﻿ASHPRINGTON 
  VOLCANIC 
  SERIES 
  OP 
  SOUTH 
  DEVON. 
  379 
  

  

  in 
  some 
  of 
  the 
  lavas 
  were 
  so 
  gradual 
  that 
  one 
  can 
  hardly 
  see 
  where 
  

   they 
  begin 
  or 
  end. 
  There 
  were 
  also 
  intruded 
  volcanic 
  rocks 
  of 
  a 
  

   similar 
  character. 
  Referring 
  to 
  the 
  errors 
  in 
  the 
  mapping 
  of 
  the 
  

   boundary 
  between 
  the 
  Carboniferous 
  and 
  Devonian 
  of 
  this 
  region, 
  

   he 
  asserted 
  that 
  the 
  town 
  of 
  Tavistock 
  is 
  actually 
  on 
  the 
  Carboni- 
  

   ferous, 
  and 
  yet 
  that 
  by 
  a 
  complex 
  series 
  of 
  foldings 
  the 
  Devonian 
  

   is 
  brought 
  up 
  north 
  and 
  south 
  of 
  it. 
  He 
  spoke 
  of 
  trap 
  dividing 
  a 
  

   series 
  of 
  " 
  Schalstein 
  " 
  beds 
  ; 
  elsewhere 
  two 
  distinct 
  lava-flows 
  might 
  

   be 
  noticed, 
  one 
  above 
  the 
  other. 
  

  

  Mr. 
  W. 
  W. 
  Beaumont 
  criticized 
  some 
  of 
  Dr. 
  Hatch's 
  remarks 
  

   with 
  reference 
  to 
  the 
  alleged 
  traces 
  of 
  shearing 
  in 
  the 
  vesicular 
  

   lavas, 
  based 
  partly 
  upon 
  the 
  assumption 
  that 
  shearing 
  would 
  destroy 
  

   the 
  continuity 
  of 
  the 
  cavities 
  ; 
  and 
  

  

  Dr. 
  Hatch 
  pointed 
  out 
  that, 
  according 
  to 
  his 
  view, 
  the 
  cavities 
  

   having 
  been 
  filled 
  at 
  the 
  time 
  that 
  the 
  shearing 
  took 
  place, 
  they 
  

   must 
  be 
  regarded 
  as 
  solid 
  bodies. 
  

  

  