64 NEW YORK STATE MUSEUM 



authors have claimed, but that they originated in deeper waters as especially 

 argued by Suess, who calls them "pelagic" and Neumayr, who has con- 

 sidered them as "abyssal." Using Renevier's term "zone bathyale" for the 

 zone intermediate between the "zone neritique " (shallow water) and the 

 abyssal zone, Haug asserts that it is the deposits of this zone which consist 

 of terrigenous muds and especially of the blue muds rich in organic matter 

 and sulfids ; and further that it is the deposits of this zone that are laid down 



important zone is lacking, a fact which can be also inferred from the distinct and close 

 genetic relationship of the succeeding faunas. The third Deepkill zone (the supposed 

 Chazy equivalent) is bound to the underlying Deepkill zones of Beekmantown age by the 

 presence of common forms and the survival of some Phyllograpti and Tetagrapti and 

 especially by the existence of an intermediate subzone (Ashhill beds of Mount Moreno, 

 see Memoir 7, p. 499); and .it is equally closely connected with the following Normanskill 

 shale by the Diplograpti and the Climacograpti and, in fact, lies at Mount Moreno in close 

 proximity to that zone as pointed out before by the writer [ibid, p-499, footnote]. 

 Undoubtedly, further study will afford still more transitional zones. If then the graptolite 

 zones in themselves give all evidence of representing a continuous series, they must also 

 comprise the time equivalent of the Chazy formation. 



The discrepancy in thickness between the graptolite zone and the Chazy limestone of 

 the Champlain basin is quite proportional to that between the Beekmantown graptolite 

 zones and the Beekmantown dolomites. To the Beekmantown shale, Mr Dale [1904, p. 33] 

 assigns 50 feet as a minimum and the present writer's estimate of 200 to 300 feet as a 

 maximum and the Beekmantown dolomite measures 1800 feet. There exists hence no 

 essential difference between the proportion of the Beekmantown shales and dolomites and 

 that of the 40 feet of Chazy shale and the 800 feet of Chazy limestone. Furthermore, it is 

 completely in line with the conception of the graptolite shales as deeper water deposits 

 and Dale's observation of the smaller thickness of the whole system of rocks in the slate 

 belt. Dale assigns (1899) to the whole mass of Champlainic slates only a thickness of 1000 

 to 1200 feet (1200 to 2500 ? in 1904 to the Hudson formation), while the Beekmantown 

 dolomite alone measures 1800 feet according to Brainerd and Seely, right on the other side 

 of the Quebec barrier in the Champlain basin. 



It could be urged that since the Chazy beds in the Champlain region do not reach as 

 far south as their supposed graptolitiferous correlative in the Levis channel, the latter 

 must be of different age, but the conclusion of the persistently deeper water in the Levis 

 basin, derived from its graptolite faunas, would naturally as a corollary also imply a 

 further southern extension of the sea in this channel during Chazy time. 



