﻿ENDLicH.] 
  HUERFANO 
  JURA-TEIAS. 
  123 
  

  

  de 
  Cristo, 
  at 
  Veta 
  and 
  at 
  Costilla 
  "passes, 
  those 
  beds 
  have 
  been 
  folded 
  

   and 
  even 
  overturned, 
  and 
  it 
  is 
  there 
  that 
  the 
  lowest 
  depressions 
  were 
  

   produced. 
  None 
  of 
  the 
  Upper 
  Carboniferous 
  limestones, 
  that 
  occur 
  

   north 
  of 
  the 
  Arkansas, 
  have 
  been 
  found. 
  It 
  is 
  possible 
  that 
  they 
  may 
  

   be 
  covered 
  entirely 
  by 
  the 
  Cretaceous, 
  but 
  it 
  does 
  not 
  seem 
  ijrobable 
  

   that 
  in 
  such 
  a 
  case 
  not 
  even 
  a 
  single 
  outcrop 
  should 
  have 
  been 
  ob- 
  

   served. 
  

  

  JURA- 
  TRIAS. 
  

  

  Nowhere 
  were 
  any 
  Mesozoic 
  beds 
  of 
  this 
  group 
  observed 
  except 
  at 
  the 
  

   southern 
  end 
  of 
  the 
  Greenhoru 
  Mountains, 
  which 
  falls 
  into 
  our 
  district. 
  

   Station 
  63 
  of 
  1874 
  is 
  located 
  on 
  a 
  prominent 
  hill 
  composed 
  of 
  porphyritic 
  

   trachyte 
  near 
  the 
  base 
  of 
  the 
  mountains, 
  and 
  this 
  may 
  be 
  regarded 
  as 
  the 
  

   central 
  point 
  near 
  which 
  the 
  red 
  Triassic 
  beds 
  are 
  found. 
  On 
  the 
  east 
  side 
  

   the 
  development 
  of 
  these 
  beds, 
  both 
  as 
  regards 
  the 
  horizontal 
  and 
  ver- 
  

   tical 
  dimensions, 
  is 
  quite 
  considerable. 
  Piiions 
  densely 
  cover 
  the 
  low 
  hills 
  

   formed 
  by 
  them 
  and 
  greatly 
  impede 
  detailed 
  examinations. 
  It 
  is 
  evident, 
  

   however, 
  that 
  the 
  " 
  red 
  beds" 
  occurring 
  there 
  are 
  identical 
  with 
  those 
  

   farther 
  north. 
  The 
  bright-red 
  color 
  shown 
  by 
  sandstones, 
  shales, 
  and 
  

   marls, 
  the 
  regular 
  stratification, 
  and 
  the 
  lithological 
  constitution, 
  all 
  

   agree. 
  Single 
  strata 
  of 
  either 
  white 
  or 
  yellowish 
  sandstones 
  give 
  the 
  

   bluffs 
  and 
  walls 
  a 
  banded 
  appearance, 
  strikingly 
  in 
  contrast 
  with 
  the 
  more 
  

   uniform 
  color 
  of 
  the 
  red 
  Carboniferous 
  sandstone. 
  As 
  heretofore 
  no 
  

   fossils 
  were 
  found, 
  save 
  some 
  impressions 
  resembling 
  Fucoids. 
  At 
  the 
  

   extreme 
  southern 
  point 
  of 
  the 
  Greenhorn 
  Range 
  the 
  red 
  beds 
  are 
  en- 
  

   tirely 
  covered 
  by 
  the 
  Lower 
  Cretaceous, 
  and 
  do 
  not 
  again 
  appear 
  until 
  

   due 
  west 
  of 
  station 
  G3 
  of 
  1874. 
  There 
  they 
  are 
  exposed 
  in 
  several 
  caiions 
  

   that 
  cut 
  deeply 
  through 
  the 
  Cretaceous. 
  Near 
  the 
  heads 
  of 
  the 
  caiions 
  the 
  

   outcrops 
  are 
  found 
  in 
  the 
  shape 
  of 
  almost 
  vertical 
  walls 
  200 
  to 
  400 
  feet 
  

   in 
  height, 
  surrounded 
  by 
  timber, 
  inclosing 
  the 
  swift 
  streams 
  that 
  form 
  

   numerous 
  small 
  cascades 
  over 
  the 
  readily 
  eroding 
  sandstone. 
  A 
  few 
  

   miles 
  nortb 
  of 
  the 
  station 
  these 
  outcrops 
  cease, 
  never 
  at 
  any 
  time 
  ex- 
  

   tending 
  into 
  the 
  valley. 
  On 
  the 
  east 
  side 
  of 
  the 
  Sangre 
  de 
  Cristo 
  no 
  

   evidence 
  of 
  Jura-Trias 
  was 
  found. 
  It 
  seems 
  almost 
  inexplicable 
  why 
  

   that 
  should 
  be 
  so, 
  but 
  I 
  doubt 
  if 
  the 
  Triassic 
  and 
  Juriassic 
  waters 
  ever 
  

   extended 
  sofarwestin 
  thatregion. 
  Jurassic 
  beds, 
  consisting 
  of 
  the 
  light 
  

   shales 
  and 
  marls, 
  occur 
  east 
  of 
  station 
  63 
  of 
  1874, 
  superincumbent 
  upon 
  

   the 
  Triassic 
  beds, 
  and 
  conformable 
  with 
  them. 
  No 
  fossils 
  were 
  found 
  

   in 
  them, 
  but 
  their 
  position 
  in 
  the 
  geological 
  horizon 
  of 
  that 
  region 
  

   seems 
  so 
  well 
  established, 
  that 
  their 
  occurrence 
  in 
  definite 
  connection 
  

   with 
  other 
  formations 
  may 
  justify 
  the 
  assumption 
  of 
  their 
  Jurassic 
  age. 
  

   None 
  were 
  found 
  on 
  the 
  west 
  slope 
  of 
  the 
  Greenhorns. 
  It 
  is 
  possible 
  

   that 
  they 
  may 
  occur 
  in 
  connection 
  with 
  the 
  red 
  beds 
  mentioned, 
  but 
  the 
  

   timber 
  is 
  so 
  dense 
  there, 
  and 
  the 
  amount 
  of 
  redeposited 
  material 
  so 
  

   large, 
  that 
  no 
  i)ositive 
  information 
  could 
  be 
  obtained 
  upon 
  the 
  subject. 
  

   Near 
  the 
  Sangre 
  de 
  Cristo 
  no 
  evidence 
  of 
  the 
  existence 
  of 
  Jurassic 
  beds 
  

   could 
  be 
  observed. 
  

  

  CRETACEOUS. 
  

  

  Quite 
  a 
  considerable 
  portion 
  of 
  this 
  district 
  is 
  covered 
  by 
  Cretaceous 
  

   beds. 
  Only 
  the 
  loAver 
  members 
  are 
  represented, 
  however, 
  not 
  reaching 
  

   higher 
  than 
  No. 
  3. 
  The 
  main 
  area 
  belonging 
  to 
  this 
  formation 
  is 
  the 
  

   Huerfano 
  Valley, 
  generally 
  termed 
  Huerfano 
  Park. 
  From 
  the 
  edge 
  of 
  

   the 
  plains 
  westward 
  Cretaceous 
  beds 
  extend 
  to 
  the 
  base 
  of 
  those 
  vol- 
  

   canic 
  mountains 
  east 
  of 
  the 
  Blanca 
  group, 
  underlying 
  some 
  of 
  the 
  

   trachytes 
  that 
  form 
  the 
  prominent 
  peaks 
  mentioned. 
  Northward 
  they 
  

  

  