′30′′w). the objective of this work is to characterize and analyze the sedimentary-pedological processes in order to a) obtain new evidences that allow to discuss the sedimentary-pedological model proposed by teruggi and imbellone (1987); b) record the correlation of the events on the perimeter of the quarry and c) correlate the presence of vitroclast-rich sediments with other profiles of la plata zone. the pedologicalsedimentary units were described and correlated in the different cut-faces of the excavation; the units were also sampled in order to characterize particle size distribution and micromorphology. six sedimentary pedologic units constituted by loessoid sediments and associated paleosols are identified. they may correspond to la postrera fm and buenos aires fm, which are found at 2.10 and 4.45 m depth, respectively. the ensenada fm may be found immediately below. the thickness varies from 2.85 to 2.30 m in the bottom units and 1.15 and 2.10 m in the upper units. lenses with very distinct hydromorphic features are observed between 4.00-4.50 m and 9.90- 10.90 m depth. each unit is separated from the underlying one by erosive surfaces that can be: a) smoothly wavy and discontinuous, b) wavy and continuous, or c) planar and abrupt. the upper part of the succession, up to 4.45 m depth, shows subtler morphological changes than the lower part. resent soil, separated in one case by a smooth erosion surface and in the other by a temporal discontinuity insinuated only by changes in color and calcrete characteristics. from 4.45 m downwards, the succession reflects very defined and identifiable sedimentary-pedological events, clearly detectable in the field by morphological features and a well defined lateral extension. three buried paleosols, separa