What does the presence of an E horizon indicate about soil formation?

The presence of an E horizon indicates that leaching processes have occurred within the soil profile. This horizon typically forms in well-drained soils as water percolates downward through the upper layers. During this process, certain minerals and nutrients, particularly iron, clay, and organic matter, are washed out of this layer, leading to a lighter color and a reduction in these materials compared to the layers above and below. By losing these components, the E horizon reflects the effects of leaching, which can significantly influence soil fertility and structure.

The other options do not accurately represent the characteristics or significance of the E horizon. The end layer of soil development is not defined by the E horizon; rather, it is often associated with deeper horizons such as the B horizon, where accumulation occurs. High organic matter content is typically found in the uppermost O or A horizons, not the E horizon. Constant water saturation pertains more to specific soil types like wetland soils or the presence of a water table, which is not indicative of the formation of an E horizon.