GRAPTOLITES OF NEW YORK, PART 2 63 



Baltic shields to the growth of the continents and Haug's view on the rela- 

 tions of the geosynclines and continental areas, advanced in his highly sug- 

 gestive paper: " Les geosynclinaux et les aires continentales, contribution a 

 l'etude des transgressions et des regressions marines" [Paris, 1900). 



We will begin with the consideration of the views of the last mentioned 

 author. Professor Haug first brings forward accumulative proof that the 

 deposits of the geosynclines were not formed in shallow water as Hall, the 

 originator of the conception of the geosyncline, and some other American 



east of it?" we would in answer use the fact of the greater thinness of the sediments in 

 the slate belt as compared with the regions to the east and west to infer that because these 

 thinner beds are graptolite shales, the dwindling of the deposition in the geosyncline 

 can point only to deeper water and corresponding less sedimentation and not to a but 

 partly submerged land surface. As the grit consists largely of angular grains of quartz 

 and feldspar and scales of muscovite, and the conglomerate bands of pebbles of very dif- 

 ferent age (Lower Cambric, Chazy, Lowville, Black River and lower Trenton in the 

 Rysedorph hill conglomerate), it is more than probable that these deposits are due to the 

 presence of powerful shifting currents (oceanic, tidal and coastal) which at times carried 

 some of the material far out into the deeper basins, conditions that are well known from 

 the other geosynclines. 



In regard to the supposed unconformity in the slate belt at the end of the Beekman- 

 town time, it is stated by Dale [1904, p. 49]: "There was also an emergence at the close 

 of Beekmantown time, for the Hudson lies in places immediately upon the Beekmantown, 

 the Chazy being absent. The full thickness of this formation in the lake region is esti- 

 mated at 890 feet. Mr Ruedemann's doubtful determination of Chazy graptolites in a 

 40-foot outcrop at the Deepkill cannot suffice to substantiate the presence of a formation 

 representing such a lapse of time as is implied in the deposition of 890 feet of limestone." 

 Professor Dale's arguments for the absence of the Chazy formation in the Levis basin, viz 

 the absence of the Chazy limestone between the Beekmantown and Trenton shales [see ibid 

 p. 33] and the insufficiency of the third Deepkill zone to represent a time interval corre- 

 sponding to the deposition of 890 feet of limestone, are not convincing to us for the follow- 

 ing reasons: It can not be expected that the Chazy stage should be alone represented by 

 a limestone in a series of rocks, where all other stages are represented by graptolite shales, 

 but it should be a priori assumed that if present, the Chazy would also appear as a graptolite 

 zone. The succession of the graptolite zones in the slate belt is now thus that it well 

 compares in completeness with that observed in Europe, and that it is apparent that no 



