Volcanoes Near Hurricane Fault exit westward with time

Sullivan's Knoll, SK, west of Hf has basalt base age on order of 200 kybp, cone at 10 kybp

Grass Valley Flow (on Hf, Hurricane fault, south of town 15 km) is slightly less than 1 mybp in age

Cones and Domes are Generally older than 3/10 mybp (.3) East of Hurricane Fault; shown is Crater Hill, near Virgin Town