BULL. GEOL. SOC. AM. 



VOL. 20, 1908, PL. 38 



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Figure 1. — Mount Pele : Rock Mass axd Tuff Agglomerate of crater Rim 

 Showing grooving due to sand-blast action of eruption clouds 



Figure 2. — Mouxe Lenard., Mount Tele 



The nearly horizontal grooving was caused by sand-blast action of eruption clouds 



VOLCANIC SAND-BLAST ACTION ON MOUNT PELE 



