AEGIRITE AND RIEBECKITE ROCKS FROM OKLAHOMA 287 
scant, but along the “‘lead”’ of this dike the vegetation is very abundant 
and a narrow strip of shrubs extends across the mountain. 
These rocks are mostly soda rich as shown by the presence and 
comparative abundance of microperthite (orthoclase-albite), aegirite, 
riebeckite, and another soda amphibole of doubtful identity. A 
study of these rocks in connection with those of other parts of the 
Wichita mountain system, especially if chemical analyses were avail- 
able, would probably give some very interesting results. 
