Sedimentology and facies architecture of the gravel deposits in the Upper Paraná River: a classification proposal

Abstract

This paper proposes a classification of gravel deposits in the upper Paraná River Basin based on their genesis, sedimentary facies and depositional processes. They were classified in four types: a) Upper slope oligomictic gravel (Fine and coarse-sand associations) – this deposit is associated with the origin of hydrographic basin during the Tertiary; b) Middle slope oligomictic gravel – It constitutes colluvial deposits related to present topography; c) Lower slope oligomictic gravel – this deposit is associated with present river valley; d) Polymictic gravel – deposited during the Pleistocene, it constitutes the basal sequence of the Paraná River fluvial deposits.