Locations:

• Oceanic Ridge system
• East African Rift Zone
• Rio Grande Rift Zone
• Basin and Range Province

Characterized by:

• Basaltic magma extrusion
• Series of Normal & Reverse faults

Trends from eastern CA to western NV

One 6+ M per decade

One 7+ M per 27 years

30 m.y. of extensional tectonics

Accommodates ~20% of
relative motion between
N.A. and Pacific plates