WITH THE AUTHORS COMPLIMENTS. 



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 OfiBce at Albany, N. Y., under 

 the act of July 16, 1894 



No. 489 



ALBANY, N. Y. 



February 15, 191 1 



New York State Museuokf-- •- -.^ 



John M. Clarke, Director .sor.ion ins^//^^ 



Museum Bulletin 146 



Z C 6 '^9^ 



GEOLOGY OF THE NEW YO|lK CI'Tyo^^^^ 

 (CATSKILL) AQUEDUC" "'^ ' "^ 



STUDIES IN APPLIED GEOLOGY COVERING PROBLEMS ENCOUNTERED 



IN EXPLORATIONS ALONG THE LINE OF THE AQUEDUCT FROM 



THE CATSKILL MOUNTAINS TO NEW YORK CITY 



BY 



CHARLES P. BERKEY ^ 



Introduction and acknowledg- 

 ment 5 



I General features 9 



Ch. I Catskill water supply 



project 9 



2 Problems encountered in 

 the project 17 



3 Relative values of differ- 

 ent sources of informa- 

 tion and stages of devel- 

 opment 25 



4 General geology of the 

 region 29 



II Geologic problems of the 



aqueduct 75 



Introduction 75 



Ch. I General position of aque- 

 duct line 77 



2 Hudson river canyon. ... 81 



3 Geological conditions 

 affecting the Hudson 

 river crossing 97 



4 Geological features in- 

 volved in selection of site 



for the Ashokan dam. ... 109 



5 Character and quality of 

 the bluestone for struc- 

 tural purposes 117 



PAGE 



Ch, 6 The Rondout valley sec- 

 tion 125 



7 The WallkiU Valley sec- 

 tion 149 



8 Ancient JNIoodna Valley. . 153 



9 Rock condition of Foundry 

 brook 163 



10 Geology of Sprout brook. 171 



11 Structure of Peekskill 

 creek valley 175 



12 Croton lake crossing 183 



13 Geology of the Kensico 

 dam site 191 



14 Stone of the Kensico 

 quarries 195 



15 The Bryn Mawr siphon. . 201 



16 A study of shaft 13 and 

 vicinity on the New Cro- 

 ton aqueduct 209 



17 Geological conditions 

 affecting the location of 

 delivery conduits in New 

 York city . 215 



18 Areal and structural 

 geology south of 59th 

 street 231 



19 Special exploration zones. 237 



20 The general question of 

 postglacial faulting 271 



Index 277 



ALBANY 



tJNIVERSITY OF THE STATE OF NEW YORK 

 I9II 



M232r-Ap 10-2500 



