﻿460 
  DR. 
  H. 
  HICKS 
  ON 
  THE 
  MORTE 
  SLATES, 
  AND 
  [Aug. 
  1 
  89 
  7, 
  

  

  the 
  two 
  bounding 
  faults 
  was 
  great, 
  but 
  that 
  it 
  was 
  rather 
  one 
  of 
  those 
  

   very 
  common 
  cases 
  in 
  which 
  a 
  displacement 
  was 
  observed 
  along 
  the 
  

   junction 
  when 
  two 
  rocks 
  of 
  different 
  compressibility 
  and 
  ductility 
  

   were 
  contorted 
  together. 
  Hence 
  the 
  theory 
  almost 
  involved 
  the 
  

   idea 
  that 
  the 
  beds 
  on 
  the 
  north 
  usually 
  referred 
  to 
  the 
  Ilfracombe 
  

   and 
  Hangman 
  stages 
  must 
  be 
  the 
  same 
  as 
  those 
  on 
  the 
  south 
  which 
  

   were 
  in 
  the 
  old 
  nomenclature 
  spoken 
  of 
  as 
  the 
  Pickwell 
  Down 
  and 
  

   Baggy 
  Beds. 
  He 
  considered, 
  therefore, 
  that 
  although 
  the 
  lithological 
  

   characters 
  might 
  enable 
  us 
  to 
  discriminate 
  between 
  the 
  various 
  

   subdivisions 
  in 
  the 
  field, 
  the 
  real 
  question 
  before 
  them, 
  namely, 
  the 
  

   relative 
  age 
  of 
  the 
  beds 
  in 
  the 
  medial 
  belt 
  and 
  the 
  beds 
  on 
  either 
  

   side 
  of 
  it, 
  was 
  chiefly 
  palseontological, 
  and 
  he 
  thought 
  that, 
  taking 
  

   into 
  account 
  the 
  difference 
  of 
  sediment 
  and 
  other 
  circumstances 
  

   which 
  tend 
  to 
  modify 
  the 
  distribution 
  of 
  life, 
  no 
  sufficient 
  

   evidence 
  had 
  yet 
  been 
  offered 
  to 
  establish 
  the 
  Author's 
  principal 
  

   contention. 
  

  

  Mr. 
  Marr 
  remarked 
  that 
  the 
  Devonian 
  system 
  had 
  been 
  founded 
  

   •on 
  stratigraphical 
  grounds 
  by 
  Sedgwick 
  and 
  Murchison, 
  on 
  palaeon- 
  

   tological 
  grounds 
  by 
  Lonsdale 
  and 
  Etheridge. 
  Dr. 
  Hicks 
  had 
  

   re-opened 
  the 
  question, 
  and 
  as 
  the 
  speaker 
  had 
  doubted 
  the 
  convincing 
  

   nature 
  of 
  the 
  proofs 
  brought 
  forward 
  by 
  the 
  Author 
  in 
  favour 
  of 
  

   the 
  Silurian 
  age 
  of 
  some 
  of 
  the 
  Morte 
  Slates, 
  he 
  felt 
  it 
  only 
  due 
  to 
  

   him 
  to 
  state 
  that 
  he 
  thought 
  the 
  fauna 
  exhibited 
  was 
  a 
  Lower 
  

   Devonian 
  one, 
  and 
  therefore 
  that 
  the 
  Author 
  had 
  established 
  one 
  

   of 
  his 
  main 
  contentions, 
  namely, 
  that 
  the 
  apparent 
  succession 
  in 
  

   North 
  Devon 
  was 
  not 
  the 
  true 
  one. 
  

  

  The 
  Eev. 
  H. 
  H. 
  Winavood 
  remarked 
  that 
  whatever 
  difference 
  may 
  

   exist 
  in 
  the 
  two 
  views 
  as 
  to 
  the 
  stratigraphy 
  of 
  the 
  North 
  Devon 
  

   beds, 
  yet 
  one 
  fact 
  was 
  indisputable, 
  that 
  the 
  Author 
  had 
  found 
  fossils 
  

   in 
  the 
  Morte 
  Slates 
  which 
  previous 
  observers 
  had 
  failed 
  to 
  do. 
  

   Whether 
  the 
  fauna 
  proved 
  to 
  be 
  Silurian 
  or 
  Lower 
  Devonian, 
  the 
  

   evidence 
  so 
  far 
  showed 
  that 
  these 
  slates 
  could 
  not 
  be 
  an 
  upward 
  

   succession 
  of 
  the 
  Middle 
  Devonian 
  or 
  Ilfracombe 
  Beds. 
  During 
  his 
  

   last 
  visit 
  to 
  this 
  district 
  in 
  company 
  with 
  the 
  Author 
  he 
  was 
  much 
  

   impressed 
  with 
  the 
  enormous 
  folding 
  and 
  disturbance 
  which 
  those 
  

   rocks 
  had 
  undergone, 
  thereby 
  very 
  much 
  reducing 
  their 
  estimated 
  

   thickness, 
  as 
  the 
  late 
  Prof. 
  Jukes 
  had 
  stated. 
  

  

  Mr. 
  B,. 
  S. 
  Herries 
  said 
  that 
  he 
  had 
  been 
  over 
  part 
  of 
  the 
  area 
  with 
  

   the 
  Author. 
  He 
  had 
  not 
  examined 
  the 
  south 
  side, 
  but 
  he 
  thought 
  

   that 
  on 
  the 
  north 
  there 
  could 
  be 
  no 
  doubt 
  that 
  on 
  stratigraphical 
  

   grounds 
  the 
  Treborough 
  Slates 
  belonged 
  to 
  a 
  series 
  entirely 
  distinct 
  

   from 
  the 
  beds 
  immediately 
  north 
  of 
  them. 
  The 
  exact 
  age 
  of 
  these 
  

   slates 
  was 
  of 
  minor 
  importance. 
  The 
  real 
  point 
  was 
  whether 
  they 
  

   were 
  older 
  or 
  younger 
  than 
  the 
  beds 
  to 
  the 
  north. 
  If 
  the 
  palseonto- 
  

   logical 
  evidence 
  showed 
  that 
  they 
  were 
  older, 
  as 
  the 
  Author 
  con- 
  

   tended, 
  then 
  the 
  inference 
  was 
  a 
  very 
  strong 
  one 
  that 
  the 
  Morte 
  

   Beds 
  of 
  North 
  Devon, 
  where 
  the 
  fossil 
  evidence 
  was 
  not 
  nearly 
  so 
  

   convincing, 
  were 
  also 
  older 
  than 
  the 
  Ilfracombe 
  Beds 
  to 
  the 
  north 
  

  

  