﻿584 
  PEOF. 
  C. 
  LAPWOETH 
  OX 
  THE 
  G1EVAN 
  SUCCESSION". 
  

  

  good 
  exposures 
  of 
  the 
  shattered 
  beds 
  of 
  the 
  calcareous 
  group. 
  The 
  

   purple, 
  veined, 
  and 
  brecciated 
  basement 
  conglomerate 
  of 
  Kirkland 
  

   and 
  Millenderdale 
  is 
  well 
  exhibited, 
  distinctly 
  lying 
  between 
  the 
  

   Ballantrae 
  rocks 
  and 
  the 
  calcareous 
  series. 
  The 
  latter 
  displays 
  both 
  

   the 
  impure 
  sandy 
  zone 
  of 
  the 
  Orthis-confinis 
  beds 
  and 
  the 
  overlying 
  

   concretionary 
  flagstones, 
  yielding 
  occasional 
  examples 
  of 
  Maclurea 
  

   Logani. 
  

  

  (B) 
  Tue 
  Gbaptolitic 
  Flagstone 
  Seeies 
  of 
  Aedmillan 
  and 
  

   Penwhapple. 
  

  

  Having 
  completed 
  our 
  description 
  of 
  the 
  chief 
  exposures 
  of 
  the 
  

   great 
  Benan 
  Conglomerate 
  and 
  the 
  calcareous 
  strata 
  which 
  naturally 
  

   underlie 
  it, 
  our 
  next 
  task 
  is 
  the 
  determination 
  of 
  the 
  nature 
  and 
  

   vertical 
  distribution 
  of 
  the 
  several 
  groups 
  of 
  strata 
  which 
  immediately 
  

   succeed 
  it 
  in 
  the 
  ascending 
  order. 
  

  

  The 
  difficulties 
  which 
  confront 
  us 
  in 
  our 
  quest 
  are 
  almost 
  insig- 
  

   nificant 
  when 
  contrasted 
  with 
  those 
  we 
  have 
  had 
  to 
  overcome 
  in 
  our 
  

   study 
  of 
  the 
  calcareous 
  zones 
  below. 
  The 
  outer 
  or 
  superior 
  edge 
  of 
  

   the 
  great 
  Benan 
  Conglomerate 
  is 
  usually 
  defined 
  with 
  tolerable 
  clear- 
  

   ness 
  upon 
  the 
  ground. 
  The 
  highest 
  zones 
  of 
  its 
  massive 
  boulder-beds 
  

   dip 
  almost 
  everywhere 
  below 
  an 
  overlying 
  series 
  of 
  Graptolitic 
  flag- 
  

   stones 
  and 
  shales 
  of 
  a 
  totally 
  distinct 
  penological 
  character. 
  

  

  These 
  Graptolitic 
  flagstones 
  occupy 
  the 
  whole 
  of 
  the 
  Lower 
  

   Palaeozoic 
  area 
  south 
  of 
  the 
  Girvan, 
  with 
  the 
  exception- 
  of 
  that 
  filled 
  

   by 
  the 
  Benan-Conglomerate 
  group 
  and 
  a 
  narrow 
  zone 
  lying 
  to 
  the 
  

   northward 
  of 
  the 
  parallel 
  of 
  Saugh 
  Hill. 
  They 
  are 
  magnificently 
  

   exposed 
  in 
  the 
  deep 
  gorge 
  of 
  Penwhapple 
  and 
  along 
  the 
  coast-line 
  

   between 
  Shalloch 
  and 
  Ar 
  dwell, 
  while 
  numberless 
  confirmatory 
  

   sections 
  occur 
  elsewhere. 
  

  

  Everywhere 
  along 
  the 
  boundary-line 
  between 
  the 
  Benan 
  Con- 
  

   glomerate 
  and 
  the 
  Graptolitic-flagstone 
  series, 
  where 
  the 
  sequence 
  

   is 
  unbroken, 
  we 
  find 
  an 
  intermediate 
  zone 
  of 
  highly 
  fossiliferous 
  

   strata, 
  which, 
  both 
  petrol 
  ogically 
  and 
  palseontologically, 
  partakes 
  of 
  

   the 
  characters 
  of 
  the 
  underlying 
  conglomeratic 
  group 
  and 
  the 
  over- 
  

   lying 
  flagstone 
  series, 
  and 
  which 
  therefore 
  it 
  will 
  be 
  more 
  convenient 
  

   to 
  treat 
  of 
  in 
  this 
  place 
  before 
  entering 
  upon 
  the 
  description 
  of 
  

   the 
  typical 
  sections 
  of 
  the 
  Graptolitic 
  series. 
  

  

  {a) 
  Description 
  of 
  the 
  Transitional 
  Zone 
  of 
  Balclatchie. 
  

  

  At 
  the 
  extreme 
  north-western 
  boundary 
  of 
  the 
  continuous 
  con- 
  

   glomeratic 
  sheet 
  of 
  Benan 
  and 
  Milljoan 
  it 
  is 
  crossed 
  by 
  the 
  infant 
  

   stream 
  of 
  Penwhapple, 
  which 
  has 
  excavated 
  a 
  narrow 
  gorge 
  in 
  

   its 
  highest 
  beds 
  near 
  the 
  Assel 
  road, 
  between 
  the 
  grassy 
  slopes 
  of 
  

   Knockgerran 
  and 
  Balclatchie, 
  exposing 
  a 
  most 
  instructive 
  section 
  

   of 
  their 
  junction 
  with 
  the 
  basal 
  beds 
  of 
  the 
  dark 
  Graptolitiferous 
  flag- 
  

   stones 
  and 
  shales 
  of 
  the 
  overlying 
  series. 
  

  

  1. 
  Balclatchie 
  Bridge 
  (fig. 
  14). 
  — 
  At 
  the 
  highway-bridge 
  of 
  Bal- 
  

   clatchie, 
  which 
  there 
  spans 
  the 
  gorge, 
  and 
  for 
  about 
  a 
  hundred 
  yards 
  

   below 
  it, 
  the 
  Benan 
  Conglomerate 
  is 
  recognizable 
  in 
  all 
  its 
  charac- 
  

  

  