Black Tusk is a glacially eroded lava dome from the earliest stage of activity of the Garibaldi Lake volcanic field about 1 million years ago. The light-colored ridge to the right is a glacial moraine.

Photo by Lee Siebert, 1983 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Keywords: lava dome | erosion | outcrop | geology

Garibaldi Lake