﻿234 
  Lahee 
  — 
  New 
  Fossiliferous 
  Horizon 
  and 
  Underlying 
  

  

  2. 
  The 
  Fitch 
  Hill 
  granite 
  gneiss 
  is 
  intrusive 
  into 
  the 
  Lyman 
  

   schists, 
  but 
  unconformably 
  underlies 
  the 
  Niagaran 
  sediments 
  

   of 
  Fitch 
  Hill, 
  Littleton, 
  thus 
  demonstrating 
  the 
  presence 
  of 
  a 
  

   regional 
  unconformity 
  beneath 
  the 
  Upper 
  Silurian 
  strata 
  of 
  the 
  

   Ammonoosuc 
  district 
  in 
  New 
  Hampshire. 
  

  

  3. 
  The 
  limestone 
  near 
  the 
  base 
  of 
  this 
  Upper 
  Silurian 
  forma- 
  

   tion 
  is, 
  at 
  least 
  in 
  part, 
  a 
  conglomerate 
  composed 
  of 
  roundish 
  

   pebbles 
  of 
  crinoidal 
  limestone, 
  together 
  with 
  a 
  very 
  few 
  pebbles 
  

   of 
  granite, 
  in 
  a 
  highly 
  calcareous, 
  argillaceous, 
  coral-bearing 
  

   paste. 
  

  

  4. 
  Marine 
  fossils 
  of 
  Devonian 
  age 
  — 
  presumably 
  Lower 
  Devo- 
  

   nian 
  — 
  have 
  been 
  discovered 
  in 
  fine-grained 
  elastics 
  ('banded 
  

   argillites') 
  about 
  3000 
  feet 
  above 
  the 
  base 
  of 
  the 
  Upper 
  Silu- 
  

   rian 
  in 
  this 
  region. 
  These 
  Devonian 
  strata 
  may 
  be 
  followed 
  

   for 
  seven 
  or 
  eight 
  miles 
  along 
  their 
  strike, 
  but 
  they 
  grow 
  liner 
  

   and 
  more 
  metamorphosed 
  south 
  westward. 
  Fossils 
  have 
  been 
  

   found 
  in 
  them 
  at 
  four 
  localities 
  within 
  a 
  distance 
  of 
  five 
  miles 
  

   along 
  the 
  strike. 
  These 
  fossils 
  confirm 
  the 
  belief, 
  long 
  ago 
  

   stated, 
  of 
  a 
  seaway 
  situated 
  near 
  the 
  Connecticut 
  River 
  valley- 
  

   in 
  Devonian 
  times. 
  

  

  Geology 
  of 
  the 
  Fitch 
  Hill 
  Section. 
  

  

  In 
  fig. 
  3 
  is 
  shown 
  a 
  vertical 
  section 
  drawn 
  nearly 
  north 
  and 
  

   south 
  across 
  the 
  strikes 
  of 
  the 
  Fitch 
  Hill 
  rocks. 
  Its 
  position 
  is 
  

   indicated 
  in 
  fig. 
  2 
  by 
  the 
  line 
  A-A. 
  Its 
  southern 
  end 
  cuts 
  

   through 
  Fitch 
  Hill. 
  The 
  rocks 
  appearing 
  in 
  this 
  section 
  are 
  

   the 
  Lyman 
  schists, 
  the 
  Fitch 
  Hill 
  granite 
  gneiss, 
  and 
  a 
  group 
  

   of 
  strata 
  which 
  may 
  be 
  called 
  the 
  Blueberry 
  Mountain 
  series. 
  

  

  The 
  Lyman 
  schists. 
  — 
  The 
  terms 
  ' 
  Lyman 
  schists 
  ' 
  and 
  

   ' 
  Lyman 
  group 
  ' 
  were 
  applied 
  by 
  Professor 
  Hitchcock 
  to 
  a 
  

   body 
  of 
  'hydro-mica 
  and 
  chlorite 
  'schists' 
  which 
  in 
  his 
  earlier 
  

   report* 
  he 
  assigned 
  to 
  the 
  Huronian. 
  Writing 
  30 
  years 
  later,f 
  

   he 
  referred 
  the 
  group 
  to 
  the 
  Cambrian 
  or 
  Ordovician, 
  but 
  not 
  

   with 
  complete 
  assurance, 
  for 
  the 
  structural 
  relations 
  of 
  the 
  for- 
  

   mation 
  are 
  obscure 
  and 
  all 
  possible 
  evidence 
  of 
  fossils 
  has 
  been 
  

   destroyed 
  by 
  metamorphism. 
  

  

  These 
  Lyman 
  schists 
  outcrop 
  in 
  the 
  northern 
  corner 
  of 
  the 
  

   map 
  (fig. 
  2). 
  They 
  are 
  highly 
  metamorphosed 
  fine-grained 
  

   sandstones 
  and 
  mudstones, 
  with 
  a 
  few 
  beds 
  of 
  fine 
  conglom- 
  

   erate 
  in 
  which 
  the 
  pebbles, 
  all 
  angular 
  and 
  mashed, 
  are 
  hardly 
  

   distinguishable 
  from 
  the 
  paste. 
  Some 
  of 
  the 
  finer 
  schists 
  are 
  

   thinly 
  banded, 
  and 
  these 
  strata 
  bear 
  evidence 
  of 
  great 
  contor- 
  

   tion. 
  In 
  one 
  place 
  a 
  zone 
  of 
  crush-conglomerate 
  was 
  seen. 
  

  

  * 
  Hitchcock, 
  C. 
  H. 
  : 
  Geology 
  of 
  New 
  Hampshire, 
  vol. 
  ii, 
  p. 
  50, 
  etc., 
  1877. 
  

   Ibid., 
  Geology 
  of 
  Northern 
  New 
  England, 
  p. 
  12, 
  1874. 
  

  

  \ 
  Geology 
  of 
  Littleton, 
  New 
  Hampshire, 
  reprint 
  from 
  the 
  History 
  of 
  Lit- 
  

   tleton, 
  pp. 
  11 
  and 
  29, 
  1905. 
  

  

  