BULL. GEOL. SOC. AM. 



VOL. 15, 1903, PL. 4 



Figure 1. — Jointed Granite in Kuna Crest, Sierra Nevada 



Figure 2. — Granite Boulder from which Spalls or Flakes have been Riven by the Heat of Forest or Meadow 



Fires 



JOINT STRUCTURE AND FIRE SPALLING 



