CONTENTS. 7 



Chapter VI. — The Intrusives — Continued. 



Section II. — A study of a. rock series, etc. — Continued. 



Peridotite — Continued. Page. 



Peridotite varieties 252 



Wehrlite 253 



Ampliibole-peridotite 253 



Gradations of amphibole-peridotite to welirlite and olivine-gabbro 254 



Process of crystallization ." 257 



Analysis of peridotite 259 



Peridotitefromsec.22, T.42N.,E.31"W., 1990N.,150W 260 



Relations of peridotites to other rocks 261 



Age of peridotites 262 



General observations on the above series 262 



Textural characters of the series 262 



Chemical composition of the series 263 



Relative ages of rocks of the series 265 



