420 NEW YORK STATE MUSEUM 



pearly calc spar, very large masses of coarse agate, quartz passing 

 into chalcedony, petrosilex and quartz crystals " (p. 73). 



Substantially the same description of the Calciferous sandrock is 

 given in Prof. Eaton's Geological nomenclature (p. 12-13). 



In the First report on the geological survey of the third district Mr 

 Conrad says *' The general inclination [of the Calciferous sandrock] 

 is 4° or 5° to s. w. which causes the rock to be generally lost to 

 observation to the south of the Mohawk except upon the immediate 

 bank of the river and that of the canal whilst it rises with the hills 

 on the opposite shore, frequently however concealed by limestone."^ 



In the Second report of the third district, Vanuxem restates the 

 features of the Calciferous sandrock, remarking that " this rock is 

 very variable in character and composition, . . . and appears to 

 contain more carbonate of lime in its composition at Tribeshill 

 and in the small streams between Amsterdam and Crane's village 

 than on the western side of Montgomery county.^ " A few fossils 

 are mentioned as occurring in the upper layers of the rock (p. 283). 



In Vanuxem's final Report on the third district, the Calciferous 

 sandrock is said to embrace three masses. The first is siliceous^ 

 compact, the second is a " mixture of fine yellow siliceous sand and 

 carbonate of lime " and is the mass from which the name of the 

 stage was derived, the third mass is a "mixture of Calciferous ma- 

 terial which is usually yellowish, very granular and sparkling when 

 fresh broken and a compact limestone which resembles the Birdseye 

 limestone. "3 These constitute the Fucoidal layers. The latter 

 rock is more fully described as follows: "These layers are . . . 

 readily distinguished from the calciferous rock by their disposition in 

 thick strata, many parts of which when long exposed show a struc- 

 ture as if formed of numerous thin ones. The mineral composition 

 is more varied, showing frequently a mixture of Calciferous sand- 

 rock and Birdseye limestone ... It often presents ramose 

 forms usually composed of the Calciferous portion (p. 35). The 

 peculiar mode of weathering of this rock is also mentioned by 

 Emmons.4 



In the i^th annual report of the state geologist (1893) five pages are 

 devoted to the consideration of the Calciferous formation in the 



^Loc. cit. Assembly doc. no. 161, p. 160. 



'Log. cit. Assembly doc. no, 200, p. 259. 



'Oeologij of New York, pt 3, p. 30, 



*Oeologij of New YorJc, pt 2, p. 105; see also Ayriculture of New York, 1846, 1:119. 



