560 STUDIES FOR STUDENTS 



EXPLANATION OF PLATE IX 



Fig. 1. — Section No. 4736. (X 12.) Dolomitic limestone from 

 Duck Creek. This figure is an excellent illustration of the way in 

 which the individuals of the coarser crystalline limestones interlock. 



Fig. 2. — Section No. 4726. (X 12.) Dolomitic limestone from 

 Sturgeon Bay. This figure shows the close, compact character of the 

 crystalline dolomites, which accounts for their low percentage of pore 

 space, and partly for their high crushing strength. 



