INDEX TO 'GEOLOGY OF THE VICINITY OP LITTLE FALLS 



95 



Silica, 86^ 



Sillimanite, 18^ 



Smyth, C. H. jr, cited, 60*. 



Sphalerite, 2T\ 



Spruce creek, 80*. 



Structural geology, SS'-SG". 



Syenite gneiss, 20'-21^ 85^ 89''-90^. 



Syenites, 15^ 16^ 89-; age, ITS 23*^; 

 augen, 89" ; mixed rocks about, 21'- 

 23* ; quarried, 82^ ; use for road 

 metal, 82S 



Taconic disturbance, 11-. 

 Till, 74^ 



Titanite, 86\ 9(P. 



Topography, 65°-73- ; influence of 

 faults on, 71''-73S 



Trenton formation, 10*, 29'-35'' ; best 

 exposures, 32^ ; ripple marks in, 

 34?; thickness, 31', 33' ; sudden 

 thickening westward, 63''-64'; un- 

 conformity at base of, 62=-63* ; use 

 for road metal, 82^ 83*. 



Utica shale, 10^, 38\ 34'-35' ; thick- 

 ness, 35S 



Vanuxem, L., cited, 25", 28=, 38^ 62*. 

 Volcanic activity, T. 



Walcott, C. D., cited, 35^ 51"-52S 53». 

 White, T. G., cited, 38». 



Zinc blende, 27^ 



Zircons, 86', 87S 88S 88", 90=, 92». 



