﻿566 
  TEOF. 
  C. 
  LAPWOETH 
  *ON 
  THE 
  GIBVAX 
  SUCCESSION. 
  

  

  along 
  this 
  extended 
  line 
  is 
  that 
  visible 
  in 
  the 
  west 
  glen 
  of 
  Dupin, 
  

   a 
  short 
  distance 
  above 
  the 
  edge 
  of 
  the 
  alluvial 
  trough 
  of 
  the 
  Assel 
  

   opposite 
  the 
  great 
  lime-quarry 
  of 
  Trainitchell. 
  

  

  (1) 
  Dupin 
  West 
  Burn 
  (fig. 
  3). 
  — 
  About 
  a 
  quarter 
  of 
  a 
  mile 
  above 
  

   the 
  mouth 
  of 
  the 
  little 
  stream 
  of 
  the 
  glen, 
  coarse 
  dark-green 
  conglo- 
  

   merates 
  are 
  visible 
  on 
  its 
  banks, 
  dipping 
  at 
  varying 
  angles 
  to 
  the 
  

   southward, 
  and 
  apparently 
  continued 
  uninterruptedly 
  above 
  to 
  the 
  

   summit 
  of 
  the 
  Benan 
  ridge. 
  A 
  few 
  yards 
  below 
  the 
  most 
  northerly 
  

   of 
  these 
  exposures, 
  thick 
  beds 
  of 
  flaggy 
  limestone 
  are 
  seen 
  plunging 
  

   into 
  the 
  hill-face 
  at 
  the 
  same 
  general 
  angle 
  of 
  inclination 
  as 
  the 
  

   green 
  conglomerates. 
  Where 
  they 
  cross 
  the 
  glen 
  these 
  limestones 
  

   give 
  origin 
  to 
  the 
  small 
  waterfall 
  of 
  Dupin 
  Linn. 
  They 
  are 
  fairly 
  

   exhibited 
  to 
  a 
  depth 
  of 
  about 
  thirty 
  feet, 
  and 
  repose 
  upon 
  a 
  similar 
  

   thickness 
  of 
  flaggy 
  and 
  more 
  or 
  less 
  impurely 
  calcareous 
  beds, 
  

   clearly 
  the 
  Maclurea-beds 
  ( 
  Ab") 
  of 
  our 
  typical 
  sections 
  of 
  the 
  Stinchar 
  

   valley. 
  These 
  are 
  underlain 
  in 
  their 
  turn 
  by 
  nodular 
  calcareous 
  

   flags 
  (Ab 
  1 
  ), 
  which 
  yield 
  examples 
  of 
  Orthis 
  eonfinis, 
  Slropliomena 
  

   eocpansa, 
  Illcenus, 
  &c. 
  Next 
  follow 
  the 
  unfossiliferous 
  Transitional 
  

   Sandstones 
  (Aa 
  2 
  ), 
  which 
  graduate 
  downwards 
  in 
  their 
  turn 
  into 
  

   purple 
  and 
  green 
  Conglomerates 
  (Aa 
  1 
  ), 
  varied 
  with 
  calcareous 
  seams. 
  

   In 
  other 
  words, 
  if 
  we 
  except 
  the 
  easily 
  eroded 
  Didymograptus-^haleB, 
  

   which 
  are 
  obscured 
  by 
  gravel, 
  we 
  find 
  that 
  all 
  the 
  members 
  of 
  the 
  

   Calcareous 
  series 
  which 
  we 
  have 
  studied 
  to 
  the 
  southward 
  are 
  

   visible 
  at 
  this 
  locality 
  in 
  their 
  natural 
  order 
  and 
  with 
  their 
  relative 
  

   thickness. 
  

  

  Fig. 
  4. 
  — 
  Section 
  of 
  the 
  Strata 
  of 
  Dupin 
  Mid 
  Bum. 
  

  

  S.E. 
  

  

  N.W. 
  

  

  Ac. 
  Benan 
  Conglomerate 
  in 
  its 
  typical 
  form. 
  

  

  Ac*. 
  Conglomerate 
  with 
  limestone 
  nodules. 
  

  

  Ab 
  4 
  . 
  Green 
  calcareous 
  shales 
  with 
  Graptolites 
  and 
  Ling 
  vice. 
  

  

  Ab. 
  Limestones 
  much 
  distorted 
  and 
  faulted. 
  

  

  A 
  ?. 
  Green 
  and 
  grey 
  flaggy 
  Sandstones. 
  

  

  (2) 
  Dupin 
  Mid 
  Bum 
  (fig. 
  4). 
  — 
  The 
  limestone 
  of 
  Dupin 
  Linn 
  may 
  

   be 
  followed 
  across 
  the 
  grass-grown 
  slopes 
  to 
  the 
  north-eastward 
  into 
  

   the 
  succeeding 
  stream-course 
  in 
  that 
  direction, 
  where 
  a 
  second 
  expo- 
  

   sure 
  of 
  the 
  band 
  is 
  laid 
  open. 
  Short 
  as 
  is 
  the 
  interval, 
  the 
  strata 
  

   are 
  much 
  shattered 
  and 
  disjointed 
  by 
  small 
  faults, 
  and 
  in 
  the 
  stream- 
  

   bed 
  itself 
  only 
  fragments 
  of 
  the 
  band 
  are 
  visible. 
  The 
  highest 
  strata 
  

   seen 
  are 
  the 
  coarse 
  boulder-beds 
  of 
  the 
  great 
  Benan 
  Conglomerates 
  

   (Ac) 
  of 
  the 
  usual 
  character. 
  The 
  lowest 
  bed 
  of 
  the 
  Conglo- 
  

   merate 
  (Ac*) 
  is 
  here 
  filled 
  with 
  rounded 
  nodules 
  of 
  limestone. 
  To 
  

   judge 
  from 
  the 
  appearances 
  observed, 
  it 
  is 
  evident 
  that 
  these 
  

   enclosures 
  have 
  not 
  been 
  derived 
  from 
  a 
  local 
  erosion 
  of 
  the 
  inferior 
  

   limestone, 
  but 
  that 
  there 
  has 
  been 
  a 
  distinct 
  continuation 
  of 
  the 
  

  

  