Figure 1.
(A) Saprock in the central Sierra Nevada, California. Note graffiti easily carved into this friable bedrock material (tile spade for scale: 1.15 m). (B) Thin section micrograph (plane light) showing porosity (in blue) and partially weathered biotite (b) and plagioclase (p). Primary minerals predominate, and very little clay has been produced by weathering. Saprock maintains rock texture (C), but is easily crushed in bare hands (D).