JEOLIAN DEPOSITS 



833 



were found to consist of fully 96% silt and 4% organic matter, 

 the latter consisting mainly of fresh-water algse, diatoms, fungi, 

 cells from decayed grasses, and shreds of woody tissue. 



Chemical Analyses of Dust Soils 



CONSTITTJKNTS 



InsoluMe matter 



Soluble silica 



Potash (K2O) 



SodaCNaaO) 



Lime (CaO) 



Magnesia (MgO) 



Brown oxide of manganese (MngOi) 

 Peroxide of iron (¥6203) .... 



Alumina (AI2O8) 



Phosphoric acid (PzOb) .... 

 Sulphuric acid (SO3) ..... 

 Water and organic matter , . . 



Total 



Humus 



Hygroscopic moisture 



Atathnam 



PRAIRIB, 



Yakima 



CotTNTY, 



Washington 



71.67 

 5.11 

 1.07 

 0.35 

 2.00 

 1.34 

 0.04 

 6.88 

 7.91 

 0.13 

 0.02 

 2.82 



/o 



} 



76.78 



99.34% 

 4.10 

 4.98 



II 



Rattlesnake 

 Creek, Kitti- 

 tas County, 

 Washington 



0/ 

 /o 



78.33 

 2.20 

 0.70 

 0.24 

 2.08 

 1.47 

 0.07 

 6.13 



0.18 

 0.02 

 2.35 



} 



80.63 



99.89% 



3.20 



in 



Plateaf on 

 Willow Creek, 



MOBBOW 



County, 

 Oregon 



0/ 

 /o 



79.21 

 2.30 

 0.89 

 0.05 

 1.37 

 1.08 

 0.06 

 5.63 

 6.02 

 0.18 

 0.03 

 2.55 



} 



81.61 



99.37% 

 0.44 

 4.92 



Mechanical Analyses of Dust Soils 



Conventional Name 



Clay. . . . 

 Pine silt , . 

 Silt .... 

 Very fine sand 

 Pine sand . . 

 Medium sand 



Diameter of 

 Paeticlks 



.0023 mm 

 .005-.011 

 .013-.027 

 .027-.05 

 .05-. 122 

 .122-. 6 



0.93 % 

 80.93 



3.20 



7.18 

 21.88 

 32.39 



96.51 % 



II 



3.59% 

 13.06 



5.82 

 27.37 

 43.78 



4.57 



98.19% 



III 



1.27% 

 32.29 

 12.75 

 37.51 

 10.92 



3.97 



98.71% 



Hilgard has examined the so-called ^'dnst soils'' of Oregon, 

 California, and Washington, which during the dry seasons are 



