﻿Vol. 
  53.] 
  SUPERFICIAL 
  DEPOSITS 
  IX 
  CUTCH. 
  233 
  

  

  blown 
  sand 
  present, 
  so 
  as 
  to 
  make 
  a 
  greater 
  slope, 
  the 
  weathered 
  

   blocks 
  which 
  fell 
  on 
  it 
  from 
  the 
  hills 
  would, 
  under 
  the 
  influence 
  of 
  

   the 
  rains 
  saturating 
  the 
  sand 
  below, 
  slip 
  gently 
  forward 
  along 
  the 
  

   slope, 
  supported 
  by 
  the 
  underlying 
  sand, 
  till 
  they 
  reached 
  their 
  

   farthest 
  destination 
  without 
  sinking 
  to 
  the 
  bottom. 
  Thus 
  the 
  

   aeolian 
  deposits 
  have 
  served 
  as 
  the 
  carrier 
  (see 
  fig. 
  2). 
  

  

  Fig. 
  2. 
  — 
  Boulder-beds 
  in 
  the 
  north 
  of 
  Patcham. 
  

  

  A 
  = 
  Boulder-beds. 
  

  

  B 
  = 
  Subrecent 
  concrete. 
  

  

  C 
  — 
  Jurassic 
  rocks. 
  

   D 
  = 
  Hypothetical 
  former 
  extension 
  of 
  

   concrete 
  with 
  boulders. 
  

  

  This 
  explanation 
  is 
  analogous 
  to 
  that 
  made 
  use 
  of 
  by 
  Sir 
  Wyville 
  

   Thomson 
  to 
  account 
  for 
  the 
  forward 
  motion 
  of 
  the 
  stone-river 
  in 
  

   the 
  Falkland 
  Islands, 
  1 
  and, 
  if 
  it 
  be 
  a 
  true 
  one, 
  it 
  is 
  possible 
  that 
  it 
  

   may 
  in 
  some 
  cases 
  account 
  for 
  deposits 
  of 
  loose 
  blocks 
  which 
  have 
  

   been 
  referred 
  to 
  glacial 
  action. 
  There 
  will 
  always 
  be 
  antagonism 
  

   between 
  this 
  process 
  and 
  the 
  running 
  away 
  of 
  the 
  water 
  in 
  definite 
  

   channels, 
  and 
  at 
  last, 
  when 
  the 
  slope 
  of 
  the 
  aeolian 
  deposits 
  became 
  too 
  

   low, 
  the 
  growth 
  of 
  the 
  mounds 
  would 
  cease 
  and 
  the 
  streams 
  would 
  

   begin 
  to 
  sensibly 
  denude 
  the 
  deposits, 
  and 
  even 
  cut 
  channels 
  in 
  the 
  

   bed-rock. 
  It 
  might 
  be 
  thought 
  that 
  all 
  along 
  the 
  rain 
  would 
  wash 
  

   the 
  sand 
  away 
  and 
  let 
  the 
  boulders 
  drop, 
  but 
  we 
  see 
  that 
  as 
  a 
  matter 
  

   of 
  fact 
  it 
  does 
  not 
  ; 
  besides 
  which, 
  the 
  boulder 
  itself 
  protects 
  the 
  

   sand 
  below 
  it, 
  as 
  in 
  the 
  case 
  of 
  earth- 
  pillars, 
  and 
  what 
  is 
  washed 
  

   away 
  above 
  or 
  below 
  will 
  be 
  replaced 
  by 
  the 
  next 
  dust-storm. 
  

  

  (3) 
  Infratrappean 
  Grits. 
  

  

  These 
  deposits, 
  lying 
  as 
  they 
  do 
  below 
  the 
  traps, 
  cannot 
  in 
  strictness 
  

   be 
  called 
  superficial, 
  but 
  it 
  will 
  be 
  seen 
  that 
  they 
  were 
  probably 
  of 
  

   that 
  character 
  — 
  that 
  is, 
  deposited 
  on 
  the 
  land 
  before 
  the 
  traps 
  

   were 
  poured 
  on 
  the 
  top 
  of 
  them. 
  This 
  is 
  what 
  Mr. 
  Wynne 
  says 
  of 
  

   them 
  : 
  — 
  'These 
  form 
  a 
  peculiar, 
  soft, 
  loosely 
  granular, 
  and 
  obscurely 
  

   stratified 
  group 
  of 
  earthy 
  and 
  sandy 
  rocks, 
  largely 
  composed 
  of 
  

   trappean 
  materials 
  . 
  . 
  [they] 
  are 
  frequently 
  associated 
  with 
  the 
  base 
  

   of 
  the 
  stratified 
  traps, 
  but 
  they 
  also 
  occur 
  in 
  separate 
  patches 
  over 
  

   the 
  country, 
  and 
  sometimes 
  at 
  a 
  considerable 
  distance 
  from 
  them. 
  

   They 
  are 
  clearly 
  beneath 
  the 
  trap 
  in 
  some 
  localities 
  ; 
  in 
  others 
  they 
  

   fill 
  up 
  hollows 
  in 
  the 
  Jurassic 
  beds, 
  the 
  planes 
  of 
  stratification 
  not 
  

  

  i 
  ' 
  Nature,' 
  vol. 
  xr. 
  (1876) 
  p. 
  359. 
  

   Q. 
  J. 
  G. 
  S. 
  No. 
  210. 
  r 
  

  

  