﻿ENDucH.] 
  TRINADAD 
  REGION 
  COAL-SERIES. 
  195 
  

  

  These 
  shales 
  and 
  siuulstones 
  reach 
  a 
  thickness 
  of 
  about 
  2,000 
  feet 
  between 
  

   Trinidad 
  and 
  the 
  voleiinic 
  capping 
  of 
  Fisher's 
  Peak-. 
  Regarded 
  as 
  a 
  

   whole, 
  the 
  group 
  is 
  one 
  of 
  uuilormity, 
  both 
  as 
  regards 
  the 
  arrange- 
  

   ment 
  and 
  general 
  character, 
  and 
  the 
  lithological 
  constitution 
  of 
  its 
  

   single 
  members. 
  Studying 
  the 
  formation 
  from 
  this 
  standpoint, 
  the 
  

   conclusion 
  is 
  forced 
  upon 
  the 
  observer 
  that 
  it 
  represents 
  essentially 
  one 
  

   single 
  epoch 
  in 
  the 
  geological 
  history 
  of 
  the 
  region. 
  The 
  entire 
  charac- 
  

   ter 
  of 
  the 
  older 
  Cretaceous 
  period 
  is 
  changed, 
  and 
  we 
  find 
  instead 
  one 
  

   new, 
  to 
  a 
  certain 
  extent, 
  both 
  iu 
  the 
  features 
  of 
  its 
  geognostic 
  details 
  

   and 
  in 
  its 
  palceoutological 
  remains. 
  

  

  THE 
  COAL-BEAEING 
  SERIES. 
  

  

  Ascending 
  from 
  the 
  Cretaceous 
  shales 
  in 
  the 
  bed 
  of 
  the 
  Purgatorio, 
  

   toward 
  Fisher's 
  Peak, 
  we 
  pass 
  through 
  170 
  feet 
  of 
  them, 
  finding 
  Inoce- 
  

   rami 
  for 
  155 
  feet 
  of 
  the 
  vertical 
  distance. 
  Characteristic 
  concretionary 
  

   nodules, 
  of 
  dolomite 
  contain 
  the 
  fragments 
  of 
  this 
  fossil 
  as 
  well 
  as 
  of 
  Os- 
  

   trea. 
  Wherever 
  freshly 
  exix)sed, 
  the 
  shales 
  are 
  a 
  dark 
  grey, 
  weathering 
  

   like 
  those 
  of 
  the 
  Colorado 
  group. 
  At 
  first 
  glance 
  I 
  was 
  inclined 
  to 
  re- 
  

   gard 
  them 
  as 
  belonging 
  to 
  a 
  higher 
  group, 
  but 
  now 
  see 
  no 
  reason 
  why 
  

   they 
  should 
  not 
  be 
  considered 
  as 
  Colorado 
  shales.* 
  As 
  will 
  be 
  seen 
  

   subsequently, 
  there 
  is 
  stratigraphical 
  evidence 
  also 
  in 
  support 
  of 
  this 
  

   view. 
  Above 
  that 
  we 
  find 
  alternating 
  sandstones 
  and 
  shales 
  120 
  feet 
  

   in 
  thickness, 
  forming 
  a 
  low 
  bluff 
  trending 
  south 
  of 
  west. 
  From 
  the 
  top 
  

   of 
  this 
  bluff" 
  to 
  the 
  base 
  of 
  the 
  coal 
  there 
  are 
  270 
  feet 
  of 
  sandstones 
  

   and 
  shales, 
  varying 
  iu 
  thickness 
  and 
  color 
  locally. 
  Then 
  follow 
  two 
  

   banks 
  of 
  coal, 
  covered 
  in 
  turn 
  by 
  sandstones 
  and 
  shales. 
  A 
  section 
  

   (Section 
  XIV) 
  taken 
  frr 
  n 
  the 
  rivei 
  -bed 
  southward 
  toward 
  Fisher's 
  Peak 
  

   will 
  iilustrat 
  3 
  the 
  coutt 
  irs 
  of 
  the 
  region, 
  and 
  give 
  the 
  beds 
  iu 
  greater 
  

   detail 
  than 
  has 
  been 
  done 
  above 
  : 
  

  

  Ft. 
  In. 
  

  

  I. 
  u. 
  Yellow 
  sandstone, 
  shaly 
  in 
  part 
  20 
  

  

  t. 
  Greyish 
  and 
  yellow 
  laminated 
  shales 
  35 
  

  

  s. 
  Light-yellow 
  sandstone, 
  weathering 
  in 
  rounded 
  outcrops.. 
  25 
  

  

  r. 
  Greyish-browu 
  shales, 
  with 
  coaled 
  remains 
  of 
  plants 
  18 
  

  

  g. 
  Coal 
  , 
  9 
  6 
  

  

  jp. 
  White 
  middle-grained 
  sandstone 
  4 
  

  

  0. 
  Yellowish-brown 
  shales 
  8 
  

  

  n. 
  Coal 
  , 
  2 
  10 
  

  

  m. 
  Light-yellow 
  sandstone 
  .• 
  . 
  . 
  . 
  3 
  8 
  

  

  1. 
  Yellow 
  shales, 
  partly 
  sandy 
  , 
  3 
  6 
  

  

  h. 
  Light 
  yellow 
  sandstones 
  • 
  45 
  

  

  i. 
  Grejish-yellow 
  shales 
  . 
  5Q 
  

  

  h. 
  Yellow 
  sardstone 
  28 
  

  

  </. 
  Yellow 
  and 
  greyish 
  shales 
  . 
  - 
  -- 
  , 
  130 
  

  

  /. 
  Yellow 
  sandstone 
  30 
  

  

  €. 
  Grey 
  shale^ 
  , 
  . 
  38 
  

  

  <^. 
  Yellow 
  sandstones 
  26 
  

  

  c. 
  Yellow-brown 
  shales 
  16 
  

  

  h. 
  Yellow 
  sandstone 
  24 
  

  

  a. 
  Dark-grey 
  shales, 
  with 
  Inoceramus 
  170 
  

  

  This 
  section 
  gives, 
  as 
  nearl\ 
  as 
  possible, 
  the 
  arrangement 
  of 
  strata 
  

   * 
  Compare 
  Report 
  Uuited 
  States 
  Geological 
  Survey, 
  lbC7-'69, 
  p. 
  154. 
  

  

  