59 JOURNAL OF THE 



"The slate in the ascendiiig" order is more and more in- 

 terlaminated with thick beds, which have an intermedi- 

 ate composition between a sandstone and slate, the second 

 division. ■^' "" " Among- them are beds of conglomerate. 

 These beds may be mistaken for trap, being- g-reenish and 

 tough, and besides like trap the broken strata become 

 concretionary and exfoliate in concentric layers." 



"The brecciated congdomerate has an arg-illaceous or 

 chloritic b^se. The mass is composed in the main of 

 frag'ments of other rocks mostly retaininj^- an ang-ular 

 form. The fra<^nKnts are sometimes eig-hteen inches, 

 and even two feet loiig\" 



"Thechiy slates and breccia, with their intermediate beds 

 are traversed by veins of milky quartz. They are some- 

 times auriferous. 



The so-called quai*t7.ite of both the Upper and T^ower 

 Taconic is considered of such peculiarity that a separate 

 chapter is dcxotcd to its descri])tion. It is described as 

 an uncrvstallized (piart/., resembling- g'un-flint, and is also 

 called flint, chert and hornstone. Color bluish-black, 

 passing- to ])urple, g-rayi^h, whiti- a'ld g'reen; sometimes 

 banded; texture line when com])ared with the finest sand- 

 stone; translucent on edg'es; fracture tlat conchoidal; often 

 ])<irjjhyritic, ]:or] hyr.xed; and it is stated that frequently 

 the Iresl. iVacture is dotted with small limpid crystals of 

 (juartz. 



"The varieties of qua-i'tzite are numerous if color and 

 texture are made g'rounds of distinction:' 



(1) "Light g'ray and compact, or very finely g-ranular. 



(2) "Smoke g-ray, with g'rains of hyaline quartz dis- 

 seminated in the mass. 



(3) "Texture line granular, with drab color. 



(4) "Porphyrized quartzite. 



(5) "Light g-reer: (luartzite. 



J ibid, p. 71. 



