 There is also more sediment deposited where agriculture has taken place because the disruption of the land has accelerated the erosion of the soil.14,000 years ago the last ice age retreated, forming the Qu'Appelle Valley and leaving many glacial deposits and evidence in the soil.The municipality of Fort Qu'Appelle sits on alluvial deposits that consists of silt, sand, clay, gravel, and other organic material deposited by the glacier.