Geographical Distribution. 15 



over the State outside of the crystalline rock regions of the Hudson 

 Highlands and the Adirondack^. And they represent all of the 

 geological periods, beginning with the Potsdam, up to the New Red 

 Sandstone. Following the order as given on page 8, the occur- 

 rences and localities may be noted briefly. 



Potsdam Sandstone. 



This formation in narrow outcrops is seen in Dutchess county, bor- 

 dering the Archaean rocks. Outcrops of limited areas are seen in the 

 Mohawk valley at several points between Fonda and Little Falls. In 

 the Champlain valley this formation has been a source of building 

 stone at Fort Ann, Whitehall, Port Henry and Keeseville. North 

 of the Adirondacks there are quarries at Malone, in Franklin county. 

 The most extensive quarries of this sandstone are on the Raquette river 

 near Potsdam, and in Hammond, St. Lawrence county. At the last 

 named place the product is largely paving blocks and curbing stone, 

 and is made out of a grayish- white, thin-bedded sandstone. The Pots- 

 dam rock occurs in moderately thick beds, and is a hard, compact 

 stone of a pink to light buff shade of color. Some of it has a lami- 

 nated structure and striped appearance. It is an excellent building 

 stone, and is widely known and esteemed for its beauty and 

 durability. 



Hudson River Group. 



This group includes shales aud standstones. The latter are gener- 

 ally shaly or argillaceous. There are some localities where more sili- 

 ceous or arenaceous beds are found. And these latter beds furnish 

 the building stone. As is well known, the formation follows the 

 Hudson River valley from the Highlands northward to Washington 

 county and the valley of the Mohawk west, and then runs north-west 

 in a broader belt across Lewis and Oswego counties to Lake Ontario. 

 Owing to the shaly nature of the sandstone, the localities for quarries 

 are few. They have been opened on the Hudson river at Highlands, 

 nearly opposite Poughkeepsie, at Rhinecliff (Rhinebeck station), near 

 Tivoli, on the river between Stuyvesant and Schodack, at New Bal- 

 timore and at Troy. In the Mohawk valley there are quarries at 

 Aqueduct, in Schenectady, on Frankfort Hill in Herkimer county, 

 east of Rome in Oneida county, and in the town of Orwell in 

 Oswego county. 



The Hudson river formation does not supply much, if any, stone 

 to markets outside of its limits. And nearly all of what is quarried 



