﻿Report 
  of 
  the 
  State 
  Geologist. 
  637 
  

  

  breaking 
  up 
  of 
  layers 
  of 
  gneiss 
  and 
  veins 
  of 
  pegmatite 
  by 
  power- 
  

   ful 
  dynamic 
  movements. 
  In 
  passing 
  from 
  TTestport, 
  witbin 
  a 
  

   sbort 
  distance 
  appeared 
  coarse 
  gabbro, 
  which 
  continued 
  as 
  far 
  as 
  

   tbe 
  region 
  was 
  penetrated 
  near 
  to 
  Mt. 
  Marcy. 
  Tbis 
  rock 
  in 
  tbe 
  

   interior 
  is 
  generally 
  massive, 
  but 
  on 
  its 
  outer 
  border 
  grades 
  into 
  

   a 
  regularly 
  laminated 
  rock, 
  in 
  exposures 
  very 
  closely 
  resembling 
  

   tbe 
  laminated 
  gneisses. 
  Tbe 
  wbole 
  is, 
  however, 
  clearly 
  an 
  eruptive 
  

   rock. 
  Granite 
  was 
  seen 
  locally 
  associated 
  with 
  the 
  gneisses." 
  

   (Bulletin 
  86 
  IT. 
  S. 
  Geol. 
  Survey, 
  p. 
  39S 
  and 
  33-34, 
  by 
  Yan 
  Hise. 
  

   See 
  also 
  Pumpelly, 
  Bull. 
  Geol. 
  Soc. 
  of 
  Amer., 
  II, 
  218, 
  1890.) 
  The 
  

   writer 
  has 
  not 
  studied 
  with 
  care 
  the 
  region 
  outside 
  of 
  Essex 
  

   county, 
  but 
  if 
  the 
  above 
  reference 
  to 
  the 
  contacts 
  between 
  the 
  

   crystalline 
  limestones 
  and 
  the 
  black 
  hornblendic 
  gneiss 
  includes 
  

   the 
  exposures 
  on 
  the 
  lake 
  shore 
  just 
  above 
  Port 
  Henry, 
  the 
  

   gneiss 
  can 
  be 
  traced 
  directly 
  into 
  massive 
  olivine 
  gabbro, 
  and 
  the 
  

   contact 
  is 
  regarded 
  by 
  him 
  (J. 
  F. 
  K.) 
  as 
  an 
  eruptive 
  one, 
  the 
  

   gabbro 
  being 
  later. 
  Subsequent 
  dynamic 
  disturbances 
  have 
  

   mixed 
  them 
  up, 
  and 
  especially 
  stretched 
  away 
  from 
  the 
  parent 
  

   gabbro-ramifying 
  apophysae. 
  

  

  C. 
  H. 
  Smyth, 
  Jr., 
  in 
  a 
  recent 
  paper 
  on 
  the 
  Geology 
  of 
  Gouver- 
  

   neur, 
  on 
  the 
  western 
  side 
  of 
  the 
  mountains, 
  mentions 
  I, 
  basal 
  

   gneiss 
  which 
  is 
  associated 
  with 
  igneous 
  granite 
  ; 
  II, 
  crystalline 
  

   limestone 
  with 
  some 
  black 
  schists 
  at 
  its 
  base, 
  but 
  without 
  serpen- 
  

   tinous 
  limestone, 
  and 
  above 
  this 
  the 
  Potsdam. 
  (Trans. 
  X. 
  Y. 
  

   Acad. 
  Sci, 
  XII, 
  97, 
  Feb., 
  1893.) 
  

  

  Before 
  leaving 
  this 
  brief 
  statement 
  of 
  previous 
  attempts 
  at 
  

   classification, 
  reference 
  should 
  be 
  made 
  to 
  the 
  arrangement 
  

   generally 
  accepted 
  in 
  Canada, 
  which 
  dates 
  from 
  Logan's 
  Keport 
  

   for 
  1863. 
  The 
  Lauren 
  tian 
  is 
  divided 
  into, 
  I. 
  The 
  Ottawa 
  or 
  

   Fundamental 
  gneiss 
  of 
  all 
  varieties 
  of 
  orthoclase-gneiss, 
  often 
  

   quite 
  massive 
  in 
  character 
  ; 
  II. 
  The 
  Grenville 
  series 
  of 
  crystal- 
  

   line 
  limestones, 
  quartzites, 
  amphibolites, 
  garnetiferous 
  gneiss, 
  and 
  

   other 
  minor 
  varieties; 
  III. 
  The 
  Upper 
  Laurentian 
  or 
  dorian 
  series 
  of 
  

   igneous 
  rocks, 
  members 
  of 
  the 
  gabbro 
  family. 
  (See 
  F. 
  D. 
  Adams, 
  

   Neues 
  Jahrbuch, 
  Beil. 
  Band 
  Till, 
  421-127, 
  1893, 
  and 
  Journal 
  of 
  

   Geology, 
  I, 
  325.) 
  

  

  In 
  the 
  following 
  report 
  much 
  the 
  same 
  general 
  division 
  is 
  made 
  

   as 
  this 
  one 
  of 
  Logan, 
  for 
  it 
  is 
  most 
  nearly 
  applicable, 
  although 
  evi- 
  

   dence 
  regarding 
  the 
  succession 
  is 
  not 
  easily 
  attainable. 
  As 
  before 
  

  

  