﻿THE 
  LATERITIC 
  FORMATIONS. 
  29 
  

  

  A 
  variety 
  of 
  laterite 
  occasionally 
  met 
  with 
  in 
  association 
  with 
  the 
  

  

  typical 
  rock 
  consists 
  of 
  an 
  aggregation 
  of 
  round 
  

   Varieties 
  of 
  laterite. 
  

  

  pellets, 
  'pisolitic 
  gravel/ 
  of 
  brown 
  haematite 
  

   united 
  together 
  by 
  a 
  ferruginous 
  argillaceous 
  cement. 
  This 
  variety 
  

   also 
  possesses 
  the 
  quality 
  of 
  hardening 
  on 
  exposure 
  into 
  a 
  useful 
  building 
  

   stone. 
  

  

  The 
  laterite 
  is 
  generally 
  a 
  conglomeratic 
  rock 
  enclosing 
  pebbles 
  and 
  

   fragments 
  of 
  other 
  rocks. 
  

  

  Associated 
  with 
  the 
  typical 
  laterite, 
  and 
  very 
  often 
  passing 
  into 
  

   similar 
  conglomerate, 
  are 
  beds 
  of 
  loose 
  lateritic 
  gravel, 
  which 
  again 
  very 
  

   often 
  pass 
  into 
  compact 
  red 
  "sandy 
  clay 
  or 
  sandy 
  loam, 
  throughout 
  which 
  

   lateritic 
  pellets 
  are 
  scattered 
  in 
  greater 
  or 
  lesser 
  quantity. 
  The 
  passage 
  

   is 
  generally 
  gradual, 
  but 
  in 
  some 
  few 
  cases 
  the 
  change 
  of 
  character 
  

   takes 
  place 
  within 
  a 
  distance 
  of 
  a 
  few 
  feet. 
  

  

  The 
  intermediate 
  forms, 
  the 
  unconsolidated 
  gravels, 
  and 
  compacted 
  

   red 
  sands, 
  occupy 
  the 
  larger 
  parts 
  of 
  the 
  lateritic 
  formation 
  area, 
  but 
  

   are 
  much 
  less 
  striking 
  features, 
  both 
  topographically 
  and 
  geologically, 
  

   than 
  the 
  conglomerate 
  beds. 
  

  

  The 
  typical 
  conglomeratic 
  laterite 
  may 
  be 
  best 
  studied 
  in 
  the 
  

   neighbourhood 
  of 
  Madras, 
  and 
  the 
  largest 
  and 
  most 
  accessible 
  develop- 
  

   ment 
  of 
  it 
  is 
  at 
  the 
  ' 
  Red 
  Hills/ 
  about 
  seven 
  miles 
  north-west 
  of 
  

   Madras; 
  but 
  other 
  equally 
  typical 
  beds 
  of 
  laterite 
  are 
  exposed 
  at 
  

   various 
  other 
  places 
  in 
  the 
  Madras 
  District, 
  and 
  will 
  be 
  referred 
  to 
  

   separately 
  further 
  on. 
  

  

  No 
  organic 
  remains, 
  either 
  animal 
  or 
  vegetable, 
  have 
  been 
  found 
  as 
  

  

  yet 
  in 
  the 
  lateritic 
  series, 
  excepting 
  some 
  pieces 
  of 
  

   Absence 
  of 
  fossils. 
  

  

  silicified 
  wood, 
  washed 
  up 
  out 
  of 
  older 
  formations, 
  

  

  as 
  the 
  Rajmahal 
  and 
  Cuddalore 
  series. 
  In 
  certain 
  lateritic 
  gravels 
  

  

  Implements 
  of 
  chipped 
  and 
  conglomerates, 
  however, 
  at 
  various 
  places 
  

  

  stone 
  - 
  in 
  the 
  Madras 
  District 
  and 
  adjoining 
  paHs 
  

  

  of 
  the 
  North 
  Areot 
  District, 
  chipped 
  stone-implements 
  of 
  human 
  

  

  ( 
  29 
  ) 
  

  

  