CHAPTER XI

THE ATTACK OF THE WEATHER

The two contrasted processes of weathering—The rôle of the percolating water—Mechanical results of decomposition: spheroidal weathering—Exfoliation or scaling—Dome structure in granite masses—The prying work of frost—Talus—Soil flow in the continued presence of thaw water—The splitting wedges of roots and trees—The rock mantle and its shield in the mat of vegetation—Reading references 149