﻿PKOE. 
  C. 
  LAPWOKTH 
  ON 
  THE 
  GIRVAN 
  SUCCESSION. 
  651 
  

  

  to 
  appear 
  on 
  the 
  northern 
  side 
  of 
  the 
  fault, 
  and 
  they 
  retain 
  this 
  

   position 
  till 
  we 
  reach 
  the 
  point 
  where 
  the 
  fault 
  passes 
  to 
  the 
  east- 
  

   ward 
  beyond 
  the 
  limits 
  of 
  the 
  region 
  under 
  description. 
  These 
  

   underlying 
  Silurian 
  strata, 
  being 
  less 
  susceptible 
  of 
  erosion 
  than 
  

   the 
  neighbouring 
  Carboniferous 
  beds, 
  form 
  the 
  outer 
  edge 
  of 
  the 
  

   bounding 
  slope 
  of 
  the 
  plateau; 
  and 
  the 
  Braehill 
  fault 
  gradually 
  

   mounts 
  higher 
  and 
  higher 
  upon 
  the 
  slope 
  as 
  we 
  pass 
  to 
  the 
  eastward 
  

   till, 
  finally, 
  for 
  the 
  last 
  four 
  miles 
  of 
  its 
  course, 
  near 
  Straiton, 
  it 
  

   runs 
  almost 
  along 
  the 
  summit. 
  

  

  The 
  band 
  of 
  Silurian 
  rocks 
  found 
  in 
  this 
  district 
  between 
  the 
  

   Old 
  Red 
  Sandstone 
  of 
  the 
  Hadyard 
  Hills 
  and 
  the 
  Carboniferous 
  of 
  

   the 
  Girvan 
  valley 
  rarely 
  exceeds 
  half 
  a 
  mile 
  in 
  width 
  ; 
  and 
  through- 
  

   out 
  much 
  of 
  its 
  extent 
  is 
  even 
  less 
  than 
  one 
  fourth 
  of 
  a 
  mile 
  in 
  

   breadth, 
  while 
  in 
  some 
  spots 
  it 
  seems 
  to 
  vanish 
  altogether. 
  It 
  

   attains 
  its 
  greatest 
  diameter 
  to 
  the 
  west, 
  along 
  the 
  line 
  of 
  Pen- 
  

   whapple 
  Glen, 
  where 
  its 
  strata 
  are 
  seen 
  following 
  in 
  unbroken 
  

   sequence 
  upon 
  the 
  yellow 
  Pentamerus-gritstones 
  of 
  Camregan 
  and 
  

   Penkill. 
  

  

  The 
  strata 
  which 
  floor 
  the 
  whole 
  of 
  this 
  narrow 
  band 
  of 
  country 
  

   consist 
  of 
  thin-bedded 
  flagstones 
  and 
  shales, 
  with 
  seams 
  of 
  hard, 
  

   but 
  essentially 
  flag-like 
  grits 
  distributed 
  irregularly 
  throughout 
  the 
  

   succession. 
  If 
  we 
  make 
  exception 
  of 
  the 
  local 
  development 
  of 
  certain 
  

   brilliant- 
  coloured 
  bands, 
  it 
  may 
  be 
  said 
  that 
  the 
  more 
  prominent 
  

   petrological 
  characters 
  of 
  these 
  strata 
  are 
  essentially 
  the 
  same 
  every- 
  

   where 
  throughout 
  the 
  area 
  ; 
  and 
  even 
  upon 
  a 
  first 
  examination 
  the 
  

   stratigraphist 
  instinctively 
  assigns 
  them 
  all 
  to 
  a 
  single 
  and 
  connected 
  

   series. 
  Prom 
  the 
  three 
  rock-series 
  already 
  defined 
  this 
  new 
  series 
  

   is 
  distinguishable, 
  not 
  only 
  by 
  its 
  petrological 
  characters, 
  but 
  also 
  

   by 
  the 
  general 
  absence 
  of 
  organic 
  remains, 
  the 
  few 
  fossils 
  it 
  has 
  

   afforded 
  being 
  restricted 
  to 
  half 
  a 
  dozen 
  widely 
  separated 
  seams, 
  

   each 
  of 
  a 
  few 
  inches 
  in 
  thickness. 
  

  

  The 
  geographical 
  distribution 
  of 
  this 
  series 
  of 
  grey 
  flagstones 
  and 
  

   shales 
  admits 
  of 
  being 
  most 
  satisfactorily 
  described, 
  as 
  they 
  present 
  

   themselves 
  in 
  : 
  — 
  

  

  (1) 
  The 
  lower 
  portion 
  of 
  the 
  gorge 
  of 
  Penwhapple 
  Glen 
  above 
  

  

  Old 
  Dailly 
  ; 
  

  

  (2) 
  The 
  steep 
  north 
  slope 
  of 
  the 
  Hadyard 
  Hills 
  above 
  New 
  

  

  Dailly; 
  

  

  (3) 
  The 
  eastern 
  or 
  Straiton 
  area 
  north 
  of 
  the 
  Bargany 
  fault 
  ; 
  

  

  and 
  the 
  entire 
  series 
  is 
  most 
  naturally 
  and 
  conveniently 
  designated 
  

   by 
  the 
  general 
  title 
  of 
  the 
  Dailly 
  Series, 
  after 
  the 
  name 
  of 
  the 
  parish 
  

   in 
  which 
  its 
  strata 
  are 
  most 
  fully 
  laid 
  open 
  for 
  study, 
  and 
  where 
  they 
  

   attain 
  their 
  widest 
  geographical 
  extension 
  in 
  the 
  Girvan 
  region. 
  

  

  1. 
  Section 
  of 
  Lower 
  Portion 
  of 
  Penwhapple 
  Glen 
  (see 
  fig. 
  28, 
  

   p. 
  645). 
  — 
  The 
  third 
  zone 
  of 
  yellow 
  gritstone, 
  which 
  forms 
  the 
  summit 
  

   of 
  the 
  Pentamerus-'bedLTmg 
  Camregan 
  beds 
  of 
  Penwhapple 
  Glen, 
  is 
  at 
  

   once 
  succeeded 
  by 
  a 
  group 
  of 
  strata 
  altogether 
  more 
  unique 
  in 
  their 
  

   petrological 
  features 
  than 
  any 
  we 
  have 
  hitherto 
  studied 
  on 
  the 
  banks 
  

   of 
  the 
  glen. 
  They 
  consist 
  of 
  beds 
  of 
  purple 
  and 
  green 
  shale 
  of 
  great 
  

  

  2x2 
  

  

  