﻿PROF. 
  C. 
  LAPWOKXH 
  ON 
  THE 
  GIEVAN 
  SUCCESSION. 
  53 
  ( 
  J 
  

  

  remote 
  pasture-farm, 
  and 
  the 
  lowly 
  sheiling 
  of 
  the 
  shepherd. 
  Its 
  

   open 
  valleys 
  and 
  less 
  elevated 
  grounds 
  are 
  those 
  of 
  the 
  Lowland 
  

   region, 
  relieved 
  by 
  steep 
  ridges 
  clothed 
  with 
  copses 
  of 
  oak 
  and 
  fir, 
  

   and 
  sheltering 
  fertile 
  corn-lands 
  and 
  busy 
  villages, 
  inhabited 
  by 
  a 
  

   population 
  employed 
  in 
  mining 
  and 
  agriculture. 
  

  

  To 
  a 
  large 
  extent 
  this 
  union 
  of 
  the 
  diverse 
  peculiarities 
  of 
  these 
  

   two 
  physical 
  regions 
  in 
  one 
  and 
  the 
  same 
  area 
  is 
  owing 
  to 
  the 
  fact 
  

   that 
  there 
  is 
  an 
  alternation 
  of 
  the 
  distinctive 
  strata 
  of 
  the 
  two 
  

   regions 
  within 
  its 
  limits 
  — 
  its 
  more 
  elevated 
  portions 
  being 
  formed 
  

   of 
  Lower 
  Palaeozoic 
  rocks, 
  and 
  its 
  low-lying 
  sections 
  floored 
  by 
  faulted 
  

   patches 
  of 
  the 
  more 
  diversified 
  Upper 
  Palaeozoic 
  strata. 
  But, 
  

   strange 
  to 
  say, 
  the 
  majority 
  of 
  the 
  diversified 
  strata 
  of 
  this 
  Carrick 
  

   district 
  are 
  of 
  the 
  same 
  general 
  geological 
  age 
  as 
  the 
  monotonous 
  

   Lower 
  Palaeozoic 
  rocks 
  of 
  the 
  Uplands, 
  and 
  many 
  of 
  the 
  more 
  abrupt 
  

   physical 
  features 
  of 
  the 
  district 
  are 
  actually 
  due 
  to 
  the 
  local 
  

   peculiarities 
  of 
  those 
  strata 
  as 
  here 
  exhibited. 
  It 
  is, 
  indeed, 
  true 
  

   that 
  upon 
  several 
  horizons 
  in 
  its 
  succession 
  we 
  meet 
  with 
  strata 
  

   whose 
  dingy 
  colours, 
  monotonous 
  lithological 
  characters, 
  and 
  utterly 
  

   barren 
  nature 
  are 
  identical 
  with 
  those 
  of 
  the 
  generality 
  of 
  the 
  

   Silurian 
  rocks 
  of 
  the 
  Uplands 
  ; 
  but, 
  as 
  a 
  rule, 
  the 
  Lower 
  Palaeozoic 
  

   strata 
  of 
  the 
  Carrick 
  district 
  are 
  vastly 
  different 
  in 
  all 
  their 
  

   characteristics 
  from 
  their 
  Upland 
  counterparts. 
  In 
  their 
  petro- 
  

   graphical 
  features 
  they 
  are 
  fully 
  as 
  diversified 
  as 
  are 
  the 
  Upper 
  

   Palaeozoic 
  strata 
  of 
  the 
  central 
  valley 
  ; 
  and 
  this 
  diversity 
  in 
  structure 
  

   is 
  accompanied 
  by 
  an 
  astounding 
  increase 
  in 
  the 
  abundance 
  and 
  

   variety 
  of 
  their 
  organic 
  remains. 
  Among 
  the 
  rocks 
  of 
  the 
  Southern 
  

   Uplands 
  limestones 
  are 
  practically 
  unknown, 
  conglomerates 
  and 
  

   shelly 
  sandstones 
  are 
  only 
  occasionally 
  present 
  ; 
  the 
  interminable 
  

   succession 
  of 
  barren 
  greywackes 
  and 
  shales 
  is 
  but 
  rarely 
  inter- 
  

   rupted 
  by 
  the 
  occurrence 
  of 
  an 
  insignificant 
  seam 
  of 
  black 
  mud- 
  

   stone 
  affording 
  a 
  few 
  GraiDtolites. 
  In 
  the 
  corresponding 
  strata 
  of 
  

   Carrick, 
  however, 
  fossils 
  of 
  all 
  the 
  invertebrate 
  classes, 
  Hydroida, 
  

   Actinozoa, 
  Trilobita, 
  Brachiopoda, 
  and 
  Cephalopoda, 
  are 
  more 
  or 
  

   less 
  plentifully 
  distributed 
  throughout 
  the 
  entire 
  succession, 
  and, 
  

   upon 
  several 
  horizons, 
  even 
  swarm 
  in 
  extraordinary 
  profusion. 
  

   Shelly 
  sandstones 
  and 
  sandy 
  grits, 
  carbonaceous 
  shales 
  and 
  Grap- 
  

   tolitic 
  mudstones 
  occur 
  in 
  great 
  force 
  ; 
  limestone 
  is 
  developed 
  to 
  an 
  

   extent 
  unequalled 
  elsewhere 
  among 
  the 
  Lower 
  Palaeozoics 
  of 
  the 
  

   south 
  of 
  Scotland 
  : 
  while 
  the 
  massive 
  conglomerates 
  and 
  tumultuous 
  

   boulder-beds 
  attain 
  a 
  thickness 
  and 
  a 
  geological 
  importance 
  as 
  yet 
  

   unparalleled 
  in 
  the 
  Lower 
  Palaeozoic 
  world. 
  

  

  In 
  a 
  further 
  and 
  yet 
  more 
  salient 
  feature 
  the 
  rocks 
  of 
  this 
  area 
  

   are 
  trenchantly 
  contrasted 
  with 
  their 
  counterparts 
  of 
  the 
  Southern 
  

   Uplands. 
  In 
  the 
  Upland 
  region, 
  if 
  we 
  except 
  the 
  scattered 
  trap- 
  

   dykes 
  and 
  the 
  intrusive 
  granitic 
  bosses 
  of 
  Cairnsmore 
  and 
  the 
  

   Kells, 
  igneous 
  outbursts, 
  either 
  contemporaneous 
  or 
  subsequent, 
  

   may 
  be 
  said 
  to 
  be 
  unknown. 
  In 
  the 
  west 
  of 
  the 
  Carrick 
  district, 
  

   on 
  the 
  contrary, 
  we 
  find 
  exhibited 
  one 
  of 
  the 
  most 
  interesting 
  

   igneous 
  areas 
  in 
  Britain, 
  whether 
  we 
  have 
  regard 
  to 
  the 
  diversified 
  

   nature 
  of 
  its 
  products, 
  to 
  their 
  enigmatical 
  mode 
  of 
  occurrence, 
  or 
  to 
  

  

  2o 
  2 
  

  

  