Quaternary geology of the southern portion of the Northville, Michigan 7.5 minute quadrangle

The Defiance Moraine is a well-defined Late Wisconsinan recessional end moraine in northern Ohio that was traced into southeastern Michigan and mapped geomorphically. In the southern portion of the Northville, MI 7.5 minute quadrangle, the Defiance Moraine was previously mapped as two separate end moraines, formed by the Erie Lobe of the Late Wisconsinan glacier, and separated by a paleochannel, commonly referred to as the Defiance Channel. Current mapping of the study area suggest that the Defiance Moraine consists of a stratified succession of interstratified alluvium and diamicton deposited between two distinct diamicton till deposits. Each of the moraines consists of the same stratified succession, therefore, suggesting that they are stratigraphically the same. The Defiance Channel, which is geologically younger then the Defiance Moraine, cut across the Defiance Moraine and over time made the Defiance Moraine appear to be two separate end moraines. Also, the Defiance Moraine was not deposited by the Erie Lobe as previously thought but by the Huron Lobe. Erosion has also produced landforms previously misidentified as kames in the study area that are actually remnants of diamicton till overlying easily eroded alluvial sediments. The results of this study suggest that mapping primarily on the basis of geomorphic expression can produce misidentification of glacial landforms. A more detailed study of the surficial geology, using data gathered from shallow auger borings, and subsurface analysis, using data gathered from geotectonic deep test borings, is needed to properly map glacial deposits of this region.