﻿Geology. 
  171 
  

  

  Rominger's 
  Report, 
  1873, 
  1, 
  part 
  III, 
  pp. 
  69-71; 
  and 
  the 
  lime- 
  

   stone 
  considered 
  from 
  its 
  fossils 
  to 
  be 
  Trenton 
  or 
  some 
  adjacent 
  

   Lower 
  Silurian 
  strata. 
  It 
  was 
  inferred 
  by 
  Jackson 
  that 
  the 
  

   limestone 
  underlies 
  the 
  sandstone 
  but 
  by 
  the 
  other 
  observers 
  that 
  

   it 
  overlies 
  it 
  although 
  no 
  direct 
  contact 
  was 
  seen. 
  

  

  Excavations 
  made 
  by 
  Mr. 
  Honnold's 
  party, 
  and 
  reported 
  by 
  

   him, 
  have 
  developed 
  the 
  contact 
  of 
  the 
  two 
  formations, 
  and 
  show 
  

   that 
  the 
  two 
  form 
  a 
  synclinal 
  or 
  oblong 
  basin-shaped 
  fold, 
  with 
  

   the 
  limestone 
  overlying, 
  and 
  in 
  direct 
  contact 
  with 
  the 
  sandstone. 
  

   The 
  existeuce 
  of 
  this 
  fold 
  in 
  the 
  sandstone 
  as 
  well 
  as 
  in 
  the 
  lime- 
  

   stone 
  removes 
  the 
  difficulty 
  previous 
  observers 
  have 
  had 
  in 
  

   reconciling 
  the 
  obviously 
  tilted 
  limestone 
  with 
  the 
  supposed 
  

   horizontal 
  sandstone, 
  and 
  proves 
  that 
  the 
  Eastern 
  sandstone 
  

   exposed 
  here 
  is 
  of 
  Lower 
  Silurian 
  age 
  and 
  older 
  than 
  this 
  lime- 
  

   stone. 
  

  

  At 
  the 
  point 
  of 
  contact 
  of 
  the 
  two 
  formations, 
  exposed 
  by 
  

   excavation, 
  the 
  sandstone 
  and 
  limestone 
  appear 
  to 
  be 
  comform- 
  

   able, 
  and 
  they 
  are 
  seen 
  to 
  constantly 
  agree 
  in 
  dip 
  and 
  strike. 
  

   The 
  contact 
  between 
  the 
  two 
  formations 
  is 
  abrupt, 
  without 
  any 
  

   beds 
  of 
  passage, 
  although 
  the 
  upper 
  layers 
  of 
  the 
  sandstone 
  

   contain 
  considerable 
  carbonate 
  of 
  lime 
  and 
  magnesia, 
  and 
  the 
  

   lower 
  layers 
  of 
  the 
  limestone 
  much 
  silica. 
  

  

  These 
  observations 
  are 
  considered 
  to 
  be 
  confirmatory 
  of 
  the 
  

   commonly 
  received 
  view 
  of 
  the 
  Potsdam 
  age 
  of 
  the 
  Eastern 
  

   Sandstone; 
  while 
  the 
  contorted 
  state 
  of 
  the 
  sandstone, 
  extending 
  

   at 
  least 
  one 
  and 
  one-half 
  miles 
  west 
  from 
  the 
  limestone 
  locality, 
  

   may 
  have 
  weight 
  in 
  deciding 
  the 
  relative 
  age 
  of 
  the 
  Eastern 
  

   sandstone 
  and 
  the 
  Copper-bearing 
  rocks. 
  

  

  A 
  careful 
  study 
  of 
  the 
  fossils 
  will 
  be 
  made 
  and 
  additional 
  field 
  

   work 
  done, 
  when 
  the 
  results 
  will 
  be 
  published 
  in 
  detail. 
  

  

  Michigan 
  Mining 
  School. 
  

   Houghton, 
  Michigan" 
  July 
  3d, 
  1891. 
  

  

  2. 
  Expedition 
  to 
  Mt. 
  St. 
  Elias 
  in 
  the 
  summer 
  of 
  1890 
  by 
  

   Israel 
  C. 
  Russell. 
  200 
  pp. 
  8vo, 
  with 
  20 
  plates 
  and 
  several 
  figures. 
  

   — 
  The 
  third 
  volume 
  of 
  the 
  National 
  Geographic 
  Magazine 
  con- 
  

   tains 
  an 
  account 
  of 
  this 
  expedition 
  to 
  Mt. 
  St. 
  Elias 
  by 
  Mr. 
  Rus- 
  

   sell. 
  It 
  went 
  out 
  under 
  the 
  auspices 
  of 
  the 
  National 
  Geographic 
  

   Society 
  and 
  the 
  United 
  States 
  Geological 
  Survey. 
  Mr. 
  Mark 
  B. 
  

   Kerr 
  was 
  the 
  topographical 
  assistant 
  in 
  the 
  survey, 
  and 
  Mr. 
  E. 
  S. 
  

   Hosmer 
  of 
  Washington, 
  a 
  volunteer 
  general 
  assistant. 
  Although 
  

   the 
  summit 
  of 
  Mt. 
  St. 
  Elias 
  was 
  not 
  reached, 
  important 
  additions 
  

   were 
  made 
  by 
  it 
  to 
  the 
  knowledge 
  of 
  the 
  glaciers 
  of 
  the 
  region 
  

   and 
  highly 
  interesting 
  discoveries 
  regarding 
  its 
  geology. 
  The 
  

   formations 
  recognized 
  are 
  (1) 
  sandstones 
  and 
  shales 
  about 
  

   Yakutat 
  Bay, 
  and 
  westward 
  to 
  Icy 
  Bay, 
  which 
  Mr. 
  Russell 
  names 
  

   the 
  Yakutat 
  system 
  ; 
  (2) 
  shales, 
  conglomerates, 
  limestones, 
  sand- 
  

   stones, 
  etc., 
  named 
  the 
  Pinnacle 
  system, 
  occurring 
  in 
  the 
  cliffs 
  of 
  

   Pinnacle 
  Pass, 
  5000 
  feet 
  above 
  the 
  sea-level, 
  and 
  along 
  the 
  north- 
  

   ern 
  and 
  western 
  borders 
  of 
  the 
  Samovar 
  Hills 
  on 
  the 
  borders 
  of 
  

   the 
  Seward 
  glacier; 
  and 
  (3) 
  the 
  metamorphic 
  schists 
  of 
  the 
  main 
  

  

  