﻿Titicaca 
  Island 
  and 
  Adjoining 
  Areas. 
  203 
  

  

  thickness, 
  extent 
  and 
  quality. 
  One 
  two-foot 
  coal 
  bed 
  is 
  fully 
  

   half 
  shale. 
  The 
  coal-bearing 
  beds 
  are 
  overlaid 
  by 
  6 
  feet 
  of 
  

   cross-bedded 
  sandstone 
  and 
  underlaid 
  by 
  30 
  feet 
  of 
  shale 
  with 
  

   lenses 
  of 
  sandstone. 
  (3) 
  Between 
  South 
  Yumani 
  and 
  Bil- 
  

   cokyma 
  the 
  section 
  from 
  bottom 
  upwards 
  is 
  : 
  

  

  1. 
  Shale 
  with 
  %" 
  to 
  1' 
  lenses 
  of 
  coal 
  15 
  feet 
  

  

  2. 
  Sandstone 
  4 
  " 
  

  

  3. 
  Shale 
  2 
  " 
  

  

  4. 
  Sandstone 
  3 
  " 
  

  

  5. 
  Carbonaceous 
  shale 
  with 
  %"-2" 
  beds 
  of 
  

  

  coal 
  5 
  " 
  

  

  6. 
  Sandstone 
  containing 
  scattering 
  frag- 
  

  

  ments 
  of 
  coal 
  30 
  " 
  

  

  At 
  Challa 
  (Kcasa 
  claim) 
  the 
  group 
  of 
  coal 
  beds 
  about 
  12 
  

   feet 
  in 
  thickness 
  are 
  approximately 
  one-third 
  " 
  bone 
  " 
  and 
  the 
  

   thickest 
  band 
  of 
  workable 
  coal 
  is 
  probably 
  less 
  than 
  two 
  feet. 
  

  

  The 
  section 
  examined 
  on 
  the 
  Taana 
  claim 
  shows 
  at 
  bottom 
  

   thin-bedded 
  sandstones 
  and 
  shales 
  followed 
  upward 
  by 
  

  

  1. 
  Carbonaceous 
  shale, 
  about 
  half 
  of 
  which 
  

  

  is 
  coal 
  in 
  wavy, 
  impure 
  lenses 
  4-6 
  feet 
  

  

  2. 
  Shales 
  and 
  sandstone 
  . 
  20 
  " 
  

  

  3. 
  White 
  sandstone 
  60 
  " 
  

  

  4. 
  Shales 
  and 
  sandstone 
  with 
  \"-\" 
  layers 
  

  

  of 
  coal 
  20 
  " 
  

  

  5. 
  White 
  sandstone 
  ._ 
  10 
  " 
  

  

  In 
  quality 
  the 
  coal 
  is 
  not 
  very 
  satisfactory, 
  pyrite 
  is 
  abundant, 
  

   and 
  " 
  high 
  ash 
  " 
  is 
  reported 
  by 
  the 
  engineers 
  of 
  the 
  Titicaca 
  

   steamers, 
  but 
  the 
  tests 
  made 
  by 
  the 
  Bolivian 
  Rubber 
  Company 
  

   appear 
  to 
  have 
  been 
  fairly 
  satisfactory. 
  Mining 
  on 
  the 
  island 
  

   will 
  necessarily 
  be 
  expensive 
  owing 
  to 
  high 
  dip 
  of 
  strata, 
  irreg- 
  

   ular 
  distribution 
  of 
  coal, 
  the 
  presence 
  of 
  water, 
  and 
  the 
  distant 
  

   source 
  of 
  supplies. 
  

  

  Stratigraphy. 
  

  

  Our 
  knowledge 
  of 
  the 
  stratigraphy 
  of 
  the 
  Titicaca 
  region 
  

   is 
  based 
  primarily 
  on 
  the 
  work 
  of 
  D'Orbigny,* 
  Forbes,f 
  and 
  

  

  * 
  Voyage 
  dans 
  L'Anierique 
  Meridionale, 
  tomo 
  iii, 
  pt. 
  3, 
  Paris, 
  1842. 
  

   This 
  volume, 
  based 
  on 
  field 
  studies 
  during 
  the 
  years 
  1826-33, 
  includes 
  nine 
  

   large 
  hand-colored 
  maps 
  and 
  sections 
  and 
  twenty-two 
  lithographic 
  plates 
  of 
  

   fossils. 
  The 
  government 
  of 
  Bolivia 
  has 
  made 
  an 
  important 
  part 
  of 
  this 
  rare 
  

   work 
  accessible 
  by 
  the 
  publication 
  of 
  a 
  Spanish 
  edition 
  (Estudios 
  sobre 
  la 
  

   Geologica 
  de 
  Bolivia, 
  translated 
  and 
  annotated 
  by 
  Victor 
  E. 
  Marchant 
  La 
  

   Paz, 
  1907). 
  

  

  f 
  Report 
  on 
  the 
  Geology 
  of 
  South 
  America 
  by 
  David 
  Forbes, 
  with 
  notes 
  on 
  

   fossils 
  by 
  Huxley, 
  J. 
  W. 
  Salter, 
  and 
  T. 
  Rupert 
  Jones. 
  Part 
  1, 
  Bolivia 
  and 
  

   southern 
  Peru. 
  Quar. 
  Jour. 
  Geol. 
  Soc, 
  vol. 
  xviii, 
  1861. 
  A 
  Spanish 
  trans- 
  

   lation 
  by 
  Edmundo 
  Sologuren 
  was 
  issued 
  by 
  the 
  Sociedad 
  Geographiea 
  de 
  

   La 
  Paz, 
  1901. 
  The 
  Carboniferous 
  as 
  delineated 
  by 
  Forbes 
  manifestly 
  occu- 
  

   pies 
  too 
  small 
  an 
  area. 
  

  

  Am. 
  Jour. 
  Sci. 
  — 
  Fourth 
  Series, 
  Vol. 
  XXXVI, 
  No. 
  213. 
  — 
  September, 
  1913. 
  

   14 
  

  

  