rim_paleo.html


Paleogeography of Central Arizona during extrusion of "Rim Basalts" (8-6 Ma) and deposition of Late Miocene to Pliocene Verde Formation.

The "Rim Basalts" are mostly confined to NE of the Mogollon Rim except where they filled and flowed down canyons cut perpendicular to the Rim. Two of these ramp basalts, 50 km north of Chino Valley (CH) and 20 km south of Sedona (S) define the routes of I-40 and I-17 respectfully across the Mogollon Rim. Ramp basalts intertongue with the Verde Formation along I-17 NE of Camp Verde (CV). The Verde Formation comprises thick sedimentary fill (up to 1000 m) of Verde Valley which formed during and after major movement on the Verde Fault (NW-SE escarpment west of Cottonwood (C) and Camp Verde). Older Hickey Basalts are grayed on the map to contrast their location with the "Rim Basalts". The Verde Formation and coeval deposits clearly overlie the Hickey Basalts and related volcanic deposits.