﻿"8 
  BOSE 
  : 
  GEOLOGY 
  OF 
  THE 
  LOWER 
  NAKBADA 
  VALLEY. 
  

  

  near 
  Pam^kheri 
  for 
  instance, 
  a 
  hard, 
  heavy, 
  black 
  doleritic-looking 
  rock 
  

   runs 
  through 
  the 
  granitoid 
  rocks 
  in 
  the 
  form 
  of 
  dykes. 
  Submitting 
  it 
  to 
  

   microscopic 
  examination, 
  however, 
  I 
  found 
  its 
  composition 
  quite 
  different 
  

   from 
  that 
  of 
  the 
  basic 
  rock 
  I 
  took 
  it 
  to 
  be. 
  The 
  blackness 
  of 
  the 
  rock 
  

   is 
  due 
  to 
  numerous 
  small 
  crystals 
  of 
  greenish-black 
  hornblende. 
  These, 
  

   along 
  with 
  small 
  grains 
  of 
  quartz, 
  are 
  interspersed 
  in 
  a 
  de 
  vitrified 
  or 
  

   altered 
  microcrystalline 
  matrix, 
  which 
  to 
  all 
  appearance 
  is 
  felspathic. 
  

   The 
  rock 
  is 
  probably 
  a 
  variety 
  of 
  quartz-syenite. 
  It 
  may 
  be 
  remarked 
  

   that 
  it 
  ' 
  has 
  not 
  in 
  any 
  way 
  affected 
  the 
  surrounding 
  rocks 
  even 
  at 
  the 
  

   junction. 
  

  

  The 
  schists, 
  of 
  which 
  quartz-schists 
  are 
  perhaps 
  the 
  commonest, 
  

   almost 
  invariably 
  strike 
  east 
  with 
  a 
  little 
  northing, 
  and 
  this 
  constancy 
  is 
  

   a 
  characteristic 
  feature 
  of 
  the 
  region. 
  

  

  //. 
  — 
  Bdg-Rdj_pur 
  Area 
  (Maps 
  No$. 
  2 
  and 
  3). 
  

  

  Proceeding 
  westward, 
  the 
  metamorphics 
  are 
  first 
  met 
  with 
  as 
  inliers 
  in 
  

   the 
  Man 
  valley. 
  Their 
  main 
  area, 
  however, 
  commences 
  near 
  Balwara, 
  

   whence 
  it 
  stretches 
  away 
  west, 
  gradually 
  widening 
  towards 
  Raj 
  pur 
  and 
  

   Chota 
  Udepur. 
  East 
  of 
  Jobat 
  in 
  the 
  valleys 
  of 
  the 
  Uri 
  and 
  Wagni 
  

   rivers, 
  well-foliated 
  gneiss 
  and 
  quartz 
  and 
  hornblende 
  schists 
  are 
  most 
  pro- 
  

   minent 
  ; 
  mica 
  schist 
  is 
  rare 
  ; 
  and 
  so 
  are 
  granitoid 
  rocks. 
  North-west 
  of 
  

   Chirakhan, 
  in 
  the 
  Man 
  valley, 
  as 
  well 
  as 
  at 
  Mohanpura 
  (near 
  Ganwani), 
  

   and 
  Baktala 
  (near 
  Balwara), 
  there 
  are 
  some 
  insignificant 
  outcrops 
  of 
  a 
  

   hard, 
  crystalline, 
  siliceous 
  limestone. 
  It 
  has 
  considerable 
  resemblance 
  to 
  

   the 
  Bijawar 
  limestone 
  ; 
  and 
  during 
  the 
  first 
  season 
  I 
  mapped 
  it 
  as 
  such. 
  

   Subsequently, 
  however, 
  I 
  noticed 
  an 
  identical 
  rock, 
  which 
  obtains 
  very 
  

   great 
  development 
  in 
  the 
  Hatni 
  valley, 
  about 
  Jobat 
  and 
  Khattali, 
  associ- 
  

   ated 
  with 
  the 
  metamorphics 
  in 
  such 
  a 
  manner 
  as 
  to 
  leave 
  no 
  doubt 
  that 
  

   they 
  formed 
  an 
  integral 
  portion 
  of 
  the 
  latter 
  system. 
  The 
  limestone 
  at 
  

   places 
  is 
  highly 
  crystalline, 
  being 
  made 
  up 
  almost 
  exclusively 
  of 
  large 
  

   crystals 
  of 
  calcite 
  with 
  well-developed 
  cleavage 
  planes. 
  Its 
  colour 
  varies 
  

   from 
  black 
  to 
  white 
  ; 
  being 
  more 
  durable 
  than 
  all 
  the 
  other 
  members 
  of 
  

   the 
  series 
  except 
  quartzite, 
  it 
  frequently 
  forms 
  ridges, 
  though 
  never 
  of 
  any 
  

   great 
  height. 
  The 
  rock 
  is 
  sometimes 
  more 
  or 
  less 
  foliated, 
  mica 
  being 
  

   ( 
  8 
  ) 
  

  

  