Porphyroblastic Biotite Schist
Gneiss, schist & quartzite. about 4,000 to 541 million years old. 20 crags on this site have their map point on it.
What the map says
Characterized by abundant porphyroblasts of coarse biotite
1:100,000 sheet: Colton, Roger B., 1976, U.S. Geological Survey Geologic Investigations Series I-855-G (20 crags). A contact line at that scale is about 100 m wide on the ground.
Served by Macrostrat (CC BY 4.0). The wording is the map's own, quoted as a fact about the mapped unit, not about any one wall.
Boulder
- The Dome28 routes · Boulder Canyon · 5,849 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Turtle Rock: A Crag for Kids11 routes · Boulder Canyon · 6,345 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Canyon Block10 routes · Boulder Canyon · 6,576 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- The Brick Wall4 routes and 3 boulder problems · Boulder Canyon · 6,178 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Long Walk Rock7 routes · Boulder Canyon · 7,234 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Little Crag6 routes · Boulder Canyon · 5,866 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- The Dome Boulder3 boulder problems · Boulder Canyon · 5,779 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Goofy Spire3 routes · Boulder Canyon · 5,760 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Island Rock3 routes · Boulder Canyon · 6,341 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Sugar Crack Buttress3 routes · Boulder Canyon · 6,077 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Three Buffoons3 routes · Boulder Canyon · 5,720 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Moon Rock3 boulder problems · Flagstaff · 6,581 ft · sandstone (Fountain Formation) (another source)
- Ament's Rock2 routes · Boulder Canyon · 5,637 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Bummers Rock2 routes · Boulder Canyon · 6,452 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Diagon Alley2 boulder problems · Boulder Canyon · 5,563 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Frogman Pinnacle2 routes · Boulder Canyon · 5,624 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Mental Rock2 routes · Boulder Canyon · 6,421 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Roadside Boulder2 boulder problems · Boulder Canyon · 5,666 ft · granodiorite (Boulder Creek Granodiorite) (another source)
- Spasmodic Rock2 routes · Boulder Canyon · 6,238 ft · granodiorite (Boulder Creek Granodiorite) (another source)