﻿18 
  ■ 
  FOOTE 
  : 
  GEOLOGY 
  OF 
  MADRAS. 
  

  

  bed 
  of 
  the 
  backwater 
  at 
  the 
  salt 
  works 
  near 
  Covelong, 
  and 
  again 
  in 
  those 
  

   sunk 
  a 
  little 
  to 
  the 
  north-west 
  of 
  Seven 
  Pagodas. 
  These 
  shells 
  are 
  gener- 
  

   ally 
  found 
  in 
  good 
  condition, 
  and 
  occasionally 
  retain 
  faint 
  traces 
  of 
  polish 
  

   and 
  color 
  ; 
  they 
  are, 
  however, 
  often 
  very 
  brittle 
  and 
  difficult 
  to 
  preserve. 
  

  

  At 
  the 
  time 
  when 
  these 
  beds 
  were 
  forming, 
  the 
  sea 
  must 
  have 
  

   extended 
  westward 
  very 
  nearly 
  to 
  the 
  Palaveram 
  hills. 
  

  

  When 
  the 
  marine 
  deposits 
  now 
  described 
  were 
  being 
  formed 
  several 
  

   T 
  , 
  , 
  . 
  . 
  small 
  islands 
  of 
  gneiss 
  stood 
  up 
  in 
  the 
  shallow 
  

  

  Islands 
  of 
  gneiss 
  in 
  & 
  r 
  

  

  the 
  alluvial 
  plam. 
  sea 
  ^ 
  which 
  now 
  appear 
  as 
  outliers 
  of 
  the 
  great 
  

  

  metamorphic 
  area 
  breaking 
  slightly 
  the 
  monotony 
  of 
  the 
  alluvial 
  

   country. 
  Several 
  of 
  these 
  are 
  noteworthy 
  — 
  Three 
  more 
  especially. 
  

  

  1st. 
  — 
  The 
  outlier 
  on 
  which 
  stand 
  the 
  famous 
  Seven 
  Pagodas, 
  the 
  

   Mahabali 
  or 
  Mahavalipuram 
  or 
  Mahamalaipuram 
  of 
  the 
  Hindus. 
  (*) 
  

  

  ZndZy. 
  — 
  .The 
  island 
  of 
  gneiss 
  at 
  Padari, 
  — 
  a 
  village 
  not 
  marked 
  on 
  

   the 
  atlas 
  maps, 
  — 
  three 
  miles 
  north 
  of 
  Seven 
  Pagodas. 
  

  

  Zrdly. 
  — 
  An 
  outlier 
  of 
  gneiss 
  surrounded 
  by 
  a 
  belt 
  of 
  lateritic 
  de- 
  

   posits 
  in 
  the 
  great 
  Puliacarany 
  flat, 
  and 
  about 
  four 
  miles 
  south-east 
  of 
  

   St. 
  Thomas' 
  Mount. 
  

  

  These 
  will 
  be 
  described 
  in 
  detail 
  when 
  treating 
  of 
  the 
  metamorphic 
  

   rocks. 
  

  

  The 
  Covelong 
  backwater 
  is 
  not 
  now 
  in 
  reality 
  the 
  great 
  sheet 
  of 
  

  

  _, 
  „ 
  . 
  , 
  , 
  salt-water 
  one 
  would 
  be 
  inclined 
  to 
  believe 
  from 
  

   The 
  Covelong 
  back- 
  

  

  water 
  - 
  looking 
  at 
  the 
  maps. 
  At 
  the 
  time 
  of 
  the 
  survey 
  

  

  of 
  that 
  part 
  of 
  the 
  Madras 
  District 
  in 
  August 
  (1862), 
  although 
  both 
  

  

  openings 
  at 
  the 
  Covelong 
  and 
  the 
  Madras 
  ends 
  were 
  closed 
  by 
  high 
  

  

  sand 
  bars, 
  by 
  far 
  the 
  greater 
  part 
  of 
  the 
  area 
  marked 
  on 
  the 
  map 
  was 
  

  

  a 
  dry 
  sandy 
  plain 
  overgrown 
  with 
  Salicomaria, 
  &c, 
  with 
  only 
  here 
  and 
  

  

  there 
  a 
  few 
  large 
  puddles. 
  

  

  The 
  broad 
  channel 
  between 
  Covelong 
  town 
  and 
  the 
  rocky 
  island 
  

  

  to 
  the 
  west 
  was 
  dry, 
  all 
  but 
  a 
  running 
  stream 
  about 
  a 
  yard 
  across. 
  This 
  

  

  * 
  A 
  complete 
  account 
  of 
  this 
  remarkable 
  spot 
  will 
  be 
  found 
  in 
  a 
  volume, 
  edited 
  for 
  the 
  

   Madras 
  Government, 
  and 
  entitled 
  ' 
  Descriptive 
  and 
  Historical 
  papers 
  relating 
  to 
  the 
  Seven 
  

   Tagodi-.s, 
  ou 
  the 
  Coromandel 
  Coast', 
  edited 
  by 
  Captain 
  M. 
  W. 
  Carr. 
  M. 
  S. 
  C. 
  

  

  ( 
  18 
  ) 
  

  

  