Figure 6.
(A) Bedrock weathering fronts move inward from fractures. The entire vadose zone is subjected to weathering processes. From an ecosystem-sustainabili-ty standpoint, functional substrate thickness is maintained when erosional losses are balanced by saprock production. (B) Weathered rock profile showing joint fractures and less-weathered corestones at the center of joint blocks. Below arrow on right, note roots along fracture plane where corestone has fallen out.