﻿SUBDIVISIONS 
  OF 
  THE 
  SPEET0N 
  CLAY. 
  577 
  

  

  the 
  " 
  JS 
  T 
  oricus-beds" 
  and 
  of 
  the 
  upper 
  part 
  of 
  the 
  " 
  zone 
  of 
  Belem- 
  

   nites 
  lateralis," 
  and 
  this 
  constitutes 
  one 
  of 
  the 
  best 
  collecting-grounds 
  

   of 
  the 
  locality. 
  These 
  beds 
  are 
  puckered 
  up 
  into 
  shallow 
  folds. 
  

  

  The 
  greatest 
  change 
  has 
  taken 
  place 
  in 
  New 
  Closes 
  Cliff, 
  where 
  

   the 
  northern 
  termination 
  of 
  the 
  clays 
  has 
  been 
  quite 
  blotted 
  out 
  

   by 
  the 
  huge 
  slip 
  of 
  drift 
  which 
  closed 
  the 
  " 
  coprolite 
  '* 
  workings. 
  

   On 
  the 
  other 
  hand, 
  the 
  sea 
  has 
  removed 
  most 
  of 
  the 
  talus 
  heaps 
  of 
  

   the 
  workings, 
  so 
  that 
  the 
  bituminous 
  shales 
  (Upper 
  Kimeridge) 
  are, 
  

   for 
  a 
  short 
  distance, 
  well 
  seen 
  in 
  the 
  cliff-foot. 
  

  

  The 
  Shoke-exposukes. 
  

  

  The 
  beach 
  off 
  the 
  clay-cliffs 
  consists 
  of 
  sand 
  with 
  a 
  little 
  shingle, 
  

   out 
  as 
  we 
  go 
  southward 
  towards 
  the 
  great 
  chalk-cliffs 
  the 
  flinty 
  

   shingle 
  increases 
  rapidly 
  both 
  in 
  quantity 
  and 
  in 
  roughness, 
  till 
  it 
  

   gives 
  place 
  to 
  a 
  rude 
  pavement 
  of 
  loose 
  blocks. 
  

  

  There 
  is 
  usually 
  a 
  rather 
  steep 
  slope 
  of 
  shingle 
  with 
  some 
  sand, 
  

   known 
  to 
  our 
  fishermen 
  as 
  the 
  " 
  canch," 
  near 
  the 
  foot 
  of 
  the 
  cliff, 
  

   and 
  below 
  this 
  a 
  broad 
  flat 
  belt 
  of 
  wet 
  ripple-marked 
  sand, 
  which 
  

   during 
  neap-tides 
  is 
  scarcely 
  uncovered, 
  but 
  during 
  springs 
  may 
  

   attain 
  a 
  breadth 
  of 
  over 
  250 
  yards. 
  

  

  In 
  stormy 
  weather 
  the 
  sand 
  forming 
  this 
  flat 
  belt, 
  instead 
  of 
  being 
  

   spread 
  evenly 
  over 
  the 
  shore, 
  is 
  driven 
  up 
  into 
  ridges, 
  or 
  is 
  carried 
  

   below 
  the 
  low-tide 
  limit, 
  leaving 
  surfaces 
  of 
  the 
  underlying 
  clay 
  

   exposed. 
  

  

  As 
  the 
  surface 
  of 
  this 
  clay 
  is 
  some 
  feet 
  below 
  the 
  normal 
  level 
  of 
  

   the 
  sandy 
  beach, 
  when 
  the 
  beds 
  are 
  thus 
  exposed, 
  the 
  breadth 
  of 
  the 
  

   tidal 
  flat 
  is, 
  of 
  course, 
  very 
  much 
  narrowed. 
  Thus, 
  in 
  the 
  accom- 
  

   panying 
  ground-plan 
  (fig. 
  1, 
  p. 
  578), 
  the 
  broken 
  line 
  indicates 
  the 
  

   limit 
  of 
  low 
  water 
  as 
  marked 
  on 
  the 
  6-inch 
  Ordnance-map, 
  while 
  

   the 
  seaward 
  edge 
  of 
  the 
  strata, 
  as 
  shown 
  in 
  the 
  figure, 
  is 
  nowhere 
  

   far 
  from 
  low-tide 
  mark 
  when 
  the 
  beach 
  is 
  thus 
  denuded. 
  

  

  These 
  exposures 
  occur 
  far 
  more 
  frequently 
  over 
  some 
  portions 
  of 
  

   the 
  beach 
  than 
  over 
  others, 
  and 
  the 
  " 
  canch 
  " 
  itself 
  is 
  rarely 
  broken 
  

   through 
  ; 
  but 
  I 
  believe 
  that 
  could 
  a 
  series 
  of 
  observations 
  be 
  carried 
  

   on 
  for 
  long 
  enough, 
  the 
  beds 
  might 
  be 
  mapped 
  over 
  the 
  whole 
  of 
  the 
  

   shore. 
  As 
  it 
  is, 
  I 
  have 
  marked 
  down 
  on 
  the 
  ground-plan 
  such 
  

   strata 
  as 
  I 
  have 
  actually 
  seen 
  ; 
  and 
  have 
  connected 
  these 
  exposures 
  

   by 
  broken 
  lines, 
  which 
  indicate 
  the 
  supposed 
  extension 
  of 
  the 
  beds 
  

   where 
  not 
  yet 
  observed. 
  

  

  That 
  part 
  of 
  the 
  shore 
  which 
  lies 
  off 
  the 
  northern 
  half 
  of 
  Black 
  

   Cliff 
  has 
  of 
  late 
  years 
  been 
  far 
  more 
  subject 
  to 
  such 
  denudation 
  

   than 
  any 
  other 
  portion. 
  Consequently 
  I 
  have 
  here 
  had 
  the 
  greatest 
  

   facilities 
  for 
  studying 
  the 
  beds, 
  and 
  my 
  measurements 
  and 
  descrip- 
  

   tions 
  of 
  the 
  section 
  have 
  been 
  chiefly 
  made 
  on 
  this 
  part 
  of 
  the 
  section, 
  

   where 
  fortunately 
  a 
  fuller 
  succession 
  of 
  the 
  beds 
  is 
  shown 
  than 
  any 
  

   other 
  portion 
  of 
  the 
  beach 
  could 
  reveal. 
  

  

  As. 
  this 
  plan 
  shows, 
  the 
  clays 
  after 
  emerging 
  from 
  beneath 
  the 
  

   chalk 
  have 
  a 
  course 
  that, 
  though 
  variable, 
  does 
  not 
  at 
  first 
  present 
  

   any 
  marked 
  irregularity 
  ; 
  but 
  a 
  little 
  further 
  northward 
  the 
  beds 
  

  

  2tj2 
  

  

  