﻿JABALPUR 
  GllOUP. 
  15 
  

  

  at 
  the 
  edge 
  of 
  the 
  basin 
  are 
  only 
  the 
  fringing- 
  deposits 
  of 
  the 
  Jabalpur 
  

   group. 
  The 
  carbonaceous 
  bands 
  here 
  as 
  elsewhere 
  occur 
  at 
  the 
  lowest 
  

   level, 
  and 
  apparently 
  at 
  or 
  near 
  the 
  base 
  of 
  the 
  group. 
  

  

  The 
  sandstone 
  of 
  the 
  Sakar 
  and 
  Hard 
  is 
  not 
  separated 
  by 
  any 
  

  

  continuous 
  overlapping 
  of 
  trap 
  from 
  that 
  of 
  the 
  

   Change 
  to 
  west 
  of 
  the 
  , 
  , 
  , 
  , 
  

   Hard: 
  introduction 
  of 
  Sitanva. 
  It 
  forms 
  the 
  north-east 
  portion 
  of 
  the 
  

   lower 
  groups. 
  

  

  triangular 
  area 
  of 
  sedimentary 
  rocks 
  bounded 
  on 
  

  

  the 
  west 
  by 
  the 
  Dudhi 
  valley, 
  on 
  the 
  north 
  by 
  the 
  Narbada 
  valley, 
  and 
  

   on 
  the 
  south-east 
  by 
  the 
  irregular 
  line 
  of 
  trap 
  gradually 
  encroach- 
  

   ing 
  from 
  the 
  south. 
  Still 
  on 
  the 
  Hard 
  the 
  section 
  is, 
  as 
  on 
  the 
  

   Machiriva, 
  composed 
  entirely 
  of 
  the 
  Jabalpur 
  group 
  ; 
  the 
  only 
  notice- 
  

   able 
  difference 
  being, 
  that 
  the 
  upper 
  portion 
  of 
  the 
  Hard 
  section 
  is 
  at 
  a 
  

   higher 
  level 
  than 
  that 
  on 
  the 
  Machiriva. 
  To 
  the 
  west 
  of 
  the 
  Hard 
  this 
  

   gradual 
  elevation 
  of 
  the 
  Jabalpur 
  beds 
  continues, 
  with 
  the 
  concomitant 
  

   effect 
  of 
  introducing 
  underlying 
  groups 
  not 
  represented 
  in 
  the 
  sections 
  

   to 
  the 
  east 
  — 
  the 
  beginning 
  of 
  the 
  features 
  noticed 
  in 
  the 
  main 
  section 
  of 
  

   the 
  Satpura 
  basin. 
  This 
  rise 
  of 
  the 
  rocks 
  to 
  the 
  west 
  is 
  not 
  solely 
  due 
  

   to 
  a 
  general 
  elevation 
  : 
  within 
  the 
  hills 
  there 
  is 
  a 
  very 
  decided 
  easterly 
  

   dip 
  in 
  the 
  sandstones 
  to 
  the 
  west 
  of 
  the 
  Hard. 
  Along 
  the 
  boundary 
  

   this 
  slope 
  is 
  not 
  observable 
  ; 
  but 
  instead 
  of 
  it 
  we 
  find 
  a 
  great 
  increase 
  of 
  

   thickness 
  of 
  the 
  conglomeritic 
  deposits. 
  Here, 
  too, 
  other 
  changes 
  take 
  

   place, 
  having, 
  no 
  doubt, 
  some 
  relation 
  to 
  those 
  in 
  the 
  newer 
  sediment- 
  

   ary 
  rocks 
  : 
  within 
  three 
  miles 
  to 
  the 
  west 
  of 
  Hatnapur 
  and 
  of 
  the 
  

   Sakar 
  gorge, 
  the 
  fringing 
  metamorphic 
  rocks 
  disappear 
  for 
  a 
  length 
  of 
  

   sixteen 
  miles 
  ; 
  and 
  the 
  massive 
  conglomerates 
  occur 
  down 
  to 
  the 
  level 
  

   of 
  the 
  plains^ 
  resting 
  at 
  first 
  upon 
  a 
  small 
  patch 
  of 
  Talchirs 
  at 
  Nibhora. 
  

   It 
  seems 
  likely 
  that 
  this 
  gap 
  in 
  the 
  fringing 
  rocks 
  was 
  due, 
  through 
  

   denudation, 
  to 
  a 
  local 
  change 
  in 
  the 
  composition 
  of 
  the 
  metamorphic 
  

   series 
  : 
  east 
  of 
  the 
  Sakar 
  the 
  limestone 
  and 
  its 
  associated 
  hornstone, 
  so 
  

   often 
  found 
  crushed 
  into 
  a 
  breccia, 
  occur 
  abundantly, 
  associated 
  with 
  

   the 
  gneissose 
  schists 
  ; 
  but 
  from 
  the 
  Sakar 
  to 
  Nibhora 
  soft 
  earthy 
  schists 
  

   are 
  the 
  only 
  rocks 
  seen. 
  

  

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