234 New York State Museum 



formed from sands resulting from long-continued 

 weathering of the crystalline floor. The Poughquag 

 is a well-cemented, exceedingly resistant quartzite 

 conglomerate in places, appreciably felspathic, and 

 varying in color, white (slightly yellow with iron 

 stain), blue gray, and mottled pink, yellow and white 

 being the commoner types. The rock is developed in 

 beds approximately 600 feet in thickness. The quart- 

 zite also outcrops in Orange county where the forma- 

 tion shows greater coarseness. Olenellus, brachiopods 

 resembling Obolella and Scolitlnis linearis (worm tubes), 

 have been listed from these beds, thus establishing its 

 Lower Cambrian age. 



The Georgia beds were named (Hitchcock '61) from 

 the occurrence at Georgia, Vermont, and the name was 

 later applied to the series which has more recently been 

 termed the Taconian series. These beds are still cur- 

 rently known as the Georgia beds but they are now 

 divided (Ruedemann '14) into a number of formations 

 (Bomoseen grit, Mettawee slate, Eddy Hill grit, Scho- 

 dack shales and limestone, Nassau beds, Diamond Rock 

 quartzite, Troy shales, Zion Hill quartzite) which total 

 a greatest thickness of about 1500 feet, of which 200 

 feet are formed by the Bomoseen grit, 250 feet by the 

 Schodack shales and limestone (figure 24), 800 feet by 

 the Nassau beds (figure 23) and 100 feet by the Troy 

 shales. The Schodack shales and limestone have fur- 

 nished the largest fauna. The beds in New York are 

 Olcnellus-bearmg shales and slates, quartzites and 

 brecciated limestones which occur in the highly folded 

 and metamorphosed region east of the Hudson river 

 in the counties bordering southern Vermont and 

 Massachusetts. The shales and slates are greenish 



