VALLEYS OF DRIFTLESS AREAS

ABSTRACT

Valley forms in two areas (southwestern Wisconsin and south-central Indiana) which were bordered on most sides by Pleistocene ice sheets are grouped into eight generic types, and into four types according to their location relative to the ice margin. Nine generic-locational valley types are typical of these two driftless areas. All valleys of the size considered have undergone some ice-related modification. Valleys which had direct ice sheet contact are more uniform than those which had indirect contact. The most recently formed valleys deviate least from the model, and the latest glacially-related modifications are most strongly reflected in present valley forms.

KEY WORDS:

• Driftless areas
• Glacially-related valley modifications
• Indiana
• Valley types
• Wisconsin