﻿236 
  rev. 
  j. 
  f. 
  blake 
  on 
  some 
  [May 
  1897, 
  

  

  The 
  section 
  west 
  of 
  Bhachau, 
  which 
  appears 
  to 
  show 
  a 
  third 
  type, 
  

   I 
  have 
  not 
  seen, 
  as 
  at 
  the 
  place 
  where 
  alone 
  I 
  was 
  able, 
  from 
  lack 
  

   of 
  more 
  time, 
  to 
  examine 
  the 
  trap, 
  it 
  was 
  lying 
  directly 
  on 
  the 
  

   Jurassic 
  rocks, 
  showing, 
  as 
  pointed 
  out 
  by 
  Mr. 
  Wynne, 
  the 
  very 
  

   local 
  character 
  of 
  the 
  subtrappean 
  group. 
  I 
  therefore 
  copy 
  here 
  

   the 
  description 
  in 
  the 
  memoir 
  (p. 
  136) 
  of 
  the 
  beds 
  referred 
  with 
  a 
  

   query 
  to 
  this 
  group, 
  as 
  taken 
  from 
  Mr. 
  Fedden's 
  note-book 
  : 
  — 
  

  

  Feet. 
  

   ' 
  7. 
  Brecciated 
  and 
  conglomeratic 
  bed, 
  lower 
  part 
  almost 
  

  

  wholly 
  of 
  pink 
  lava? 
  3 
  

  

  6. 
  Yellow 
  sandstone 
  2 
  

  

  5. 
  Conglomeratic 
  and 
  concretionary 
  bed 
  of 
  pale 
  lavender 
  

   and 
  pink 
  lava 
  ?, 
  with 
  large 
  pebbles 
  of 
  bornstone, 
  frag- 
  

   ments 
  of 
  yellow 
  clay, 
  and 
  fine 
  sandstone 
  1-4 
  

  

  4. 
  Hard, 
  yellow 
  and 
  pinkish, 
  gritty 
  sandstone 
  5 
  ' 
  

  

  It 
  will 
  be 
  seen 
  from 
  this 
  description 
  that 
  the 
  only 
  ingredients 
  which 
  

   could 
  not 
  be 
  derived 
  from 
  the 
  Jurassic 
  rocks 
  are 
  the 
  fragments 
  of 
  

   ' 
  pale 
  lavender 
  and 
  pink 
  lava 
  ? 
  ' 
  I 
  think 
  it 
  is 
  very 
  doubtful 
  whether 
  

   these 
  are 
  really 
  volcanic 
  fragments. 
  Even 
  Mr. 
  Fedden 
  queries 
  

   them, 
  and 
  as 
  the 
  large 
  area 
  south 
  of 
  Bhachau, 
  mapped 
  as 
  trap, 
  is 
  now 
  

   seen 
  in 
  the 
  cuttings 
  of 
  the 
  new 
  road 
  to 
  be 
  entirely 
  lateritic, 
  it 
  is 
  

   more 
  probable 
  that 
  the 
  fragments 
  here 
  noted 
  are 
  also 
  of 
  that 
  

   character. 
  Perhaps, 
  however, 
  it 
  comes 
  to 
  the 
  same 
  thing 
  if 
  laterite 
  

   is 
  derived 
  from 
  trap, 
  in 
  which 
  case 
  the 
  basalt 
  of 
  Bhachau 
  must 
  be 
  

   one 
  of 
  the 
  later 
  flows. 
  The 
  stratification 
  also 
  of 
  these 
  deposits 
  

   indicates 
  the 
  agency 
  of 
  water, 
  so 
  that 
  we 
  may 
  perhaps 
  sum 
  up 
  as 
  

   follows 
  : 
  — 
  

  

  The 
  subtrappean 
  rocks 
  are 
  all 
  superficial 
  deposits 
  on 
  the 
  pre- 
  

   trappean 
  land-surface, 
  those 
  at 
  Artara 
  and 
  Sanosra 
  being 
  the 
  

   ordinary 
  results 
  of 
  weathering 
  : 
  those 
  at 
  Bhachau, 
  the 
  washing-down 
  

   of 
  similar 
  debris 
  onto 
  a 
  lower, 
  water-covered 
  level 
  ; 
  and 
  those 
  of 
  

   Bhujia 
  Hill, 
  etc., 
  aeolian 
  drift. 
  

  

  Taking 
  this 
  last 
  in 
  connexion 
  with 
  the 
  subrecent 
  concrete, 
  we 
  

   have 
  thus 
  a 
  record 
  of 
  the 
  constancy 
  of 
  the 
  meteorological 
  con- 
  

   ditions 
  in 
  Cutch, 
  from 
  recent 
  times 
  as 
  far 
  back 
  as 
  the 
  Cretaceous 
  

   epoch. 
  

  

  (4) 
  The 
  Laterite. 
  

  

  The 
  deposits 
  hitherto 
  dealt 
  with 
  are 
  on 
  a 
  small 
  scale 
  and 
  more 
  or 
  

   less 
  peculiar 
  to 
  Cutch, 
  but 
  those 
  which 
  remain 
  to 
  be 
  discussed 
  are 
  

   widely 
  distributed 
  in 
  this 
  part 
  of 
  India. 
  

  

  The 
  various 
  deposits 
  which 
  in 
  different 
  parts 
  of 
  India 
  have 
  gone 
  

   by 
  the 
  name 
  of 
  laterite 
  are, 
  with 
  exceptions, 
  superficial 
  in 
  origin. 
  

   As, 
  however, 
  the 
  term 
  has 
  been 
  so 
  widely 
  applied 
  that 
  the 
  only 
  

   definition 
  which 
  will 
  cover 
  all 
  the 
  varieties 
  is 
  that 
  it 
  is 
  a 
  very 
  

   ferruginous 
  rock 
  of 
  peculiar 
  character, 
  it 
  follows 
  that 
  the 
  rocks 
  

   included 
  under 
  this 
  definition 
  may 
  be 
  of 
  many 
  origins 
  and 
  of 
  many 
  

   ages. 
  All 
  the 
  laterites 
  of 
  Cutch 
  are 
  classed 
  and 
  mapped 
  by 
  

   Mr. 
  "Wynne 
  as 
  ' 
  sub-Nummulitic,' 
  so 
  that 
  they 
  stand, 
  with 
  those 
  of 
  

  

  