﻿Hatcher 
  — 
  Sedimentary 
  Rocks 
  of 
  Southern 
  Patagonia. 
  99 
  

  

  gonian 
  beds 
  ; 
  he 
  therefore 
  considers 
  the 
  Magellanian 
  beds 
  as 
  

   of 
  Late 
  Eocene 
  or 
  Early 
  Oligocene 
  age. 
  I 
  may 
  also 
  add 
  that 
  

   this 
  paleontological 
  evidence 
  as 
  to 
  the 
  age 
  and 
  position 
  of 
  the 
  

   Magellanian 
  beds 
  is 
  fully 
  supported 
  by 
  stratigraphic 
  evi- 
  

   dences, 
  since 
  the 
  same 
  Coal 
  Measures 
  found 
  at 
  Punta 
  Arenas 
  

   have 
  been 
  observed 
  farther 
  north 
  underlying 
  beds 
  that 
  contain 
  

   a 
  fauna 
  characteristic 
  of 
  the 
  Patagonian 
  beds. 
  Moreover 
  the 
  

   beds 
  which 
  at 
  Punta 
  Arenas 
  overlie 
  the 
  Coal 
  Measures 
  contain 
  

   a 
  fauna 
  essentially 
  characteristic 
  of 
  the 
  Patagonian 
  beds 
  

   farther 
  north. 
  

  

  The 
  Magellanian 
  beds 
  at 
  Punta 
  Arenas 
  are 
  represented 
  in 
  

   the 
  bluffs 
  of 
  the 
  stream 
  by 
  perhaps 
  1,000 
  feet 
  of 
  strata, 
  and 
  

   the 
  core 
  from 
  a 
  hole 
  sunk 
  by 
  a 
  diamond 
  drill 
  to 
  a 
  depth 
  of 
  

   360 
  feet 
  in 
  the 
  bottom 
  of 
  the 
  valley 
  opposite 
  the 
  anticline 
  

   already 
  mentioned, 
  did 
  not 
  pass 
  through 
  them. 
  At 
  present 
  

   these 
  beds 
  have 
  not 
  been 
  observed 
  elsewhere 
  than 
  at 
  the 
  

   Punta 
  Arenas 
  locality. 
  "Very 
  similar 
  deposits 
  were 
  observed 
  

   underlying 
  certain 
  lignites 
  about 
  the 
  headwaters 
  of 
  the 
  south 
  

   fork 
  of 
  the 
  Rio 
  Chico, 
  but 
  it 
  was 
  not 
  possible 
  to 
  secure 
  other 
  

   than 
  fragmentary 
  fossils 
  from 
  them. 
  It 
  is 
  quite 
  probable 
  also 
  

   that 
  certain 
  marine 
  beds 
  mentioned 
  by 
  Ameghino 
  as 
  occurring 
  

   near 
  Lake 
  Argentina 
  and 
  about 
  the 
  source 
  of 
  the 
  Pio 
  Shehuen 
  

   belong 
  to 
  the 
  Magellanian 
  beds. 
  It 
  may 
  also 
  be 
  found 
  advis- 
  

   able 
  to 
  correlate 
  certain 
  horizons 
  in 
  Dr. 
  Ameghino's 
  Pyro- 
  

   therium 
  beds 
  with 
  the 
  Magellanian 
  as 
  representing 
  lacustrine 
  

   or 
  aeolian 
  deposits 
  contemporaneous 
  in 
  origin 
  with 
  the 
  marine 
  

   beds 
  farther 
  south. 
  In 
  the 
  excellent 
  section 
  of 
  the 
  Pio 
  Tarde 
  

   Caiion 
  near 
  Lake 
  Pueyrredon 
  the 
  Magellanian 
  beds 
  and 
  the 
  

   overlying 
  lignites 
  are 
  entirely 
  wanting. 
  

  

  Upper 
  Lignite 
  beds. 
  — 
  In 
  the 
  Pio 
  de 
  las 
  Minas 
  section 
  the 
  

   Magellanian 
  beds 
  are 
  conformably 
  overlaid 
  by 
  a 
  series 
  of 
  

   strata 
  of 
  unknown 
  vertical 
  extent, 
  containing 
  several 
  veins 
  of 
  

   almost 
  pure 
  lignite 
  varying 
  from 
  a 
  few 
  inches 
  to 
  ten 
  or 
  twelve 
  

   feet 
  in 
  thickness. 
  These 
  beds, 
  which 
  constitute 
  the 
  upper 
  

   limits 
  of 
  the 
  Magellanian 
  Series, 
  have 
  been 
  observed 
  at 
  

   various 
  places 
  along 
  the 
  eastern 
  Andes 
  from 
  Punta 
  Arenas 
  to 
  

   the 
  head 
  of 
  the 
  Pio 
  Chico 
  north 
  of 
  Lake 
  San 
  Martin. 
  They 
  

   are 
  probably 
  of 
  Middle 
  or 
  Upper 
  Oligocene 
  age. 
  

  

  Oligocene 
  and 
  31iocene. 
  

  

  Patagonian 
  Series. 
  — 
  Under 
  this 
  head 
  I 
  shall 
  include 
  those 
  

   deposits 
  which 
  have 
  been 
  commonly 
  referred 
  to 
  by 
  students 
  

   of 
  the 
  geology 
  of 
  Patagonia 
  under 
  the 
  names 
  of 
  Pata- 
  

   gonian, 
  Supr 
  a- 
  Patagonian 
  and 
  Santa 
  Cruz 
  beds. 
  On 
  account 
  

   of 
  the 
  fossils 
  found 
  in 
  them 
  and 
  their 
  great 
  surface 
  distri- 
  

   bution 
  throughout 
  southern 
  Patagonia, 
  they 
  are 
  the 
  most 
  

   important 
  of 
  all 
  the 
  sedimentary 
  rocks 
  of 
  this 
  region. 
  

  

  