State by State
- Specimen Number
Rough block of gray granodiorite. Identified by survey staff. Filled fracture from lower right to upper left suggests contraction during cooling.
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
Andes style arc magmatism. The newspaper description provided the clue to where in the state it was from..
The Washington Geological Survey provides an example for the rest of the nation.