BULL. GEOL. SOC. AM. 



VOL. 22, 1910, PL. 12 



Figure 1. — A coisiPOSiTE uectaxgulau ItELiEF I'atteun 



This composite repeating pattern of joints is made strikingly apparent 

 through subsequent erosion of deposits baclt of an old irrigation dam at El Beida, 

 in the Syrian Desert. (After a photograph by Ellsworth Huntington.) 



Figure 2. — Rectangular Buttressing of a wall of Quader Sandstone due to 



THE perfect P'RACTURE SVSTEM 



Valley of the Elbe, in Saxon Switzerland 

 RECTANGULAR FRACTURE AND RELIEF PATTERNS 



