GRD01XPS0

M-81

Lineation

Mesozoic › Cretaceous
65.5 - 145.5

1

Ritter 154 › Cabinet 24 › Drawer I

medium-grained,lineations

Large sample of gneiss composed of plagioclase-biotite-quartz. Well-foliated with lineations. Fine- to medium-grained. Original description: hornblende gneiss or amphibolite; Jurassic-Cretaceous.

-

-

California
Glenview
Latitude: 32.8°
Longitude: -116.9°

-

Inclusion-rich plagioclase with a cluster of biotite in quartz groundmass

2.5

plane

Inclusion-rich plagioclase with a cluster of biotite in quartz groundmass

2.5

crossed

-

scan

crossed

GRD01XPT0: 40% plagioclase, 35% quartz, 25% biotite. Inclusion-rich plagioclase. Inclusions include biotite and amphibole?. Quartz is inclusion-free. Small to large grains of biotite. The biotite typically forms aggregates (i.e. few individual crystals). (C. Eichler)

N/A

N/A