GEOLOGY OF SARATOGA SPRINGS AND VICTXH^' 6y 



established the succession of the subdivisions of the Georgian with 

 such accuracy as the great difficulties arising from the extremely 

 disturbed condition of the beds will permit. He distinguishes, in 

 ascending order (see chart facing page 178, op. cit.) : 



A Olive grit. Olive green grit (graywacke), more or less 

 massive, spangled with minute scales of hematite or graphite, 

 sometimes with small quartzite beds, frequently calcareous, gen- 

 erally weathering a pale brick red. Associated with it in places 

 a bed of quartzite 12 to 55 feet thick, 50 to 200 feet. 



B Cambric roofing slates. Roofing slate, grayish green, purple 

 or mixed green and purple, alternating with beds of calcareous 

 quartzite up to 5 feet and limestone breccia up to 40 feet thick. 

 Fauna : 01enellus;Microdiscus lobatus,M.spe- 

 ciosus; M. connexus; Solenopleura, possibly 

 nana; Obolella; Iphidea pannula; Hyolithes 

 communis; Hyolithellus micans; trails of annelids. 

 200 to 240 feet. 



C Black patch grit. Dark gray grit or sandstone with black 

 shaly patches, sometimes with calcareous nodules. Olenellus in 

 both grit and calcareous nodules. 10 to 40 feet. 



D Cambric black shale. Black shale or slate, generally weather- 

 ing blue black, sometimes pyritiferous, with thin beds of lime- 

 stone and less frequently limestone breccia. Fauna : L i n n a r - 

 sonia sagittalis var. taconica; Orthis, probably 

 salemensis; Lingula?; Lingulella coelata?; 

 Lingulella granvillensis; Hyolithes com- 

 munis; Leperditia dermatoidea; Conoco- 

 ryphe — sp.?; Solenopleura, probably t u m i d a ; a 

 phyllocarid crustacean, closely related to Ccratiocaris; 

 spicules of Protospongia; also M i c r o d i s c u s s p e - 

 c i o s u s ; M . 1 o b a t u s and Iphidea pannula. 50 to 

 250 feet. 



E Ferruginous quartzite and sandstone. Quartzite, usually 

 with spots of limonite ; in places, however, a bluish calcareous 

 sandstone (grains of quartz with a calcareous and ferruginous 

 cement). 25 to 100 feet. 



Professor Dale found 335 to 1400 feet of Lower Cambric rocks 

 exposed but since the thickness of the basal member, the olive 

 grit, is not known, the thickness may easily exceed the maximum. 

 The upper divisions, C, D and E, are described as intermittent 

 and B as often wanting in the western part. 



In a later paper Dale ^ has arranged the Georgian beds of the 

 region adjoining south of the one here discussed, somewhat differ- 

 ently. He there constructs the following table of formations : 



^ Dale, T. Nelson. Geology of the Hud.son Valley between the Hoosic and 

 the Kinderhook. U. S. Geol. Surv. Bui. 242. IQ04, p. 2g. 



