﻿Notes 
  upon 
  the 
  Litholooy 
  of 
  the 
  Adikondacks. 
  85 
  

  

  I 
  II 
  

  

  Titanic 
  Acid 
  5.73 
  0.75 
  

  

  Ignition 
  : 
  1 
  . 
  22 
  

  

  100.86 
  97.77 
  

  

  The 
  gabbro-norite 
  of 
  Scheerer 
  is 
  characterized 
  by 
  the 
  pre- 
  

   dominance 
  of 
  its 
  feldspathic 
  constituent, 
  which 
  is 
  aggregated 
  

   into 
  concretionary 
  masses, 
  the 
  augite 
  being 
  very 
  subordinate. 
  

   This 
  description 
  recalls 
  the 
  structure 
  of 
  the 
  orbicular- 
  diorite, 
  

   or 
  napoleonite, 
  of 
  Corsica, 
  which 
  consists 
  of 
  concretions 
  of 
  

   anorthite 
  and 
  hornblende, 
  together 
  with 
  some 
  quartz. 
  In 
  a 
  

   general 
  inspection 
  of 
  the 
  suite 
  of 
  Adirondack 
  rocks, 
  whose 
  

   particular 
  description 
  is 
  to 
  be 
  given 
  later, 
  the 
  most 
  striking 
  

   peculiarity 
  of 
  their 
  structure 
  is 
  a 
  similar 
  aggregation 
  of 
  the 
  

   feldspar, 
  and 
  sometimes 
  though 
  more 
  rarely 
  of 
  the 
  hyper- 
  

   sthenic 
  element, 
  into 
  masses 
  which 
  have 
  a 
  stratified 
  appearance, 
  

   arising 
  from 
  the 
  parallel 
  arrangement 
  of 
  the 
  constituent 
  

   minerals. 
  Moreover, 
  the 
  Canadian 
  norites, 
  according 
  to 
  Dr. 
  

   Hunt, 
  are 
  undoubtedly 
  a 
  bedded 
  rock, 
  and 
  also 
  the 
  mixtures 
  

   of 
  labradorite, 
  pyroxene 
  and 
  menaccanite, 
  described 
  by 
  

   Haughton 
  as 
  occurring 
  at 
  Loch 
  Scavig,* 
  and 
  whose 
  similarity 
  

   in 
  lithological 
  characters 
  to 
  the 
  Canadian 
  norites, 
  had 
  pre- 
  

   viously 
  been 
  noted.f 
  The 
  identity 
  of 
  these 
  rocks 
  with 
  those 
  of 
  

   Norway, 
  was 
  further 
  established 
  by 
  Dr. 
  Hunt 
  in 
  a 
  personal 
  

   examination 
  of 
  the 
  rocks, 
  sent 
  by 
  the 
  Royal 
  University 
  of 
  

   Christiania 
  to 
  the 
  Universal 
  Exhibition 
  at 
  Paris, 
  as 
  a 
  part 
  of 
  

   its 
  geological 
  display, 
  and 
  exhibited 
  under 
  the 
  name 
  of 
  norites. 
  

   In 
  a 
  printed 
  note 
  accompanying 
  this 
  collection 
  from 
  the 
  Uni- 
  

   versity, 
  it 
  is 
  said 
  that 
  the 
  numerous 
  varieties 
  of 
  rocks 
  consisting 
  

   of 
  labradorite 
  with 
  hypersthene, 
  diallage 
  and 
  bronzite, 
  have, 
  

   in 
  the 
  geological 
  map 
  of 
  Southern 
  Norway, 
  published 
  at 
  

   Christiania 
  in 
  1866, 
  been 
  designated 
  by 
  the 
  common 
  name 
  of 
  

   gabbro. 
  This 
  note 
  at 
  the 
  same 
  time 
  suggests 
  that 
  "the 
  name 
  

   of 
  norite 
  should 
  be 
  preserved 
  for 
  certain 
  varieties 
  of 
  gabbro 
  

   rich 
  in 
  labradorite, 
  which 
  varieties 
  may 
  in 
  great 
  part 
  with 
  

   justice 
  be 
  called 
  labradorite 
  rock, 
  since 
  labrador 
  feldspar 
  is 
  

   their 
  predominant 
  element." 
  If 
  along 
  with 
  labradorite, 
  the 
  

   other 
  related 
  triclinic 
  feldspars 
  from 
  anorthite 
  to 
  andesine 
  be 
  

   included, 
  the 
  term 
  norite 
  becomes 
  generically 
  descriptive 
  of 
  

  

  * 
  Dublin 
  Quarterly 
  Journal, 
  1865, 
  Haughton, 
  

  

  fib., 
  July, 
  1863, 
  T. 
  S. 
  Hunt, 
  quoted 
  in 
  Amer. 
  Jour. 
  Sci., 
  1870, 
  loc. 
  cit 
  

  

  