THE CRYSTALLINE ROCKS OF THE OAK HILL AREA 
NEAR SAN JOSE, CALIFORNIA 
E. P. CAREY anp W. J. MILLER 
CONTENTS 
INTRODUCTION. 
‘TOPOGRAPHY. 
THE DIorITES. 
Occurrence and Relations. 
Petrographic Characters. 
Chemical Analysis. 
THE GABBROS. 
Occurrence. 
Petrographic Characters. 
Relations. 
Chemical Analysis. 
THE OLIVINE PYROXENITE. 
Occurrence. 
Petrographic Characters. 
‘THE PERIDOTITE-SERPENTINE. 
Occurrence and Associations. 
Petrographic Characters. 
Genesis of Serpentine from Peridotite. 
Chromite. 
Cinnabar. 
Analysis. 
SLICKENSIDED SERPENTINE. 
Mot?rrLleD SERPENTINE. 
“SILICA CARBONATE SINTER.” 
Petrographic Characters. 
THE GLAUCOPHANE SCHISTS. 
‘t. Ordinary Typical Glaucophane Schist. 
2. Garnetiferous Schist. 
3. Acid or Quartz-bearing Schist. 
Suggestions as to Origin. 
MacmMatic DIFFERENTIATION. 
INTRODUCTION 
The Oak Hill area is situated about four miles south of the city 
of San José, in the Santa Clara Valley, California. On the north of 
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