14 



to carry mucli of this salt away, so it is found incrnstiiig" the banks of 

 the creeks and the margins and beds of the dry or sliallow lakes. 

 Some of the abrupt slopes where lieaA^y winter snowdrifts lie are fairly 

 free from injurious salts, and, judging from the a>ppearance of the vege- 

 tation, have nearly normal mountain soil. Almost all the soils are 

 poor in humus. 



The character of the soil as determined by constituents and water 

 content gives five fairly distinctive formations. These may be desig- 

 nated and characterized under the following divisions: 



Flains soils. — Surface more or less undulating, hence fairly well 

 drained and losing slowly some of the soluble salts; soil consisting of 

 clay, gravel, or sand, or these mixed in various i)roportions. Strictly 

 speaking, it is not a true plain, but undulating or even hilly, with long 

 gentle slopes leading to the basins and ravines. It includes all the 

 land with sutticient slope for drainage. 



AlJcali soils. — Depressions or basins without drainage and flats adja- 

 cent to creek beds; salt constituents increasing; soil, a mixture of fine 

 clay and sand with the salts. 



Paludal soils. — Marshy bogs about springs and the margins of some 

 of the few creeks; bogs of all characters from nearly fresh to highly 

 saline or mineralized. 



Snowdrift soils. — The draws and abrupt slopes where snow accunui- 

 lates and lies till late spring or early summer; gravelly or sandy soil, 

 often of a loamy character, due to the considerable amount of decom- 

 posing vegetation. 



Cedar Bluffs soils. — More or less abrupt slopes of shale, sandstone, 

 or sand; soil inferior, but fairly free from salts; hence a somewhat 

 varied, though stunted, vegetation. 



COMPOSITION OF ALKALI IN RED DESERT SOIL. 



The analyses^ of some representative soils from the desert show that 

 they are among the most pronounced of the so called alkali soils, and 

 that the principal salts are sodium chloride and sodium sulphate, while 

 sodium carbonate, or black alkali, is not wholly absent. 



The following analysis of soil for the alkali contents from the desert 

 21 miles northwest of llawlins may be taken as fairly representative 

 of the better soils of the Ked Desert in general : 



Alkali (water-soluble a.ilts), 0.12 per ceut of soil. 



Composition of alkali: 



I'er oent. 



.Sodiuin chloride 18. 5 



Sodium sulphate :i7. 1 



Calcium sulphate 35. 



Magnesium sulphate 9. 4 



100.0 



' The author is indebted to Prof. E. E. Slosson, chemist of the Wyoming Experiment 

 Station, for the analyses, and to Professors IJutVuni and Kuight for one each of the 

 samples. 



