﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  3I 
  

  

  AMPHIBOLITES 
  AND 
  PYROXENITES. 
  

  

  Intercalated 
  with 
  the 
  Manhattan 
  schist 
  and 
  also 
  with 
  the 
  beds 
  of 
  

   the 
  Fordham 
  gneiss 
  we 
  find 
  at 
  a 
  great 
  number 
  of 
  localities 
  on 
  New 
  

   York 
  Island 
  and 
  in 
  Westchester 
  county, 
  hornblendic 
  and 
  augitic 
  

   bands 
  and 
  lenses 
  of 
  Hmited 
  thickness, 
  usually 
  only 
  a 
  few 
  feet. 
  In 
  

   composition, 
  these 
  rocks 
  resemble 
  dioriies 
  and 
  diabases, 
  and 
  in 
  

   structure 
  they 
  are 
  granular, 
  and 
  though 
  they 
  are 
  at 
  present 
  in 
  a 
  

   foliated 
  condition, 
  their 
  general 
  characters 
  suggest 
  that 
  they 
  were 
  

   originally 
  eruptive 
  rocks. 
  Locally 
  the 
  magnesian 
  silicates 
  in 
  these 
  

   rocks 
  are 
  altered 
  into 
  epidote. 
  

  

  SERPENTINES. 
  

  

  A 
  large 
  number 
  of 
  observations 
  have 
  been 
  made 
  on 
  these 
  inter- 
  

   esting 
  rocks, 
  the 
  result 
  of 
  which 
  are 
  given 
  in 
  the 
  following 
  paper. 
  

  

  