124 NEW YORK STATE MUSEUM 



a not unlikely case, as this limestone, so far as known, follows 

 conformably on the upper Champlainic strata.^ 



Even at the typical locality in Oneida county the conglomerate 

 appears to be not earlier than the Medina but rather the equiva- 

 lent of the upper Medina, corresponding in age to a part of the 

 upper hundred feet of the Medina of western New York. At least 

 this is true of the upper part of this conglomerate which appears 

 to belong to the advancing instead of the retreating shore line 

 phase. This is indicated by the fact that the Medina sandstones 

 overlying the conglomerate are less than 100 feet thick in Oneida 

 county. It is true, of course, that we may have a slower sub- 

 sidence here than in western New York and therefore a smaller 

 deposition. If that is the case, we might expect coarser deposits, 

 unless indeed the shore bj this time was far removed. There 

 might also be an hiatus in the middle of the sandstone series. 



In Montgomery and parts of Herkimer counties however, we 

 find a conglomerate between the Clinton and Lorraine with a 

 total absence of the Medina sandstones. Here the conglomerate 

 certainly represents the upper Medina, and belongs to the advanc- 

 ing phase of the Medina seashore. At Rosendale and in the 

 Shawangunk mountains the conglomerate rests on the folded and 

 eroded shales whose age may be Lorraine or earlier.^ The thick- 

 ness of the conglomerate is something over 200 feet in the Shaw- 

 angunk mountains but thins away northeastward, disappearing 

 near Binnewater. Locally the conglomerate often becomes a 

 coarse quartz sand. Above the conglomerate in the Shawangunk 

 region are shales (=High Falls) and sandstones (Binnewater) 

 commonly but erroneously referred to the Medina or Clinton. They 



^If no unconformity exists between the upper Richmond and the May- 

 ville beds and if the latter are of the age of the Clinton of New York, the 

 lower Medina shales of the Niagara region resting upon the Lorraine, must 

 be of Richmond age. The upper Medina, however, has a marine fauna 

 closely linking it with the Clinton. ^ " 



2 The Champlainic is almost wholly represented by shales and sandstones 

 in the northern Hudson valley. These shales are the Hudson shales in the 

 modern acceptation of the term, their age ranging from Upper Cambric 

 (Dictyonema beds) to Lorraine. 



