Geologic map of the Spirit Lake East Quadrangle, Skamania County, Washington.
Evarts, R C; Ashley, R P (1993) Geologic map of the Spirit Lake East Quadrangle, Skamania County, Washington. Geologic Quadrangle Map - U. S. Geological Survey. 1993.
| Authors | Evarts, R C; Ashley, R P |
|---|---|
| Year | 1993 |
| Title | Geologic map of the Spirit Lake East Quadrangle, Skamania County, Washington. |
| Source | Geologic Quadrangle Map - U. S. Geological Survey. 1993. |
| Publisher | U. S. Geological Survey. Reston, VA, United States. Pages: 12, 1 sheet. 1993. |
| Document type | Map; Serial; Report |
| ISSN | 0375-8117 |
| GeoRef | 1993-043739 |
| Keywords | Cascade-Range; Cenozoic-; copper-ores; explanatory-text; geologic-maps; granites-; hydrothermal-alteration; igneous-rocks; intrusions-; lava-; maps-; metal-ores; metasomatism-; mineral-deposits,-genesis; mineralization-; Mount-Saint-Helens; plutonic-rocks; plutons-; porphyry-copper; Skamania-County-Washington; southwestern-Washington; Spirit-Lake-East-Quadrangle; United-States; USGS-; volcanic-rocks; volcaniclastics-; Washington- |
| Notes | Prepared in cooperation with the Washington Department of Natural Resources Geology and Earth Resources Division |
Abstract
The Spirit Lake East Quadrangle, located about 15 km northeast of Mount St. Helens, is underlain by late Oligocene to early Miocene volcanic and volcaniclastic rocks locally veneered by Pleistocene glacial deposits and tephra derived from Mount St. Helens. The Tertiary rocks are dominantly andesite and dacite flows and associated fragmental rocks deposited in a subaerial environment. They have been gently tilted to the east and intruded by several granitic bodies including the 21-Ma Spirit Lake Pluton. Several areas of hydrothermal alteration and mineralization, including a porphyry-copper deposit, are also shown.
35 samples from this reference
| Sample | Rock name | Major | Trace | Isotope |
|---|---|---|---|---|
| 2E65A | Basaltic-andesite | yes | yes | |
| 2R27 | Basalt | yes | yes | |
| 8E117B | Diorite | yes | yes | |
| 5E66A | Diorite | yes | yes | |
| 8M74 | Diorite | yes | yes | |
| 8E167A | Basaltic-andesite | yes | yes | |
| 2E07 | Basaltic-andesite | yes | yes | |
| 2E14 | Basaltic-andesite | yes | yes | |
| 9C35B | Diorite | yes | yes | |
| 8R82 | Basaltic-andesite | yes | yes | |
| 2E09 | Basaltic-andesite | yes | yes | |
| 8W56 | Basaltic-andesite | yes | yes | |
| 5E21A | Diorite | yes | yes | |
| 3E52 | Andesite | yes | yes | |
| 2E125B | Diorite | yes | yes | |
| 7R22 | Basaltic-andesite | yes | yes | |
| 3E81B | Andesite | yes | yes | |
| 2E53 | Andesite | yes | yes | |
| 8E181 | Andesite | yes | yes | |
| 6E22 | Andesite | yes | yes | |
| 2E63 | Andesite | yes | yes | |
| 2E70 | Andesite | yes | yes | |
| 3E53C | Andesite | yes | yes | |
| 8M75B | Andesite | yes | yes | |
| 3E72A | Andesite | yes | yes | |
| 8M88A | Andesite | yes | yes | |
| 2E31 | Diorite | yes | yes | |
| 2E42A | Diorite | yes | yes | |
| 8E168A | Andesite | yes | yes | |
| 1E70 | Andesite | yes | yes | |
| 2E12A | Dacite | yes | yes | |
| 8E199A | Pyroclastic-fall | yes | yes | |
| 8M70A | Dacite | yes | yes | |
| 9I17B | Dacite | yes | yes | |
| 1E68 | Dacite | yes | yes |