Dust Bowl Windmill

Origin
The Dust Bowl was a period of severe dust storms that affected the Midwestern United States in the 1930s. Waves of drought and removal of topsoil by previous settlers with harvesters removed all the native drought resistant grasses. The crops farmers planted sapped the soil of even more nutrients and stability. The soil was crushed into dust and swept across the plains, blanketing acres in dust. The Dust Bowl caused many farmers to migrate to California and more fertile farmlands. Occurring simultaneously with the Great Depression, these migrant workers found little economic refuge and fell into poverty.

Effects
So long as the blades turn (even without the input of the engines), the artifact will produce storms of dust clouds. Emanating from the center like a giant fan, they will travel for miles and cover vast areas of land. Line of sight and air quality will be greatly diminished, and the land can be rendered uncultivable by stunting plant growth.