﻿26 
  FEDDEN 
  : 
  GEOLOGY 
  OF 
  KATHIAWAR 
  PENINSULA 
  IN 
  GUZERAT. 
  

  

  specific 
  varieties 
  ; 
  some 
  are 
  very 
  compact, 
  tough, 
  and 
  silicious 
  ; 
  others 
  

   are 
  trachytic. 
  

  

  Compact 
  earthy 
  felsitic 
  rocks 
  are 
  also 
  met 
  with 
  in 
  several 
  other 
  parts 
  

   of 
  the 
  trappean 
  area. 
  In 
  the 
  eastern 
  division 
  of 
  the 
  province 
  a 
  lami- 
  

   nated, 
  or 
  striped, 
  felsite 
  prevails, 
  as, 
  for 
  example, 
  in 
  the 
  hills 
  at 
  Sihor, 
  12 
  

   miles 
  west 
  of 
  Bhavnagar, 
  and 
  again 
  at 
  Rajula, 
  near 
  Jaferabad. 
  It 
  is 
  

   often 
  porphyritic 
  and 
  in 
  part 
  agglomeratic. 
  At 
  the 
  former 
  locality 
  the 
  

   rock 
  is 
  extensively 
  quarried 
  for 
  building 
  purposes, 
  while 
  at 
  the 
  latter 
  

   place 
  it 
  is 
  worked 
  for 
  querns, 
  or 
  hand-mills. 
  

  

  The 
  hills 
  west 
  of 
  Bhavnagar, 
  called 
  the 
  Sihor 
  range, 
  though 
  broken 
  

   The 
  Sihor, 
  or 
  Sonpuri, 
  an( 
  l 
  irregular 
  in 
  outline, 
  have 
  a 
  general 
  bearing 
  

   1 
  ailge 
  * 
  east 
  and 
  west. 
  The 
  trap 
  beds, 
  of 
  which 
  these 
  hills 
  

  

  are 
  composed, 
  are 
  tilted 
  slightly, 
  showing 
  a 
  tolerably 
  uniform, 
  easy 
  slope 
  

   towards 
  the 
  south, 
  while 
  their 
  northern 
  outcrops 
  form 
  a 
  long 
  scarp 
  

   running 
  east 
  and 
  west. 
  At 
  the 
  foot 
  of 
  this 
  scarp 
  commences 
  an 
  extensive 
  

   alluvial 
  plain, 
  which 
  stretches 
  away 
  northward, 
  beyond 
  the 
  limit 
  of 
  the 
  

   province. 
  

  

  In 
  the 
  broken 
  hilly 
  ground 
  opposite 
  the 
  town 
  of 
  Sihor, 
  a 
  band 
  of 
  

   Ohsidian 
  and 
  pitch- 
  obsidian 
  was 
  observed 
  among 
  contorted 
  and 
  irre- 
  

   stone 
  * 
  gular 
  trappean 
  rocks. 
  Mr. 
  Theobald 
  observed 
  a 
  

  

  bed 
  of 
  'pitchstone 
  * 
  in 
  the 
  hills 
  near 
  Rajula. 
  He 
  writes 
  (loc. 
  cit.) 
  : 
  " 
  At 
  

   the 
  base 
  occurs 
  a 
  bed 
  of 
  very 
  amygdaloidal 
  trap 
  having 
  much 
  the 
  aspect 
  

   of 
  some 
  of 
  the 
  Deccan 
  amygdaloids. 
  Above 
  this 
  rests 
  a 
  thick 
  bed 
  of 
  

   pitchstone 
  not 
  less 
  than 
  20 
  feet 
  in 
  thickness, 
  very 
  compact 
  in 
  parts, 
  and 
  

   these 
  breaking 
  with 
  a 
  highly 
  conchoidal 
  fracture. 
  This 
  bed 
  can 
  be 
  

   traced 
  for 
  15 
  miles 
  to 
  the 
  eastward 
  (E.N.E.), 
  in 
  which 
  direction 
  it 
  

   gradually 
  dips, 
  eventually 
  disappearing 
  beneath 
  the 
  surface." 
  A 
  bed 
  

   of 
  pitchstone 
  is 
  also 
  exposed 
  in 
  the 
  Bhadar 
  stream 
  bank 
  at 
  Nagnesh 
  

   below 
  Ranpur 
  : 
  it 
  is 
  here 
  very 
  impure, 
  enclosing 
  fragments 
  and 
  lapilli 
  of 
  

   volcanic 
  products 
  ; 
  above 
  it 
  is 
  a 
  bed 
  of 
  sphseroidal 
  felsite, 
  whose 
  nodules 
  

   have 
  a 
  nucleus 
  of 
  chalcedony. 
  Below 
  the 
  bed 
  of 
  pitchstone, 
  which 
  be- 
  

   comes 
  trachytic 
  in 
  the 
  lower 
  part, 
  is 
  a 
  compact 
  felsite 
  of 
  a 
  dull 
  red 
  colour 
  ; 
  

   this 
  latter 
  rock 
  has 
  been 
  used 
  in 
  the 
  wall 
  round 
  the 
  town 
  of 
  Nagnesh. 
  

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