﻿398 
  PROP. 
  J. 
  D. 
  DANA 
  ON 
  THE 
  GEOLOGICAL 
  

  

  range 
  is 
  nearly 
  north 
  and 
  south 
  (about 
  K. 
  10° 
  E., 
  and 
  S. 
  10° 
  W.), 
  

   and 
  the 
  length 
  about 
  150 
  miles. 
  The 
  schists 
  make 
  the 
  centre 
  of 
  

   the 
  belt. 
  Against 
  nearly 
  all 
  the 
  eastern 
  side 
  of 
  these 
  schists 
  there 
  

   lies 
  a 
  stratum 
  of 
  crystalline 
  limestone 
  called 
  the 
  Stoclcbridge 
  Limestone 
  

   by 
  Prof. 
  Emmons 
  : 
  and 
  against 
  the 
  greater 
  part 
  of 
  the 
  -western, 
  

   another 
  range 
  of 
  limestone, 
  less 
  perfectly 
  crystalline, 
  the 
  Sparry 
  

   Limestone 
  of 
  Prof. 
  Emmons. 
  These 
  three 
  ranges 
  of 
  rocks 
  (the 
  cen- 
  

   tral 
  of 
  schists, 
  the 
  two 
  outer 
  of 
  limestone) 
  are 
  all 
  that 
  need 
  be 
  con- 
  

   sidered 
  : 
  for 
  the 
  question 
  is 
  only 
  this 
  — 
  are 
  these 
  strata 
  conformable, 
  

   or, 
  as 
  the 
  cited 
  paragraph 
  implies, 
  is 
  the 
  eastern 
  of 
  these 
  limestones 
  

   a 
  newer 
  rock 
  than 
  the 
  Taconic 
  schists, 
  and 
  unconformable 
  to 
  it 
  ? 
  

  

  It 
  is 
  plain, 
  from 
  these 
  statements 
  as 
  to 
  the 
  position 
  of 
  the 
  range, 
  

   that 
  the 
  opportunities 
  for 
  ascertaining 
  the 
  relation 
  in 
  stratification 
  

   of 
  the 
  Taconic 
  schists 
  and 
  the 
  adjoining 
  limestones 
  are 
  not 
  confined 
  

   to 
  a 
  single 
  disturbed 
  area. 
  They 
  occur 
  all 
  along 
  the 
  150 
  miles 
  ; 
  

   and 
  observations 
  have 
  been 
  made 
  from 
  the 
  northern 
  end 
  of 
  the 
  

   range 
  to 
  the 
  southern. 
  

  

  The 
  Taconic 
  range 
  or 
  belt 
  here 
  referred 
  to 
  does 
  not 
  include 
  all 
  

   the 
  slates 
  of 
  Western 
  New 
  England 
  and 
  Eastern 
  New 
  York 
  to 
  which 
  

   the 
  term 
  was 
  applied 
  by 
  Professor 
  Emmons. 
  But 
  it 
  does 
  include 
  

   those 
  slates 
  upon 
  which 
  the 
  system 
  was 
  founded. 
  He 
  says, 
  on 
  page 
  

   130 
  of 
  his 
  New- 
  York 
  Geological 
  Eeport, 
  already 
  referred 
  to 
  as 
  his 
  

   earliest 
  publication 
  on 
  the 
  subject 
  : 
  — 
  

  

  " 
  The 
  Taconic 
  system, 
  as 
  its 
  name 
  is 
  intended 
  to 
  indicate, 
  lies 
  

   along 
  both 
  sides 
  of 
  the 
  Taconic 
  range 
  of 
  mountains, 
  whose 
  direction 
  

   is 
  nearly 
  north 
  and 
  south, 
  or 
  for 
  a 
  great 
  distance 
  parallel 
  with 
  the 
  

   boundary 
  line 
  between 
  the 
  States 
  of 
  New 
  York, 
  Connecticut, 
  Massa- 
  

   chusetts, 
  and 
  Vermont. 
  The 
  counties 
  [of 
  New 
  York 
  State] 
  through 
  

   which 
  the 
  Taconic 
  rocks 
  pass 
  are 
  Westchester, 
  Columbia, 
  Eensselaer, 
  

   and 
  Washington 
  [or 
  those 
  directly 
  west 
  of 
  the 
  New 
  England 
  boun- 
  

   dary] 
  ; 
  and 
  after 
  passing 
  out 
  of 
  the 
  State, 
  they 
  are 
  found 
  stretching 
  

   through 
  the 
  whole 
  length 
  of 
  Vermont, 
  and 
  into 
  Canada 
  as 
  far 
  north 
  

   as 
  Quebec. 
  It 
  is, 
  however, 
  in 
  Massachusetts, 
  in 
  the 
  county 
  of 
  

   Berkshire 
  [the 
  western 
  county 
  of 
  the 
  State] 
  that 
  we 
  find 
  the 
  most 
  

   satisfactory 
  exhibition 
  of 
  these 
  rocks." 
  I 
  may 
  add 
  to 
  this 
  statement 
  

   of 
  his 
  that 
  it 
  was 
  in 
  the 
  north-western 
  part 
  of 
  the 
  State, 
  about 
  Wil- 
  

   liamstown 
  (long 
  Prof. 
  Emmons's 
  place 
  of 
  residence), 
  where 
  stands 
  its 
  

   highest 
  summit, 
  Graylock, 
  3505 
  feet 
  above 
  tide-level, 
  that 
  his 
  in- 
  

   vestigations 
  were 
  commenced. 
  

  

  We 
  have 
  no 
  occasion, 
  therefore, 
  for 
  taking 
  into 
  consideration 
  here 
  

   the 
  Taconic 
  slates 
  or 
  schists 
  and 
  associated 
  strata 
  of 
  Northern 
  Ver- 
  

   mont 
  and 
  Canada, 
  which 
  are 
  the 
  subject 
  of 
  papers 
  by 
  Mr. 
  Jules 
  

   Marcou 
  ; 
  or 
  the 
  " 
  black 
  slate 
  " 
  of 
  the 
  vicinity 
  of 
  Bald 
  Mountain, 
  N. 
  Y., 
  

   which 
  was 
  proved 
  by 
  its 
  fossils 
  to 
  be 
  primordial 
  ; 
  or 
  the 
  so-called 
  

   Taconics 
  of 
  other 
  States 
  or 
  countries. 
  

  

  The 
  stratigraphical 
  structure 
  of 
  the 
  Taconic 
  range 
  and 
  its 
  asso- 
  

   ciated 
  rocks 
  is 
  so 
  simple 
  that 
  all 
  observers 
  who 
  have 
  studied 
  it 
  have 
  

   described 
  the 
  schists 
  and 
  limestones 
  as 
  conformable. 
  

  

  In 
  1841, 
  Professors 
  W. 
  B. 
  and 
  H. 
  D. 
  Eogers 
  announced 
  before 
  

   the 
  American 
  Philosophical 
  Society 
  at 
  Philadelphia, 
  as 
  the 
  result 
  of 
  

  

  