GRD0012S0
I-40
Andesite
Cenozoic › Neogene › Miocene
5.3
-
23.0
1
Ritter 154 › Cabinet 16 › Drawer B
porphyry
Plagioclase and hornblende in glassy matrix
-
Van Winkel Mtns
California
Van Winkel Mtns, 30 mi NE of Amboy
Latitude: 34.99°
Longitude: -115.29°
-
Resorbed feldspar, euhedral amphibole, small biotite, and oxide crystals
2.5
plane
Resorbed feldspar, euhedral amphibole, small biotite, and oxide crystals
2.5
crossed
-
scan
crossed
GRD0012T0: 30% phenocrysts: 20% plagioclase, 5% biotite, 5% hornblende, minor pyroxene (J. Gee)
N/A
N/A