TV 
CONTENTS. 
Chapter III.—Description and petrology of the metamorphic and igneous rocks—Continued. 
Ancient crystalline rocks—Continued. 
Schist. 
Olivine syenite.. 
Anorthosite.. 
Diabase . 
Tertiary volcanic rocks. 
Pbonolite. 
General description. 
Definition... 
Occurrence. 
Appearance. 
Mineralogical character... 
Feldspar. 
Nepheline. 
Sodalite and nosean.. 
Analcite. 
iEgirine and segirine-augite. 
Blue amphibole. 
Other minerals. 
Texture . 
Chemical character. 
Summary. 
Leucitophyre (?). 
Latite-phonolite. 
General description. 
Necessity for a new division. 
Definition. 
Occurrence... 
Appearance. 
Mineralogical character. 
General statement. 
Feldspar.. 
Pyroxene. 
Hornblende and biotite. 
Nosean, sodalite, and analcite. 
Apatite. 
Titanite.. 
Other minerals. 
Trachytic facies. 
Texture . 
Chemical character. 
Transitions to phonolite... 
Syenite. 
General description.. 
Mineralogical character. 
Chemical character... 
Trachydolerite (Bull Cliff type). 
General description. 
Mineralogical character. 
Chemical character. 
Summary. 
Basic dike rocks. 
General description. 
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