320 
MR.  0.  A.  SHRUBSOLE  ON  THE 
[Aug.  1893, 
27.  Cn  the  Plateau-gravel  South  oe  Beading. 
By  0.  A.  Shrubsole,  Esq.,  E.G.S.  (Bead  March  8th,  1893.) 
[Abridged.] 
The  gravel  of  the  Easthampstead-Yateley  plateau,  to  which  this 
paper  refers,  has  already  been  fully  described  in  the  Quarterly 
.Journal  of  this  Society  and  elsewhere.1  It  is  therefore  proposed 
now  to  submit  only  a  few  supplementary  observations. 
The  gravel  may  be  briefly  described  as  consisting  principally  of 
rolled  and  subangular  flints.  YTith  these  is  a  small  proportion  of 
tlint-pebbles,  with  fragments  of  chert,  sandstone,  etc.,  and  a  few 
very  small  quartz-pebbles.2  The  flint-material,  excluding  the 
pebbles  of  flint,  has  usually  a  worn  and  altered  appearance  (noted 
already  by  Dr.  Irving),  and  consists  chiefly  of  nodular  flints  of 
small  size,  the  nodules  frequently  being  entire.  Internally  the 
flint  is  usually  of  a  bright  brown  or  amber  colour.  It  is  generally 
understood  that  these  ordinary  materials  of  the  gravel  have  had  a 
local  and  southern  origin.  There  is  a  small  element,  however, 
which  cannot  be  so  readily  referred  to  the  same  source.  The 
finding  of  boulders  of  quartz  and  a  specimen  of  quartzite  at  various 
points  on  the  plateau  has  been  already  referred  to  by  Mr.  H.  Y  . 
Monckton.3 
I  have  at  different  times  found  several  fragments  of  white  vein- 
quartz  varying  in  longest  diameter  from  2  to  6  inches,  the  larger 
specimens  being  less  rolled  than  the  smaller.  They  were  found 
chiefly  in  the  gravel-pits  near  Caesar’s  Camp  (Easthampstead)  and 
at  Emchampstead  Bidges,  lying  on  the  heaps  of  gravel,  in  the 
former  case  at  about  400  feet,  and  in  the  latter  case  at  about  330 
feet  above  sea-level.  I  also  found,  under  similar  circumstances,  in 
a  gravel-pit  at  the  summit  of  the  northern  continuation  of  Chobham 
Bidges,4  at  about  400  feet  above  sea-level,  a  large  pebble  of  purplish, 
highly  metamorphosed,  veined  quartzite. 
Noticing  its  strong  resemblance  to  the  quartzites  of  the  Glacial 
Gravel  in  the  Thames  Talley,  I  searched  a  gravel  of  the  Tilehurst 
plateau,  and  had  no  difficulty  in  finding  in  the  Norcot  gravel-pit  a 
pebble  of  an  exactly  similar  character.  Becognizing  the  desira¬ 
bility  of  obtaining  more  than  a  single  specimen,  I  have  since  visited 
the  Olddean  pit  on  one  or  two  occasions,  but  without  success. 
Only  two  pebbles  of  quartzite,  which  might  be  of  northern  origin, 
1  Quart.  Journ.  Geol.  Soc.  toI.  xlvi.  (1890)  pp.  120  &  557,  and  vol.  xlviii. 
(1892)  p.  29.  See  also  Proc.  Geol.  Assoc,  vol.  vi.  (1880)  p.  437,  and  vol.  viii. 
(1883)  p.  161. 
2  See  Prof.  Prestwick s  description  of  ‘Southern  Drift’  in  Quart.  Journ. 
Geol.  Soc.  vol.  xlvi.  (1890)  p.  156. 
3  Quart.  Journ.  Geol.  Soc.  vol.  xlviii.  (1892)  p.  29. 
4  At  the  eastern  end  of  Olddean  Common,  a  little  to  the  left  of  the  road 
from  Blackwater  to  Bagshot. 
