Quaternary terraces of the Diamante River along the eastern border of the Central Andes at 825 m a.s.l., 34° 37′ S, 68° 26′ W show evidence of past cryogenic activity (ice wedge casts), indicating a temperature rise of 19,0°C during Pleistocene time. The interpretation of ice-wedge casts is based on analysis of fabric diagrams of the natural deposits, the infilling material, sag material and the past active layer. There are other indicators of geocryogenic phenomena such as plications and involutions, and polygonal patterns. Ventifacts are also present. Gravel material is indurated with two types of secondarily precipitated minerals: gypsum, cementing the original deposit; and three episodes of CaCO3 deposition, which is related to ice wedge casts, the past active layer and cryoturbations.The necessary thermal contraction, to produce thermal-contraction cracks derived from these features, probably occurred when the eastern piedmont of Andes was subject to strong temperature changes produced by southern antarctic winds and warmer (föhn type) katabatic effects from the Pacific.The Diamante River near San Rafael has five terraces made up of a coarse gravel-sandy deposits of Quaternary age. Three of these terraces are Pleistocene in age and are cemented by gypsum and calcrete (caliche) (Co3Ca).Three geocryogenic episodes are recorded in these three older river terraces: stronger activity (ice wedges) are obseved in the first and second terraces; milder cryogenic action (cryoturbation) in the third one. Neither past cryogenic activity nor chemically precipitated minerals are present in the two lower (Holocene) terraces.Geocryogenic concepts and processes are proving to be useful for the understanding of the origin and disturbances of river terraces.