﻿1 
  % 
  FOOTE 
  : 
  GEOLOGY 
  OF 
  MADRAS. 
  

  

  Chapter 
  III. 
  — 
  Sub-aerial 
  formations. 
  

  

  a. 
  — 
  Blown 
  sands. 
  

   The 
  blown 
  sands 
  in 
  this 
  region 
  are 
  nowhere 
  so 
  well 
  developed 
  in 
  

   distinct 
  ridges 
  as 
  they 
  are 
  further 
  south 
  near 
  Pondicheriy 
  and 
  Porto 
  Novo. 
  

   They 
  form 
  a 
  belt, 
  from 
  a 
  quarter 
  of 
  a 
  mile 
  to 
  a 
  mile 
  wide, 
  of 
  irregular 
  

   sand-hillocks 
  stretching 
  all 
  along 
  the 
  coast, 
  but 
  nowhere 
  attaining 
  to 
  

   any 
  great 
  size. 
  The 
  largest 
  observed 
  southward 
  of 
  Madras 
  were 
  im- 
  

   mediately 
  south 
  of 
  Covelong, 
  and 
  some 
  of 
  these 
  

   South 
  of 
  Madras. 
  

  

  appeared 
  to 
  cover 
  old 
  ruined 
  buildings. 
  At 
  

  

  Mahavalipooram 
  they 
  have 
  encroached 
  on 
  the 
  base 
  of 
  some 
  of 
  the 
  

   Monolith 
  temples 
  at 
  the 
  southern 
  end 
  of 
  the 
  gneiss-ridge. 
  At 
  Padari, 
  

   a 
  small 
  rock-hewn 
  temple 
  is 
  so 
  filled 
  with 
  sand 
  that 
  it 
  cannot 
  be 
  entered. 
  

  

  Only 
  one 
  inland 
  ridge 
  of 
  sand 
  was 
  observed, 
  and 
  this 
  occurs 
  on 
  the 
  

   west 
  side 
  of 
  the 
  back 
  water, 
  a 
  few 
  miles 
  north-west 
  of 
  Covelong. 
  

  

  The 
  blown 
  sands, 
  which 
  form 
  a 
  continuous 
  ridge 
  except 
  where 
  

   broken 
  by 
  the 
  embouchures 
  of 
  the 
  Corteliar 
  at 
  Ennore 
  and 
  Carangoly, 
  

   and 
  of 
  the 
  Narnaveram 
  river 
  at 
  Pulicat,* 
  offer 
  no 
  very 
  striking 
  

   features. 
  They 
  are 
  generally 
  low 
  spread, 
  varying 
  in 
  width 
  from 
  a 
  few 
  

   hundred 
  yards 
  to 
  about 
  a 
  mile 
  (a 
  few 
  miles 
  north 
  of 
  Ennore) 
  . 
  

  

  The 
  highest 
  and 
  most 
  striking 
  sandhills 
  are 
  those 
  at 
  Chinto- 
  

   minicoil 
  near 
  Pulicat. 
  The 
  sands 
  here 
  have 
  been 
  raised 
  by 
  the 
  wind 
  

   in 
  irregular 
  mounds 
  40 
  or 
  50 
  feet 
  high, 
  and 
  are 
  rapidly 
  covering 
  a 
  small 
  

   pagoda 
  which 
  had 
  been 
  built 
  there 
  on 
  a 
  much 
  lower 
  sandhill. 
  The 
  

   north 
  face 
  of 
  these 
  hills 
  is 
  by 
  far 
  the 
  steepest, 
  which 
  is 
  in 
  part 
  

   owing 
  to 
  the 
  presence 
  of 
  thickets 
  of 
  Cashew 
  nut 
  trees 
  {Anacardium 
  

   occidentale), 
  the 
  Hnndrimaram 
  of 
  the 
  Tamulians. 
  This 
  tree 
  grows 
  in 
  

   great 
  profusion 
  on 
  the 
  sandhills 
  in 
  many 
  other 
  places, 
  and 
  when 
  mixed 
  

   with 
  the 
  wild 
  screw-pine, 
  or 
  Pandanus, 
  is 
  very 
  effective 
  in 
  staying 
  the 
  

  

  * 
  The 
  tars 
  of 
  these 
  two 
  rivers 
  were 
  both 
  closed 
  when 
  I 
  visited 
  them 
  in 
  August 
  and 
  

   October 
  1864, 
  and 
  hillocks 
  of 
  sand 
  had 
  been 
  raised 
  by 
  the 
  wind 
  on 
  them, 
  as 
  well 
  as 
  elsewhere 
  

   along 
  the 
  coast. 
  

  

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