﻿125 
  

   CHAPTER 
  IX, 
  

  

  SlJB-METAMORPHIC 
  ROCKS. 
  

  

  If 
  the 
  extraordinary 
  masses 
  of 
  quartzite 
  conglomerate 
  described 
  

   as 
  occurring 
  at 
  the 
  base 
  of 
  the 
  Rajmahal 
  series 
  on 
  the 
  south-west 
  slopes 
  

   of 
  the 
  Naikenpolliam 
  ridge 
  (see 
  pages 
  67-71) 
  be 
  considered 
  as 
  the 
  

   ruins 
  in 
  situ 
  of 
  a 
  once 
  existing 
  bed 
  and 
  not 
  as 
  carried 
  blocks, 
  the 
  sub- 
  

   metamorphic 
  rocks 
  are 
  represented 
  in 
  the 
  area 
  treated 
  of 
  in 
  this 
  report, 
  

   and 
  the 
  quartzite 
  conglomerate 
  in 
  question 
  may 
  be 
  regarded 
  as 
  the 
  base- 
  

   ment 
  of 
  the 
  older 
  of 
  the 
  two 
  series 
  into 
  which 
  the 
  sub-metamorphic 
  

   rocks 
  of 
  Southern 
  India 
  have 
  been 
  divided. 
  

  

  Of 
  these 
  two 
  series, 
  called, 
  respectively, 
  the 
  Kaddapa 
  and 
  Karniil 
  

   series, 
  the 
  first, 
  which 
  is 
  the 
  older, 
  consists 
  chiefly 
  of 
  alternating 
  beds 
  

   of 
  quartzite 
  and 
  slate 
  of 
  great 
  thickness, 
  together 
  with 
  some 
  limestones. 
  

  

  In 
  the 
  region 
  adjoining 
  the 
  Madras 
  area, 
  the 
  lower 
  part 
  cf 
  the 
  

   Kaddapa 
  series 
  consists 
  of 
  very 
  thick 
  beds 
  of 
  quartzite 
  and 
  quartzite 
  

   conglomerate, 
  which 
  constitute 
  the 
  main 
  mass 
  of 
  the 
  Naggery 
  moun- 
  

   tains,* 
  and 
  are 
  so 
  finely 
  exposed 
  in 
  the 
  huge 
  scarps 
  formed 
  on 
  the 
  flanks 
  

   of 
  these 
  mountaios. 
  It 
  is 
  not 
  difficult 
  to 
  conceive 
  that 
  these 
  great 
  beds 
  

   once 
  extended 
  much 
  further 
  south 
  and 
  covered 
  the 
  gneiss 
  which 
  now 
  

   forms 
  the 
  base 
  of 
  the 
  Naikempolliam 
  hills, 
  and 
  that 
  subsequent 
  erosive 
  

   action 
  failed 
  to 
  remove 
  them 
  entirely. 
  

  

  The 
  members 
  of 
  the 
  younger 
  or 
  Karniil 
  series 
  do 
  not 
  appear 
  ever 
  

   to 
  have 
  extended 
  so 
  far 
  south 
  as 
  the 
  Madras 
  area. 
  

  

  * 
  A 
  group 
  of 
  four 
  isolated 
  mountain 
  masses 
  lying 
  between 
  the 
  Naggery 
  and 
  

  

  Soornamooky 
  rivers. 
  They 
  consist 
  of 
  the 
  Naggery 
  Nose, 
  the 
  Narnaveram 
  peak, 
  the 
  

  

  Sathoosconda 
  (or 
  Saddashamallei) 
  and 
  the 
  Ramagherry 
  ridge, 
  with 
  their 
  spurs 
  and 
  a 
  few 
  

   small 
  outliers. 
  

  

  ( 
  125 
  ) 
  

  

  