﻿W. 
  T. 
  Lee 
  — 
  Type 
  Section 
  of 
  Morrison 
  Formation. 
  185 
  

  

  In 
  some 
  places 
  this 
  "lower 
  Dakota" 
  or 
  No. 
  3 
  rests 
  

   on 
  shale 
  and 
  its 
  under 
  surface 
  is 
  covered 
  with 
  worm-like 
  

   bodies 
  such 
  as 
  I 
  have 
  seen 
  in 
  many 
  places 
  associated 
  

   with 
  unconformities. 
  In 
  other 
  places 
  near 
  Morrison 
  the 
  

   quartzose 
  cliff-making 
  "lower 
  Dakota" 
  is 
  separated 
  

   from 
  the 
  softer 
  sandstone 
  of 
  No. 
  4 
  by 
  a 
  thin 
  layer 
  of 
  

   porous 
  rock 
  full 
  of 
  small 
  fragments 
  of 
  carbonized 
  wood. 
  

   These 
  features 
  suggest 
  a 
  time 
  break 
  but 
  it 
  may 
  be 
  one 
  

   of 
  slight 
  significance. 
  

  

  No. 
  4 
  of 
  the 
  section 
  is 
  a 
  part 
  of 
  the 
  Morrison 
  as 
  origi- 
  

   nally 
  defined. 
  Yet 
  it 
  contains 
  fossil 
  plants 
  which 
  

   Knowlton 
  describes 
  as 
  belonging 
  in 
  the 
  Dakota 
  flora. 
  

   It 
  should 
  be 
  noted 
  here 
  that 
  the 
  ■ 
  i 
  Dakota 
  flora 
  ' 
  ' 
  of 
  this 
  

   locality 
  comes 
  from 
  "lower 
  Dakota/' 
  a 
  formation 
  which 
  

   some 
  geologists 
  place 
  in 
  the 
  Lower 
  Cretaceous 
  series, 
  

   No 
  obvious 
  break 
  was 
  found 
  in 
  the 
  section 
  between 
  the 
  

   plant 
  horizon 
  and 
  the 
  base 
  of 
  the 
  Saurian 
  conglomerate. 
  

   If 
  No. 
  4 
  is 
  referred 
  to 
  Dakota 
  on 
  the 
  basis 
  of 
  plant 
  evi- 
  

   dence, 
  it 
  will 
  carry 
  No. 
  5 
  with 
  it, 
  thereby, 
  putting 
  into 
  

   the 
  Dakota 
  group 
  the 
  dinosaurs 
  of 
  this 
  conglomerate, 
  

   provided 
  they 
  are 
  of 
  this 
  time. 
  The 
  origin 
  of 
  these 
  

   dinosaur 
  remains, 
  however, 
  may 
  have 
  an 
  important 
  bear- 
  

   ing 
  on 
  this 
  question. 
  If 
  they 
  are 
  reworked 
  material 
  and 
  

   derived 
  from 
  the 
  older 
  beds, 
  then 
  the 
  conglomerate 
  is 
  

   seemingly 
  the 
  base 
  of 
  the 
  proposed 
  Dakota 
  group. 
  

  

  It 
  should 
  also 
  be 
  noted 
  that 
  Nos. 
  1-5 
  have 
  no 
  marine 
  

   fossils 
  of 
  any 
  kind. 
  This, 
  along 
  with 
  the 
  irregularity 
  

   of 
  deposition 
  from 
  place 
  to 
  place, 
  the 
  presence 
  of 
  fire- 
  

   clay, 
  and 
  the 
  further 
  fact 
  that 
  when 
  fossils 
  are 
  present 
  

   they 
  are 
  the 
  remains 
  of 
  land 
  plants, 
  apparently 
  indicates 
  

   that 
  all 
  of 
  these 
  deposits 
  are 
  of 
  fresh-water 
  origin. 
  

  

  No. 
  6 
  of 
  the 
  section 
  is 
  the 
  well 
  known 
  dinosaur-bear- 
  

   ing 
  member 
  of 
  the 
  Morrison 
  and 
  bones 
  have 
  been 
  found 
  

   in 
  it 
  at 
  several 
  horizons. 
  No. 
  7 
  is 
  a 
  basal 
  member 
  of 
  

   No. 
  6, 
  is 
  slightly 
  conglomeratic, 
  marks 
  the 
  lowest 
  hori- 
  

   zon 
  at 
  which 
  dinosaur 
  bones 
  have 
  been 
  found, 
  and 
  lies 
  

   unconformably 
  on 
  the 
  older 
  rocks. 
  In 
  the 
  old 
  quarry 
  

   from 
  which 
  the 
  bones 
  were 
  taken, 
  I 
  found 
  pebbles 
  one- 
  

   half 
  inch 
  in 
  diameter 
  above 
  the 
  uneven 
  line 
  of 
  erosion. 
  

   Cannon 
  assured 
  me 
  that 
  the 
  bones 
  were 
  taken 
  from 
  the 
  

   pebble 
  bed. 
  

  

  The 
  rocks 
  of 
  Nos. 
  8-10 
  of 
  the 
  section 
  between 
  the 
  peb- 
  

   ble 
  bed 
  just 
  mentioned 
  and 
  the 
  typical 
  Red 
  Beds 
  have 
  

   been 
  examined 
  in 
  many 
  places 
  north 
  of 
  Morrison. 
  They 
  

  

  