INORGANIC COMPOSITION OF SOME AMERICAN SOILS. 17 



Silt. — Minerals other than quartz, 40 per cent; potash feldspars, 

 7 per cent; muscovite, 0.5 per cent. Epidote is present in fairly large 

 quantities. Hornblende, rutile, zircon, chlorite, magnetite, and 

 sponge spicules are also present. 



(2) NORFOLK SANDY LOAM, SUBSOIL. 



No. 4 sand.— "No potash feldspars. Practically pure quartz with 

 rutile and apatite inclusions. Andesite present. 



No. 5 sand. — Minerals other than quartz, 4.7 per cent. Quartz 

 grains very clear and bright, mostly well rounded, with a few aub- 

 angular and angular grains. Tourmaline, rutile, zircon, chlorite, 

 magnetite, cyanite, hypersthene, weathered feldspars, and apatite 

 inclusions in quartz are present. 



Silt. — Minerals other than quartz, 60 per cent. Potash feldspars 

 (orthoclase), 1 per cent, characterized by a large amount of highly 

 kaolinized feldspars and the presence of sponge spicules. Epidote, 

 chlorite, rutile, orthoclase, and zircons are also present. 



(3) DECATUR CLAY LOAM, SOIL. 



No. 4 sand. — Minerals other than quartz, 4 per cent. Potash 

 feldspars, negligible. No muscovite. Magnetite, hematite, rutile 

 inclosed in quartz, orthoclase, and epidote are present. 



No. 5 sand. — Minerals other than quartz, 4.2 per cent. Potash 

 feldspars (orthoclase), less than 0.5 per cent. No muscovite. The 

 feldspars are much altered and few in number. Rutile, zircon, tour- 

 maline, magnetite, and epidote are also present. Characterized by 

 quartz crystals inclosing iron oxide. 



Silt. — Minerals other than quartz, 39 per cent. Potash feldspars, 

 6 per cent. The feldspars are much altered. Epidote and chlorite 

 are the predominating minerals. Tourmaline, rutile, and zircon are 

 also present. 



(4) DECATUR CLAY LOAM, SUBSOIL. 



No. 4 sand. — No potash feldspars or muscovite found. The quartz 

 is very impure. Magnetite, hematite, and rutile inclosed in quartz 

 are present. 



No. 5 sand. — Minerals other than quartz, 4 per cent. Potash 

 feldspars less than 0.5 per cent. The quartz grains are well rounded 

 and subangular. Tourmaline, zircon, rutile, magnetite, and calcite 

 inclosed in quartz are also present. Characterized by quartz crystals. 



Silt. — Minerals other than quartz, 37.5 per cent. Potash feld- 

 spars, 9 per cent. Zircon, epidote, tourmaline, magnetite, muscovite, 

 chlorite, and sponge spicules are also present. 



