Plate 4 



Photo by W. J. Miller, 1914 



A ledge of Grenville limestone on Cedar river, one-half mile northeast of the 

 main road bridge across the river. Stratification of the limestone is well shown as 

 well as the rounded masses (dark colored) of Grenville pyroxene gneiss which 

 have been kneaded into the relatively plastic limestone under pressure. 



