Part D
Geology of Agua Fria Canyon
Located north of Phoenix in central Arizona, the Agua Fria River carves a canyon into Early Proterozoic and Tertiary igneous rocks. The intrusive rocks tell us about some of Arizona's early geologic history, going back as far as almost 2 billion years. Other rocks are much younger (10-20 Ma) and yield insight into relatively recent geologic events.
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Figure 4-11. Igneous rocks underlie most of the Agua Fria National Monument in central Arizona. A xenolith-rich Early Proterozoic boulder in the Agua Fria River channel (left), and Scott finds several pertoglyphs carved onto a basalt boulder (right). |
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Figure 4-12. The Agua Fria Canyon sequence diagram. Unit E represents a landslide unit that is younger than unit G. |
Quiz Me! questions D41 through D50 refer to the Agua Fria Canyon sequence diagram (Figure 4-12). Also refer to the Key to Map Fill Patterns (click HERE for a printable PDF version) and the geologic time scale (click HERE for a printable PDF version).
After finishing this lesson, complete the form below: