﻿9Q 
  FOOTE 
  : 
  GEOLOGY 
  OF 
  MADRAS. 
  

  

  In 
  another 
  large 
  walled 
  well, 
  a 
  few 
  hundred 
  yards 
  westward, 
  a 
  thick- 
  

   ness 
  of 
  8 
  or 
  9 
  feet 
  of 
  the 
  boulder-bed 
  could 
  be 
  seen 
  below 
  the 
  base 
  of 
  

   the 
  wall. 
  Here 
  the 
  masses 
  of 
  granite 
  were 
  still 
  very 
  large 
  ; 
  one 
  and 
  

   a 
  half 
  to 
  two 
  feet 
  in 
  diameter 
  being 
  a 
  common 
  size. 
  The 
  quartzite 
  

   boulders 
  did 
  not 
  exceed 
  a 
  large 
  man's 
  head 
  in 
  size 
  ; 
  many 
  were 
  smaller, 
  

   and 
  with 
  them 
  are 
  mixed 
  up 
  large 
  pebbles 
  of 
  brownish-purple 
  slate. 
  

   The 
  matrix 
  enclosing 
  these 
  boulders 
  and 
  pebbles 
  is 
  a 
  buffy-brown 
  friable 
  

   sandstone. 
  

  

  Proceeding 
  south-west 
  from 
  Trevatankadu, 
  the 
  boulder-bed 
  changes 
  

   its 
  character 
  somewhat, 
  the 
  large 
  boulders 
  become 
  less 
  numerous, 
  and 
  the 
  

   bedding 
  of 
  the 
  sandstone 
  matrix 
  is 
  recognizable. 
  

  

  The 
  bedding 
  rolls 
  very 
  much, 
  and 
  as 
  the 
  sections 
  seen 
  are 
  only 
  in 
  

  

  the 
  vertical 
  sides 
  of 
  the 
  wells 
  and 
  bowries, 
  it 
  is 
  difficult 
  to 
  determine 
  the 
  

  

  direction 
  of 
  the 
  general 
  dip, 
  but 
  it 
  is 
  most 
  probably 
  to 
  the 
  eastward. 
  

  

  Still 
  further 
  west 
  at 
  the 
  village 
  of 
  Veerapooram, 
  

  

  Veerapooram 
  section. 
  

  

  the 
  boulder-bed 
  reappears 
  in 
  a 
  well 
  section 
  dimi- 
  

   nished 
  in 
  thickness 
  and 
  underlaid 
  by 
  friable 
  sandstone, 
  both 
  dipping 
  

   eastward 
  at 
  an 
  angle 
  of 
  from 
  20 
  to 
  25 
  degrees. 
  

  

  Friable 
  sandstone 
  of 
  precisely 
  similar 
  character 
  is 
  seen 
  in 
  well 
  sec- 
  

   tions 
  north 
  of 
  Pyanoor. 
  In 
  two 
  new 
  well 
  sections 
  occurring 
  about 
  a 
  

  

  mile 
  north 
  of 
  the 
  village 
  brownish-buff 
  friable 
  

   Section 
  north 
  ot 
  ° 
  

  

  Pyanoor. 
  sandstone 
  and 
  greyish, 
  or 
  buffy-brown, 
  gritty 
  sand- 
  

  

  stones 
  were 
  seen 
  at 
  the 
  base 
  of 
  the 
  lining 
  wall 
  at 
  a 
  depth 
  of 
  between 
  20 
  

   and 
  30 
  feet 
  from 
  the 
  surface, 
  with 
  occasional 
  clayey 
  partings 
  and 
  a 
  few 
  

   small 
  quartzite 
  boulders 
  enclosed. 
  In 
  the 
  more 
  westerly 
  of 
  the 
  two 
  wells 
  

   which 
  are 
  of 
  large 
  size 
  (from 
  25 
  to 
  30 
  feet 
  in 
  diameter), 
  the 
  beds 
  appear 
  

   to 
  dip 
  about 
  6° 
  towards 
  a 
  point 
  lying 
  between 
  east 
  by 
  south 
  and 
  east- 
  

   south-east. 
  The 
  lining 
  walls 
  prevented 
  my 
  ascertaining 
  exactly 
  the 
  

   thickness 
  of 
  the 
  superincumbent 
  lateritic 
  shingle 
  beds, 
  which 
  is 
  here 
  very 
  

   considerable. 
  Whether 
  this 
  sandstone 
  under- 
  or 
  over-lies 
  the 
  Pyanoor 
  

   ( 
  96 
  ) 
  

  

  