﻿564 
  PROF. 
  C. 
  LAP 
  WORTH 
  ON" 
  THE 
  GIRVAN 
  SUCCESSION. 
  

  

  finis 
  beds. 
  In 
  no 
  other 
  locality 
  known 
  to 
  myself 
  are 
  they 
  so 
  clearly 
  

   exhibited, 
  or 
  their 
  fossils 
  so 
  easily 
  procured 
  or 
  so 
  well 
  preserved. 
  

  

  This 
  quarry 
  lies 
  at 
  the 
  south-western 
  extremity 
  of 
  the 
  continuous 
  

   band 
  of 
  limestone 
  we 
  have 
  followed 
  from 
  Auchensoul 
  and 
  Benan 
  

   Hill 
  along 
  the 
  north 
  slope 
  of 
  the 
  Stinchar 
  valley. 
  The 
  band 
  here 
  

   comes 
  to 
  an 
  abrupt 
  conclusion. 
  It 
  is 
  bent 
  back 
  in 
  a 
  sharp 
  curve, 
  

   with 
  an 
  accompanying 
  fault, 
  and 
  is 
  thrown 
  into 
  an 
  abrupt 
  synclinal 
  

   from 
  below 
  which 
  rise 
  the 
  underlying 
  strata 
  of 
  the 
  deep-seated 
  

   Purple 
  Conglomerate. 
  

  

  This 
  is 
  well 
  exposed 
  in 
  the 
  floor 
  of 
  a 
  small 
  stream 
  which 
  here 
  de- 
  

   scends 
  the 
  slopes 
  of 
  the 
  hill 
  to 
  the 
  northward. 
  It 
  presents 
  all 
  the 
  

   peculiar 
  features 
  of 
  this 
  remarkable 
  formation 
  as 
  exhibited 
  in 
  the 
  

   typical 
  section 
  of 
  Kirkland 
  and 
  Benan. 
  In 
  the 
  little 
  wood 
  we 
  re- 
  

   cognize 
  it 
  by 
  its 
  deeply 
  purple 
  matrix, 
  marbled 
  with 
  veins 
  of 
  calcite, 
  

   and 
  filled 
  with 
  boulders 
  of 
  green 
  porphyrites, 
  grey 
  granites, 
  and 
  frag- 
  

   ments 
  of 
  altered 
  rocks. 
  Hard 
  and 
  firmly 
  compacted, 
  it 
  is 
  beautifully 
  

   polished 
  by 
  the 
  waters 
  of 
  the 
  cascade, 
  and 
  forms 
  a 
  most 
  striking 
  

   floor 
  to 
  the 
  darkened 
  stream-course. 
  

  

  The 
  synclinal 
  and 
  fault 
  at 
  this 
  locality 
  bring 
  the 
  typical 
  line 
  of 
  

   the 
  Stinchar 
  calcareous 
  series 
  to 
  an 
  abrupt 
  termination 
  in 
  the 
  

   westerly 
  direction, 
  as 
  do 
  the 
  anticlinal 
  and 
  accompanying 
  faults 
  of 
  

   Dularg 
  the 
  same 
  line 
  in 
  the 
  opposite 
  direction 
  to 
  the 
  east. 
  Before 
  

   proceeding 
  to 
  the 
  study 
  of 
  the 
  scattered 
  exposures 
  of 
  the 
  strata 
  of 
  

   this 
  group 
  in 
  the 
  more 
  complicated 
  district 
  to 
  the 
  northward, 
  it 
  may 
  

   perhaps 
  be 
  advisable 
  to 
  re- 
  summarize 
  the 
  points 
  already 
  established 
  

   in 
  the 
  Girvan 
  succession 
  as 
  here 
  exhibited. 
  

  

  We 
  find, 
  that 
  is 
  to 
  say, 
  in 
  the 
  northern 
  slopes 
  of 
  the 
  Stinchar 
  

   valley, 
  that 
  the 
  great 
  Benan 
  conglomerate 
  is 
  underlain 
  by 
  a 
  thick 
  

   scries 
  of 
  more 
  or 
  less 
  calcareous 
  strata, 
  constituted 
  of 
  the 
  following 
  

   members 
  in 
  ascending 
  order 
  : 
  — 
  

  

  feet. 
  

   Kirkland 
  Beds 
  : 
  — 
  

  

  Aa 
  1 
  . 
  Purple 
  Conglomerate 
  of 
  Kirkland 
  (at 
  least) 
  150 
  

  

  Aa 
  2 
  . 
  Transitional 
  zone 
  of 
  Purplish 
  Sandstones 
  (possibly) 
  50 
  

  

  Stinchar 
  Limestone 
  group 
  : 
  — 
  

  

  Ab 
  1 
  . 
  Impure 
  Calcareous 
  Flagstones 
  with 
  Orthis 
  con/mis 
  40 
  

  

  Ab 
  2 
  . 
  Machirca-bedB 
  30 
  

  

  Ab 
  3 
  . 
  Compact 
  Limestones, 
  less 
  fossiliferous 
  30 
  

  

  Ab 
  4 
  . 
  Didymograptus-shales 
  with 
  Graptolites 
  30 
  

  

  That 
  all 
  these 
  relations 
  are 
  retained 
  essentially 
  unmodified 
  among 
  

   the 
  remaining 
  exposures 
  of 
  this 
  series 
  in 
  the 
  Girvan 
  district 
  will 
  

   next 
  be 
  demonstrated. 
  

  

  (6) 
  Description 
  of 
  the 
  Confirmatory 
  Exposures 
  of 
  the 
  Calcareous 
  

   Sei'ies 
  in 
  the 
  Valley 
  of 
  the 
  Assel 
  Water. 
  

  

  The 
  whole 
  of 
  the 
  great 
  Benan-Hill 
  ridge 
  lying 
  to 
  the 
  northward 
  

   of 
  the 
  uninterrupted 
  line 
  of 
  calcareous 
  rock 
  just 
  described 
  is, 
  as 
  we 
  

   have 
  already 
  pointed 
  out, 
  composed 
  of 
  a 
  continuous 
  sheet 
  of 
  the 
  

   dark 
  green 
  or 
  Benan 
  Conglomerate 
  (Ac), 
  which 
  in 
  our 
  typical 
  localities 
  

   immediately 
  overlies 
  the 
  Didymograptus-sh&les 
  (Ab 
  4 
  ). 
  From 
  the 
  

  

  