﻿nouxEs] 
  UPPER 
  AXD 
  MIDDLE 
  CRETACEOUS 
  FORMA! 
  IONS. 
  257 
  

  

  From 
  station 
  25 
  it 
  could 
  be 
  plainly 
  seen 
  that, 
  although 
  the 
  Upper 
  

   Escarpment 
  sandstones 
  hold 
  their 
  place 
  on 
  the 
  summit 
  of 
  the 
  western 
  

   border 
  of 
  the 
  mesa, 
  they 
  are 
  much 
  broken 
  in 
  the 
  interior, 
  and 
  espe- 
  

   cially 
  along 
  the 
  line 
  of 
  the 
  Mancos 
  Cailon. 
  There 
  is 
  a 
  slight 
  upward 
  

   dip 
  westward 
  from 
  the 
  caGon, 
  so 
  that 
  the 
  drainage 
  has 
  in 
  no 
  case 
  been 
  

   to 
  the 
  west, 
  while 
  a 
  multitude 
  of 
  caiions 
  head 
  very 
  close 
  to 
  the 
  western 
  

   border 
  and 
  open 
  out 
  into 
  the 
  Mancos. 
  Indeed, 
  there 
  seems 
  to 
  be 
  a 
  

   slight 
  clip 
  inward 
  from 
  all 
  sides 
  of 
  the 
  mesa, 
  and 
  this 
  no 
  doubt 
  accounts 
  

   for 
  the 
  rather 
  remarkable 
  fact 
  that 
  from 
  without 
  we 
  get 
  the 
  idea 
  of 
  an 
  

   unbroken 
  and 
  well 
  sustained 
  table-laud, 
  while 
  from 
  within 
  we 
  discover 
  

   only 
  a 
  skeleton 
  — 
  a 
  sort 
  of 
  rude 
  wheel, 
  which 
  might 
  be 
  described 
  as 
  

   having 
  pretty 
  well 
  defined 
  tire 
  and 
  spokes, 
  but 
  no 
  hub. 
  

  

  On 
  the 
  divide 
  between 
  the 
  head 
  of 
  the 
  McElmo 
  and 
  the 
  Upper 
  Mancos 
  

   a 
  high 
  promontory 
  extends 
  far 
  out 
  to 
  the 
  north. 
  It 
  is 
  capped 
  by 
  the 
  

   Lower 
  Escarpment 
  sandstones, 
  beneath 
  which 
  are 
  the 
  shales. 
  

  

  East 
  of 
  the 
  Mancos 
  there 
  are 
  two 
  great 
  fragments 
  almost 
  severed 
  

   from 
  the 
  main 
  eastern 
  mesa, 
  by 
  caiions 
  which 
  have 
  cut 
  down 
  through 
  

   the 
  mesa 
  sandstones 
  and 
  exposed 
  the 
  shales 
  throughout 
  most 
  of 
  their 
  

   courses. 
  

  

  The 
  more 
  easterly 
  of 
  these, 
  reaches 
  north 
  along 
  the 
  divide 
  between 
  

   the 
  Mancos 
  and 
  Cherry 
  Creek, 
  and 
  ends 
  in 
  a 
  high 
  promontory 
  which 
  

   overlooks 
  the 
  beautiful 
  valley 
  that 
  lies 
  between 
  the 
  mesa 
  and 
  the 
  La 
  

   Plata 
  Mountains. 
  At 
  Cherry 
  Creek 
  the 
  mesa 
  proper 
  ends, 
  and 
  the 
  

   Mesa 
  Verde 
  group 
  of 
  strata 
  extends 
  eastward 
  in 
  a 
  long 
  ridge, 
  or 
  hog- 
  

   back, 
  at 
  first 
  quite 
  flat, 
  but 
  at 
  the 
  crossing 
  of 
  the 
  La 
  Plata 
  at 
  the 
  base 
  

   of 
  the 
  Parrot 
  t 
  City 
  bar 
  the 
  dip 
  rises 
  to 
  five 
  or 
  six 
  degrees. 
  

  

  A 
  clearer 
  notion 
  of 
  the 
  character 
  and 
  surroundings 
  of 
  the 
  Mesa 
  Verde 
  

   can 
  be 
  obtained 
  from 
  the 
  bird's-eye 
  view, 
  Plate 
  XXXVII, 
  than 
  from 
  

   any 
  word 
  description, 
  however 
  deta-iled. 
  

  

  MIDDLE 
  CRETACEOUS 
  ROCKS. 
  

  

  The 
  Middle 
  Cretaceous 
  rocks, 
  which 
  include 
  numbers 
  2 
  and 
  3 
  of 
  the 
  

   ordinary 
  classification, 
  have 
  an 
  average 
  thickness 
  of 
  nearly 
  1,400 
  feet, 
  

   and 
  throughout 
  the 
  district 
  examined 
  are 
  chiefly 
  shales, 
  dark 
  in 
  color, 
  

   and 
  usually 
  homogeneous. 
  They 
  occupy 
  considerably 
  more 
  surface- 
  

   area 
  than 
  the 
  Upper 
  Cretaceous 
  rocks. 
  At 
  the 
  south 
  they 
  first 
  rise 
  to 
  

   the 
  surface 
  at 
  the 
  base 
  of 
  the 
  Great 
  Hogback 
  5 
  from 
  this 
  poin 
  t 
  they 
  

   extend 
  to 
  the 
  base 
  of 
  the 
  Sierra 
  Carriso, 
  a 
  distance 
  of 
  nearly 
  25 
  miles. 
  

   The 
  dip 
  to 
  the 
  east 
  is 
  very 
  gentle, 
  so 
  that 
  the 
  San 
  Juan 
  flows 
  22 
  miles 
  to 
  

   the 
  westward 
  in 
  descending 
  through 
  1,400 
  feet 
  of 
  strata. 
  The 
  actual 
  

   descent 
  of 
  the 
  bed 
  of 
  the 
  stream 
  in 
  this 
  distance 
  is 
  only 
  200 
  feet. 
  After 
  

   passing 
  the 
  gateway 
  in 
  the 
  Hogback 
  the 
  river 
  enters 
  a 
  broad 
  valley 
  

   which 
  extends 
  to 
  the 
  base 
  of 
  the 
  Mesa 
  Verde 
  on 
  the 
  north, 
  far 
  away 
  to 
  

   the 
  south 
  in 
  a 
  stretch 
  of 
  smooth, 
  grassy 
  plain, 
  which 
  has 
  not 
  been 
  fully 
  

   defined. 
  The 
  monotony 
  of 
  this 
  plain 
  is 
  somewhat 
  broken 
  by 
  a 
  contin- 
  

   uation 
  of 
  the 
  Great 
  Hogback, 
  which 
  crosses 
  indefinitely 
  to 
  the 
  south- 
  

   west. 
  Tlie 
  one 
  remarkable 
  feature 
  of 
  this 
  part 
  of 
  the 
  valley 
  of 
  the 
  San 
  

   Juan, 
  however, 
  is 
  known 
  as 
  the 
  "Needles," 
  a 
  mass 
  of 
  volcanic 
  rock 
  

   which 
  rises 
  abruptly 
  from 
  the 
  plain 
  and 
  terminates 
  in 
  a 
  cluster 
  of 
  needle- 
  

   like 
  points 
  or 
  spires, 
  which 
  presents 
  from 
  the 
  distance 
  at 
  which 
  we 
  

   were 
  compelled 
  to 
  view 
  it, 
  the 
  appearance 
  of 
  a 
  gigantic 
  cathedral. 
  Its 
  

   height 
  is 
  said 
  to 
  be 
  nearly 
  1,800 
  feet. 
  It 
  is 
  located 
  some 
  10 
  miles 
  south 
  

   of 
  the 
  San 
  Juan, 
  and 
  nearly 
  opposite 
  the 
  opening 
  of 
  the 
  Mancos 
  Caiion. 
  

   It 
  is 
  a 
  great 
  landmark 
  and 
  visible 
  from 
  many 
  distant 
  points. 
  

  

  Along 
  the 
  course 
  of 
  the 
  river 
  there 
  are 
  occasional 
  terraces 
  which 
  rise 
  

   17 
  o 
  s 
  

  

  