36 



SOIL PHYSICS AND MANAGEMENT 



Classes of Sedimental Soils. There are three classes of sedi- 

 mental soils, marine or sea-laid, lacustrine or lake-laid, and alluvial 

 or stream-laid. 



Fio. 25. Map showing the early stages in the formation of coast marshes. The numbers 

 indicate the depth of water in fathoms. (C. and G. Survey.) 



(a) The marine or sea-laid deposits are formed along sea coasts 

 (Fig. 25) and include bars, spits, hooks, and marshes. Bars fre- 

 quently produce lagoons that ultimately become marshes. Marine 



Fio. 26. Section of marine marsh; 6, grass marsh; c, mud bank, or mud Sate; d, eel-grass. 



(Shaler.) 



