﻿\\Q 
  F00TE 
  : 
  GEOLOGY 
  OF 
  MADRAS. 
  

  

  bank 
  of 
  the 
  Channel 
  shows 
  the 
  following 
  complete 
  series 
  of 
  formations 
  

   in 
  their 
  true 
  stratigraphical 
  arrangement 
  : 
  — 
  

  

  1. 
  Laterite 
  gravel, 
  

  

  2. 
  Mottled 
  grits 
  obscurely 
  bedded. 
  

  

  3. 
  Drab, 
  friable 
  sandstones. 
  

   4- 
  Sandy 
  sbale. 
  

  

  5. 
  Light-brown 
  friable 
  sandstones. 
  

  

  6. 
  Sandy 
  shale. 
  

  

  7. 
  Drab 
  sandstones, 
  with 
  ferruginous 
  sandstone 
  nodules, 
  obscurely 
  

  

  bedded 
  in 
  some 
  parts. 
  

  

  8. 
  Ferruginous 
  grits. 
  

  

  9. 
  Sandy 
  shales. 
  

  

  10. 
  Ferruginous 
  grits. 
  

  

  11. 
  Thin 
  sandy 
  shales. 
  

  

  12. 
  Ferruginous 
  grits. 
  

  

  13. 
  Grey 
  micaceous 
  sandstones. 
  

  

  14. 
  Ferruginous 
  grits. 
  

  

  15. 
  Fine 
  white 
  micaceous 
  sandstone. 
  

  

  16. 
  Light-brown 
  sandstone. 
  

  

  17. 
  Ferruginous 
  crust 
  (hard) 
  of 
  grit. 
  

  

  18. 
  Sandy 
  shales. 
  

  

  19. 
  Grey 
  sandstone, 
  gritty. 
  

  

  Towards 
  the 
  base 
  of 
  No. 
  7, 
  the 
  sandstones 
  become 
  increasingly 
  

   ferruginous 
  ; 
  and 
  are 
  much 
  false 
  bedded 
  on 
  a 
  small 
  scale. 
  

  

  On 
  the 
  west 
  side 
  of 
  the 
  channel 
  other 
  greyish-white, 
  gritty 
  sand- 
  

   stones 
  appear 
  underlying 
  the 
  above, 
  and 
  in 
  a 
  ferruginous 
  parting 
  

   between 
  two 
  of 
  these, 
  shown 
  in 
  the 
  gully 
  next 
  the 
  Madras-Arcot 
  road, 
  

   a 
  few 
  Estheria-\\ke, 
  forms 
  and 
  the 
  crushed 
  cast 
  of 
  a 
  bivalve 
  shell 
  were 
  

   found. 
  

  

  The 
  beds 
  east 
  of 
  the 
  channel 
  proved 
  altogether 
  unfossiliferous, 
  

   except 
  a 
  few 
  unrecognizable 
  vegetable 
  fragments 
  occurring 
  a 
  little 
  

   northward 
  of 
  the 
  section 
  gully 
  at 
  the 
  level 
  of 
  No. 
  1-7, 
  in 
  hard, 
  purplish, 
  

   thin 
  laminated 
  sandstone. 
  

  

  The 
  thickness 
  of 
  the 
  whole 
  series 
  of 
  beds 
  here 
  cannot 
  be 
  estimated 
  

   as 
  less 
  than 
  from 
  100 
  to 
  15 
  feet. 
  

  

  ( 
  H6 
  ) 
  

  

  