INDEX TO THE GEOLOGY OF THE BROADALBIN QUADRANGLE 65 



Northville, 5, 9, 10, H' I4, 23, 24, 

 27, 28, 30, 31, 32, 41, 49, 52, 61, 62 

 Northville fault, 43 

 Noses fault, 38-40, 49 



Oligoclase, 10, 11, 14, 15, I7, 18 

 Ophicalcite, 8 



Orthis (Dalmanella) testudinaria, 36 

 Orthoclase, 9, 10, 11, 14, 15, 17, 18, 



Paleozoic physiography, SO~52 



Paleozoic rocks, 7, 25-38 



Parks Mill, 29, 31, 48 



Pegmatite dikes, 23 



Perth, 32, 34, 36, 60 



Physiography, 50-56 



Plagioclase, 9, 10, 11, 14, 15, 24, 25 



Pleistocene deposits, 7 



Postpaleozoic physiography, 53 



Potsdam conglomerate, 30 



Potsdam sandstone, 25-28, 40, 43, 44, 



45, 46, 51, 52, 58, 60, 61 

 Prasopora lycoperdon, see Monti- 



culipora (Prasopora) lycoperdon 

 Precambric physiography, 50 

 Precambric rocks, 7, 8-25 

 Precambric surface, present slope of, 



53-54 

 Prosser, cited, 8, 38, 46 

 Pyrite, 9, 10, 25 

 Pyroxene, 8, 9, 15 



Quartz, 9, 10, 11, 13, 14, 15, 17, 18, 



20, 23 

 Quartzite, 9, 12, 13, 14 

 Quicklime, 61 



Rzifinesquina alternata, 36 

 Road metal, 60 

 Roberts creek, 28, 30 

 Roberts creek fault, 40-41, 42 

 Rock City Falls, 32 

 Round lake, 53 



Round lake era, syenite, 15 

 Ruedemann, cited, 36, 38 



Sacandaga lake, 56 



Sacandaga Park, 5, 10, 13, 18, 23, 42 



Sacandaga Park fault, 41, 43 



Sacandaga river, 6, 49, 54 



Schists, 13 



Sillimanite, 9 



Sillimanite gneiss, 13 



Smyth, cited, 27, 50 



Steele, cited, 7 



Streptelasma, 35 



Syenite, description, 14-17; analy- 

 ses, 15; compared with other 

 Adirondack rocks, 20-21 ; mixed 

 with other rocks, 22 



Syenite-granite series, analyses, 21 



Syenitic rocks, 12 



Theresa formation, 28-31, 39, 41, 42, 

 43, 44. 45, 46, 48, 51, 58, 60 



Traprock, 60 



Trenton limestone, 32, 35-36, 42, 43, 

 48, 49, 60, 61 



Tribes Hill, limestone, 32-33, 58, 59 



Trinucleus concentricus, 36 



Trough faulting, 49-50 



Ulrich, cited, 8, 29, 30, 32, 33 



Union Mills, 32 



Utica shale, 36, 37, 48, 59 



Vail Mills, 36, 37, 48, 56 

 Vanuxem, cited, 7 

 Vly, 6, 56 



Watertown limestone, 34 

 West Galway, 29, 32 



Yosts, 38 



Zircon, 9, 10, 11, 14, 15, 18, 25 



Zoisite, 9, 10, 14, 15, 18 



