 A maar complex, containing pyroclastic and extrusive minette, is exposed along New Mexico Highway 134 in Narbona Pass (Brand et al., 2008).Argon-argon dating of four minette samples at Narbona Pass yielded consistent ages of 25 million years.Very little oil has been produced in Arizona, and much of that production has come from a minette sill, the reservoir rock of the Dineh-bi-Keyah field in the northwestern Chuska Mountains near Roof Butte.