﻿108 
  Hatcher 
  — 
  Sedimentary 
  Rocks 
  of 
  Southern 
  Patagonia. 
  

  

  ing 
  alike 
  upon 
  the 
  rocks 
  of 
  the 
  Patagonian 
  and 
  Santa 
  Cruz 
  

   beds 
  or 
  as 
  has 
  been 
  occasionally 
  observed 
  upon 
  some 
  of 
  the 
  

   older 
  basalts 
  of 
  the 
  interior 
  region. 
  

  

  The 
  typical 
  locality 
  for 
  the 
  Cape 
  Fairweather 
  beds 
  is 
  near 
  

   Cape 
  Fairweather, 
  where 
  they 
  may 
  be 
  seen 
  at 
  a 
  distance 
  of 
  

   about 
  two 
  miles 
  north 
  of 
  the 
  Gallegos 
  River, 
  near 
  the 
  summit 
  

   of 
  the 
  bluffs, 
  unconformably 
  overlying 
  the 
  Santa 
  Cruz 
  beds. 
  

   They 
  have 
  also 
  been 
  observed 
  near 
  Darwin 
  Station, 
  south 
  of 
  

   San 
  Julian, 
  where 
  they 
  rest 
  unconformably 
  upon 
  the 
  Patagonian 
  

   beds. 
  They 
  attain 
  their 
  maximum 
  development 
  in 
  the 
  region 
  

   of 
  Lake 
  Pueyrredon, 
  where 
  they 
  form 
  the 
  upper 
  300 
  feet 
  of 
  

   two 
  isolated 
  buttes 
  on 
  the 
  top 
  of 
  the 
  high 
  bluff 
  just 
  south 
  of 
  

   the 
  east 
  end 
  of 
  the 
  lake. 
  At 
  this 
  locality 
  they 
  lie 
  with 
  appar- 
  

   ent 
  conformity 
  upon 
  the 
  Santa 
  Cruz 
  beds, 
  and 
  the 
  sedimenta- 
  

   tion 
  appears 
  to 
  have 
  been 
  continuous 
  at 
  this 
  place, 
  at 
  least, 
  

   from 
  the 
  one 
  to 
  the 
  other 
  series. 
  

  

  Drs. 
  H. 
  A. 
  Pilsbry 
  and 
  A. 
  E. 
  Ortmann, 
  both 
  of 
  whom 
  have 
  

   studied 
  our 
  collections 
  of 
  invertebrates 
  from 
  these 
  beds, 
  are 
  

   agreed 
  as 
  to 
  their 
  Pliocene 
  age, 
  which 
  is 
  moreover 
  in 
  strict 
  

   accord 
  with 
  their 
  stratigraphic 
  position 
  in 
  relation 
  to 
  the 
  Santa 
  

   Cruz 
  beds. 
  

  

  Distributed 
  over 
  almost 
  the 
  entire 
  surface 
  of 
  the 
  Patagonian 
  

   plains 
  and 
  resting 
  unconformably 
  upon 
  the 
  various 
  sediment- 
  

   ary 
  deposits 
  mentioned 
  above, 
  is 
  the 
  great 
  Shingle 
  formation 
  

   of 
  Pleistocene 
  age 
  and 
  of 
  combined 
  ice 
  and 
  aqueous 
  origin. 
  

  

  The 
  following 
  table 
  is 
  intended 
  to 
  show 
  the 
  sequence 
  of 
  the 
  

   various 
  sedimentary 
  rocks 
  of 
  Patagonia 
  and 
  their 
  age 
  as 
  at 
  

   present 
  indicated 
  by 
  paleontologic 
  and 
  stratigraphic 
  evidences. 
  

  

  Pleistocene. 
  

  

  Shingle 
  formation. 
  

  

  Pliocene. 
  

  

  Cape 
  Fairweather 
  beds. 
  

  

  Miocene. 
  

  

  Santa 
  Cruz 
  beds. 
  

  

  

  Patagonian 
  beds. 
  

  

  

  Oligocene. 
  

  

  Upper 
  Lignites. 
  

  

  

  Magellanian 
  beds. 
  

  

  

  Eocene. 
  

  

  Wanting. 
  

  

  

  Guaranitio 
  beds. 
  

  

  

  Lower 
  Lignites. 
  

  

  

  Variegated 
  Sandstones. 
  

  

  Cretaceous. 
  

  

  Upper 
  Conglomerates. 
  

  

  

  Belgrano 
  beds. 
  

  

  

  Lower 
  Conglomerates. 
  

  

  

  Gio 
  beds. 
  

  

  

  Wanting. 
  

  

  

  Jurassic 
  ? 
  

  

  Mayer 
  River 
  Shales. 
  

  

  

  

  Princeton, 
  N. 
  J., 
  December 
  26, 
  1899. 
  

  

  