18 BULLETIN 122, U. S. DEPARTMENT OF AGRICULTURE. 



(5) HAGERSTOWN LOAM, SOIL. 



No. 5 sand. — Minerals other than quartz, 40 per cent. Potash 

 feldspars (microcline), 8 per cent. Dolomite, rutile, augite, biotite, 

 plagioclase, tourmaline, and quartz crystals are also present. Char- 

 acterized by many rhombohedral fragments of dolomite and also by a 

 large amount of microcline, biotite, and rutile, which is gener. lly 

 twinned in knee-shaped forms. 



Silt. — Minerals other than quartz, 49 per cent. Potash feldspars 

 (microcline), 11 per cent. Muscovite, 2 per cent. Epidote, dolo- 

 mite, microcline, rutile, biotite, chlorite, tourmaline, augite, and 

 sponge spicules are also present. This silt is characterized by the 

 absence of altered minerals. 



(6) HAGERSTOWN LOAM, SUBSOIL. 



No. 5 sand. — Minerals other than quartz, 18 per cent. Potash 

 feldspars (microcline and orthoclase), 11.5 per cent. Quartz crystals, 

 biotite, dolomite, augite, tourmaline, rutile, and zircon are also 

 present. Characterized by a predominance of potash feldspars and 

 biotite. 



Silt. — Minerals other than quartz, 67 per cent. Potash feldspars 

 (orthoclase), 18 per cent; muscovite, 2 per cent. Epidote, twinned 

 rutile, biotite, chlorite, tourmaline, and augite are present. 



(7) VOLUSIA SLLT LOAM, SOIL. 



No. 4 sand. — Minerals other than quartz, 6 per cent. Potash 

 feldspars (microcline and orthoclase), 4 per cent. Magnetite, rutile 

 inclosed in quartz, garnet, augite, and plagioclases are also present. 



No. o sand. — Minerals other than quartz, 8 per cent. Potash 

 feldspars (microcline and orthoclase), 4.4 per cent. Predominant 

 minerals are microcline, orthoclase, garnet, hornblende, and augite. 

 Epidote, tourmaline, zircon, rutile, magnetite, hypersthene, zoisite, 

 and plagioclase are also present. 



Silt. — Minerals other than quartz, 38 per cent. Potash feldspars 

 (orthoclase), 8.9 per cent. Biotite, hornblende, muscovite, rutile, 

 epidote, tourmaline, garnet, and augite are also present. 



(8) VOLUSIA SILT LOAM, SUBSOIL. 



No. 4 sand. — Minerals other than quartz, 7 per cent. Potash feld- 

 spars (microcline and orthoclase), 4 per cent. Magnetite, albite, 

 rutile inclosed in quartz, zircon, and hornblende are also present. 



No. 5 sand. — Minerals other than quartz, 10.8 per cent. Potash 

 feldspars (orthoclase), 5.7 per cent. Microcline, hornblende, and 

 garnet predominate. Zircon, diallage, magnetite, tourmaline, and 

 hypersthene are also present. 



