INDEX TO GEOLOGY OF SARATOGA SPRINGS AND VICINITY 1 73 



Faults, 10, 16, 30, 103; general re- 

 marks on, 63-65 ; of Mohawk val- 

 ley, 53-57; of Saratoga and 

 Broadalbin quadrangles, diagram, 



55 



Feldspar, 18, 19, 20, 21, 23,. 25, 28, 

 29 



Feldspar-quartz gneisses, 18 



Ferruginous quartzite and sand- 

 stone, 67, 70 



Fish creek, 12, 13, 104 



Fisher, W. L., cited, 54 



Folded area, 102-7 



Foliation, 30 



Ford, S. W., investigations by, 66 



Fort Cassin beds, 78 



Fort Edward, 12, loi, 102 



Fort Miller, 94 



Frankfort formation, 52, 53 



Gabbros, 17, 21, 26 



Gansevoort, loi 



Garnets, 18, 21, 23, 25, 28 



Geology, general, by H. P. Gush- 

 ing, 15-16; descriptive by H, P. 

 Gushing, 16-30; control of de- 

 velopment and history of Saratoga 

 region by, i68 



Georgian overthrust blanket, 107-8 



Georgian rocks, 49, 66, 108, iii, 165 



Girvanella sp., 77 



Glacial period, 13, 146-48 



Glens Falls limestone, 31, 47-48, 165 



Glossograptus, 86 

 ciliatus, 93 



quadrimucronatus mut. cornutus, 

 50, 51 

 mut. pertenuis, 97 



Glowegee, loi 



Glowegee creek, 34 



Glyptocrinus, 96 

 cf. decadactylus, 98 



Gneiss, 18, 24 



Grabau, A. W., cited, 75 



Graben, 16 



Granite, 16, 17, 21-22, 25, 26, 28. 149 



Grants hollow, 112 



Graphite, 18. 20, 148-49 



Graptospongia pusilla, 92 



Greenfield township, 34, 35 

 Greenfield limestone, 38 

 Greenwich, no 

 Greenwich plateau, 11; structure, 



107-15 

 Grenville series, 16, 17-20, 27, 135, 



148 

 Gurnspring fault, 60 



Hall, James, cited, 38, 39 



Hathorn spring record, 63 



Heterocrinus gracilis, 96 



High Rock spring, 62 



Hill, B. F., cited, 21 



Historical geology, by Gushing and 



Ruedemann, 135-48 

 Hoffmans Ferry, 10 

 Hoffmans Ferry fault, 54, 56, 58 

 Hoosic river, in 

 Hormotoma (Murchisonia) cassina, 



77 

 Hornblende, 18, 28 

 Hoyt limestone, 31, 32, 38-42, 60. 61, 



137, 141, 151, 165 

 Hudson Falls, 102 

 Hudson grit, 86 



" Hudson River " formation, 52. 90 

 Hudson Valley lowland, 10-12 

 Hyolithes communis, 67 

 Hyolithellus communis, 72 



micans, 67, 72 

 rugosa, 72 



Igneous rocks, Precambric, 21-30 

 Indian Ladder beds, $3, 142 

 Iphidea pannula, 67 

 Isochilina armata var. pygmaea. 80 



Joints, 65 



Kayaderosseras creek, 12. 13. 48, 49, 



50, loi 

 Kemp, J. F.. acknowledgments to, 



6; cited. 21, 28. 30. 154, 162 

 Kendrick's hill, 11 

 Kings Station, 20, 60 



Labradorite, 29 

 Lake Albany, 147 



