﻿274 
  

  

  Galloway 
  — 
  Hounding 
  of 
  Sand 
  by 
  Solution. 
  

  

  Garnets, 
  feldspars, 
  magnetite, 
  hornblende, 
  tourmaline, 
  

   zircon 
  and 
  apatite 
  are 
  more 
  soluble 
  in 
  water 
  than 
  pure 
  

   quartz, 
  as 
  proven 
  by 
  the 
  fact 
  that 
  quartz 
  remains 
  when 
  

   every 
  other 
  mineral 
  is 
  removed, 
  and 
  should 
  more 
  often 
  

   occur 
  in 
  rounded 
  forms. 
  I 
  have 
  seen 
  rounded 
  grains 
  of 
  

   these 
  minerals 
  and 
  of 
  smoky 
  quartz 
  varying 
  from 
  -05 
  to 
  

   •1 
  mm. 
  in 
  diameter 
  in 
  young 
  beach 
  sand 
  from 
  Rockaway, 
  

   L. 
  I., 
  the 
  smallest 
  grains 
  of 
  which 
  are 
  shown 
  in 
  fig. 
  2. 
  

  

  Fig. 
  3. 
  

  

  Fig. 
  3. 
  Grains 
  from 
  the 
  same 
  sand 
  as 
  that 
  shown 
  in 
  Fig. 
  2, 
  varying 
  

   from 
  -1 
  to 
  -2 
  mm. 
  in 
  diameter. 
  Note 
  that 
  fewer 
  of 
  the 
  grains 
  are 
  rounded 
  

   than 
  in 
  the 
  finer 
  sand. 
  Transmitted 
  light. 
  X 
  50. 
  

  

  Grains 
  of 
  the 
  same 
  minerals 
  from 
  -1 
  to 
  -2 
  mm. 
  in 
  diameter 
  

   are 
  much 
  less 
  rounded 
  in 
  the 
  same 
  sand, 
  as 
  illustrated 
  

   in 
  fig. 
  3. 
  The 
  smallest 
  grains 
  were 
  probably 
  mostly 
  

   rounded 
  by 
  solution, 
  for 
  the 
  larger 
  the 
  grain 
  the 
  more 
  the 
  

   abrasion 
  both 
  in 
  water 
  and 
  in 
  wind, 
  although 
  abrasion 
  

   and 
  the 
  original 
  roundish 
  form 
  partly 
  account 
  for 
  the 
  

   present 
  outlines. 
  The 
  surfaces 
  of 
  the 
  rounded 
  grains 
  

   have 
  a 
  dull, 
  corroded 
  appearance 
  when 
  seen 
  by 
  reflected 
  

   light, 
  probably 
  indicating 
  their 
  production 
  both 
  by 
  solu- 
  

  

  