﻿Education 
  Department 
  Bulletin 
  

  

  Published 
  fortnightly 
  by 
  the 
  University 
  of 
  the 
  State 
  of 
  New 
  York 
  

  

  Entered 
  as 
  second-class 
  matter 
  June 
  24, 
  1908, 
  at 
  the 
  Post 
  Office 
  at 
  Albany, 
  N. 
  Y., 
  under 
  

   the 
  act 
  of 
  Congress 
  01 
  July 
  16, 
  1894 
  

  

  No. 
  485 
  ALBANY, 
  N. 
  Y. 
  December 
  15, 
  1910 
  

  

  New 
  York 
  State 
  Museum 
  

  

  John 
  M. 
  Clarke, 
  Director 
  

   Museum 
  Bulletin 
  145 
  

  

  GEOLOGY 
  OF 
  THE 
  THOUSAND 
  ISLANDS 
  REGION 
  

  

  ALEXANDRIA 
  BAY, 
  CAPE 
  VINCENT, 
  CLAYTON, 
  GRIND- 
  

   STONE 
  AND 
  THERESA 
  QUADRANGLES 
  

  

  BY 
  

  

  H. 
  P. 
  GUSHING, 
  H. 
  L. 
  FAIRGHILD, 
  R. 
  RUEDEMANN 
  & 
  

   G. 
  H. 
  SMYTH 
  JR 
  

  

  INTRODUCTION 
  1 
  

  

  The 
  field 
  work 
  on 
  which 
  the 
  accompanying 
  report 
  is 
  based 
  was 
  

   done 
  during- 
  the 
  field 
  seasons 
  of 
  1906, 
  1907 
  and 
  1908. 
  The 
  dis- 
  

   trict 
  Avas 
  chosen 
  for 
  work 
  chiefly 
  on 
  the 
  recommendation 
  of 
  

   Professor 
  Smyth, 
  and 
  work 
  was 
  begun 
  by 
  the 
  w^riter 
  with 
  the 
  

   understanding 
  that 
  we 
  were 
  to 
  collaborate 
  in 
  doing 
  it. 
  Unfortu- 
  

   nately 
  this 
  plan 
  failed 
  of 
  realization, 
  owing 
  to 
  Mr 
  Smyth's 
  inability 
  

   to 
  take 
  the 
  field, 
  so 
  that 
  his 
  actual 
  participation 
  in 
  the 
  w^ork 
  was 
  

   limited 
  to 
  a 
  portion 
  of 
  the 
  season 
  of 
  1908, 
  during 
  which 
  he 
  

   mapped 
  the 
  major 
  portion 
  of 
  Wellesley 
  island. 
  

  

  Dr 
  Ruedemann 
  assisted 
  in 
  the 
  mapping 
  of 
  the 
  southern 
  part 
  

   of 
  the 
  Theresa 
  quadrangle 
  during 
  two 
  weeks 
  of 
  the 
  season 
  of 
  

   1907 
  and 
  in 
  1908, 
  mapped 
  Cape 
  Vincent 
  and 
  the 
  southern 
  half 
  of 
  

   Clayton. 
  The 
  remainder 
  of 
  the 
  areal 
  mapping 
  is 
  the 
  writer's 
  

   contribution, 
  comprising 
  the 
  Theresa, 
  Alexandria 
  and 
  Grind- 
  

   stone 
  sheets 
  (with 
  the 
  exception 
  of 
  Wellesley 
  island) 
  and 
  the 
  

   north 
  half 
  of 
  Clayton. 
  

  

  Note. 
  The 
  photographs 
  credited 
  to 
  Ami 
  and 
  Ulrich 
  are 
  published 
  b}' 
  

   permission 
  of 
  the 
  Directors 
  of 
  the 
  Geological 
  Surveys 
  of 
  Ganada 
  and 
  of 
  

   the 
  United 
  States. 
  

  

  1 
  By 
  H. 
  P. 
  Gushing. 
  

  

  