﻿THE 
  LATERITIC 
  FORMATIONS. 
  37 
  

  

  sands 
  contain 
  rounded 
  pebbles 
  and 
  masses 
  of 
  quartzite 
  of 
  various 
  colors 
  

   and 
  sizes 
  : 
  — 
  for 
  example, 
  in 
  a 
  new 
  well-section 
  seen 
  at 
  Ulandur, 
  five 
  miles 
  

   north-west 
  of 
  Sripermatoor, 
  pale 
  sands 
  full 
  of 
  large 
  pebbles 
  and 
  

   small 
  boulders 
  of 
  quartzite 
  of 
  pale-drab, 
  whitish, 
  purplish 
  and 
  brown 
  

   colors 
  (mixed 
  in 
  this 
  case 
  with 
  rounded 
  fragments 
  of 
  gneiss 
  and 
  mica- 
  

   schist 
  and 
  some 
  debris 
  of 
  the 
  plant-shales) 
  occur, 
  which 
  pass 
  up 
  into 
  the 
  

   red 
  lateritic 
  sand. 
  Occasionally 
  small 
  portions 
  of 
  the 
  sand 
  have 
  been 
  

   cemented 
  together, 
  apparently 
  by 
  subsequent 
  infiltration 
  of 
  calciferous 
  

  

  water, 
  into 
  flaggy 
  cakes, 
  parts 
  of 
  which 
  are 
  some- 
  

   Sandy 
  marl 
  concre- 
  

   tions 
  formed 
  by 
  infiltra- 
  times 
  rather 
  concretionary 
  in 
  structure 
  and 
  consist 
  

   tions. 
  

  

  of 
  very 
  impure 
  sandy 
  marl. 
  Many 
  of 
  these 
  may 
  

  

  be 
  seen 
  in 
  a 
  rain-gully 
  south 
  of 
  the 
  Madras 
  — 
  Arcot 
  road, 
  opposite 
  

   Tirumungalum. 
  Also 
  on 
  the 
  high 
  grounds 
  east 
  of 
  Manoor 
  (three 
  

   miles 
  north 
  -north-east 
  of 
  Sripermatoor), 
  and 
  scattered 
  over 
  the 
  fields 
  

   south 
  of 
  Wallaveram 
  and 
  northwards 
  of 
  that 
  village 
  near 
  the 
  tank 
  

   at 
  Paduvalur 
  (Pullilore 
  of 
  the 
  Atlas 
  sheet). 
  

  

  Westward 
  of 
  the 
  high 
  ground 
  near 
  Tirumungalum 
  (four 
  miles 
  

   south-west 
  of 
  Sripermatoor), 
  the 
  lateritic 
  character 
  of 
  the 
  sands 
  ceases 
  

   and 
  the 
  surface 
  of 
  the 
  country 
  is 
  covered 
  by 
  pale 
  sandy 
  or 
  gritty 
  pebble 
  

   and 
  shingle 
  beds. 
  As 
  the 
  exact 
  relationship 
  of 
  these 
  beds 
  to 
  the 
  un- 
  

   questionably 
  lateritic 
  formations 
  is 
  obscure 
  and 
  doubtful, 
  thev 
  will 
  be 
  

   separately 
  described. 
  

  

  The 
  two 
  small 
  quasi-insular 
  patches 
  of 
  lateritic 
  formations 
  lying 
  

   ■ 
  T 
  . 
  ... 
  , 
  .. 
  east 
  and 
  south-east 
  of 
  Trivellore, 
  consist 
  al- 
  

  

  JLiatentic 
  formations 
  ' 
  

  

  S. 
  _ 
  of 
  the 
  Corteliar 
  at 
  most 
  entirely 
  of 
  the 
  sandy 
  varieties 
  of 
  laterite, 
  

   lnvellore. 
  J 
  ' 
  

  

  but 
  small 
  sections 
  of 
  the 
  massive 
  variety 
  are 
  

   exposed 
  in 
  the 
  case 
  of 
  the 
  southern 
  patch— 
  close 
  to 
  the 
  overflow 
  

   (kalingula) 
  of 
  the 
  large 
  tank 
  east 
  of 
  the 
  town— 
  and 
  again 
  in 
  a 
  small 
  

   irrigation 
  channel 
  immediately 
  south 
  of 
  the 
  railway 
  station. 
  

  

  The 
  central 
  portion 
  of 
  the 
  Red 
  Hills 
  laterite 
  area 
  is 
  very 
  sandy, 
  

   and 
  the 
  massive 
  rock 
  or 
  lateritic 
  gravel 
  only 
  shows 
  in 
  a 
  few 
  localities, 
  

  

  ( 
  37 
  ) 
  

  

  