﻿104 
  foote: 
  geology 
  op 
  madras. 
  

  

  intermediate 
  bed 
  No. 
  3 
  of 
  the 
  Vellakottei 
  section 
  is 
  not 
  clearly 
  seen 
  in 
  

   this 
  section. 
  If, 
  as 
  supposed, 
  the 
  small 
  bed 
  of 
  gritty 
  shales 
  above 
  des- 
  

   cribed 
  agrees 
  with 
  No. 
  4 
  of 
  the 
  Vellakottei 
  section, 
  the 
  position 
  of 
  the 
  

   underlying 
  grits 
  is 
  fixed, 
  and 
  agrees 
  with 
  No. 
  5 
  at 
  Vellakottei. 
  The 
  

   grit 
  bed 
  is 
  well 
  exposed 
  at 
  Vellum 
  in 
  the 
  gully 
  just 
  mentioned 
  and 
  

  

  in 
  the 
  square 
  tank 
  between 
  it 
  and 
  the 
  village. 
  

   Silicified 
  wood. 
  

  

  At 
  the 
  bottom 
  of 
  the 
  north 
  end 
  of 
  the 
  gully, 
  and 
  

  

  close 
  to 
  the 
  sandy 
  shale 
  bed, 
  lies 
  imbedded 
  part 
  of 
  a 
  silicified 
  tree, 
  about 
  

  

  a 
  yard 
  long 
  and 
  10 
  inches 
  to 
  1 
  foot 
  in 
  diameter. 
  This 
  fossil 
  wood, 
  

  

  which 
  is 
  firmly 
  imbedded 
  in 
  the 
  grit, 
  is 
  beautifully 
  silicified, 
  every 
  pore 
  

  

  of 
  the 
  close-grained 
  woody 
  structure 
  having 
  been 
  perfectly 
  preserved, 
  

  

  and 
  the 
  exogenous 
  character 
  being 
  extremely 
  distinct. 
  

  

  A 
  gritty 
  sandstone 
  of 
  identical 
  appearance 
  and 
  white 
  color 
  has 
  been 
  

  

  cut 
  through, 
  and 
  exposed 
  to 
  the 
  depth 
  of 
  2 
  to 
  

   Tirumimgalum 
  section. 
  

  

  3 
  feet 
  in 
  the 
  new 
  irrigation 
  canal 
  at 
  Tirumun- 
  

  

  galum 
  on 
  the 
  Arcot 
  road 
  and 
  not 
  quite 
  two 
  miles 
  west-north-west 
  of 
  the 
  

  

  Araneri 
  section. 
  The 
  Tirumungalum 
  grit, 
  if 
  belonging 
  to 
  the 
  Sriper- 
  

  

  matoor 
  group, 
  which 
  it 
  most 
  likely 
  does, 
  has 
  had 
  the 
  overlying 
  shales 
  

  

  denuded 
  away 
  from 
  off 
  it, 
  for 
  it 
  is 
  capped 
  by 
  lateritic 
  conglomerate. 
  

  

  This 
  grit 
  is 
  probably 
  continuous 
  over 
  the 
  whole 
  area 
  of 
  high 
  ground 
  

  

  between 
  Tirumungalum, 
  Kiranullur, 
  Kandoor, 
  and 
  Punnoor, 
  though 
  

  

  perfectly 
  covered 
  up 
  by 
  lateritic 
  formations. 
  

  

  The 
  whole 
  of 
  the 
  remaining 
  area 
  of 
  the 
  northern 
  half 
  of 
  the 
  

   Sripermatoor 
  area 
  appears 
  to 
  be 
  occupied 
  by 
  the 
  plant 
  shales 
  only, 
  

   for 
  they 
  only 
  are 
  seen 
  in 
  the 
  numerous 
  shallow 
  sections 
  there 
  met 
  

   with. 
  

  

  The 
  high 
  ground 
  lying 
  east 
  of 
  Araneri 
  and 
  north 
  of 
  Vellum 
  offers 
  

   the 
  largest 
  area 
  of 
  the 
  Sripermatoor 
  rocks 
  free 
  from 
  a 
  lateritic 
  capping, 
  

   and 
  affords 
  several 
  good 
  sections 
  of 
  the 
  plant 
  shales, 
  which 
  are 
  not, 
  

   however, 
  remarkably 
  rich 
  in 
  plant 
  remains. 
  

  

  ( 
  101 
  ) 
  

  

  