Volcanic stratigraphy of part of McLendon Volcano, Yavapai County, Arizona

McLendon volcano, 70 km northwest of Wickenburg, Arizona, is a 100 sq km composite Miocene volcano that lies within the transition zone between the Colorado Plateau and the Basin and Range provinces. Only the northeast flank of a larger, but now disrupted, volcanic center remains. Field, petrographic, and geochemical data from the study area are used to define lava chemistry, location of the central vent, and the relationship of this calcalkaline volcano to genetically similar volcanoes. Volcanic stratigraphy at McLendon volcano comprises a basal section of basalts and andesites of unknown extent erupted upon Precambrian rocks. A 400 m volcaniclastic section of pyroclastic and reworked facies conformably overlies the basal mafic unit. Lithology and geochemistry of the McLendon lavas show a calcalkaline affinity similar to other volcanic suites from the transition zone. This association is comparable to the calc-alkaline provinces of the Aleutians, Cascades, and New Zealand.