﻿594 
  PROF. 
  C. 
  LAPWORTH 
  ON 
  TEE 
  GIRVAN 
  SUCCESSION. 
  

  

  of 
  Hadyard 
  and 
  Garleffin. 
  Throughout 
  this 
  extended 
  area 
  these 
  

   beds 
  consist 
  essentially 
  of 
  thin-bedded 
  flagstones 
  and 
  shales, 
  with 
  

   occasional 
  zones 
  of 
  sandy 
  and 
  pebbly 
  grit. 
  Where 
  they 
  become 
  car- 
  

   bonaceous 
  they 
  contain 
  an 
  abundance 
  of 
  Graptolites, 
  generally, 
  

   however, 
  of 
  few 
  species. 
  A 
  few 
  calcareous 
  seams 
  are 
  met 
  with 
  at 
  

   intervals 
  ; 
  and 
  these 
  yield 
  fragmentary 
  Trilobites, 
  Cephalopoda, 
  and 
  

   Brachiopoda. 
  The 
  whole 
  of 
  the 
  beds 
  are 
  thrown 
  into 
  innumerable 
  

   folds 
  and 
  contortions, 
  are 
  frequently 
  inverted, 
  and 
  are 
  much 
  dislo- 
  

   cated 
  by 
  local 
  faults. 
  But 
  the 
  lowest 
  beds 
  everywhere 
  distinctly 
  

   repose 
  conformably 
  upon 
  the 
  great 
  sheet 
  of 
  Benan 
  Conglomerate, 
  

   from 
  which 
  they 
  graduate 
  through 
  the 
  transitional 
  zone 
  of 
  the 
  

   Balclatchie 
  Beds. 
  This 
  fact, 
  as 
  we 
  have 
  shown, 
  holds 
  good, 
  not 
  only 
  

   with 
  respect 
  to 
  the 
  main 
  mass 
  of 
  conglomerate 
  itself 
  as 
  seen 
  at 
  

   Balclatchie, 
  but 
  also 
  in 
  the 
  many 
  disconnected 
  exposures 
  of 
  the 
  same 
  

   rock 
  in 
  the 
  hills 
  of 
  Barlae, 
  Laggan 
  Gill, 
  and 
  in 
  the 
  terminal 
  strip 
  of 
  

   Benan 
  Conglomerate 
  which 
  descends 
  from 
  the 
  Ballantrae 
  rocks 
  of 
  

   Grey 
  Hill, 
  and 
  runs 
  out 
  to 
  sea 
  in 
  the 
  headland 
  of 
  Kennedy's 
  Pass. 
  

  

  It 
  is 
  in 
  the 
  last 
  of 
  these 
  localities 
  that 
  the 
  succeeding 
  Graptolitic 
  

   scries 
  is 
  most 
  completely 
  exposed 
  to 
  the 
  inspection 
  of 
  the 
  stratigraphist 
  

   and 
  palaeontologist. 
  Its 
  strata 
  constitute 
  the 
  floor 
  of 
  the 
  old 
  raised 
  

   shore-terrace 
  of 
  Ardraillan 
  and 
  Woodlands, 
  and 
  are 
  truncated 
  

   obliquely 
  by 
  the 
  sea 
  along 
  the 
  rocky 
  coast-line 
  between 
  Kennedy's 
  

   Pass 
  and 
  the 
  hamlet 
  of 
  Shulloch. 
  for 
  a 
  distance 
  of 
  about 
  three 
  miles. 
  

  

  An 
  almost 
  continuous 
  section 
  of 
  the 
  beds 
  is 
  laid 
  bare 
  along 
  the 
  

   shore 
  throughout 
  the 
  whole 
  of 
  this 
  extent. 
  The 
  strata 
  run 
  out 
  to 
  

   sea 
  in 
  a 
  low 
  platform 
  which 
  is 
  never 
  entirely 
  covered 
  by 
  the 
  waves 
  

   and 
  is 
  wholly 
  exposed 
  to 
  the 
  investigator 
  at 
  low 
  tide. 
  

  

  The 
  main 
  highway 
  from 
  Girvan 
  to 
  Ballantrae 
  is 
  carried 
  along 
  the 
  

   seaward 
  edge 
  of 
  this 
  platform 
  : 
  so 
  that 
  the 
  student 
  of 
  the 
  geology 
  of 
  

   the 
  district 
  enjoys 
  exceptional 
  advantages 
  in 
  the 
  study 
  of 
  the 
  flag- 
  

   like 
  Graptolitic 
  deposits 
  of 
  this 
  locality. 
  

  

  The 
  most 
  conspicuous 
  object 
  upon 
  this 
  raised 
  platform 
  is 
  the 
  

   ancient 
  house 
  of 
  Ardmillan, 
  the 
  seat 
  of 
  the 
  proprietor 
  of 
  the 
  neighbour- 
  

   ing 
  estate. 
  It 
  lies 
  at 
  the 
  foot 
  of 
  the 
  wooded 
  slopes 
  of 
  Mains 
  Hill, 
  

   and 
  about 
  the 
  centre 
  of 
  the 
  area 
  occupied 
  by 
  the 
  flagstone 
  group. 
  

   This 
  circumstance 
  has 
  suggested 
  to 
  me 
  the 
  title 
  of 
  Ardmillan 
  Group 
  

   as 
  a 
  collective 
  name 
  for 
  the 
  flagstone 
  series, 
  a 
  title 
  which 
  marks 
  

   definitely 
  the 
  special 
  locality 
  where 
  its 
  strata 
  are 
  most 
  satisfactorily 
  

   exposed. 
  

  

  A 
  section 
  drawn 
  transversely 
  across 
  the 
  rocks 
  of 
  this 
  area 
  displays 
  

   the 
  succession 
  shown 
  in 
  the 
  accompanying 
  figure 
  (fig. 
  16). 
  The 
  

   elevated 
  heights 
  of 
  Mains 
  Hill 
  and 
  Grey 
  Hill 
  are 
  formed 
  of 
  the 
  bedded 
  

   and 
  intrusive 
  rocks 
  of 
  the 
  Ballantrae 
  region 
  — 
  sj'enitic, 
  dioritic 
  and 
  

   felspathic. 
  Upon 
  these, 
  inclined 
  at 
  a 
  steep 
  angle, 
  leans 
  the 
  great 
  

   sheet 
  of 
  Benan 
  Conglomerate 
  and 
  its 
  associated 
  Balclatchie 
  beds, 
  

   extending 
  to 
  the 
  ehore-line 
  in 
  the 
  cliffs 
  of 
  Kennedy's 
  Pass. 
  This 
  

   occupies 
  all 
  the 
  higher 
  portions 
  of 
  the 
  northern 
  slopes 
  of 
  these 
  hills, 
  

   and 
  ranges 
  downwards 
  to 
  the 
  edge 
  of 
  the 
  cultivated 
  grounds 
  of 
  

   Ardmillan 
  and 
  Ardwell. 
  

  

  1. 
  Ardwell 
  Shales 
  and 
  Flags. 
  — 
  The 
  Conglomerate 
  series 
  is 
  succeeded 
  

  

  