﻿638 
  PJK0E. 
  C. 
  LAPWORTH 
  ON 
  THE 
  GIRVAtf 
  SUCCESSION-. 
  

  

  1. 
  Shalloch 
  Forge. 
  — 
  At 
  the 
  back 
  of 
  the 
  blacksmith's 
  shop 
  of 
  

   Shalloch, 
  where 
  the 
  Braehill 
  fault 
  comes 
  upon 
  the 
  sea-shore, 
  we 
  find 
  

   excellent 
  exposures 
  of 
  the 
  strata 
  of 
  this 
  conspicuous 
  protecting 
  

   series. 
  The 
  general 
  succession 
  there 
  apparent 
  is 
  given 
  in 
  the 
  following 
  

   section 
  (fig. 
  26). 
  

  

  Fig. 
  26.— 
  Section 
  of 
  the 
  Rods 
  of 
  Shulloch 
  Forge. 
  

  

  B. 
  Arc! 
  mil 
  Ian 
  Series 
  : 
  — 
  

  

  Be. 
  Barren 
  flagstones. 
  

  

  C. 
  Newlands 
  Series 
  :— 
  

  

  Cba. 
  Woodland 
  beds. 
  

  

  Cba 
  1 
  . 
  Coarse 
  green 
  boulder-conglomerate 
  of 
  Craigskelly. 
  

   Cba~. 
  Coralline 
  limestone, 
  with 
  Pentamems 
  oblongus 
  &c. 
  

   Oba 
  8 
  . 
  Striped 
  shales, 
  with 
  -Diplograptus 
  onodestus, 
  Monograptus 
  

   leptofheca, 
  &c. 
  

   Cc. 
  Saugh-Hill 
  beds. 
  

  

  Cc 
  1 
  . 
  Quartz 
  conglomerate 
  of 
  Shalloch 
  Forge. 
  

   ff. 
  Faults. 
  

  

  The 
  beds 
  which 
  have 
  the 
  appearance 
  of 
  being 
  lowest 
  in 
  the 
  succes- 
  

   sion 
  are 
  certain 
  green 
  flagstones 
  and 
  shales 
  (Be), 
  lithologically 
  similar 
  

   to 
  those 
  of 
  the 
  Barren 
  Flagstones 
  of 
  the 
  Ardmillan 
  group 
  and 
  the 
  

   green 
  flagstones 
  occasionally 
  found 
  in 
  the 
  Graptolitiferous 
  zones 
  of 
  

   the 
  Saugh-Hill 
  beds. 
  They 
  are 
  only 
  seen 
  at 
  low 
  water, 
  imme- 
  

   diately 
  to 
  the 
  south 
  of 
  the 
  rugged 
  boss 
  of 
  the 
  Horse 
  Rock, 
  which 
  at 
  

   high 
  tide 
  forms 
  the 
  most 
  northerly 
  of 
  the 
  protecting 
  fringe 
  of 
  islands 
  

   already 
  referred 
  to. 
  Of 
  these 
  green 
  flagstones 
  only 
  about 
  30 
  feet 
  

   are 
  seen, 
  and 
  they 
  dip 
  at 
  an 
  angle 
  of 
  about 
  45 
  degrees 
  to 
  the 
  north- 
  

   ward, 
  and 
  are 
  succeeded, 
  with 
  a 
  slight 
  unconformity, 
  by 
  the 
  remark- 
  

   able 
  mass 
  of 
  boulder 
  conglomerate 
  of 
  which 
  the 
  Horse 
  Rock 
  itself 
  

   is 
  made 
  up. 
  This 
  conglomerate 
  is 
  from 
  50 
  to 
  60 
  feet 
  in 
  total 
  thick- 
  

   ness, 
  and 
  contains 
  many 
  interbedded 
  seams 
  of 
  gritstones, 
  which 
  show 
  

   that 
  the 
  general 
  inclination 
  of 
  the 
  rock 
  is 
  almost 
  identical 
  with 
  that 
  

   of 
  the 
  flagstones 
  below. 
  The 
  main 
  mass 
  of 
  the 
  conglomerate 
  is 
  

   made 
  up 
  of 
  well-rounded 
  boulders 
  varying 
  from 
  one 
  inch 
  to 
  a 
  foot 
  

   and 
  a 
  half 
  in 
  diameter. 
  They 
  consist 
  of 
  pieces 
  of 
  granite, 
  porphyry, 
  

   fclstone, 
  greywacke, 
  shale, 
  Lydian 
  stone, 
  quartz, 
  and 
  jasper, 
  imbedded 
  

   in 
  a 
  coarse 
  sandy 
  matrix 
  of 
  a 
  dark 
  green 
  colour 
  and 
  excessively 
  

   indurated. 
  In 
  its 
  general 
  aspect 
  the 
  rock 
  reminds 
  us 
  of 
  the 
  Benan 
  

   Conglomerate, 
  and 
  also 
  in 
  the 
  special 
  association 
  of 
  its 
  enclosed 
  

   boulders, 
  but 
  it 
  is 
  altogether 
  harder 
  and 
  much 
  more 
  firmly 
  com- 
  

   pacted 
  than 
  is 
  generally 
  the 
  case 
  with 
  that 
  deposit. 
  

  

  Above 
  this 
  Horse-Rock 
  conglomerate 
  there 
  is 
  a 
  break 
  in 
  the 
  

  

  