﻿PLIOCENE 
  PERIOD 
  IN 
  ENGLAND. 
  715 
  

  

  arrived 
  at 
  the 
  H 
  umber-gorge, 
  that 
  it 
  collected 
  some 
  subangular 
  chalk. 
  

   Then 
  spreading 
  out 
  over 
  the 
  low 
  ground 
  of 
  Holder 
  ness 
  and 
  that 
  which 
  

   skirts 
  the 
  seaboard 
  of 
  the 
  Lincolnshire 
  Wold, 
  it 
  enveloped 
  those 
  parts 
  

   with 
  a 
  coat 
  of 
  moraine 
  everywhere 
  of 
  small 
  thickness, 
  but 
  thickest 
  

   in 
  the 
  hollows, 
  as 
  it 
  appears 
  in 
  the 
  foregoing 
  cut 
  of 
  Kelsea 
  Hill, 
  

   where 
  the 
  small 
  boulders 
  in 
  it, 
  other 
  than 
  the 
  subangular 
  chalk, 
  

   appear 
  for 
  the 
  most 
  part 
  to 
  be 
  derived 
  from 
  the 
  coarse 
  gravel-beds 
  

   in 
  the 
  C 
  1/ 
  re 
  na- 
  for 
  motion 
  which 
  it 
  overlies. 
  Thus 
  this 
  clay 
  in 
  Holder- 
  

   ness 
  and 
  East 
  Lincolnshire 
  has 
  scarcely 
  any 
  of 
  that 
  small 
  angular 
  rock 
  

   debris 
  with 
  which 
  the 
  Purple 
  Clay 
  it 
  often 
  rests 
  upon 
  is 
  crammed. 
  

   What 
  little 
  it 
  may 
  have 
  of 
  this 
  (and 
  I 
  never 
  observed 
  any) 
  may 
  well 
  

   have 
  been 
  collected 
  from 
  the 
  Purple 
  Clay 
  over 
  which 
  it 
  passed. 
  On 
  

   the 
  other 
  hand, 
  while 
  chalk 
  debris 
  gradually 
  disappears 
  from 
  the 
  

   uppermost 
  part 
  of 
  the 
  Purple 
  Clay 
  where 
  this 
  is 
  thickest, 
  as 
  in 
  

   fig. 
  XLYL, 
  the 
  Hessle 
  Clay 
  thus 
  wrapping 
  it 
  has 
  much 
  chalk, 
  but 
  

   of 
  the 
  more 
  subangular 
  shape 
  which 
  distinguishes 
  it 
  from 
  the 
  rolled 
  

   chalk 
  of 
  the 
  Purple 
  and 
  Basement 
  Clays. 
  

  

  The 
  Kelsea-Hill 
  section 
  given 
  in 
  Cut 
  iv. 
  p. 
  713, 
  and 
  figures 
  XLVI. 
  

   and 
  XL 
  VII. 
  of 
  the 
  Plate, 
  show 
  the 
  way 
  in 
  which 
  this 
  ice, 
  thickening 
  

   in 
  depressions, 
  has 
  cut 
  into 
  and 
  cut 
  out 
  the 
  Ctymw-formation 
  <1>, 
  and 
  

   laid 
  its 
  moraine 
  (r) 
  in 
  the 
  parts 
  thus 
  cut 
  out, 
  as 
  well 
  as 
  over 
  <I>. 
  The 
  

   woodcut 
  also 
  shows 
  the 
  ridge-like 
  arrangement 
  of 
  the 
  beds 
  described 
  

   by 
  Mr. 
  Dakyns 
  in 
  the 
  case 
  of 
  the 
  same 
  sand 
  and 
  gravel, 
  where 
  it 
  is 
  

   overlain 
  by 
  this 
  Clay 
  near 
  York, 
  as 
  " 
  dipping 
  away 
  from 
  the 
  crown 
  

   of 
  the 
  arch 
  " 
  (p. 
  386 
  of 
  vol. 
  xxviii. 
  of 
  the 
  Journal). 
  This 
  seems 
  to 
  

   have 
  been 
  caused 
  by 
  the 
  lateral 
  pressure 
  of 
  the 
  land-ice 
  in 
  the 
  

   hollows 
  of 
  the 
  gravel. 
  

  

  There 
  is 
  on 
  the 
  west 
  side 
  of 
  the 
  Humber-gorge 
  a 
  low 
  tract 
  occupied 
  

   by 
  alluvial 
  accumulations 
  of 
  recent 
  origin, 
  which 
  seems 
  to 
  have 
  been 
  

   a 
  hollow 
  excavated 
  by 
  this 
  ice 
  thickening 
  therein 
  consequence 
  of 
  the 
  

   constriction 
  caused 
  by 
  that 
  gorge. 
  

  

  Another 
  important 
  feature 
  in 
  this 
  clay 
  is 
  the 
  way 
  in 
  which, 
  towards 
  

   its 
  southern 
  extremity, 
  it 
  passes 
  the 
  mouth 
  of 
  the 
  Steeping 
  valley, 
  

   and, 
  as 
  it 
  were, 
  peeps 
  into 
  it, 
  making 
  only 
  a 
  slight 
  deflection 
  so 
  as 
  

   to 
  occur 
  on 
  one 
  side 
  of 
  it 
  only, 
  and 
  just 
  at 
  the 
  mouth. 
  Had 
  the 
  

   . 
  clay 
  been 
  an 
  aqueous 
  accumulation, 
  it 
  should 
  stretch 
  up 
  this 
  valley, 
  

   just 
  as 
  the 
  marine 
  brickclay 
  of 
  the 
  Cyrena- 
  formation 
  extends 
  up 
  the 
  

   valley 
  of 
  the 
  Nar. 
  The 
  accompanying 
  cut, 
  taken 
  from 
  the 
  paper 
  of 
  

  

  Cut 
  v. 
  — 
  Section 
  across 
  tlie 
  Mouth 
  of 
  the 
  Steeping 
  Valley 
  (from 
  

   vol. 
  xxiv. 
  p. 
  163, 
  line 
  A 
  P 
  on 
  Map 
  5). 
  

  

  E.N.E. 
  

   W.S.W. 
  River 
  North 
  ride 
  Wold 
  brow 
  at 
  

  

  Mavis 
  Euderby. 
  Eundleby. 
  Steeping, 
  of 
  Ashby. 
  Welton 
  Mill. 
  

  

  1. 
  Jurassic. 
  2. 
  Neocomian. 
  3. 
  The 
  Red 
  Chalk. 
  4. 
  The 
  (Jhulk. 
  

   a. 
  The 
  Chalky 
  Clay, 
  consisting 
  here 
  of 
  reconstructed 
  Chalk 
  similar 
  to 
  thai 
  of 
  

   the 
  masses 
  buried 
  in 
  the 
  Contorted 
  Drift 
  of 
  North 
  Norfolk, 
  e. 
  The 
  Hessle 
  

   Clay. 
  

  

  3b2 
  

  

  