﻿46 
  

  

  Age. 
  — 
  In 
  correlating 
  the 
  marine 
  limestones 
  of 
  Bag 
  with 
  the 
  fresh-water 
  

   limestone 
  (Lameta) 
  of 
  the 
  Upper 
  Narbada, 
  Mr. 
  Blanford 
  suggested 
  that 
  

   the 
  cherty 
  character 
  common 
  to 
  both 
  might 
  be 
  due 
  to 
  the 
  action 
  of 
  

   superincumbent 
  trap. 
  1 
  That 
  such 
  is 
  not 
  the 
  case 
  is 
  perhaps 
  sufficiently 
  

   shown 
  by 
  the 
  fact 
  that, 
  when 
  the 
  trap 
  rests 
  on 
  the 
  undoubtedly 
  marine 
  

   limestone, 
  no 
  such 
  effect 
  has 
  ensued; 
  as 
  near 
  Ghursul, 
  &c. 
  But 
  the 
  

   cherty 
  limestone 
  of 
  the 
  Lower 
  Narbada 
  valley, 
  besides 
  overlapping, 
  is 
  

   clearly 
  distinguishable 
  from, 
  the 
  underlying 
  beds 
  described 
  in 
  the 
  pre- 
  

   vious 
  sections 
  : 
  first 
  in 
  the 
  absence 
  of 
  marine 
  fossils 
  ; 
  and, 
  secondly, 
  litho- 
  

   logically. 
  We 
  therefore 
  suggest 
  the 
  correlation 
  of 
  the 
  cherty 
  band 
  

   alone 
  with 
  the 
  Lametas. 
  

  

  Mode 
  of 
  deposition. 
  — 
  In 
  the 
  western 
  portion 
  of 
  our 
  area 
  the 
  Lametas 
  

   generally 
  rest 
  upon 
  the 
  nodular-limestone 
  ; 
  at 
  places 
  the 
  Deola 
  and 
  

   Chirakhan 
  marl 
  and 
  the 
  "coralline," 
  or 
  the 
  " 
  coralline" 
  alone, 
  intervene. 
  

   The 
  manner 
  in 
  which 
  these 
  latter 
  groups 
  have 
  been 
  preserved 
  — 
  only 
  in 
  

   small 
  patches 
  at 
  wide 
  intervals 
  — 
  would 
  tend 
  to 
  prove 
  the 
  denudation 
  they 
  

   had 
  suffered 
  to 
  have 
  been 
  marine 
  : 
  and 
  the 
  Lameta 
  beds 
  appear 
  to 
  have 
  

   been 
  deposited 
  in, 
  perhaps, 
  brackish 
  lakes 
  formed 
  in 
  the 
  course 
  of 
  the 
  

   movement 
  of 
  upheaval 
  during 
  the 
  upper 
  cretaceous 
  period 
  in 
  the 
  western 
  

   portion 
  of 
  the 
  Central 
  Indian 
  cretaceous 
  basin. 
  

  

  In 
  the 
  Nimawar-Barwai 
  area 
  the 
  Lametas 
  are 
  clearly 
  of 
  fresh- 
  water 
  

   origin. 
  

  

  Passage 
  into 
  agglomerates. 
  — 
  In 
  the 
  Kawant 
  area 
  the 
  Lametas 
  present 
  

   no 
  little 
  difficulty 
  in 
  mapping, 
  passing, 
  as 
  they 
  do 
  almost 
  imperceptibly 
  

   at 
  places, 
  into 
  stratified 
  beds 
  of 
  volcanic 
  ejecta. 
  These 
  beds 
  are 
  thick- 
  

   est 
  between 
  Siriwasan 
  and 
  Mankui, 
  and 
  thin 
  away 
  in 
  all 
  directions 
  

   except 
  the 
  southern, 
  where 
  they 
  are 
  continued 
  as 
  far 
  as 
  Mongra, 
  sending 
  

   off 
  an 
  arm 
  westward. 
  Beyond 
  Mongra 
  they 
  stretch 
  away 
  south- 
  

   ward 
  probably 
  for 
  some 
  distance. 
  They 
  are 
  met 
  with 
  as 
  stragglers 
  

   near 
  Baisingpura. 
  Here, 
  as 
  well 
  as 
  between 
  Mongra 
  and 
  Mankui, 
  

   the 
  agglomerates 
  nave 
  a 
  decidedly 
  trappean 
  look, 
  with 
  angular 
  frag- 
  

   ments 
  of 
  basaltic 
  rocks 
  scattered 
  in 
  the 
  matrix, 
  associated 
  with 
  similar 
  

  

  1 
  Manual, 
  pp. 
  295 
  ; 
  Memoirs, 
  Vol. 
  VI, 
  pt. 
  3, 
  p. 
  54. 
  

  

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  46 
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