﻿BOUNDARIES. 
  35 
  

  

  which 
  is 
  owing 
  the 
  outcrop 
  of 
  the 
  Sitariva 
  coal-field. 
  The 
  last 
  beds 
  

   seen 
  in 
  the 
  river 
  are 
  massive 
  coarse 
  conglomerates, 
  quite 
  vertical 
  ; 
  and 
  

   this, 
  too, 
  is 
  nearly 
  on 
  a 
  line 
  with 
  the 
  outer 
  fringe 
  of 
  the 
  metamorphics. 
  

   The 
  anticlinal 
  flattens 
  rapidly 
  to 
  the 
  east, 
  obliquely 
  to 
  the 
  general 
  strike 
  

   of 
  the 
  rocks 
  : 
  in 
  the 
  most 
  northerly 
  outcrop 
  seen, 
  at 
  Pakuhi, 
  on 
  the 
  

   run 
  of 
  the 
  outermost 
  beds 
  in 
  the 
  Sitariva, 
  and 
  only 
  one 
  and 
  a 
  half 
  

   miles 
  to 
  east, 
  the 
  dip 
  is 
  south-easterly. 
  

  

  The 
  fact 
  of 
  special 
  disturbance 
  along 
  the 
  boundary 
  conveys 
  as 
  posi- 
  

   tive 
  an 
  indication, 
  as 
  does 
  the 
  presence 
  of 
  peculiar 
  

  

  Wbat 
  it 
  may 
  signify. 
  

  

  deposits, 
  that 
  the 
  present 
  limit 
  to 
  the 
  extension 
  of 
  

  

  the 
  sedimentaries 
  at 
  this 
  blank 
  boundary 
  is 
  not 
  due 
  merely 
  to 
  denuda- 
  

   tion 
  — 
  that 
  the 
  deposits 
  were 
  especially 
  affected 
  by 
  other 
  rocks 
  in 
  this 
  

   position 
  ; 
  but 
  it 
  leaves 
  it 
  an 
  open 
  question 
  whether 
  this 
  were 
  due 
  to 
  

   original 
  conditions 
  or 
  to 
  subsequent 
  faulting. 
  The 
  coincidence 
  of 
  the 
  

   evidence 
  from 
  the 
  composition 
  of 
  the 
  rocks 
  gives, 
  of 
  course, 
  a 
  presump- 
  

   tion 
  in 
  favor 
  of 
  the 
  former 
  supposition 
  ; 
  in 
  accordance 
  with 
  which 
  view 
  

   a 
  figured 
  section 
  was 
  given 
  in 
  my 
  report 
  on 
  this 
  coal-field 
  at 
  page 
  65, 
  

   Vol. 
  iii, 
  of 
  the 
  Records, 
  Geological 
  Survey. 
  Whatever 
  the 
  structure 
  may 
  

   be 
  in 
  the 
  concealed 
  ground 
  to 
  the 
  north 
  of 
  the 
  exposed 
  section, 
  the 
  

   flexure 
  we 
  see 
  would 
  be 
  fully 
  accounted 
  for 
  by 
  simple 
  compression 
  ; 
  and 
  

   it 
  necessarily 
  implies 
  compression 
  whatever 
  other 
  effects 
  may 
  have 
  been 
  

   associated 
  with 
  this. 
  Any 
  argument 
  for 
  faulting 
  must, 
  therefore, 
  be 
  

   purely 
  conjectural, 
  there 
  being 
  no 
  direct 
  evidence 
  whatever. 
  If, 
  however, 
  

   the 
  feature 
  is 
  to 
  any 
  dominant 
  extent 
  due 
  to 
  faulting, 
  and 
  if 
  the 
  flexure 
  

   seen 
  continues 
  up 
  to 
  the 
  fault, 
  this 
  form 
  of 
  contortion 
  would 
  suggest 
  

   a 
  downthrow 
  to 
  the 
  north, 
  the 
  edges 
  of 
  the 
  broken 
  beds 
  on 
  the 
  south 
  

   being 
  turned 
  down 
  along 
  the 
  direction 
  of 
  relative 
  motion. 
  But 
  a 
  down- 
  

   throw 
  to 
  the 
  north, 
  unless 
  succeeded 
  by 
  an 
  upthrow 
  of 
  greater 
  amount, 
  

   would, 
  unless 
  the 
  fault 
  had 
  occurred 
  along 
  a 
  bank 
  of 
  deposition, 
  imply 
  

   the 
  present 
  existence, 
  to 
  the 
  north 
  of 
  the 
  fault, 
  of 
  a 
  more 
  complete, 
  at 
  

   least, 
  a 
  less 
  denuded, 
  series 
  of 
  the 
  sedimentaries 
  than 
  to 
  the 
  south 
  ; 
  and 
  

  

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