Comment on 'Correlation of Arizona Paleozoic Formations' by A. A. Stoyanow

Stratigraphy, Correlation, Unkar Group - Grand Canyon Supergroup - Middle Proterozoic, Vishnu Schist(Vishnu fm) - [Granite Gorge metamorphic suite][Vishnu group][Vishnu metamorphic complex](Vishnu terrane)(Vishnu series)(Vishnu complex) - Early Proterozoic, Chuar Group - Late Proterozoic, Apache Group - Middle Proterozoic, Mazatzal Group, Troy Quartzite - Middle Proterozoic, Tapeats Sandstone - Tonto Group - Cambrian,