16 Instructions to Field Parties. 



type names. If the field men acquaint themselves with the general 

 characteristics of these series, they Avill find it a great aid in plac- 

 ing soils of new areas. Furthermore, if any type in a series is 

 thoroughly understood, the remaining types can be called to mind 

 without reference to the printed description, thereby reducing the 

 number of type descriptions necessary to be carried in the head_. 



To complete the Norfolk series, the Susquehanna gravel has 

 been changed to Norfolk gravel, the Windsor sand to Norfolk 

 coarse sand, the Windsor sandy loam, encountered for the first 

 time in 1903, to the Norfolk coarse sandy loam, and the Sassafras 

 loam to the Norfolk silt loam. This i)ractically perfects the series. 

 Several of the old local names have been dropped as the true rela- 

 tionship of these soils to the Norfolk series has become apparent. 

 Similar work has been done with the other principal series, so 

 that many of them now are practically complete, having a stony 

 loam, gravel, gravelly loam, sand, fine sand,sandy loam, fine sandy 

 loam, loam, silt loam, clay loam, and clay, of related materials. 



The grouping of the soils in these series is not only a great aid 

 in correlation, but it is entirely logical. When the Norfolk sand 

 is being deposited, the conditions somewhere in the area will 

 undoubtedly be favorable to the deposition of gravel, of silt, of tine 

 sand, of loam, and of clay, and wherever material of these char- 

 acters is encountered, pret^umably coming from the same source 

 and being dei)osited essentially at the same time and in the same 

 manner, it should be given this distinctive name so as to show the 

 relation of the soils to one another. Knowing as we do the proc- 

 esses of soil formation, either from the disintegration of rocks in 

 place or tlirough transportation by wind or water, we should expect 

 that materials from the same source would differ in their texture. 

 The relationship of the derived soils should be shown by the use 

 of a commiju name. 



There will be found in nearly all areas soils of local origin and 

 of exceptional cliaracter whidi will have to be given local names, 

 but so far as i)OSsible the soils encountered in new areas should 

 be correlated with estaV)lished types, prefen'uce being given wliere 

 possible to some of the great series descril)ed liereafter. As a rule, 

 a series siiould l)e confined to certain i)hysiographic areas, that is, 

 the names of the Coastal Plain soils should not be carried over 



