﻿426 
  ME. 
  E. 
  P. 
  RICHARDS 
  ON 
  THE 
  GRAVELS 
  AND 
  [Aug. 
  1897, 
  

  

  Here 
  a 
  lenticular 
  mass 
  of 
  soft 
  green 
  sand 
  is 
  the 
  lowest 
  bed 
  

   exposed, 
  of 
  very 
  irregular 
  thickness, 
  and 
  with 
  an 
  eroded 
  surface, 
  

   upon 
  which 
  the 
  terrace-gravel 
  rests. 
  I 
  consider 
  this 
  sand 
  to 
  have 
  

   been 
  derived 
  higher 
  up-stream 
  from 
  a 
  former 
  exposure 
  of 
  the 
  

   hard 
  green 
  sand 
  first 
  mentioned. 
  The 
  surface-level 
  is 
  usually 
  about 
  

   260 
  feet 
  above 
  O.D., 
  but 
  rises 
  and 
  falls 
  with 
  the 
  general 
  level 
  of 
  

   the 
  river 
  above 
  and 
  below 
  Newbury, 
  as 
  is 
  natural 
  in 
  a 
  river-terrace 
  

   gravel. 
  

  

  A 
  very 
  typical 
  section, 
  about 
  26 
  feet 
  deep, 
  is 
  exposed 
  in 
  the 
  

   Enborne 
  Road 
  gravel-pit, 
  a 
  little 
  west 
  of 
  Newbury, 
  and 
  on 
  the 
  south 
  

   side 
  of 
  the 
  Kennet. 
  It 
  is 
  very 
  near 
  the 
  edge 
  of 
  the 
  terrace. 
  

  

  At 
  the 
  base 
  of 
  the 
  section 
  (fig. 
  4) 
  a 
  thickness 
  of 
  12 
  feet 
  is 
  

  

  J?ig. 
  4. 
  — 
  Section 
  in 
  gravel-pit 
  on 
  the 
  Enborne 
  Road, 
  near 
  Newbury. 
  

   (No. 
  8 
  in 
  the 
  Map, 
  PI. 
  XXX.) 
  

  

  [Vertical 
  scale 
  : 
  1 
  inch 
  = 
  20 
  feet. 
  Horizontal 
  scale 
  : 
  1 
  inch 
  = 
  40 
  feet.] 
  

  

  occupied 
  by 
  hard, 
  green, 
  slightly 
  bedded, 
  ferruginous 
  sand, 
  to 
  

   which 
  the 
  overlying 
  mass 
  of 
  river-gravel 
  is 
  sometimes 
  conform- 
  

   able 
  and 
  sometimes 
  unconformable. 
  Hard, 
  much 
  oxidized, 
  ferru- 
  

   ginous 
  nodules, 
  about 
  2 
  inches 
  in 
  diameter, 
  are 
  fairly 
  numerous 
  : 
  

   they 
  weather 
  concentrically. 
  The 
  surface 
  of 
  this 
  sand, 
  upon 
  which 
  

   the 
  river-gravel 
  rests, 
  is 
  eroded 
  : 
  swallow-holes 
  and 
  inclusions 
  of 
  

   gravel 
  being 
  frequent 
  in 
  the 
  upper 
  portion. 
  There 
  are 
  usually 
  

   small 
  sarsens 
  * 
  and 
  large 
  flint-nodules, 
  the 
  latter 
  both 
  stained 
  and 
  

   black, 
  resting 
  on 
  the 
  eroded 
  surface, 
  at 
  intervals. 
  This 
  hard 
  

   green 
  sand 
  may 
  be 
  the 
  base 
  of 
  the 
  Reading 
  Series, 
  judging 
  from 
  

   the 
  evidence 
  obtained 
  in 
  the 
  Greenham 
  Park 
  boring 
  (p. 
  422). 
  The 
  

   occasionally 
  apparent 
  conformity 
  of 
  the 
  river-gravel, 
  I 
  was 
  inclined 
  

   to 
  think 
  (at 
  the 
  time 
  of 
  observation) 
  due 
  to 
  concentric 
  weathering 
  

   of 
  the 
  sand 
  from 
  the 
  eroded 
  surface 
  downward 
  : 
  the 
  river-gravel 
  

   being 
  very 
  permeable 
  to 
  water, 
  and 
  possibly 
  to 
  air. 
  I 
  may 
  add 
  that 
  

   this 
  was 
  a 
  freshly-exposed 
  section. 
  

  

  The 
  gravel 
  shown 
  in 
  fig. 
  4 
  is 
  coarser 
  than 
  at 
  Bull's 
  Lane, 
  and 
  

   a 
  few 
  carbonaceous 
  layers 
  occur 
  ; 
  its 
  composition 
  is 
  as 
  follows 
  : 
  — 
  

  

  1 
  About 
  12 
  inches 
  in 
  their 
  longest 
  diameter. 
  

  

  