The finely divided, red, brown, and yellow soil-coloring minerals originate by what process?
A. mechanical weathering of very fine-grained, blue-gray clays
B. chemical weathering of quartz and feldspars
C. precipitation of iron oxides during the chemical weathering process
D. mechanical weathering of the feldspars and micas in granite and rhyolite
Answer:C
The finely divided, red, brown, and yellow soil-coloring minerals originate by what process?
A. mechanical weathering of very fine-grained, blue-gray clays B. chemical weathering of quartz and feldspars C. precipitation of iron oxides during the chemical weathering process D. mechanical weathering of the feldspars and micas in granite and rhyolite