Tertiary geologic history of the Salt River Canyon region, Gila County, Arizona

Abstract

An early Tertiary northeast-flowing consequent drainage in the Transition Zone of east-central Arizona excavated an 1170+-m-deep, 14- to 23-km-wide, 30+-km-long, northeast-trending paleocanyon in a broad Laramide uplift west of the Canyon Creek fault, which included, but was not confined to, the Apache uplift of Davis et al. (1982). Detritus removed from the paleocanyon was deposited in the form of Eocene-early Oligocene gravels in the Flying "V" Canyon region. The northeast-flowing drainage was disrupted by down-to-the-west Oligocene normal faulting, which induced a long period of internal drainage in which the paleocanyon served as a depositional basin for Oligocene fanglomerates, the 20 m.y. Apache Leap Tuff, and Miocene fanglomerates, evaporites, and basalts. Post-14 m.y. down-to-the-west normal faulting completed the 180° Tertiary drainage reversal by permitting development of the southwest-flowing Salt River, which has partly exhumed the paleocanyon.