State by State
Washington
- Specimen Number
45
- Description
Rough block of gray granodiorite. Identified by survey staff. Filled fracture from lower right to upper left suggests contraction during cooling.
- Classification
Igneous. Plutonic. Granitic. Granodiorite.
- Location & Occurrence
From the "State of Washington's new tunnel," as described in the 1937 Hartford Courant. Search indicates that the "New Cascade Tunnel" was a railroad tunnel through Stephen's Pass of the Cascades east of Seattle that was dedicated in 1930 as a great wonder, drawing national attention. Formation name not known. A Cascade Range batholith.
- Geologic Age
Mesozoic
- Geoheritage
Andes style arc magmatism. The newspaper description provided the clue to where in the state it was from..
- Links
Link to State Geological Map from USGS. Link to Washington Geological Survey.
- Other
The Washington Geological Survey provides an example for the rest of the nation.
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