﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  165 
  

  

  ent 
  geologic 
  formations. 
  As 
  regards 
  quality 
  of 
  soils, 
  Mr 
  Ver- 
  

  

  meule 
  also 
  says 
  : 
  

  

  It 
  may 
  be 
  inferred 
  that 
  the 
  kind 
  of 
  soil 
  has 
  much 
  less 
  to 
  do 
  

   with 
  the 
  amount 
  of 
  evaporation 
  than 
  has 
  the 
  temperature. 
  

  

  As 
  regards 
  the 
  relation 
  between 
  geology 
  and 
  runoff, 
  it 
  is 
  

   undoubtedly 
  complicated, 
  although 
  it 
  is 
  interesting 
  to 
  note 
  that 
  in 
  

   the 
  State 
  of 
  New 
  York 
  streams 
  which 
  flow 
  from 
  the 
  north 
  into 
  the 
  

   Mohawk 
  river, 
  after 
  crossing 
  over 
  a 
  narrow 
  strip 
  of 
  Trenton 
  lime- 
  

   stone 
  and 
  Calciferous 
  sand 
  rock, 
  and 
  which 
  head 
  in 
  the 
  Laurentian 
  

   granite 
  of 
  the 
  Adirondacks, 
  have 
  larger 
  flows 
  than 
  those 
  coming 
  

   to 
  the 
  Mohawk 
  from 
  the 
  south, 
  which 
  lie 
  mostly 
  in 
  the 
  horizon 
  of 
  

   the 
  Hamilton 
  shales, 
  the 
  headwaters 
  of 
  some 
  of 
  them 
  — 
  as, 
  for 
  

   instance, 
  Schoharie 
  creek 
  — 
  being 
  in 
  the 
  sandstones 
  of 
  the 
  Che- 
  

   mung 
  and 
  Portage 
  groups. 
  In 
  their 
  lower 
  reaches 
  they 
  cross 
  over 
  

   the 
  sandstones 
  and 
  shales 
  of 
  the 
  Hudson 
  and 
  Utica 
  groups, 
  with 
  

   narrow 
  strips 
  of 
  Helderberg 
  limestone, 
  Oriskany 
  sandstone, 
  and 
  

   Onondaga 
  limestone. 
  

  

  However, 
  there 
  is 
  another 
  consideration. 
  The 
  headwaters 
  of 
  

   the 
  streams 
  to 
  the 
  north 
  of 
  the 
  Mohawk 
  nearly 
  all 
  lie 
  in 
  a 
  region 
  

   heavily 
  timbered 
  — 
  some 
  of 
  it 
  is 
  still 
  primeval 
  forest 
  — 
  while 
  those 
  

   to 
  the 
  south 
  are 
  from 
  a 
  highly 
  cultivated 
  country, 
  practically 
  

   deforested. 
  

  

  We 
  may 
  now 
  consider 
  the 
  case 
  of 
  the 
  Genesee 
  and 
  Oswego 
  rivers, 
  

   referring 
  to 
  the 
  large 
  Geologic 
  Map 
  of 
  the 
  State 
  of 
  New 
  York. 
  

  

  Genesee 
  river 
  has 
  an 
  average 
  rainfall 
  of 
  about 
  40 
  inches 
  and 
  

   Oswego 
  river 
  1 
  of 
  about 
  37 
  inches. 
  That 
  portion 
  of 
  Genesee 
  river 
  

   which 
  has 
  been 
  gaged 
  lies 
  almost 
  entirely 
  in 
  the 
  shales 
  and 
  sand- 
  

   stones 
  of 
  the 
  Portage 
  and 
  Chemung 
  groups. 
  Oswego 
  river, 
  on 
  the 
  

   contrary, 
  lies 
  in 
  the 
  horizon 
  of 
  the 
  Portage 
  sandstones 
  and 
  shales, 
  

   Hamilton 
  shales, 
  Onondaga 
  and 
  Helderberg 
  limestones, 
  Oriskany 
  

   sandstone, 
  the 
  rocks 
  of 
  the 
  Salina 
  or 
  Salt 
  group, 
  the 
  Lockport 
  

   limestone, 
  Clinton 
  limestone 
  and 
  shales, 
  Medina 
  sandstones, 
  and 
  

   Utica 
  sandstones 
  and 
  shales, 
  including 
  the 
  Oswego 
  sandstone. 
  

   The 
  Chemung, 
  Portage, 
  and 
  Hamilton 
  formations 
  have 
  a 
  wide 
  

   outcrop, 
  while 
  the 
  Onondaga, 
  Oriskany, 
  and 
  Helderberg 
  are 
  com- 
  

  

  