﻿30 
  EEDDEN 
  : 
  GEOLOGY 
  OF 
  KATHIAWAR 
  PENINSULA 
  IN 
  GUZERAT. 
  

  

  Among 
  the 
  dykes 
  north 
  of 
  Wasawad, 
  those 
  in 
  one 
  direction 
  are 
  of 
  one 
  

  

  kind 
  of 
  trap, 
  while 
  those 
  crossing 
  are 
  of 
  a 
  differ- 
  

   Differently 
  bearing 
  

   dykes 
  have 
  different 
  kinds 
  ent 
  kind. 
  The 
  north-east, 
  and 
  east-north-east, 
  

  

  set 
  have 
  a 
  crystalline 
  texture, 
  with 
  grey 
  felspar 
  

  

  and 
  black 
  hornblende 
  ; 
  the 
  rock 
  is 
  massive, 
  or 
  transversely 
  columnar 
  : 
  

  

  while 
  the 
  north-west 
  and 
  south-east 
  dykes 
  have 
  a 
  much 
  finer 
  texture, 
  are 
  

  

  micro 
  or 
  crypto-crystalline, 
  and 
  the 
  rock 
  — 
  which 
  is 
  dark 
  grey 
  internally, 
  

  

  but 
  weathers 
  to 
  a 
  pale 
  olive 
  green 
  on 
  the 
  surface 
  — 
  is 
  fissured 
  into 
  angular 
  

  

  shingle, 
  or 
  gravel, 
  along 
  the 
  surface 
  of 
  the 
  dyke. 
  This 
  latter 
  set, 
  it 
  

  

  would 
  appear, 
  is 
  the 
  older 
  ; 
  for, 
  in 
  several 
  instances, 
  the 
  dykes 
  of 
  this 
  

  

  series 
  were 
  cut 
  through 
  by 
  those 
  of 
  the 
  other. 
  It 
  was 
  also 
  observed 
  that 
  

  

  the 
  dykes 
  with 
  the 
  splintered 
  fine-grainec 
  crap 
  with 
  olive 
  green 
  surface 
  

  

  (i.e., 
  the 
  older 
  dykes) 
  are 
  more 
  regular, 
  on 
  the 
  whole, 
  than 
  the 
  others 
  : 
  

  

  they 
  are 
  long 
  and 
  straight 
  in 
  their 
  course, 
  or 
  nearly 
  so, 
  and 
  uniform 
  in 
  

  

  thickness 
  throughout 
  : 
  they 
  seldom 
  make 
  much 
  show 
  above 
  the 
  surface 
  

  

  of 
  the 
  country, 
  at 
  most 
  forming 
  low 
  knolls, 
  or 
  elongated 
  mounds, 
  hardly 
  

  

  perceptible 
  from 
  a 
  distance; 
  whereas 
  the 
  more 
  crystalline 
  lumpy 
  

  

  boulder-like 
  trap-dykes 
  are 
  most 
  irregular 
  in 
  their 
  bearing, 
  vary 
  much 
  in 
  

  

  thickness, 
  and 
  often 
  die 
  out 
  rapidly, 
  or 
  terminate 
  abruptly, 
  starting 
  

  

  again, 
  perhaps, 
  a 
  little 
  out 
  of 
  the 
  normal 
  bearing. 
  They 
  almost 
  invariably 
  

  

  form 
  ridges 
  that 
  may 
  be 
  traced 
  by 
  the 
  eye 
  across 
  country 
  for 
  many 
  

  

  miles. 
  Some 
  of 
  these 
  ridges 
  attain 
  a 
  height 
  of 
  150 
  feet 
  above 
  the 
  level 
  

  

  of 
  the 
  surrounding 
  country 
  ; 
  as, 
  for 
  example, 
  the 
  one 
  north-east 
  of 
  Kotra 
  

  

  Pita 
  that 
  passes 
  the 
  deserted 
  village 
  called 
  Bhabhisana. 
  These 
  ridges 
  are 
  

  

  buttressed, 
  or 
  fringed, 
  on 
  either 
  side 
  by 
  remnants 
  of 
  bedded 
  traps 
  removed 
  

  

  elsewhere 
  by 
  denudation. 
  

  

  There 
  are 
  exceptions 
  to 
  the 
  rule 
  given 
  above, 
  that 
  dykes 
  trending 
  in 
  

  

  one 
  direction 
  bear 
  the 
  same 
  kind 
  of 
  trap; 
  for 
  

  

  instance, 
  of 
  the 
  eight 
  dykes 
  more 
  or 
  less 
  parallel, 
  

  

  north 
  of 
  Darwa, 
  and 
  all 
  within 
  two 
  miles 
  of 
  the 
  village 
  of 
  Umrala, 
  five 
  

  

  are 
  of 
  the 
  fine-grained 
  trap 
  that 
  weathers 
  on 
  the 
  surface 
  into 
  angular 
  

  

  gravel, 
  while 
  three 
  are 
  of 
  a 
  coarser 
  variety 
  of 
  trap 
  weathering 
  into 
  large 
  

  

  boulder-like 
  masses. 
  

  

  ( 
  ioa 
  ) 
  

  

  