transports it further inland. It constitutes for the most part dunes 

 along the lake shore and is of no importance agriculturally. 



As is frequently the case with alluvial and sedimentary soils, the 

 soils of Salt Lake Valley, especially those north of Twelfth street 

 road, are heterogeneous and much mixed up, perhaps more so than 

 is usual. They were probably first formed in the bed of the old lake, 

 Bonneville, by sedimentation, and after its subsidence further modi- 

 fied by the vacillating shore of the more modern Great Salt Lake 

 and the iiifiowing streams from the adjacent mountains. 



ALKALI. 



The salts, as they occur in the soil, vary greatly in quantity. In 

 the best agricultural lands the amount present is frequently less than 

 .05 of I per cent, while in the salt flats there may be as high as ten 

 per cent, exclusive of the crust that frequently forms in much greater 

 concentration. Sodium chloride, or the common salt of commerce, 

 forms from fifty to ninety-seven per cent of the total salts present. 

 Besides this, there are considerable quantities of the sulphates of 

 soda, lime, and magnesia, chlorides of lime and magnesia, and also 

 carbonate of soda, or true black alkali. The black alkali is nearly 

 always present in amounts varying from a trace up to several per 

 cent in small local spots. There is, in the aggregate, a large area in 

 which it occurs in sufficient quantity (.1 per cent) to be fatal to crops. 



It seems quite probable that this accumulation of salt came chiefly 

 from two sources i. e., from the higher lands to the south and from 

 the waters of Great Salt Lake. It is most likely that the lake is the 

 source of the greater portion of them, for when it was from thirty to 

 fifty feet higher than now, it would have submerged nearly all the 

 area under consideration, and must have also contained much salt in 

 solution. Upon the subsidence of the water the soil would, of course, 

 be left heavily impregnated with salts. Besides, within the memory 

 of the present inhabitants, the lake has again submerged a consider- 

 able part of this area, and, according to reliable records, the lake in 

 1868 was twelve feet above its present level, and at this height must 

 have covered at least fifty square miles of what is now mapped as 

 dry land. The water at that time carried, approximately, 13.5 per 

 cent of salt, and land submerged for a considerable length of time in 

 such a solution would certainly be left very salty when the water 

 subsided. More land than that merely covered by the lake must 

 have been affected by it. The water-table of the low land adjacent 

 to the shore must have risen to an elevation equal to or exceeding 

 the level of the lake water, while in time of storms the waves may 

 have rolled inland for considerable distances. It is fair to assume 

 that all land now having an elevation not to exceed twenty feet 



