Composition:

Petrographic Description:  An equigranular, hypidiomorphic rock composed 
of subhedral plagioclase laths showing albite twinning,sometimes Carlsbad
twinning, and frequently gradational zonation.  There are anhedra of green
pyroxene and colorless pyroxene (as exsolution), minor green hornblende 
and abundant opaque anhedra.  Modes were:  66% plagioclase, 28% 
pyroxene and 6% opaque.

Microprobe Analysis:  Bytownite was the predominant feldspar 
composition, ranging from An80 to An84.  One plagioclase analysed proved 
to be andesitic (An42).  The pyroxene phases proved to be green, subcalcic 
augite and exsolved (colorless) salite.  Opaque phases were either magnetite 
or a mixture of ilmenite and magnetite.

Chemical Analysis:
SiO2  44.20
CaO  12.61
TiO2  1.49
Na2O  1.80
Al2O3  17.82
K2O  0.16
Fe2O3  6.26
H2O  1.11
FeO  8.34
P2O5  0.04
MnO  0.16
MgO  5.30
TOTAL  99.29
