GRD00GDS0
I-674
Ignimbrite
Cenozoic › Paleogene › Eocene › Late Eocene › Priabonian
33.9
-
37.2
1
Ritter 154 › Cabinet 15 › Drawer K
-
Wall Mtn tuff. Also known as Castle Rock rhyolite. Rhyolite (San-Pla-Bi-Mt-Q) tuff.
36.7 Ma
-
Colorado
Castle Rock
Latitude: 39.4°
Longitude: -104.8°
-
Sanidine crystals
5.0
plane
Sanidine with polysynthetic twinning and faint zonation
5.0
crossed
-
scan
crossed
GRD00GDT0: Sanidine (polysynthetic twinning, obvious zonation), opaques, small biotite phenocrysts in fine grained matrix. (C. Eichler)
N/A
N/A