@article {, title = {Petrography and major element chemistry of the volcanic rocks of the Andes, southern Peru}, journal = {Geochemical Journal}, volume = {18}, year = {1984}, note = {Volcanism over the Thickest crust in the world (70km)}, pages = {217-232}, author = {Aramaki, Shigeo and Onuma, Naoki and Portillo, Felix} }