Mogollon Rim Region (East-Central Arizona)

About this guidebook

Welcome to the Thirteenth Annual Field Conference of the New Mexico Geological Society in the Mogollon Rim country of Arizona. This is our second conference to be held in cooperation with the Arizona Geological Society, and the road logs and technical papers in this guidebooks shed light on many problems which are of mutual interest to geologists in both states . The first day of our trip takes us southward and westward from Gallup, New Mexico into Arizona and the Mogollon Rim country. As we travel the rim, we will see Cretaceous and younger rocks that have been deposited on the beveled surface of progressively older rocks. We will drive through the northwestern edge of the Datil volcanic field and will be able to trace some of the ancient drainage channels of the Little Colorado River, down which the lava flowed, by the erosional remnants. The second day will be devoted to viewing and discussing the geologic setting of two of Arizona’s copper mining districts, Globe-Miami and Superior. The third day’s route traverses the northwest-southeast trending Plateau-Basin Range boundary zone. The earlier part of the trip will be in Tonto Basin, situated between relatively flat-lying younger Precambrian rocks of the Sierra Ancha Mountains to the north or Plateau side, and the structurally-deformed Precambrian rocks of the centrral mountain belt to the south. Midway we will be on the plateau proper, but will go back down into the northwest-trending Verde Valley, a continuation of the Tonto Basin trend. From the largely Precambrian terrain of the Jerome area, we will cross the Verde Valley into the dominantly Paleozoic sedimentary and Cenozoic volcanic terrain of Flagstaff and Plateau region.