Windrow formation: An upland gravel formation of the driftless and adjacent areas of the upper Mississippi Valley
Introduction At widely separated points on the higher uplands of the Driftless and adjacent areas of Wisconsin, Iowa, and Minnesota, there occur conglomerates and gravels with associated limonite, clay, and sandstone. The interest of the writers was drawn to these gravels while they were engaged in the study of the. geology of the Tomah and Sparta quadrangles, in western Wisconsin. As the problem of their origin could not be solved within the limits of that area, the study has been extended over a wider field and the available literature has been examined for descriptions of similar formations in adjacent States. These studies have led to the assembling of a considerable amount of information and to conclusions relating to the origin and age of the deposits. As these deposits merit a name, it is proposed to call them the Windrow formation, the name being selected because of an excellent exposure on . . .