44 NEW YORK STATE MUSEUM 



outliers well within the Precambric rock area of this region are 

 given in the following list : 



I A small exposure of Potsdam sandstone near the southwestern 

 corner of the Elizabethtown quadrangle and near the village of 

 North Hudson. 



2, 3, 4 Three outliers of Potsdam sandstone along the eastern 

 side of the Paradox Lake quadrangle. 



5 The Little Falls dolomite outlier (probably with underlying 

 Potsdam) at Schroon Lake village, Schroon Lake quadrangle. 



6 A small outlier of Potsdam sandstone one and one-half miles 

 west of the village of North River in the northeastern corner of 

 the Thirteenth Lake quadrangle. 



7 A small outcrop of Theresa sandstone and dolomite (prob- 

 ably with underlying Potsdam) near the northern border of the 

 Luzerne quadrangle and one mile due west of High Street village. 



8 The Wells outlier in the Lake Pleasant quadrangle. 



9 The Hope outlier in the Lake Pleasant quadrangle. 



Of these, numbers 7 and 9 have been discovered by the writer 

 within the past four or five years. 



In addition to these, there are certain other outliers close to the 

 main body of Paleozoic strata. 



It is important to note that all the outliers above mentioned as 

 occurring well within the Precambric rock area, lie on the down- 

 throw sides of faults. In the case of the Wells outlier, the valley 

 is of the nature of a " graben " where the block of Paleozoic rock 

 has been dropped down no less than 1600 feet to its present posi- 

 tion. Thus there appears to be no escape from the conclusion that 

 the valleys containing these outliers have been largely produced by 

 faulting, and that the Paleozoic strata formerly lay at a much higher 

 level, that is the general level of the Precambric rock surface. 

 Simple downfaulting of the Paleozoic strata has often carried masses 

 of these so far down that remnants have been protected from com- 

 plete removal by subsequent erosion. As is well known the southern 

 Adirondack region was, by the beginning of the Potsdam, worn 

 down to a peneplain upon whose surface only a few very minor 

 irregularities 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 distinctly marine forma- 

 tion of exactly the same character as that of the general Paleozoic 



