﻿GEOLOGY 
  OF 
  THE 
  NORTH 
  GREEK 
  QUADRANGLE 
  

  

  17 
  

  

  

  

  

  

  

  

  TABLE 
  

  

  I 
  

  

  

  

  

  

  

  

  

  

  

  

  

  Pyroxene 
  syenite 
  

  

  

  

  

  

  

  D 
  

  

  <D 
  

  

  IS 
  

  

  V 
  

  

  0) 
  

  

  

  4) 
  

   13 
  

  

  

  .3§ 
  

  

  

  

  

  

  

  

  

  *o 
  

   

  

  O 
  

  

  O 
  

  

  l-l 
  

   O 
  

  

  0) 
  

   ft 
  

  

  O 
  

  

  

   <5 
  

  

  J2 
  

   "0 
  

   

   "be 
  

   cd 
  

  

  Oh 
  

  

  O 
  

  

  a 
  

   

  

  O 
  

  

  

  

  a 
  

   

  

  a 
  

  

  bo 
  

  

  "0 
  

  

  (S3 
  

  

  ft 
  

   < 
  

  

  a 
  

  

  

  

  8 
  

  

  'u 
  

   >. 
  

  

  Ph 
  

  

  0) 
  

  

  1 
  

  

  

  

  

  

  

  Ol-Lab 
  

  

  

  

  

  

  

  

  

  

  

  

  I 
  

  

  17 
  

   13 
  

  

  25 
  

   15 
  

  

  

  

  55 
  

   01 
  

   14 
  

  

  12 
  

  

  

  5 
  

  

  25 
  

  

  10 
  

  

  2 
  

  

  i 
  

  

  1 
  

  

  1 
  

  

  

  

  2 
  

  

  25 
  

  

  15 
  

  

  t8 
  

  

  1 
  

  

  

  1 
  

  

  1 
  

  

  1 
  

  

  

  

  

  01 
  

  

  

  

  

  

  

  

  

  

  

  

  3 
  

  

  14 
  

  

  25 
  

  

  25 
  

  

  

  5 
  

  

  20 
  

  

  8 
  

  

  

  15 
  

  

  

  1 
  

   2 
  

  

  1 
  

   4 
  

  

  1 
  

   4 
  

  

  little 
  

  

  

  

  

  

  

  Granitic 
  hornblende 
  syenite 
  

  

  

  

  

  

  

  

  

  

  01 
  

  

  

  

  

  

  

  

  

  

  

  

  4 
  

  

  15 
  

  

  25 
  

  

  25 
  

  

  

  6 
  

  

  22 
  

  

  t8 
  

  

  2 
  

  

  

  

  I 
  

  

  1 
  

  

  1 
  

  

  

  

  

  

  01 
  

  

  

  

  

  

  

  

  

  

  

  

  5 
  

   6 
  

  

  34 
  

  

  12 
  

  

  5 
  

   10 
  

  

  50 
  

   35 
  

   65 
  

  

  

  5 
  

   01 
  

   12 
  

  

  24 
  

  

  25 
  

  

  25 
  

  

  12 
  

  

  

  

  

  I 
  

  

  1 
  

  

  1 
  

  

  

  1 
  

  

  2 
  

  

  14 
  

  

  1 
  

   2 
  

  

  

  

  

  1 
  

  

  2 
  

  

  1 
  

   2 
  

  

  little 
  

  

  \ 
  

  

  little 
  

  

  

  

  7 
  

  

  16 
  

  

  5 
  

  

  

  01 
  

   3 
  

  

  1 
  

   2 
  

  

  

  2 
  

  

  

  

  

  

  

  

  The 
  color 
  of 
  the 
  fresh 
  rock 
  is 
  the 
  usual 
  greenish 
  gray 
  of 
  the 
  

   Adirondack 
  syenites, 
  while 
  the 
  weathered 
  surfaces 
  are 
  of 
  yellowish 
  

   brown 
  to 
  brown 
  color. 
  Because 
  of 
  vigorous 
  glaciation 
  even 
  the 
  

   weathered 
  surfaces 
  are' 
  hard, 
  decomposed 
  rock 
  seldom 
  being 
  seen 
  

   except 
  in 
  a 
  few 
  protected 
  places 
  on 
  the 
  south 
  sides 
  of 
  mountains. 
  

   Below 
  this 
  weathered 
  surface 
  it 
  is 
  usually 
  not 
  more 
  than 
  a 
  few 
  

   inches 
  to 
  the 
  fresh 
  greenish 
  gray 
  rock. 
  

  

  That 
  the 
  syenite 
  has 
  been 
  intruded 
  into 
  the 
  Grenville 
  is 
  abund- 
  

   antly 
  proved 
  by 
  the 
  many 
  inclusions 
  of 
  all 
  sorts 
  of 
  Grenville 
  rocks, 
  

   but 
  most 
  of 
  these 
  are 
  too 
  small 
  to 
  be 
  represented 
  on 
  the 
  geologic 
  

   map. 
  Some 
  of 
  the 
  best 
  examples 
  of 
  Grenville 
  inclusions 
  are 
  to 
  be 
  

   found 
  in 
  the 
  mixed 
  gneiss 
  areas 
  which 
  will 
  be 
  described 
  below. 
  

  

  Pyroxene 
  syenite. 
  This 
  syenite 
  represents 
  the 
  most 
  basic 
  facies 
  

   of 
  the 
  great 
  syenite-granite 
  intrusive 
  mass. 
  The 
  generally 
  faint 
  

   development 
  of 
  gneissoid 
  structure, 
  low 
  quartz 
  and 
  hornblende 
  con- 
  

   tents, 
  and 
  the 
  presence 
  of 
  pyroxene 
  are 
  the 
  chief 
  differences 
  be- 
  

   tween 
  this 
  and 
  the 
  granitic 
  hornblende 
  syenite. 
  The 
  range 
  in 
  com- 
  

   position 
  is 
  well 
  brought 
  out 
  in 
  table 
  1 
  which 
  represents 
  thin 
  sections 
  

   of 
  carefully 
  selected 
  samples. 
  The 
  pyroxene 
  is 
  seen 
  to 
  be 
  the 
  

   most 
  characteristic 
  mineral 
  of 
  the 
  rock. 
  This 
  pyroxene 
  is 
  of 
  a 
  

   beautiful 
  green 
  color, 
  clearly 
  monoclinic, 
  and 
  shows 
  good 
  cleavages. 
  

  

  