﻿Geology 
  and 
  Mineralogy. 
  417 
  

  

  topographic 
  elements 
  of 
  southern 
  Peru 
  are: 
  1. 
  A 
  system 
  of 
  high 
  

   level 
  slopes 
  of 
  gentle 
  gradient 
  and 
  great 
  areal 
  extent 
  developed 
  

   on 
  rocks 
  of 
  various 
  types 
  and 
  attitudes, 
  deeply 
  covered 
  by 
  soil 
  

   and 
  standing 
  at 
  an 
  elevation 
  4,000 
  to 
  5,000 
  feet 
  above 
  the 
  level 
  

   at 
  which 
  they 
  were 
  formed; 
  2. 
  deep, 
  steep- 
  walled, 
  narrow-floored 
  

   canyons 
  sunk 
  below 
  the 
  plateau 
  surface; 
  3. 
  lofty, 
  residual, 
  highly 
  

   sculptured 
  mountains; 
  4. 
  volcanic 
  cones 
  and 
  lava 
  plateaus 
  of 
  the 
  

   western 
  Cordilleras; 
  5. 
  glacial 
  features 
  at 
  valley 
  heads; 
  6. 
  deep 
  

   alluvial 
  fill 
  in 
  valley 
  bottoms, 
  now 
  in 
  process 
  of 
  dissection. 
  The 
  

   system 
  of 
  high 
  level 
  slopes 
  is 
  substantially 
  the 
  surface 
  of 
  denuda- 
  

   tion 
  elsewhere 
  called 
  the 
  Inca 
  peneplain 
  (Gregory, 
  H. 
  E., 
  A 
  geo- 
  

   logic 
  reconnaissance 
  of 
  the 
  Cuzco 
  Valley, 
  Peru: 
  this 
  Journal, 
  

   vol. 
  xli, 
  pp. 
  1 
  to 
  100). 
  Dr. 
  Bowman 
  finds 
  that 
  along 
  the 
  seventy- 
  

   third 
  meridian 
  a 
  stage 
  of 
  maturity 
  or 
  post-maturity, 
  but 
  not 
  

   peneplanation, 
  has 
  been 
  reached 
  and 
  considers 
  the 
  well-marked 
  

   peneplaned 
  areas 
  in 
  the 
  Cuzco 
  region 
  and 
  in 
  Bolivia 
  as 
  remnants 
  

   of 
  an 
  older 
  land 
  surface. 
  It 
  appears 
  that 
  the 
  extent 
  of 
  the 
  Inca 
  

   peneplain 
  and 
  its 
  relation 
  to 
  other 
  features 
  must 
  await 
  further 
  

   field 
  work. 
  The 
  canyons 
  sunk 
  below 
  the 
  level 
  of 
  the 
  Peruvian 
  

   plateau 
  are 
  represented 
  by 
  the 
  Urubamba 
  (pp. 
  8 
  to 
  21) 
  and 
  the 
  

   mountains 
  rising 
  above 
  that 
  surface 
  by 
  the 
  Cordillera 
  Vilcapampa 
  

   (pp. 
  202 
  to 
  224). 
  A 
  separate 
  chapter 
  is 
  devoted 
  to 
  glacial 
  features. 
  

  

  The 
  strictly 
  geologic 
  results 
  of 
  this 
  geographic 
  reconnaissance 
  

   are 
  appropriately 
  meager. 
  Geologic 
  maps 
  and 
  measured 
  sections 
  

   are 
  lacking, 
  and 
  conclusions 
  drawn 
  regarding 
  geologic 
  history 
  

   necessarily 
  rest 
  on 
  scant 
  field 
  evidence 
  and 
  are 
  subject 
  to 
  radical 
  

   revision. 
  The 
  oldest 
  sediments 
  recognized 
  along 
  the 
  seventy- 
  

   third 
  meridian 
  are 
  unfossiliferous 
  slates 
  and 
  shales, 
  provisionally 
  

   assigned 
  to 
  the 
  Silurian, 
  and 
  underlain 
  by 
  early 
  Paleozoic 
  (?) 
  

   schists. 
  The 
  Upper 
  Pennsylvanian 
  is 
  widely 
  represented 
  and 
  

   fossils 
  were 
  obtained 
  at 
  Huascatay, 
  Pampaconas 
  and 
  Pongo 
  de 
  

   Mainique. 
  Fossils 
  from 
  2,000 
  feet 
  of 
  limestone 
  at 
  Cotahuasi 
  

   were 
  determined 
  by 
  Professor 
  Schuchert 
  as 
  Lower 
  Cretaceous. 
  

   The 
  physical 
  history 
  of 
  the 
  Tertiary 
  of 
  the 
  Coastal 
  region 
  is 
  pre- 
  

   sented 
  in 
  a 
  new 
  form. 
  The 
  lacustrine 
  deposits 
  of 
  the 
  Cuzco 
  and 
  

   other 
  intermontane 
  basins, 
  also 
  considered 
  Tertiary, 
  are 
  probably 
  

   late 
  Pliocene 
  or 
  Pleistocene 
  (Eaton, 
  G. 
  F., 
  Vertebrate 
  fossils 
  

   from 
  Ayusbamba, 
  Peru: 
  this 
  Journal, 
  vol. 
  xxxvii, 
  1914, 
  pp. 
  141 
  

   to 
  154, 
  and 
  papers 
  by 
  the 
  present 
  writer: 
  this 
  Journal, 
  vol. 
  xxxvii, 
  

   1914, 
  pp. 
  125 
  to 
  140, 
  and 
  vol. 
  xli, 
  1916, 
  pp. 
  78 
  to 
  85). 
  

  

  When 
  one 
  realizes 
  the 
  advancement 
  of 
  geographic 
  knowledge 
  

   of 
  the 
  Andes 
  represented 
  by 
  this 
  book 
  and 
  notes 
  that 
  it 
  has 
  

   upwards 
  of 
  40 
  smaller 
  companions 
  resulting 
  from 
  the 
  devotion 
  

   of 
  Professor 
  Hiram 
  Bingham 
  to 
  pioneer 
  scientific 
  work, 
  he 
  can 
  

   but 
  regret 
  that 
  the 
  work 
  of 
  the 
  Yale 
  Peruvian 
  Expeditions 
  has 
  

   been 
  suspended. 
  The 
  topographic 
  maps 
  of 
  Kai 
  Hendriksen 
  and 
  

   A. 
  H. 
  Bumstead 
  alone 
  justify 
  the 
  expenditure 
  of 
  time 
  and 
  money. 
  

  

  H. 
  E. 
  G. 
  

  

  2. 
  Mount 
  Rainier, 
  A 
  Record 
  of 
  Exploration 
  / 
  edited 
  by 
  

   Edmond 
  S. 
  Meant. 
  Pp. 
  xi, 
  325, 
  11 
  pis. 
  New 
  York, 
  1916 
  (The 
  

  

  