﻿Report 
  oi 
  the 
  Siate 
  Geologist. 
  429 
  

  

  invaded 
  by 
  the 
  Little 
  Schoharie 
  creek, 
  from 
  the 
  south 
  by 
  several 
  

   important 
  branches 
  of 
  the 
  Catskill, 
  and 
  from 
  the 
  southeast 
  by 
  

   Hannecrois 
  creek. 
  These 
  drainage 
  systems 
  quite 
  widely 
  overlap 
  

   each 
  other 
  in 
  the 
  central 
  part 
  of 
  the 
  region, 
  and 
  the 
  main 
  stems 
  

   of 
  their 
  upper 
  waters 
  are 
  in 
  greater 
  part 
  separated 
  by 
  divides 
  

   which 
  are 
  considerably 
  lower 
  than 
  the 
  adjacent 
  hills. 
  The 
  most 
  

   noteworthy 
  of 
  these 
  low 
  divides 
  is 
  north 
  of 
  Rensselaerville, 
  where 
  

   the 
  elevation 
  of 
  the 
  divide 
  between 
  the 
  Switzkill 
  and 
  Ten 
  -Mile 
  

   creek 
  is 
  approximately 
  1480 
  feet, 
  while 
  the 
  surrounding 
  hills 
  

   have 
  an 
  altitude 
  of 
  about 
  300 
  feet 
  more. 
  

  

  The 
  divide 
  between 
  Little 
  Schoharie 
  creek 
  and 
  Ten-Mile 
  creek 
  

   is 
  at 
  about 
  1700 
  feet 
  above 
  tide, 
  which 
  is 
  considerably 
  below 
  the 
  

   level 
  of 
  the 
  adjacent 
  hills. 
  This 
  feature 
  of 
  low 
  divides 
  is 
  general 
  

   throughout 
  the 
  region, 
  as 
  reference 
  to 
  the 
  topographic 
  base 
  of 
  

   the 
  geologic 
  map 
  will 
  show. 
  

  

  Along 
  the 
  steep 
  eastern 
  front 
  of 
  the 
  region 
  there 
  is 
  consider- 
  

   able 
  invasion 
  by 
  small 
  streams, 
  mainly 
  by 
  the 
  head-waters 
  of 
  

   Oniskethau 
  creek, 
  which 
  cuts 
  across 
  the 
  ridge 
  of 
  the 
  Helderberg 
  

   mountain, 
  and 
  by 
  some 
  branches 
  which 
  head 
  behind 
  Bennett, 
  

   Oopeland 
  and 
  Blodgett 
  hills. 
  

  

  A 
  very 
  large 
  part 
  of 
  the 
  region 
  presents 
  a 
  terraced 
  surface 
  

   due 
  to 
  alternations 
  of 
  hard 
  and 
  soft 
  beds. 
  

  

  General 
  Structural 
  Relations. 
  

   The 
  general 
  geologic 
  structure 
  of 
  Albany 
  county 
  is 
  indicated 
  

   by 
  the 
  section 
  in 
  figure 
  1. 
  

  

  