ABSA ROKITE-SHOSHONITE-BANAKITE SERIES. 957 
DIAGRAM SHOWING THE RANGE IN ALKALI-SILICA RATIOS 
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IN CERTAIN GENETICALLY RELATED SERIES OF IGNEOUS ROCKS. 
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Grorudite-Tinguaite Series, Christiania region. 
Nepheline-Porphyry, Beemersville, N. J. 
Shonkinite-Sodalite-Syenite Series, Square Butte, Montana. 
Shonkinite-Yogoite-Syenite Series, Yogo Peak, Montana. 
Absarokite-Sodalite-Syenite Series, Bozeman District, Montana. 
Banakite 
Shoshonite } Series, Yellowstone National Park. 
Absarokite 
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