FOLDS RESULTING FROM VERTICALLY ACTING FORCES 339 



On the accompanying structure contour map (Fig. i) several 

 of these folds are indicated, but these are perhaps not the most 

 typical examples because they are folds of larger dimensions, and 



Fig. I. — Structure contour map of Michigan. Contours drawn to the top of 

 the Dundee (Onondaga-Hamilton). Areal distribution of Dundee, in outcrop and 

 beneath the drift, in solid black. Contour interval 100 feet. 



