Of course, the parent rock for the soil might not be a local rock, though. This is because of another important factor, topography. Areas that are steeper will be more susceptible to mass wasting and erosional forces. This will remove much of the smaller grains of inorganic material, leaving behind only the larger variety. The smaller grains will be moved to places where the land is not as steep, such as a valley or an alluvial plain. This means that the parent
rock for a local soil can actually be hundreds or even thousands of miles away.