BULL. GEOL. SOC. AM. 



VOL. 19, 1907, PL. 39 



Figure 1. — Sierra Oscura^ ix Ce.\tral New Mexico 

 Range rises isle-like out of sea of eartli ; distance, 15 miles ; height, 3,000 feet 





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Figure l!. — Socoro Mountain, New Me.xico 

 Height, 2,000 feet 



ABSENCE OF FOOTHILLS IN DESERT RANGES 



