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  °^* 
  53'] 
  ASSOCIATED 
  BEDS, 
  IX 
  N". 
  DEVON 
  AND 
  W. 
  SOMEKSET. 
  459 
  

  

  Pickwell 
  Down 
  Series, 
  was 
  derived, 
  it 
  being 
  sufficient 
  to 
  announce 
  it 
  

   on 
  the 
  assumption 
  of 
  doubtful 
  fossil 
  evidence. 
  If 
  these 
  Morte 
  Slates 
  

   are 
  the 
  oldest 
  rocks 
  in 
  North 
  Devon, 
  it 
  is 
  incumbent 
  upon 
  those 
  who 
  

   assert 
  the 
  fact 
  to 
  show 
  clearly 
  by 
  good 
  evidence 
  that 
  such 
  inter- 
  

   polation 
  took 
  place, 
  and 
  whence 
  and 
  how 
  derived 
  ; 
  but 
  no 
  evidence 
  

   exists 
  of 
  the 
  asserted 
  thrust-faults 
  over 
  this 
  part 
  or 
  in 
  any 
  of 
  the 
  

   northern 
  or 
  eastern 
  rocks 
  or 
  areas 
  of 
  North 
  Devon. 
  The 
  great 
  red 
  

   sandstone 
  series 
  and 
  limestone-beds 
  of 
  Ilfracombe, 
  ranging 
  from 
  

   Mortehoe 
  to 
  Hangman 
  Point, 
  show 
  no 
  evidence 
  of 
  thrust-faults, 
  

   however 
  great 
  their 
  foldings. 
  There 
  is 
  as 
  yet 
  no 
  proof 
  in 
  the 
  Morte 
  

   Group 
  of 
  passage-beds 
  between 
  Silurian 
  and 
  Lower 
  Devonian, 
  either 
  

   on 
  the 
  dip 
  or 
  strike. 
  Sedimentation 
  along 
  this 
  strike 
  of 
  the 
  Morte 
  

   Beds 
  of 
  North 
  Devon 
  and 
  West 
  Somerset 
  for 
  40 
  miles 
  may 
  readily 
  

   be 
  misunderstood, 
  and 
  very 
  difficult 
  to 
  determine 
  ; 
  numerous 
  enough 
  

   have 
  been 
  the 
  traverses 
  across 
  the 
  so-called 
  thrust-fault 
  on 
  the 
  

   north 
  side 
  of 
  the 
  Morte 
  line 
  of 
  fault, 
  and 
  also 
  the 
  less 
  faulted 
  beds 
  

   upon 
  the 
  South 
  or 
  Pickwell 
  Down 
  side. 
  These 
  traverses 
  have 
  not 
  

   yet 
  shown 
  any 
  affiliation 
  of 
  Silurian 
  species 
  with 
  those 
  in 
  the 
  

   Morte 
  Series. 
  The 
  assertion, 
  therefore, 
  that 
  'the 
  position 
  now 
  

   given 
  to 
  the 
  Morte 
  beds 
  removes 
  one 
  of 
  the 
  greatest 
  

   difficulties 
  experienced 
  by 
  previous 
  writers 
  in 
  their 
  

   attempts 
  to 
  correlate 
  the 
  strata 
  in 
  North 
  Devon' 
  

   has 
  yet 
  to 
  be 
  proved. 
  Again, 
  the 
  assertion 
  that 
  'the 
  diversity 
  

   of 
  fossils 
  in 
  the 
  Morte 
  Slates 
  belonging 
  to 
  several 
  

   horizons 
  as 
  low 
  as 
  the 
  base 
  of 
  the 
  Upper 
  Silurian, 
  

   added 
  to 
  the 
  stratigraphical 
  evidence, 
  enables 
  us 
  

   to 
  speak 
  with 
  confidence 
  as 
  to 
  their 
  place 
  in 
  the 
  

   North 
  Devon 
  succession,' 
  has 
  yet 
  to 
  be 
  determined. 
  

  

  Prof. 
  Hughes 
  thought 
  that 
  the 
  point 
  which 
  the 
  Author 
  wished 
  to 
  

   emphasize 
  was 
  that 
  there 
  was 
  in 
  the 
  area 
  described 
  an 
  anticlinal 
  

   carrying 
  newer 
  beds 
  belonging 
  to 
  the 
  Devonian 
  Series 
  over 
  an 
  axis 
  

   of 
  rocks 
  belonging 
  to 
  an 
  older 
  part 
  of 
  the 
  same 
  series 
  ; 
  this 
  structure 
  

   confirming 
  the 
  view 
  previously 
  advanced 
  by 
  the 
  Author, 
  that 
  there 
  

   was 
  a 
  fold 
  of 
  Devonian 
  rocks 
  stretched 
  unconformably 
  over 
  a 
  ridge 
  

   of 
  Silurian 
  farther 
  west 
  at 
  Mortehoe. 
  These 
  two 
  sections 
  showing 
  

   a 
  different 
  sequence 
  could 
  certainly 
  be 
  reconciled 
  on 
  the 
  hypothesis 
  

   that 
  along 
  the 
  belt 
  of 
  country 
  indicated 
  by 
  the 
  area 
  referred 
  on 
  the 
  

   older 
  maps 
  to 
  the 
  Morte 
  Slates 
  there 
  was 
  an 
  anticlinal, 
  the 
  axis 
  of 
  

   which 
  sloped 
  to 
  the 
  east, 
  thus 
  bringing 
  on 
  the 
  newer 
  beds 
  in 
  that 
  

   direction 
  in 
  a 
  succession 
  of 
  half-spoon 
  shaped 
  folds. 
  And 
  he 
  was 
  

   willing 
  to 
  build 
  this 
  golden 
  bridge 
  for 
  his 
  friend 
  Dr. 
  Hicks. 
  

  

  The 
  evidence 
  for 
  the 
  Silurian 
  upfold 
  he 
  had 
  already 
  criticized, 
  

   and 
  he 
  would 
  only 
  add 
  that 
  all 
  his 
  subsequent 
  examination 
  of 
  

   specimens 
  had 
  confirmed 
  the 
  views 
  which 
  he 
  then 
  expressed. 
  The 
  

   particular 
  traverse 
  now 
  exhibited 
  by 
  the 
  Author 
  in 
  support 
  of 
  his 
  

   contention 
  showed 
  a 
  fault 
  at 
  either 
  end, 
  at 
  the 
  junction 
  of 
  the 
  up- 
  

   thrust 
  part 
  of 
  the 
  Series 
  with 
  the 
  supposed 
  overfolded 
  newer 
  beds. 
  

   He 
  did 
  not 
  think 
  there 
  was 
  reason 
  for 
  believing 
  that 
  the 
  throw 
  in 
  

  

  