﻿HOLMES.] 
  MANGOS 
  CANON. 
  255 
  

  

  however, 
  and 
  have 
  no 
  great 
  horizontal 
  extent. 
  As 
  compared 
  with 
  the 
  

   section 
  in 
  the 
  Great 
  Hogback 
  on 
  the 
  San 
  Jaan, 
  the 
  sandstones 
  are 
  

   doubled 
  in 
  quantity. 
  In 
  one 
  locality 
  I 
  found 
  a 
  number 
  of 
  fossil 
  leaves 
  

   which 
  correspond 
  closely 
  to 
  those 
  found 
  near 
  the 
  same 
  horizon 
  in 
  the 
  

   Hogback 
  section. 
  Midway 
  in 
  the 
  caiion 
  and 
  in 
  the 
  neighborhood 
  of 
  the 
  

   two-story 
  cliff-house 
  (see 
  map) 
  Mr. 
  Brandegee 
  procured 
  the 
  following 
  

   section. 
  ' 
  Beginning 
  with 
  the 
  Upper 
  Escarpment, 
  we 
  have 
  — 
  

  

  200 
  feet 
  sandstone 
  ; 
  massive, 
  reddish 
  and 
  yellowish. 
  Beneath 
  this 
  

   is 
  the 
  Coal 
  Group 
  (7, 
  general 
  section). 
  

   6 
  feet 
  black 
  shales. 
  (The 
  niches 
  which 
  contain 
  the 
  cliff-houses 
  

   are 
  eroded 
  from 
  this.) 
  

   50 
  feet 
  light-colored 
  sandstone, 
  massive 
  and 
  soft. 
  

  

  1 
  foot 
  black 
  shale. 
  

  

  100 
  feet 
  sandstones, 
  soft, 
  yellowish. 
  

   20 
  feet 
  shale. 
  

   10 
  feet 
  sandstone. 
  

   75 
  feet 
  sandstone, 
  argillaceous. 
  

   10 
  feet 
  sandstone. 
  

   30 
  feet 
  blackish 
  clay 
  shale. 
  

   1 
  feet 
  sandstones. 
  

  

  2 
  feet 
  shales. 
  

  

  4 
  feet 
  sandstones. 
  

  

  6 
  feet 
  black 
  shale. 
  

  

  6 
  feet 
  sandstone. 
  

  

  6 
  feet 
  coal 
  shale, 
  containing 
  small 
  seam 
  of 
  good 
  coal. 
  

  

  3 
  feet 
  sandstone. 
  

  

  150 
  feet 
  shale 
  alternating 
  with 
  sandstone. 
  

   10 
  feet 
  coal 
  and 
  coal 
  shale, 
  2 
  feet 
  of 
  good 
  coal. 
  

   160 
  feet 
  sandstones 
  and 
  shales 
  alternating. 
  

  

  It 
  appears 
  by 
  this 
  that 
  the 
  sandstones 
  occupy 
  at 
  least 
  three-fourths 
  

   of 
  the 
  entire 
  section, 
  whereas 
  in 
  the 
  San 
  Juan 
  Hogback 
  they 
  are 
  scarcely 
  

   half. 
  

  

  The 
  scenery 
  throughout 
  the 
  canon 
  is 
  quite 
  striking. 
  The 
  bold 
  cliffs 
  

   of 
  the 
  Upper 
  Escarpment 
  fairly 
  overhang 
  the 
  valley 
  and 
  the 
  projecting 
  

   angles 
  are 
  sentineled 
  with 
  tottering 
  crags 
  and 
  half-poised 
  masses 
  of 
  

   rock. 
  

  

  The 
  trail 
  is 
  in 
  many 
  places 
  a 
  difficult 
  one 
  to 
  follow, 
  and 
  the 
  tourist 
  

   who 
  may 
  be 
  tempted 
  to 
  visit 
  this 
  locality 
  for 
  the 
  purpose 
  of 
  studying 
  

   the 
  works 
  of 
  the 
  ancient 
  inhabitants 
  will 
  find 
  it 
  no 
  holiday 
  task 
  to 
  work 
  

   his 
  way 
  through 
  the 
  mazes 
  of 
  fallen 
  rocks 
  and 
  sharp-cut 
  gulches. 
  In 
  

   many 
  places 
  the 
  river 
  washes 
  the 
  bases 
  of 
  the 
  cliffs, 
  and 
  forces 
  the 
  trail 
  

   back 
  up 
  the 
  rocky 
  slopes. 
  The 
  fringe 
  of 
  tangled 
  underbrush 
  that 
  

   borders 
  the 
  stream, 
  the 
  deep 
  ditch-like 
  channel 
  and 
  the 
  quicksands 
  of 
  

   the 
  bed, 
  make 
  it 
  next 
  to 
  impossible 
  to 
  cross 
  from 
  side 
  to 
  side. 
  

  

  Lower 
  down, 
  the 
  shales 
  of 
  the 
  Middle 
  Cretaceous 
  appear 
  again, 
  the 
  

   cliffs 
  retreat 
  to 
  the 
  right 
  and 
  left, 
  and 
  narrow 
  sage 
  and 
  grass 
  covered 
  

   flats 
  border 
  the 
  river. 
  Still 
  lower, 
  the 
  Upper 
  Escarpment 
  falls 
  back 
  out 
  

   of 
  sight 
  from 
  below, 
  and 
  the 
  cliffs 
  of 
  the 
  Lower 
  Escarpment 
  are 
  deeply 
  

   indented 
  by 
  the 
  side-canons, 
  so 
  that 
  in 
  looking 
  down 
  the 
  valley 
  one 
  sees 
  

   nothing 
  but 
  a 
  series 
  of 
  bold 
  promontories. 
  

  

  At 
  one 
  point 
  within 
  five 
  or 
  six 
  miles 
  of 
  the 
  foot 
  of 
  the 
  caQon 
  the 
  

   upper 
  line 
  of 
  cliffs 
  approachs 
  the 
  river-front 
  on 
  the 
  east 
  side. 
  This 
  point, 
  

   on 
  which 
  Station 
  25 
  was 
  made, 
  commands 
  a 
  fine 
  view 
  of 
  the 
  southern 
  

   and 
  western 
  borders 
  of 
  the 
  tableland 
  as 
  well 
  as 
  of 
  the 
  Late 
  and 
  Carriso 
  

   Mountains 
  and 
  the 
  valley 
  of 
  the 
  San 
  Juan. 
  In 
  Plate 
  XLI, 
  I 
  present 
  an 
  

   outline 
  sketch 
  of 
  the 
  view 
  to 
  the 
  north 
  and 
  west 
  from 
  this 
  station. 
  

  

  