﻿326 
  W. 
  T. 
  Lee 
  — 
  Notes 
  on 
  the 
  Manzano 
  Group. 
  

  

  known 
  to 
  extend 
  from 
  western 
  New 
  Mexico 
  to 
  Wyoming. 
  

   Those 
  interested 
  in 
  this 
  subject 
  must 
  regret 
  that 
  details 
  

   upon 
  which 
  proof 
  must 
  rest 
  are 
  wanting. 
  

  

  Of 
  even 
  greater 
  consequence 
  is 
  the 
  author's 
  treatment 
  

   of 
  beds 
  which, 
  although 
  admitting 
  that 
  they 
  "may 
  not 
  

   be 
  Triassic" 
  he 
  describes 
  as 
  the 
  upper 
  member 
  of 
  the 
  

   Upper 
  Triassic. 
  He 
  describes 
  two 
  of 
  these 
  beds 
  in 
  such 
  

   a 
  manner 
  that 
  they 
  are 
  plainly 
  recognizable. 
  They 
  are 
  

   the 
  "conspicuous 
  bed 
  of 
  white 
  much 
  cross-bedded 
  sand- 
  

   stone 
  which 
  was 
  traced 
  from 
  the 
  southern 
  Sangre 
  de 
  

   Cristo 
  Mountains 
  eastward 
  to 
  beyond 
  Tucumcari," 
  and 
  

   "a 
  bed 
  of 
  gypsum 
  about 
  50 
  feet 
  in 
  thickness, 
  underlain 
  

   by 
  thin 
  dark 
  brown 
  flaggy 
  and 
  very 
  bituminous 
  lime- 
  

   stone." 
  "Without 
  doubt 
  the 
  cross-bedded 
  sandstone 
  is 
  

   the 
  Wingate, 
  which 
  has 
  been 
  correlated 
  6 
  with 
  lower 
  La 
  

   Plata 
  and 
  Vermilion 
  Cliff 
  to 
  the 
  west 
  and 
  with 
  Exeter 
  

   to 
  the 
  east, 
  and 
  which 
  is 
  now 
  classed 
  as 
  Jurassic. 
  7 
  

   These 
  and 
  the 
  gypsum 
  beds 
  have 
  been 
  described 
  at 
  some 
  

   length 
  in 
  the 
  Smithsonian 
  publication 
  just 
  referred 
  to 
  

   where 
  the 
  gypsum 
  is 
  explained 
  as 
  a 
  deposit 
  from 
  the 
  

   interior 
  sea 
  of 
  Upper 
  Jurassic 
  time. 
  This 
  brief 
  note 
  is 
  

   not 
  the 
  place 
  for 
  extended 
  discussion 
  as 
  to 
  whether 
  the 
  

   beds 
  of 
  gypsum 
  are 
  of 
  Triassic 
  or 
  Jurassic 
  age, 
  but 
  it 
  is 
  

   appropriate 
  to 
  raise 
  the 
  question 
  whether 
  the 
  author 
  is 
  

   justified 
  in 
  including 
  a 
  gypsum 
  formation 
  of 
  the 
  thick- 
  

   ness, 
  character 
  and 
  extent 
  of 
  those 
  mentioned, 
  in 
  beds 
  

   which 
  he 
  describes 
  as 
  "entirely 
  of 
  terrestrial 
  origin, 
  in 
  

   the 
  main 
  river 
  and 
  stream 
  deposits." 
  It 
  is 
  equally 
  

   appropriate 
  to 
  call 
  attention 
  to 
  the 
  fact 
  that 
  reasons 
  

   have 
  been 
  presented 
  for 
  connecting 
  the 
  beds 
  of 
  gypsum 
  

   with 
  the 
  Jurassic 
  marine 
  invasion. 
  If 
  the 
  gypsum 
  was 
  

   derived 
  from 
  sea 
  water 
  it 
  can 
  not 
  be 
  included 
  in 
  rocks 
  of 
  

   non-marine 
  origin. 
  

  

  6 
  Lee, 
  Willis 
  T.: 
  Early 
  Mesozoic 
  physiography 
  of 
  the 
  southern 
  Rocky 
  

   Mountains, 
  Smithsonian 
  Misc. 
  Collection, 
  vol. 
  69, 
  pp. 
  1-41, 
  figs. 
  5 
  and 
  6, 
  

   1918. 
  

  

  7 
  Emery, 
  Wilson 
  B.: 
  The 
  Green 
  Eiver 
  desert 
  section, 
  Utah, 
  this 
  Journal, 
  

   (4), 
  vol. 
  46, 
  pp. 
  551-577, 
  1918. 
  

  

  