Earth:Mazama Member
| Mazama Member Stratigraphic range: Holocene | |
|---|---|
| Type | Member |
| Unit of | Mount Mazama Formation[1] |
| Sub-units | Tsoyawata Bed and Mazama Bed[1] |
| Location | |
| Region | western United States and Canada |
| Country | United States , Canada |
| Type section | |
| Named for | Mount Mazama |
The Mazama Member (informally, Mazama ash) is a large geologically recent volcanic ash deposit that covers portions of the U.S. states of California , Oregon, Washington (state) , Idaho, Montana, Nevada, Wyoming and Utah, as well as the Canadian provinces of British Columbia, Alberta and southwestern Saskatchewan. It was created by a massive explosive eruption of Mount Mazama ~6,900 years ago, during which it collapsed to create the caldera of Crater Lake.[2][|permanent dead link|dead link}}]
To the south, the Mazama Ash overlies the older Bishop Tuff. To the north, it is overlain by the 508-year-old Wn Ash and the 3,400-year-old Yn Ash from Mount St. Helens, as well as the 2,400-year-old Bridge River Ash from the Mount Meager massif.[2]
The ash is found in marine sediments off Oregon and Washington.[3]
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