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)mechanical weathering of the feldspars and micas in granite and rhyolite
C)precipitation of iron oxides during the chemical weathering process
D)chemical weathering of quartz and feldspars

Question

Quizplus · Accepted Answer

The finely divided, red, brown and yellow soil-coloring minerals are typically iron oxides that are precipitated during the chemical weathering process. This process involves the dissolution and breakdown of minerals such as feldspars and micas, releasing iron ions that can react with oxygen and water to form iron oxides. This process is known as oxidation, and it is responsible for the distinctive red and yellow colors of many soils. Mechanical weathering (options A and B) involves physical processes that break down rocks into smaller pieces, but do not result in the formation of new minerals. Chemical weathering of quartz and feldspars (option D) may result in the formation of clay minerals, but not iron oxides.

The Finely Divided, Red, Brown, and Yellow Soil- Coloring Minerals