﻿590 
  PROF. 
  C. 
  LAPWOJEtTH 
  ON 
  TEE 
  GIRVAN 
  SUCCESSION, 
  

  

  fact 
  that 
  they 
  lie 
  out 
  of 
  the 
  usual 
  track 
  of 
  fossil-collectors. 
  But, 
  with 
  

   the 
  exception 
  of 
  the 
  thin 
  seams 
  on 
  Daldowie 
  Hill, 
  few 
  of 
  the 
  localities 
  

   would 
  repay 
  an 
  extended 
  study 
  ; 
  for 
  fossils, 
  though 
  certainly 
  present, 
  

   seem 
  generally 
  to 
  be 
  rare. 
  

  

  In 
  the 
  fine 
  exposure 
  of 
  the 
  same 
  beds 
  near 
  the 
  shore 
  at 
  Ardwell, 
  

   next 
  to 
  be 
  described, 
  fossils 
  are 
  remarkably 
  abundant, 
  and 
  are 
  speci- 
  

   fically 
  even 
  more 
  crowded 
  than 
  in 
  the 
  typical 
  shales 
  of 
  Balclatchie 
  

   Bridge. 
  

  

  The 
  great 
  mass 
  of 
  Benan 
  Conglomerate, 
  which 
  reposes 
  upon 
  the 
  

   igneous 
  and 
  metaraorphic 
  rocks 
  of 
  Penbain 
  and 
  the 
  Grey 
  Hill, 
  and 
  

   stretches 
  in 
  a 
  continuous 
  sheet 
  from 
  Kennedy's 
  Pass 
  to 
  the 
  rugged 
  

   mound 
  of 
  the 
  Byne 
  Hill, 
  plunges 
  at 
  a 
  steep 
  angle 
  below 
  the 
  great 
  

   mass 
  of 
  Graptolitic 
  flagstones 
  o* 
  Ardwell 
  shore. 
  The 
  line 
  of 
  junction 
  

   between 
  the 
  conglomerate 
  and 
  flagstones 
  is 
  obscured 
  for 
  the 
  greater 
  

   part 
  of 
  its 
  extent 
  ; 
  but 
  for 
  a 
  limited 
  distance 
  about 
  the 
  centre 
  of 
  

   its 
  range 
  the 
  intermediate 
  Balclatchie 
  Beds 
  are 
  seen 
  in 
  some 
  old 
  

   quarries 
  in 
  the 
  hill-face 
  above 
  Ardwell 
  farm, 
  and 
  in 
  the 
  steep 
  burn- 
  

   course 
  of 
  the 
  little 
  stream 
  which 
  passes 
  the 
  ancient 
  castle 
  of 
  Ard- 
  

   millan. 
  

  

  In 
  the 
  old 
  road 
  which 
  ascends 
  the 
  heights 
  southeastward 
  from 
  

   the 
  farm 
  of 
  Ardwell, 
  the 
  Graptolitic 
  flagstones 
  are 
  seen 
  striking 
  from 
  

   S.W. 
  to 
  N.E., 
  and 
  dipping 
  at 
  a 
  steep 
  angle 
  seaward. 
  On 
  the 
  heights 
  

   above, 
  the 
  Benan 
  Conglomerate 
  is 
  easily 
  identified, 
  having 
  all 
  its 
  

   usual 
  characters, 
  and 
  coinciding 
  in 
  its 
  range 
  with 
  the 
  more 
  recent 
  

   Graptolitic 
  flagstones 
  below. 
  Midway 
  between 
  these 
  two 
  exposures, 
  

   and 
  thus 
  occupying 
  their 
  usual 
  intermediate 
  geographical 
  and 
  geolo- 
  

   gical 
  position, 
  the 
  green 
  concretionary 
  mudstones 
  of 
  Balclatchie 
  are 
  

   visible 
  in 
  several 
  quarries, 
  trending 
  in 
  precisely 
  the 
  samo 
  general 
  

   direction 
  as 
  the 
  conglomerate 
  and 
  flagstones 
  which 
  enclose 
  them. 
  

   Some 
  small 
  streamlets 
  which 
  run 
  past 
  the 
  quarries 
  have 
  trenched 
  the 
  

   superficial 
  coating 
  of 
  the 
  hill 
  sufficiently 
  to 
  allow 
  us 
  to 
  make 
  out 
  the 
  

   details 
  of 
  the 
  succession 
  from 
  the 
  fossiliferous 
  mudstone 
  into 
  the 
  

   heart 
  of 
  the 
  great 
  Conglomerate. 
  

  

  Commencing 
  at 
  the 
  summit 
  of 
  the 
  section, 
  we 
  notice 
  that 
  some 
  40 
  

   or 
  50 
  feet 
  of 
  the 
  Benan 
  Conglomerate 
  are 
  exposed. 
  The 
  matrix 
  has 
  

   the 
  usual 
  gritty 
  character 
  of 
  the 
  upper 
  beds 
  of 
  the 
  formation, 
  and 
  

   shows 
  the 
  normal 
  preponderance 
  of 
  porphyrite 
  and 
  quartzite 
  pebbles. 
  

  

  In 
  immediate 
  contact 
  with 
  the 
  conglomerate, 
  but 
  dipping 
  almost 
  

   vertically 
  in 
  the 
  opposite 
  direction, 
  occur 
  some 
  20 
  feet 
  of 
  coarse 
  

   well-bedded 
  gritstones, 
  with 
  a 
  greenish 
  grey 
  interior, 
  but 
  weather- 
  

   ing 
  to 
  a 
  purplish 
  tint 
  upon 
  their 
  edges. 
  These 
  are 
  succeeded 
  

   by 
  a 
  slightl}" 
  greater 
  thickness 
  of 
  calcareous 
  sandstones, 
  abundantly 
  

   fossiliferous 
  upon 
  several 
  horizons. 
  They 
  contain 
  Remopleurides 
  

   dorsospinifer, 
  Asaphus 
  gifjas, 
  iStaurocepJialus 
  globiceps, 
  Pliacops 
  

   Bronc/mctrti, 
  Orthis 
  calligramma, 
  0. 
  Actonice, 
  Leptama 
  tennicincta, 
  

   Murcliisonia, 
  and 
  all 
  the 
  characteristic 
  Balclatchie 
  fossils. 
  

  

  After 
  a 
  short 
  interval 
  of 
  concealment 
  we 
  reach 
  the 
  green 
  concre- 
  

   tionary 
  mudstones, 
  of 
  which 
  60 
  or 
  70 
  feet 
  are 
  exposed 
  in 
  the 
  quarries 
  

   and 
  in 
  the 
  natural 
  sections. 
  In 
  their 
  mineralogical 
  characters 
  they 
  

   are 
  identical 
  with 
  the 
  shell-bearing 
  beds 
  that 
  follow 
  immediately 
  

   upon 
  the 
  Benan 
  Conglomerate 
  in 
  our 
  typical 
  exposure 
  at 
  Balclatchie 
  

  

  