What volcanic events formed Crater Lake, OR? When did they take place?
A) The crater of a large, extinct cinder cone filled with water; 5 million years ago.
B) Caldera collapse followed major ash and pyrodastic- flow eruptions; 7700 years ago.
C) A powerful explosion blew away the top of a composite cone; 10 million years ago.
D) Landslides and volcanic mudflows dammed the Mazama River; 500 years ago.

Question

Quizplus · Accepted Answer

Crater Lake in Oregon was formed by the collapse of Mount Mazama following a series of major ash and pyroclastic flow eruptions approximately 7,700 years ago. This event created a caldera that eventually filled with water, forming Crater Lake.

What Volcanic Events Formed Crater Lake, OR? When Did They