﻿546 
  PR0E. 
  C. 
  LAP 
  WORTH 
  OX 
  THE 
  GIRVAN 
  SUCCESSION. 
  

  

  the 
  more 
  varied 
  and 
  richly 
  fossiliferous 
  deposits 
  lying 
  to 
  the 
  north- 
  

   ward 
  were 
  assigned 
  to 
  the 
  Caradoc. 
  

  

  I 
  shall 
  show 
  in 
  the 
  sequel 
  that 
  these 
  great 
  faults 
  are 
  accompanied 
  

   by 
  a 
  host 
  of 
  others, 
  some 
  of 
  which 
  are 
  of 
  even 
  greater 
  geological 
  

   importance, 
  and 
  that 
  to 
  the 
  presence 
  of 
  these 
  gigantic 
  dislocations 
  

   many 
  of 
  the 
  most 
  vital 
  difficulties 
  which 
  beset 
  the 
  study 
  of 
  the 
  

   stratigraphy 
  of 
  this 
  region 
  are 
  primarily 
  due. 
  

  

  3. 
  History 
  of 
  Previous 
  Discovery 
  and 
  Opinion. 
  

  

  The 
  earliest 
  notice 
  of 
  the 
  fossiliferous 
  Lower 
  Palaeozoic 
  rocks 
  of 
  

   Carrick 
  occurs 
  in 
  a 
  memoir 
  on 
  " 
  Some 
  Fossiliferous 
  Beds 
  in 
  the 
  

   Lower 
  Palaeozoic 
  Rocks 
  of 
  Wigtownshire," 
  contributed 
  to 
  the 
  Geo- 
  

   logical 
  Society 
  of 
  London 
  by 
  Mr. 
  J. 
  Carrick 
  Moore, 
  in 
  1849, 
  and 
  

   published 
  in 
  the 
  Quarterly 
  Journal 
  of 
  the 
  Society 
  for 
  the 
  following 
  

   year. 
  The 
  author, 
  after 
  describing 
  the 
  Graptolitic 
  strata 
  of 
  the 
  Gallo- 
  

   way 
  coast 
  in 
  some 
  detail, 
  gives 
  a 
  brief 
  account 
  of 
  a 
  fossiliferous 
  lime- 
  

   stone 
  he 
  had 
  detected 
  among 
  the 
  so-called 
  Silurian 
  rocks 
  of 
  Carrick. 
  

   This 
  limestone 
  he 
  had 
  personally 
  examined 
  in 
  five 
  different 
  localities 
  

   in 
  the 
  valley 
  of 
  the 
  Stinchar, 
  and 
  had 
  procured 
  from 
  it 
  many 
  well- 
  

   preserved 
  fossils, 
  principally 
  Brachiopoda. 
  These 
  fossils 
  he 
  submitted 
  

   to 
  Mr. 
  Salter, 
  who 
  at 
  once 
  assigned 
  this 
  Stinchar 
  Limestone 
  to 
  the 
  

   general 
  epoch 
  of 
  Murchison's 
  Lower 
  Silurian, 
  and 
  paralleled 
  

   it 
  'with 
  that 
  of 
  the 
  Wrae 
  Hill 
  in 
  the 
  Uplands 
  of 
  Peebleshirc, 
  which 
  

   had 
  been 
  recently 
  brought 
  into 
  notice 
  by 
  the 
  discoveries 
  of 
  Professor 
  

   Nicol. 
  In 
  Salter's 
  description 
  and 
  figures 
  of 
  these 
  Carrick 
  fossils, 
  

   published 
  as 
  an 
  Appendix 
  to 
  Mr. 
  Moore's 
  paper, 
  we 
  find 
  the 
  earliest 
  

   notice 
  of 
  the 
  genus 
  Maclurea 
  in 
  Britain, 
  together 
  with 
  incidental 
  

   references 
  to 
  the 
  collateral 
  results 
  of 
  Professor 
  Sedgwick's 
  simultane- 
  

   ous 
  discoveries 
  in 
  the 
  Carrick 
  rocks 
  north 
  of 
  the 
  Stinchar 
  valley. 
  

  

  At 
  the 
  meeting 
  of 
  the 
  British 
  Association 
  held 
  at 
  Edinburgh 
  in 
  

   1850, 
  Professor 
  Sedgwick 
  gave 
  a 
  verbal 
  description 
  of 
  his 
  partial 
  

   study 
  of 
  these 
  Carrick 
  rocks, 
  which 
  he 
  had 
  studied 
  in 
  the 
  field 
  a 
  year 
  

   or 
  two 
  previously, 
  and 
  from 
  which 
  a 
  large 
  suite 
  of 
  fossils 
  had 
  already 
  

   been 
  collected 
  under 
  his 
  superintendence. 
  From 
  the 
  brief 
  abstracts 
  

   of 
  his 
  remarks 
  subsequently 
  published 
  in 
  the 
  Report 
  of 
  the 
  Associa- 
  

   tion* 
  and 
  in 
  the 
  ' 
  New 
  Edinburgh 
  Philosophical 
  Journal' 
  f, 
  we 
  gather 
  

   that 
  Sedgwick 
  recognized 
  two 
  successive 
  groups 
  of 
  Lower 
  Palaeozoic 
  

   strata 
  in 
  this 
  region 
  — 
  a 
  South-Girvan 
  Group 
  and 
  a 
  North- 
  Girvan 
  

   Group. 
  His 
  South-Girvan 
  Group, 
  which 
  included 
  the 
  Stinchar 
  

   Limestone 
  and 
  all 
  the 
  remaining 
  strata 
  of 
  the 
  plateau 
  south 
  of 
  the 
  

   Girvan 
  valley, 
  was 
  assigned, 
  with 
  doubt, 
  to 
  the 
  Llandeilo 
  formation 
  of 
  

   Murchison. 
  His 
  jNorth-Girvan 
  Group, 
  which 
  embraced 
  all 
  the 
  

   strata 
  of 
  the 
  Craighead 
  inlier 
  to 
  the 
  north 
  of 
  the 
  Girvan 
  valley, 
  

   was 
  more 
  confidently 
  paralleled 
  with 
  the 
  shelly 
  limestones 
  then 
  

   supposed 
  to 
  lie 
  between 
  the 
  Llandeilo 
  Flags 
  and 
  the 
  higher 
  Silurian 
  

   rocks 
  of 
  South 
  Wales. 
  

  

  * 
  Eeport 
  British 
  Association, 
  1850, 
  pp. 
  103 
  &c. 
  

  

  t 
  Edinburgh 
  Philosophical 
  Journal, 
  vol. 
  li. 
  pp. 
  253, 
  254. 
  

  

  