﻿I 
  Og 
  E00TE 
  : 
  GEOLOGY 
  OE 
  MADRAS. 
  

  

  The 
  southern 
  part 
  of 
  the 
  Sripermatoor 
  area. 
  — 
  As 
  already 
  men- 
  

   tioned; 
  there 
  is 
  a 
  great 
  change 
  in 
  the 
  mineral 
  character 
  of 
  the 
  forma- 
  

   tion 
  occurring 
  in 
  this 
  part 
  of 
  the 
  Sripermatoor 
  area 
  from 
  that 
  of 
  the 
  

   beds 
  described 
  above. 
  Topographically 
  also 
  the 
  southern 
  half 
  of 
  the 
  

   area 
  should 
  be 
  treated 
  distinctly 
  as 
  it 
  is 
  separated 
  from 
  the 
  basin-like 
  

   valleys 
  to 
  the 
  north, 
  by 
  a 
  ridge 
  of 
  rather 
  high 
  ground 
  running 
  

   across, 
  and 
  forming 
  the 
  water-shed 
  about 
  half 
  a 
  mile 
  north 
  of 
  the 
  old 
  

   and 
  now 
  abandoned 
  road 
  from 
  Madras 
  to 
  Wallajabad. 
  

  

  The 
  area 
  thus 
  separated 
  from 
  the 
  Sripermatoor 
  basin 
  is 
  itself 
  

   divisible 
  into 
  two 
  parts, 
  as 
  a 
  line 
  of 
  water-shed 
  runs 
  across 
  it 
  in 
  a 
  north, 
  

   west 
  by 
  north 
  to 
  south-east 
  by 
  south 
  direction 
  immediately 
  west 
  of 
  the 
  

   village 
  of 
  Omeallicherry. 
  

  

  The 
  south 
  part 
  of 
  this 
  area 
  is 
  greatly 
  obscured 
  by 
  a 
  thick 
  covering 
  

  

  of 
  reddish 
  sandy 
  soil 
  apparently 
  washed 
  down 
  

   Want 
  of 
  sections. 
  

  

  from 
  the 
  higher-lying 
  gneiss 
  region 
  to 
  the 
  east, 
  

  

  and 
  the 
  laterite 
  plateau 
  of 
  Oragidam 
  (Woodagurm 
  of 
  map) 
  to 
  the 
  

  

  north. 
  

  

  It 
  is 
  only 
  north 
  of 
  a 
  line 
  drawn 
  from 
  Vellikaram 
  to 
  Wadakupat 
  

   (Warracapett 
  of 
  map), 
  where 
  the 
  ground 
  rises, 
  that 
  the 
  surface 
  soil 
  

   begins 
  to 
  be 
  derived 
  from 
  the 
  underlying 
  white 
  and 
  greyish 
  shaley 
  clays. 
  

   No 
  good 
  sections 
  are 
  to 
  be 
  found 
  here, 
  and 
  the 
  clays 
  are 
  only 
  seen 
  in 
  the 
  

   material 
  turned 
  out 
  of 
  tank 
  bottoms 
  and 
  wells. 
  

  

  The 
  soil 
  is 
  white 
  and 
  sandy 
  and 
  scattered 
  very 
  thinly 
  with 
  patches 
  

  

  of 
  large 
  and 
  small 
  quartzite 
  pebbles. 
  Fine 
  dark- 
  

   Vellikaranei 
  section. 
  . 
  

  

  grey 
  sandy 
  clay 
  occurs 
  underlying 
  the 
  white 
  soil 
  

  

  at 
  Vellikaranei. 
  It 
  is 
  exposed 
  only 
  in 
  a 
  small 
  well, 
  and 
  to 
  a 
  cursory 
  

  

  examination 
  proved 
  unfossiliferous. 
  

  

  North-east 
  of 
  Vellikaranei 
  the 
  surface 
  of 
  the 
  Rajmahal 
  beds 
  is 
  

   much 
  hidden 
  by 
  reddish 
  soils, 
  and 
  nearer 
  the 
  gneiss 
  boundary 
  by 
  scrubby 
  

   jungle. 
  

  

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