The muddy Mississippi, transporting soils that have eroded from farm fields, represents a mixing of which spheres?

The correct answer highlights the interaction between the lithosphere and the hydrosphere. The lithosphere refers to the Earth's solid outer layer, which includes soil, rocks, and minerals. In the scenario described, soil that has eroded from farm fields is a product of the lithosphere since it originates from the land's surface.

On the other hand, the hydrosphere encompasses all water bodies on Earth, including rivers, lakes, and oceans. The muddy Mississippi River represents the hydrosphere as it transports the eroded soil particles downstream. This transportation of materials illustrates an essential process in the earth system, where water (hydrosphere) interacts with land (lithosphere), leading to sediment transport and deposition.

This interaction is important in understanding river systems and erosion processes, as well as how human activities like agriculture can impact these natural systems.