BULL. GEOL. SOC. AM. 



VOL. 22, 1910 PL. 8 



Figure 1. 



-Bkoinxix(;s of Erosion above a Reuies of .Toixts subequally Spaced. Spitzbergen 

 (After a photograph by Oscar llalldin, of Stockholm) 



FioruE 2. — Erosion Gullies in various Stages developing ox ax Escarpment above subequally 



spaced .Joint Planes 



Erosion somewhat more advanced than in figure 1. Spitzbergen. (After a photograph by Oscar 



Halldin, of Stocliholm) 



ROCK STRUCTURE BECOMING IMPRESSED UPON THE RELIEF THROUGH FROST ACTION 



