﻿ne 
  

  

  GEOKGE 
  MAW'S 
  NOTES 
  ON 
  A 
  JOURNEY 
  

  

  tions. 
  Lower 
  down 
  on 
  either 
  side 
  of 
  the 
  rocky 
  ridge 
  were 
  the 
  Arab 
  

   flat-roofed 
  habitations, 
  built 
  of 
  sun-dried 
  mud 
  bricks, 
  embosomed 
  

   in 
  a 
  dense 
  forest 
  of 
  date-palms, 
  many 
  of 
  them 
  from 
  90 
  to 
  100 
  feet 
  

   high 
  ; 
  and 
  stretching 
  away 
  from 
  this 
  dark 
  green 
  and 
  brown 
  mass, 
  

   lines 
  and 
  patches 
  of 
  light 
  green 
  vegetation 
  spread 
  out 
  into 
  the 
  desert, 
  

   where 
  its 
  thirsty 
  sand 
  was 
  sucking 
  in 
  the 
  last 
  drainings 
  from 
  the 
  oasis. 
  

   During 
  my 
  stay 
  at 
  L'Aghouat, 
  I 
  took 
  sketches 
  and 
  sections 
  of 
  several 
  

   of 
  the 
  escarpments 
  and 
  rocky 
  outliers 
  (represented 
  in 
  Pigs. 
  3, 
  

   4, 
  and 
  5), 
  the 
  most 
  important 
  of 
  which 
  is 
  the 
  Rocher 
  de 
  Chien, 
  

   W.S.W. 
  of 
  the 
  town, 
  a 
  jagged 
  hill 
  (Fig. 
  5), 
  rising 
  up 
  300 
  feet 
  

  

  Fig. 
  5, 
  — 
  Rocher 
  de 
  Chien, 
  an 
  isolated 
  Roclc, 
  Sahara 
  plain, 
  west 
  of 
  

  

  S.E 
  

  

  L'Aghouat. 
  

  

  N.W. 
  

  

  out 
  of 
  the 
  sandy 
  plain, 
  and 
  consisting 
  of 
  a 
  hard 
  calcareo-argilla- 
  

   ceous 
  rock, 
  with 
  a 
  N.E. 
  and 
  S.W. 
  strike, 
  dipping 
  S.E. 
  under 
  the 
  

   plain 
  at 
  an 
  angle 
  of 
  65°. 
  At 
  the 
  foot 
  of 
  its 
  N.W. 
  escarpment 
  

   occurs 
  a 
  calcareous 
  cream-coloured 
  rock, 
  with 
  casts 
  of 
  fossils, 
  inclu- 
  

   ding 
  a 
  Chemnitzia 
  or 
  Turritella, 
  underlain 
  by 
  a 
  fine-grained 
  sand- 
  

   stone, 
  with 
  casts 
  of 
  bivalve 
  shells, 
  which 
  Mr, 
  Etheridge 
  thinks 
  may 
  

   be 
  of 
  Miocene 
  age. 
  The 
  sandstone 
  is 
  succeeded 
  by 
  grey 
  gypseous 
  

   marls, 
  which 
  are 
  lost 
  under 
  the 
  Posttertiary 
  deposit 
  of 
  grey 
  loam, 
  

   filling 
  up 
  as 
  a 
  plain 
  two 
  miles 
  wide 
  the 
  denuded 
  anticlinal 
  between 
  

   the 
  Rocher 
  de 
  Chien 
  and 
  the 
  boundary 
  escarpment 
  to 
  the 
  north. 
  

   The 
  lower 
  beds 
  of 
  marl 
  and 
  sandstone 
  on 
  the 
  north 
  side 
  of 
  the 
  

   Rocher 
  de 
  Chien 
  have 
  a 
  less 
  steep 
  inclination 
  than 
  the 
  overlying 
  rock, 
  

   and 
  dip 
  S.E. 
  at 
  an 
  angle 
  of 
  about 
  35°. 
  The 
  face 
  of 
  the 
  main 
  escarp- 
  

   ment 
  N.E. 
  of 
  the 
  town 
  (Figs. 
  3 
  and 
  4) 
  presents 
  the 
  following 
  succession 
  

   of 
  beds 
  in 
  ascending 
  order. 
  At 
  its 
  base 
  white 
  gypseous 
  marls, 
  inter- 
  

   stratified 
  with 
  bands 
  of 
  fine-grained 
  white 
  stone, 
  occur 
  as 
  a 
  low 
  

   terrace 
  a 
  little 
  in 
  advance 
  of 
  the 
  cliff 
  face, 
  and 
  dip 
  15° 
  N.N.E. 
  with 
  

   a 
  W.S.W. 
  and 
  E.N.E. 
  strike. 
  The 
  main 
  face 
  of 
  the 
  cliff 
  consists 
  of 
  

   grey 
  marls 
  interstratified 
  with 
  hard 
  bands 
  and 
  gypseous 
  green 
  marls 
  ; 
  

   and 
  its 
  jagged 
  summit 
  is 
  capped 
  with 
  hard 
  calcareous 
  bands, 
  con- 
  

   taining 
  curious 
  concretionary 
  masses, 
  which 
  are 
  very 
  fossiliferous, 
  

   including 
  a 
  spatangoid 
  Urchin, 
  which 
  Dr. 
  Wright 
  thinks 
  may 
  be 
  a 
  

  

  