INDEX TO GEOLOGY OF THE VICINITY OF LITTLE FALLS 95 



Silica, 86^ 



Sillimanite, 18«. 



Smyth, C. H. jr, cited, 60». 



Sphalerite, 27^ 



Spruce creek, 80*. 



Structural geology, 35«-36^ 



Syenite gneiss, 20«-21», 85S 89«-90«. 



Syenites, 15^ 16^ 89^; age, 17^, 23«; 

 augen, 89® ; mixed rocks about, 2V- 

 23®; Quarried, 82^; use for road 

 metal, 82^ 



Taconic disturbance, 11^ 

 Till, 74«. 



Titanite, 86^ 9(P. 



Topography, 65^-73^; influence of 

 faults on, 71«-73\ 



Trenton formation, 10*, 29^-350 ; 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, l(f, 33\ 34^-35^ thick- 

 ness, 35^ 



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

 Volcanic activity, 7*. 



Walcott, 0. D., cited, 35^ 51«-52\ 53». 

 White, T. G., cited, 38». 



Zinc blende, 27^ 



Zircons, 86«, 87^ 88S 88', 90=^, 92«. 



