﻿rl08 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  This 
  point, 
  when 
  established 
  and 
  finally 
  settled, 
  will 
  be 
  a 
  very 
  

   interesting 
  as 
  well 
  as 
  needful 
  one 
  in 
  the 
  history 
  of 
  each 
  of 
  the 
  lake 
  

   systems. 
  

  

  Comparison 
  of 
  the 
  abandoned 
  deltas 
  with 
  the 
  deltas 
  

   forming 
  in 
  the 
  present 
  lakes 
  

  

  . 
  In 
  all 
  normally 
  formed 
  deltas 
  the 
  interaction 
  between 
  stream 
  and 
  

   lake 
  tends 
  to 
  the 
  production 
  of 
  a 
  fan 
  shaped 
  outline 
  in 
  the 
  deposition 
  

   of 
  the 
  stream 
  borne 
  material. 
  The 
  delta 
  apex 
  is 
  turned 
  up 
  stream 
  

   or 
  landward 
  with 
  the 
  point 
  of 
  maximum 
  convexity 
  in 
  its 
  periphery 
  

   practically 
  opposite. 
  (Figure 
  29) 
  

  

  Fig. 
  29 
  

  

  Lake 
  shoi^e 
  

  

  Outline 
  of 
  the 
  normal 
  delta 
  as 
  exemplified 
  in 
  the 
  higher 
  level 
  deltas 
  of 
  the 
  Finger 
  lakes 
  

  

  The 
  opposite 
  outline 
  or 
  that 
  of 
  a 
  Y-shaped 
  mass'* 
  in 
  delta 
  form 
  

   may 
  result 
  in 
  several 
  ways, 
  dependent 
  upon 
  the 
  direction 
  of 
  the 
  

   dominant 
  current. 
  In 
  this 
  type 
  the 
  apex 
  is 
  pointed 
  lakeward 
  with 
  

   pne 
  side 
  toward 
  the 
  land. 
  All 
  gradations 
  in 
  modified 
  forms 
  maybe 
  

   obtained 
  between 
  these 
  two 
  extremes, 
  dependent 
  upon 
  the 
  variation 
  

   in 
  the 
  forces 
  concerned. 
  (Figure 
  30) 
  

  

  a 
  Gilbert, 
  G. 
  K., 
  The 
  topographic 
  features 
  of 
  lake-shores. 
  

  

  Fifth 
  ann'l 
  report, 
  U. 
  S. 
  G. 
  S., 
  1SS3-84, 
  p. 
  108. 
  

  

  