How does the C horizon form?

A) color and chemistry
B) texture and pure space
C) decayed organic matter
D) oil

The C horizon, also known as the parent material horizon, forms through the weathering and breaking down of the underlying rock or sediment. The correct answer to your question is A) color and chemistry.

To better understand the formation of the C horizon, we need to briefly discuss the soil formation process. Soils are formed over long periods of time from weathered parent material and the actions of organisms, climate, and topography. This process is known as pedogenesis.

The parent material is the rock or sediment from which the soil is derived. As weathering and erosion occur, the parent material undergoes chemical and physical changes. These changes result in the formation of different soil horizons, including the C horizon.

Color and chemistry are crucial factors in the formation of the C horizon. The C horizon is typically composed of partially weathered parent material. It is usually characterized by a lack of distinct soil structure and low amounts of organic matter. The color and chemistry of the parent material influence the characteristics of the C horizon.

Regarding the other options you mentioned:
B) Texture and pure space primarily influence the formation of other soil horizons, such as the A and B horizons, which are located above the C horizon.
C) Decayed organic matter influences the formation of the O and A horizons, which are layers of organic material near the soil surface.
D) Oil does not directly contribute to the formation of the C horizon or any other soil horizon.