Vol. 13 Núm. 2 (2006)

Cover Photo: Photomicrograph illustrating a detrital K-feldspar with multiphase alteration from Peñas Coloradas Formation, Golfo San Jorge Basin, Chubut. This grain has been partially dissolved and replaced by clay minerals cement (rim cement) as well as opal (occluding cement). Photo: María Sol Raigemborn.