﻿H. 
  E. 
  Gregory 
  — 
  Gravels 
  at 
  Ciizco. 
  

  

  21 
  

  

  3. 
  Sand, 
  coarse, 
  mingled 
  with 
  clay-adobe, 
  firmly 
  cemented 
  

  

  with 
  lime 
  ; 
  dull 
  yellow 
  on 
  weathered 
  surfaces, 
  

   brown 
  and 
  white 
  beneath 
  

  

  4. 
  Gravel, 
  composed 
  of 
  flattened 
  subangular 
  pebbles 
  of 
  

  

  grey 
  and 
  brown 
  sandstone, 
  1 
  to 
  6 
  inches 
  in 
  length. 
  

   Many 
  pebbles 
  partially 
  decomposed. 
  Contains 
  

  

  irregular 
  lenses 
  of 
  coarse 
  sand 
  _ 
  _ 
  

  

  For 
  Sections 
  II- 
  VIII 
  see 
  accompanying 
  figures. 
  

  

  Feet 
  

  

  Fig. 
  6. 
  

  

  Fig. 
  7. 
  

  

  

  

  $ 
  •<!?■$ 
  

  

  &?, 
  .'f$X.^r.°*<§? 
  : 
  %*? 
  

  

  

  

  til 
  

  

  

  

  

  

  

  i 
  » 
  ° 
  

  

  o°->o.„ 
  0° 
  ° 
  »'. 
  'a 
  n 
  

  

  a, 
  15 
  ft., 
  very 
  coarse 
  gravel. 
  

  

  b, 
  1 
  ft., 
  fine 
  sand, 
  stratified. 
  

  

  c, 
  50 
  ft., 
  very 
  coarse 
  gravel, 
  massive. 
  

  

  a, 
  30 
  ft., 
  coarse 
  gravel, 
  with 
  lenses 
  

  

  of 
  sand. 
  

  

  b, 
  120 
  ft., 
  coarse 
  gravel, 
  massive. 
  

  

  Fig. 
  6. 
  Section 
  V, 
  North 
  bank 
  of 
  Rio 
  Sappi 
  at 
  mouth 
  of 
  tributary 
  descend- 
  

   ing 
  from 
  the 
  Cuzco-Anta 
  divide. 
  

  

  Fig. 
  7. 
  Section 
  VI, 
  Bank 
  of 
  tributary 
  to 
  Rio 
  Sappi, 
  descending 
  from 
  the 
  

   Cuzco-Anta 
  divide. 
  

  

  Composition. 
  Source 
  of 
  Material. 
  

  

  The 
  highlands 
  which 
  contributed 
  material 
  to 
  the 
  Cuzco 
  fan 
  

   consist, 
  on 
  the 
  northeast, 
  of 
  grey-blue 
  limestone 
  through 
  which 
  

   protrude 
  small 
  knobs 
  of 
  greenish 
  igneous 
  rock 
  (altered 
  diabase) 
  

  

  