﻿638 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  stated, 
  this 
  is 
  rather 
  a 
  report 
  of 
  progress 
  than 
  a 
  final 
  word 
  on 
  the 
  

   subject, 
  and 
  deals 
  with 
  the 
  stratigraphy 
  of 
  the 
  most 
  difficult 
  

   district. 
  The 
  best 
  exposures 
  of 
  the 
  gneiss 
  and 
  crystalline 
  lime- 
  

   stone 
  series 
  will 
  be 
  met 
  in 
  the 
  country 
  more 
  remote 
  from 
  the 
  

   Norian. 
  It 
  is 
  not 
  certain 
  that 
  we 
  have 
  the 
  Ottawa 
  gneiss, 
  for 
  our 
  

   gneisses 
  have 
  magnetite 
  beds 
  which 
  in 
  Canada 
  are 
  limited 
  to 
  the 
  

   Grenville 
  series. 
  

  

  We 
  have; 
  I. 
  A 
  gneiss 
  series 
  consisting 
  of 
  orthoclase 
  gneisses, 
  

   usually 
  laaminated, 
  but 
  at 
  times 
  quite 
  massive. 
  They 
  almost 
  

   always 
  contain 
  quartz. 
  There 
  are 
  varieties 
  with 
  hornblende, 
  

   biotite 
  and 
  with 
  almost 
  no 
  dark 
  silicate, 
  but 
  one 
  of 
  the 
  common- 
  

   est 
  of 
  all, 
  and 
  that 
  chiefly 
  associated 
  with 
  the 
  Moriah 
  mag- 
  

   netites, 
  contains 
  an 
  emerald 
  green 
  monoclinic 
  pyroxene. 
  Faint 
  

   pink 
  garnet 
  is 
  occasionally 
  met. 
  The 
  orthoclase 
  is 
  almost 
  inva- 
  

   riably 
  microperthitic. 
  Plagioclase 
  is 
  frequent 
  but 
  is 
  subordi- 
  

   nate. 
  Quartz 
  may 
  largely 
  fail 
  and 
  aggregates 
  of 
  orthoclase, 
  

   brown 
  hornblende 
  and 
  pyroxene, 
  with 
  subordinate 
  plagioclase 
  

   result, 
  as 
  in 
  the 
  great 
  gneiss 
  ridges 
  that 
  enter 
  southeastern 
  Ticon- 
  

   deroga 
  from 
  the 
  south. 
  

  

  The 
  rocks 
  are 
  red 
  and 
  gray 
  in 
  typical 
  specimens, 
  and 
  in 
  those 
  

   lacking 
  dark 
  silicates 
  even 
  very 
  light 
  colored. 
  In 
  the 
  more 
  basic 
  

   varieties 
  they 
  are 
  darker 
  and 
  dioritic 
  in 
  appearance. 
  

  

  The 
  rocks 
  of 
  this 
  series 
  contain 
  the 
  workable 
  iron 
  ores. 
  

  

  II. 
  A 
  series 
  of 
  crystalline 
  limestone, 
  ophicalcites, 
  black 
  horn- 
  

   blendic-pyroxenic 
  schists 
  and 
  thinly 
  laminated 
  garnetiferous 
  

   gneisses. 
  Great 
  pegmatite 
  veins 
  are 
  a 
  frequent 
  associate 
  of 
  these 
  

   rocks. 
  The 
  limestone 
  beds 
  are 
  sometimes 
  quite 
  thick, 
  50 
  to 
  100 
  

   feet, 
  as 
  in 
  Port 
  Henry, 
  but 
  they 
  are 
  seldom 
  continuous 
  for 
  any 
  

   great 
  distance 
  and 
  are 
  broken 
  by 
  great 
  horses 
  of 
  silicates 
  with 
  very 
  

   complex 
  aggregates 
  of 
  minerals. 
  The 
  alternation 
  of 
  the 
  limestone 
  

   with 
  the 
  black 
  schists* 
  is 
  often 
  many 
  times 
  repeated. 
  Ophicalcite 
  is 
  

   abundant 
  in 
  Moriah. 
  Coccolite 
  is 
  a 
  characteristic 
  associate, 
  and 
  

   granular 
  masses 
  of 
  pyroxene 
  are 
  often 
  met. 
  Graphite 
  is 
  

   nearly 
  universal. 
  Scapolite 
  is 
  a 
  common 
  mineral 
  in 
  the 
  black 
  

   schists. 
  The 
  beds 
  give 
  every 
  evidence 
  of 
  intense 
  dynamic 
  dis- 
  

   turbances 
  and 
  have 
  often 
  suffered 
  from 
  the 
  intrusion 
  of 
  gabbros, 
  

   if, 
  indeed, 
  the 
  black 
  schists 
  themselves 
  are 
  not 
  metamorphosed 
  

   gabbro-sheets. 
  Quartzite, 
  or 
  any 
  related 
  rock, 
  has 
  thus 
  far 
  not 
  

   been 
  met, 
  unless 
  the 
  granulite 
  of 
  the 
  "Weston 
  iron 
  mines 
  in 
  Keene 
  

  

  