84 NEW YORK STATE MUSEUM 



It should be pointed out that the possible exceptions in the 

 cases of the outliers along the eastern side of the Paradox Lake 

 (juadrangle, as well as those of the Ticonderoga quadrangle and 

 to the east of Lake George, all lie close to the general Paleozoic 

 rock area and in that portion of the southern Adirondacks upon 

 which the late Cambric sea first encroached and where the topog- 

 raphy was most rugged so that it is quite possible that local 

 embaynients receiving Cambric sediments did there exist. 



Li the cases of all the other and important outliers there does 

 not appear to be any direct evidence favoring the existence of 

 embaynients nor any need for such an explanation- to account for 

 the phenomena of the outliers. Simple downfaulting of the 

 Paleozoic strata has often carried masses of these so far down 

 that remnants have been protected from complete removal by 

 subsequent erosion. As already shown the southern Adiron- 

 dack region was, by the beginning of the Potsdam, w^orn down 

 to a peneplain upon whose surface only a few very minor irregu- 

 larities existed. This being the case, anything like prominent 

 embayments or estuaries could not possibly have existed. 

 Another argument decidedly against the embayment idea comes 

 out of the character of the sediments within the outliers. Thus 

 the dolomite in the Schroon Lake and Wells outliers is a dis- 

 tinctly marine formation of exactly the same character as that 

 of the general Paleozoic rock area. Or again, the Canajoharie 

 black shale at Wells is both faunally and lithologically distinctly 

 marine and precisely like that of the Mohawk valley. Estuarine 

 deposits Avould show certain distinct local variations and hence 

 the very uniformity of sediments in the outliers precludes the 

 possibility of deposition in estuaries. Thus we are forced to 

 conclude that when the early Paleozoic sea encroached upon the 

 southern Adirondacks, the shore line was fairly regular, with 

 possibly some very small local embayments along the eastern 

 side, and that a general mantle of sediments was deposited over 

 the whole southeastern Adirondack region. 



Extent of the Cambric seas. Nearly all the Paleozoic outliers 

 show the presence of Potsdam sandstone, and in the few cases 

 where it does not actually outcrop it is most likely present 

 though concealed from view. In the southern Adirondacks no 

 Potsdam sandstone outcrops west of a nearly straight northeast- 

 southwest line passing through the outliers at or near North 

 Hudson (No. i), x\orth River (No. 6), Wells (No. 8), and 



