Year: 1984
Type: report
Abstract: DESCRIPTION OF MAP UNITS [To convert feet (ft) to meters, multiply feet by 0.3048] Countyarea number Map symbol Geologic and radiometric age in millions of years (m.y.) Lithology and comments References for Olivine-basalt flows.Locally, contacts with older basalt flows indefinite.Part of San Francisco volcanic field.Flows and dikes of olivine basalt with brecciated tops and bottoms which may be vesicular to scoriaceous or agglomeratic.Flows generally 10 to 20 ft thick but locally 50 ft or more thick.Youngest basaltic flows (about 4.5 to 6.0 m.y.) and intercalated gravels comprises Perkinsville Formation along and north of Verde River, and a few flows in small outcrops in equivalent Verde Formation along Sycamore Creek.Older basaltic flows (about 7.8±0.3 to 11.9±1.3m.y.) exposed along the Mogollon Rim at south edge of San Francisco volcanic field.Some are equivalent in age to flows in sequence of interbedded lavas and basaltic tuff, gravel, and conglomerate, comprising the Hickey Formation (10.1 to 14.6 m.y.), exposed along Sycamore Creek.
DOI: 10.3133/wri834114g
Author: W. D. Johnson
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
OpenAlex ID: W166815635