THE TOMAH AND SPARTA QUADRANGLES 619 



EXPLANATION OF THE DIAGRAMS OF FIG. 2 



The ordinates represent percentages by weight, the sum of all the rectangles 

 in each diagram totaling 100 per cent. Abscissae represent the dimensions of 

 the quantity indicated by the rectangle immediately above it. These for 

 convenience are numbered i to 10, the dimensions corresponding to the numbers 

 being as given below. The analyses were made with Tyler Standard Screen 

 Scale Testing sieves : 



1. Between 1.168 and ,833 mm. 



2. Between .833 and .589 mm. 



3. Between .589 and .417 mm. 



4. Between .417 and .295 mm. 



5. Between . 295 and . 208 mm. 



6. Between . 208 and . 147 mm. 



7. Between .147 and .104 mm. 



8. Between .104 and .074 mm. 



9. Smaller than . 074 mm. 



10. This does not represent dimensions, but material which is different 

 from the main body of the sand. The loss in sifting (generally less 

 than I per cent) has been added to No. 9, as the finest grades suffer the 

 greatest loss. 



A. Dresbach sandstone. Tunnel City, 65 feet from the top of formation. 



Percentage 



1. 0.036, spherical grains of transparent quartz. 



2. o. 755, well-rounded grains of transparent quartz. 



3. 1 2 . 080, transparent quartz, most grains well rounded, a few sub- 



angular. 



4. 32 . 120, transparent quartz, grains well rounded to subangular. 



5. 28.270, transparent quartz, grains well rounded to subangtdar, a 



few grains angular. 



6. 20 . 460, transparent quartz, estimated 10 per cent angular, 25 per cent 



well rounded. 



7. 5 . 600, transparent quartz, a few grains well rounded, most sub- 



angular to angular. 



8. 0.312, transparent quartz, nearly all grains sharply angular. 



9. 0.367, transparent quartz, grains angular. 

 This sand is of beach origin. 



B. Lower greensand of the Franconia formation, collected at Boscobel on the 

 Wisconsin River, south of the quadrangles. 



Percentage 



1. 0.00. 



2. 0.00. 



3. 0.00. 



4. 0.00. 



