﻿430 
  mr. 
  e. 
  p. 
  richards 
  on 
  the 
  gravels 
  and 
  [aug. 
  1 
  897, 
  

  

  § 
  6. 
  The 
  Neolithic 
  Lake-Series 
  and 
  Recent 
  Deposits. 
  

  

  Section 
  CD, 
  in 
  PL 
  XXX, 
  shows 
  two 
  of 
  these 
  ridges 
  (see 
  Map), 
  

   which 
  I 
  have 
  been 
  able 
  to 
  trace 
  more 
  or 
  less 
  completely 
  across 
  the 
  

   valley. 
  Gaps 
  appear 
  in 
  them 
  near 
  the 
  present 
  river-channel 
  ; 
  and 
  

   they 
  appear 
  to 
  have 
  been 
  cut 
  by 
  ancient 
  river-action, 
  which 
  gradually 
  

   drained 
  the 
  lakes, 
  leaving 
  the 
  peat 
  and 
  marl 
  to 
  ultimately 
  clothe 
  

   themselves 
  with 
  meadow 
  and 
  wood. 
  

  

  The 
  typical 
  strata 
  in 
  these 
  Neolithic 
  lake-basins 
  are 
  well 
  illustrated 
  

   in 
  fig. 
  7, 
  taken 
  in 
  Northbrook 
  Street. 
  The 
  beds 
  shown 
  in 
  this 
  

   interesting 
  section 
  are 
  fairly 
  constant 
  throughout 
  the 
  two 
  lake-sites, 
  

   with 
  the 
  exception 
  of 
  the 
  green 
  loam, 
  which 
  is 
  frequently 
  absent. 
  

   The 
  successive 
  stages 
  of 
  formation, 
  and 
  the 
  subsequent 
  disappearance 
  

   of 
  the 
  lakes, 
  are 
  well 
  marked 
  by 
  the 
  strata. 
  First 
  the 
  clay, 
  pro- 
  

   bably 
  deposited 
  over 
  the 
  lower 
  gravel 
  by 
  the 
  river 
  when 
  in 
  flood 
  ; 
  

   next 
  the 
  partial 
  barrier, 
  producing 
  a 
  peat-marsh 
  and 
  the 
  peaty 
  

   pools, 
  in 
  which 
  the 
  green 
  loam 
  was 
  laid 
  down 
  ; 
  followed 
  by 
  a 
  

   further 
  raising 
  of 
  the 
  barrier, 
  sufficient 
  to 
  drown 
  the 
  peat 
  and 
  form 
  

   a 
  lake, 
  the 
  water 
  teeming 
  with 
  the 
  mollusca 
  found 
  in 
  the 
  white 
  

   shell-marl 
  ; 
  and 
  lastly, 
  the 
  breached 
  barrier 
  draining 
  the 
  lake. 
  

  

  The 
  peat 
  and 
  marl 
  are 
  very 
  constant 
  associates 
  throughout; 
  and, 
  

   as 
  a 
  rule, 
  where 
  the 
  peat 
  is 
  thick 
  the 
  marl 
  is 
  thin, 
  and 
  vice 
  versa. 
  

   This 
  I 
  account 
  for 
  by 
  supposing 
  the 
  thin 
  peat 
  to 
  indicate 
  the 
  deepest 
  

   parts 
  of 
  the 
  lake-bottoms, 
  which 
  would 
  be 
  the 
  first 
  portions 
  con- 
  

   verted 
  into 
  pools, 
  stopping 
  the 
  growth 
  of 
  peat 
  and 
  giving 
  a 
  more 
  

   prolonged 
  period 
  for 
  the 
  deposition 
  of 
  marl. 
  The 
  contrary 
  of 
  thi3 
  

   would, 
  of 
  course, 
  explain 
  the 
  thick 
  marl 
  and 
  thin 
  peat; 
  the 
  differ- 
  

   ences 
  in 
  level, 
  however, 
  are 
  not 
  sufficient 
  to 
  clearly 
  show 
  this. 
  

  

  Taking 
  this 
  little 
  lake-series 
  in 
  order 
  : 
  — 
  the 
  base, 
  which 
  rests 
  

   upon 
  the 
  ' 
  Lower 
  Eiv 
  T 
  er-gravel,' 
  is 
  generally 
  a 
  bed 
  of 
  very 
  stiff, 
  

   dark-yellowish 
  clay, 
  probably 
  resulting 
  from 
  the 
  denudation 
  of 
  

   surrounding 
  London 
  Clay 
  hills. 
  Several 
  roughly-worked 
  black 
  flints 
  

   were 
  found 
  in 
  this 
  clay, 
  and 
  occasional 
  pieces 
  of 
  rolled 
  wood, 
  but 
  

   no 
  bones. 
  

  

  The 
  green 
  loam 
  lying 
  above 
  it 
  consists 
  of 
  about 
  equal 
  parts 
  of 
  

   fine 
  sand 
  and 
  dark-greenish 
  clay. 
  Freshwater 
  shells 
  and 
  logs 
  of 
  

   birch 
  and 
  oak, 
  with 
  leaves, 
  twigs, 
  and 
  nuts 
  of 
  the 
  hazel, 
  occur 
  

   frequently, 
  and 
  are 
  identical 
  with 
  those 
  in 
  the 
  peat 
  above. 
  I 
  

   obtained 
  a 
  pelvis 
  of 
  roedeer 
  from 
  the 
  green 
  loam 
  near 
  the 
  pumping- 
  

   station. 
  

  

  The 
  peat 
  next 
  in 
  the 
  series 
  is 
  of 
  great 
  interest 
  as 
  being 
  here 
  the 
  

   chief 
  repository 
  of 
  human 
  relics. 
  1 
  Among 
  those 
  found 
  were 
  flint- 
  

   implements, 
  one 
  fragment 
  of 
  carved 
  bone, 
  pieces 
  of 
  sun-dried 
  

   pottery, 
  and 
  bone-drills, 
  all 
  of 
  Neolithic 
  types. 
  No 
  bronze 
  or 
  iron 
  

   weapons 
  were 
  found 
  in 
  the 
  peat. 
  I 
  observed 
  a 
  kidney-shaped 
  

   pebble 
  of 
  Bath 
  Oolite 
  in 
  the 
  peat, 
  the 
  presence 
  of 
  which 
  I 
  attri- 
  

   buted 
  to 
  human 
  agency. 
  

  

  As 
  in 
  the 
  green 
  loam 
  underneath, 
  logs 
  of 
  birch, 
  oak, 
  and 
  fir 
  

   (trunks 
  and 
  roots) 
  were 
  abundant. 
  I 
  also 
  found 
  large 
  tree-fungi, 
  

  

  1 
  Note 
  IV. 
  in 
  Appendix 
  I, 
  p. 
  433. 
  

  

  