Composition:

Petrographic Description:  A porphyritic sample with a slightly trachytic
texture.  The phenocrysts are all olivine.  The groundmass is fine-grained 
and consists of olivine, plagioclase laths, opaques, augite, and brownish
interstitial glass; the analysis for the glass is given below.

Microprobe Analysis:  (by Rosalind Helz).  The olivine analysis gave a
composition of Fo80, while the feldspar was bytownite (An78).  Titanaugite 
was also probed.  Glass composition was:

SiO2  51.00
Cr2O3  0.03
TiO2  3.92
CaO  9.82
Al2O3  13.44
Na2  3.14
FeO  10.88
K2O  0.90
MnO  0.13
P2O5  0.36
MgO  6.01
TOTAL 99.63

Chemical Analysis:  (by Herb Kirschenbaum, USGS, Reston, VA.)
SiO2  44.87
CaO  7.66
TiO2  1.09
Na2O  0.98
Al2O3  7.64
K2O  0.21
Fe2O3  1.1
H2O  0.05
FeO  11.24
P2O5  0.10
MnO  0.18
Cr2O3 - 0.20
MgO  24.53
TOTAL  99.85
