22 



Table 7. — Coarse i!,ravcl in the different sections from the five fields on Fargo 

 silt loam. 



Depth 

 Inches 



1— 6 



7—12 

 13—24 

 25—36 

 Average 



1—36 



1— 6 



7—12 



13—24 



25—36 



Average 



1—36 



Field 

 I 



per cent 



0.00 

 0.00 

 0.00 

 0.36 



0.12 



0.67 

 1.00 

 0.94 

 1.65 



1.14 



Field 

 II 



per cent 



0.35 

 0.17 

 0.16 

 2.21 



0.23 

 0.23 

 0.79 

 1.06 



0.69 



Field 



III 



per cent 



1. Kansan. 



0.00 

 0.00 

 0.20 



017 



Field 



IV 



per cent 



0.00 

 0.70 

 0.27 

 0.85 



0.8« 0.12 0.49 



2. Late Wiscon.sin. 



0.64 

 1.06 

 1.51 

 2.07 



1.48 



0.58 

 1.44 

 4.28 

 4.38 



3.22 



Field 



V 



per cent 



0.00 

 0.07 

 0.36 

 0.82 



0.40 



0.46 

 0.83 

 0.68 

 1.57 



0.96 



Average for 



5 fields 



per cent 



0.07 

 0.19 

 0.20 

 0.88 



0.40 



0.52 

 0.91 

 1.64 

 2.15 



1.50 



Table 8. — Average weight of coarse gravel particles in the different sections 

 on Fargo silt loam. 



Deptl 

 Inche 



1— 6 



7—12 



13—24 



25—36 



Average 



1—36 



1— 6 



7—12 



13—24 



25—36 



Average 



1—36 



Field 



I 



grams 



.000 

 .000 

 .000 

 .046 



.015 



.025 

 .025 

 .023 

 .030 



.026 



Field 



11 

 grams 



.011 



.020 

 .017 

 .029 



.027 

 .019 

 .025 

 .020 



.023 



Field 

 III 



grams 



1. Kansan. 



.000 

 .011 

 .193 

 .028 



Field 

 IV 



grams 



.000 

 .049 

 .030 

 .081 



.020 .075 .045 



2. Late Wiscon.sin. 



.023 

 .014 

 .017 

 .018 



.018 



.020 

 .022 

 .051 

 .025 



.032 



Field 



V 

 grams 



.000 

 .017 

 .024 

 .044 



.025 



.014 

 .018 

 .015 

 .020 



.017 



Average for 

 5 fields 

 grams 



.002 

 .019 

 .053 

 .046 



.036 



.022 

 .020 

 .026 

 .023 



.023 



Carrington Loam. On both drifts (Table 9) the variation from 

 field to field is much greater than with the two other types. Here also 

 in general the maximum is found in the third foot. The average for 

 the five fields is somewhat the higher on the Kansan, the opposite of 

 what was found for the two other types. This is caused by the excep- 

 tionally high percentages for the third foot of Fields I, II and III on 

 the older drift. The topography of this type, as mentioned above 

 (p. 12) is the most rolling of any sampled and accordingly the soil is 

 the most apt to be stronglv eroded, hence it is not unlikely that much 

 of the material originally at the surface on these three fields has been 

 carried away, thus l)ringing less weathered layers within the three 

 foot section. 



