Permian stratigraphy and structure, northern Canelo Hills, Arizona
Measured sections in the northern Canelo Hills show 2,223 feet of Middle Permian (Snyder Hill) limestones, dolomites, and clastics overthrust upon two distinct series of younger rocks: (1) redbeds and brown conglomerates and sandstones, probably Cretaceous in age; and (2) lava flows and interbedded tuffs and sandstones interpreted as Tertiary. Major structural events discovered are: (1) the overthrusting which started in late Cretaceous or early Tertiary time; (2) high-angle faulting trending north-south and east-west; (3) formation of an anticline whose axis trends northwest-southeast. These movements affect all rocks within the area older than a late Tertiary fanglomerate. This fanglomerate and extensive terraced gravels are the youngest rocks in the area. Some of the g avels contain interbedded, spring-deposited travertines bearing a gastropod faunule identified as late Pleistocene.