﻿Vol. 
  53.] 
  GLACIO-MAELNE 
  DRIFT 
  OF 
  THE 
  VALE 
  OF 
  CLWTD. 
  347 
  

  

  the 
  south-west. 
  We 
  have 
  also 
  seen 
  that 
  the 
  Arenig 
  rocks 
  are 
  to 
  

   be 
  found 
  at 
  various 
  localities, 
  even 
  among 
  the 
  marine 
  deposits 
  of 
  

   the 
  mouth 
  of 
  the 
  Vale. 
  

  

  It 
  is 
  not 
  my 
  object 
  here 
  to 
  attempt 
  to 
  explain 
  these 
  phenomena, 
  

   but 
  to 
  place 
  on 
  record 
  the 
  results 
  of 
  a 
  more 
  minute 
  examination 
  of 
  

   the 
  nature 
  of 
  the 
  clays 
  and 
  sands 
  found 
  at 
  the 
  entrance 
  of 
  the 
  Vale 
  

   of 
  Clwyd 
  than 
  appears 
  to 
  have 
  been 
  hitherto 
  made. 
  It 
  is 
  interesting, 
  

   however, 
  to 
  observe 
  from 
  the 
  lists 
  and 
  localities 
  given 
  that 
  the 
  

   Marine 
  Boulder 
  Clays 
  of 
  Lancashire, 
  Cheshire, 
  and 
  Denbighshire 
  

   contain 
  more 
  frequently, 
  and 
  in 
  a 
  much 
  greater 
  profusion 
  than 
  was 
  

   suspected, 
  the 
  tests 
  of 
  foraminifera. 
  As 
  a 
  rule, 
  these 
  are 
  found 
  in 
  

   the 
  finer 
  and 
  more 
  plastic 
  brown 
  or 
  red 
  Boulder 
  Clays, 
  which 
  often 
  

   contain 
  intensely-striated 
  erratic 
  stones, 
  and 
  they 
  occur 
  in 
  just 
  the 
  

   sort 
  of 
  deposits 
  in 
  which 
  they 
  are 
  mostly 
  found 
  at 
  the 
  present 
  day. 
  

   It 
  is 
  certainly 
  remarkable 
  that 
  they 
  are 
  so 
  well 
  preserved, 
  when 
  

   frequently 
  large 
  boulders 
  of 
  dolerite 
  and 
  other 
  originally 
  hard 
  rocks 
  

   have 
  crumbled 
  to 
  sand 
  in 
  the 
  same 
  beds. 
  

  

  PLATE 
  XXV. 
  

  

  Geological 
  Map 
  of 
  part 
  of 
  the 
  Vale 
  of 
  Clwyd 
  on 
  the 
  

   scale 
  of 
  2 
  miles 
  to 
  the 
  inch. 
  

  

  Discussion. 
  

  

  Mr. 
  Strahan 
  drew 
  the 
  attention 
  of 
  the 
  Author 
  to 
  Prof. 
  Hughes's 
  

   exhaustive 
  papers 
  on 
  the 
  drifts 
  of 
  the 
  Vale 
  of 
  Clwyd. 
  The 
  

   occurrence 
  of 
  foraminifera 
  was 
  to 
  be 
  expected 
  in 
  clay 
  so 
  similar 
  to 
  

   that 
  of 
  Cheshire, 
  in 
  which 
  they 
  had 
  long 
  since 
  been 
  recorded 
  by 
  

   Mr. 
  Shone. 
  One 
  of 
  the 
  most 
  interesting 
  points 
  in 
  the 
  drifts 
  of 
  the 
  

   Vale 
  was 
  the 
  meeting 
  of 
  drift 
  from 
  the 
  north 
  with 
  the 
  local 
  drift 
  

   of 
  North 
  Wales. 
  He 
  congratulated 
  the 
  Author 
  on 
  the 
  result 
  of 
  his 
  

   careful 
  examination 
  of 
  the 
  clay. 
  

  

  Prof. 
  Hughes 
  said 
  that 
  he 
  had 
  laid 
  pretty 
  fully 
  before 
  the 
  Society 
  

   his 
  views 
  as 
  to 
  the 
  origin 
  and 
  classification 
  of 
  the 
  drifts 
  of 
  the 
  Vale 
  

   of 
  Clwyd 
  (Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xliii. 
  1887, 
  p. 
  73) 
  ; 
  and 
  he 
  

   gathered 
  from 
  the 
  too 
  short 
  exposition 
  of 
  Mr. 
  Mellard 
  Eeade's 
  recent 
  

   observations 
  in 
  that 
  area, 
  that 
  the 
  foraminifera 
  which 
  he 
  had 
  obtained 
  

   all 
  occurred 
  in 
  the 
  newer 
  or 
  St. 
  Asaph 
  Drift. 
  This 
  had 
  all 
  the 
  

   characteristics 
  of 
  the 
  shore-deposits 
  on 
  that 
  coast 
  at 
  the 
  present 
  day. 
  

   It 
  contained 
  boulders 
  washed 
  out 
  of 
  pre-existing 
  Boulder 
  Clays, 
  

   thus 
  commingling 
  the 
  products 
  of 
  the 
  land-ice 
  from 
  the 
  Welsh 
  

   mountains 
  with 
  the 
  northern 
  boulders 
  rolled 
  in 
  the 
  shore-deposits. 
  

   There 
  were 
  lumps 
  of 
  the 
  older 
  clay 
  which 
  had 
  been 
  trundled 
  along 
  

   the 
  shore, 
  so 
  that 
  the 
  outside 
  was 
  covered 
  with 
  gravel, 
  sand, 
  and 
  

   shells 
  which 
  had 
  stuck 
  to 
  it. 
  There 
  were 
  fragments 
  and 
  rarely 
  

   whole 
  specimens 
  of 
  shells 
  thrown 
  up 
  from 
  various 
  habitats, 
  just 
  as 
  

   they 
  occur 
  in 
  the 
  shore-shingle 
  at 
  the 
  present 
  day 
  ; 
  and 
  in 
  some 
  of 
  

   the 
  gasteropods 
  foraminifera 
  were 
  found 
  washed 
  up 
  from 
  sea- 
  

   bottoms 
  of 
  various 
  character 
  and 
  depth, 
  as 
  at 
  the 
  present 
  time. 
  

  

  