Click on an image for more details Deeply incised stream and rugged topography on the eastern slope of the souther Peruvian Andes. Spectacular angular unconformity attributed to sub-Carboniferous folding, between vertically dipping lower Paleozoic strata (middle ground) and subhorizontally overlying Mesozoic rocks (skyline). Photograph is taken near Tayataya, Puno quadrangle, in the antiplano of souther Peru. Lecture presentation on geology of parts of Western Canada at offices of INGEMMET, Lima, Peru (see figure caption 4). Office of INGEMMET (Instituto Geologico Minero y Metalurgico), the Peruvian Geological Survey, in Lima, Peru.