Austin, TX, United States
Pilot Knob. Pilot Knob, the only example of an exposed submarine volcano in Texas, appears today as a prominent hill one mile northwest. It was formed some 80 million years ago on the bottom of a warm, shallow sea which covered much of the continent during the Cretaceous Period. The molten rock whic
h it spewed forth rose to the surface from deep within the earth's crust, following a channel opened by a belt of fractures known as the Balcones Fault zone. Reef organisms were attracted to the irreg
Listen to the audio guide for Black plaque № 27389 Free on WIP — starts by itself when you arrive, even with the screen off