﻿Formations 
  of 
  Southeastern 
  Idaho. 
  403 
  

  

  group 
  was 
  introduced 
  by 
  Hayden 
  6 
  in 
  the 
  following 
  

   words 
  : 
  

  

  "In 
  the 
  valley 
  of 
  Weber 
  Kiver, 
  from 
  Morgan 
  City 
  to 
  Devil's 
  

   Gate, 
  there 
  is 
  a 
  thickness 
  of 
  1,000 
  to 
  1,200 
  feet 
  of 
  sands, 
  sand- 
  

   stones, 
  and 
  marls 
  of 
  a 
  light 
  color 
  for 
  the 
  most 
  part, 
  which 
  I 
  

   regard 
  as 
  of 
  upper 
  Tertiary 
  age. 
  These 
  newer 
  beds 
  must 
  have 
  

   not 
  only 
  occupied 
  this 
  expansion 
  of 
  the 
  "Weber 
  Valley 
  but 
  also 
  

   all 
  of 
  Salt 
  Lake 
  Valley, 
  for 
  remnants 
  of 
  it 
  are 
  seen 
  along 
  the 
  

   margins 
  of 
  the 
  mountains 
  inclosing 
  Salt 
  Lake 
  Valley. 
  ... 
  I 
  

   found 
  this 
  series 
  of 
  beds 
  so 
  widely 
  extended 
  and 
  so 
  largely 
  devel- 
  

   oped 
  in 
  Weber 
  Valley 
  and 
  Salt 
  Lake 
  Valley, 
  that 
  I 
  regard 
  it 
  

   as 
  worthy 
  of 
  a 
  distinct 
  name, 
  and 
  in 
  consequence 
  have 
  called 
  it 
  

   the 
  Salt 
  Lake 
  group." 
  

  

  This 
  term 
  was 
  introduced 
  by 
  Peale 
  7 
  into 
  southeastern 
  

   Idaho 
  and 
  has 
  been 
  employed 
  in 
  a 
  quotational 
  sense 
  (the 
  

   Salt 
  Lake 
  group 
  of 
  Hayden 
  and 
  Peale) 
  in 
  later 
  publica- 
  

   tions 
  on 
  the 
  region 
  as 
  the 
  designation 
  of 
  the 
  Pliocene 
  (1) 
  

   rocks. 
  In 
  the 
  above 
  citation 
  the 
  name 
  appears 
  to 
  be 
  used 
  

   in 
  a 
  strictly 
  geographical 
  sense 
  with 
  neither 
  a 
  definite 
  

   implication 
  of 
  lacustrine 
  origin 
  of 
  the 
  beds 
  nor 
  implica- 
  

   tion 
  of 
  connection 
  with 
  Great 
  Salt 
  Lake. 
  It 
  is 
  true, 
  how- 
  

   ever, 
  that 
  members 
  of 
  the 
  Hayden 
  Surveys 
  did 
  regard 
  

   these 
  beds 
  as 
  lacustrine 
  in 
  origin, 
  for 
  Peale, 
  8 
  referring 
  

   to 
  similar 
  beds 
  in 
  Marsh 
  Valley 
  to 
  the 
  west, 
  states 
  : 
  

  

  ' 
  ' 
  I 
  believe 
  they 
  were 
  deposited 
  in 
  the 
  same 
  lake 
  that 
  occupied 
  

   this 
  valley, 
  Cache 
  Valley, 
  Salt 
  Lake 
  Valley, 
  and 
  the 
  valley 
  of 
  the 
  

   Upper 
  Portneuf, 
  and 
  of 
  Bear 
  Lake 
  Valley." 
  

  

  The 
  long 
  usage 
  of 
  the 
  name 
  in 
  this 
  region 
  and 
  the 
  fact 
  

   that 
  it 
  was 
  directly 
  applied 
  by 
  Peale 
  to 
  the 
  beds 
  under 
  

   consideration 
  make 
  its 
  retention 
  desirable. 
  It 
  has 
  been 
  

   shown 
  by 
  Gilbert, 
  9 
  however, 
  that 
  these 
  deposits 
  long 
  

   antedate 
  the 
  origin 
  of 
  the 
  present 
  Great 
  Salt 
  Lake 
  and 
  

   it 
  is 
  now 
  believed 
  that 
  the 
  beds, 
  though 
  probably 
  partly 
  

   lacustrine, 
  are 
  largely 
  of 
  fluviatile 
  origin. 
  

  

  The 
  modification 
  of 
  Hayden' 
  s 
  term 
  to 
  Salt 
  Lake 
  for- 
  

   mation 
  appears 
  to 
  meet 
  the 
  need 
  of 
  an 
  appropriate 
  

   geographical 
  name 
  and 
  at 
  the 
  same 
  time 
  to 
  avoid 
  doubt- 
  

  

  6 
  Hayden, 
  F. 
  V.: 
  U. 
  S. 
  Geol. 
  Survey 
  Terr., 
  vol. 
  3, 
  p. 
  92 
  (p. 
  192 
  in 
  com- 
  

   bined 
  1-3 
  Ann. 
  Kept.), 
  1869. 
  

  

  7 
  Peale, 
  A. 
  C: 
  U. 
  S. 
  Geol. 
  Survey 
  Terr., 
  Eleventh 
  Ann. 
  Kept., 
  pp. 
  588 
  

   and 
  640, 
  1879. 
  

  

  8 
  Peale, 
  A. 
  G. 
  : 
  Op. 
  cit., 
  p. 
  567. 
  

  

  9 
  Gilbert, 
  G. 
  K.: 
  Lake 
  Bonneville, 
  U. 
  S. 
  Geol. 
  Survey, 
  Mon. 
  1, 
  p. 
  214, 
  

   1890. 
  

  

  