ERIE DIVISION. 
317 
11. ERIE DIVISION. 
Synonims. Lower part of the Catsldll mountain series. Third greywacke of Eaton. Formation 
No. 8 of Prof. Rodgers, [Olive slates) \ Skaneateles shales, Dark grey fossiliferous shale, Com¬ 
pact calcareous blue shale, Olive shale, Ludlowville shale, Encrinal limestone, Moscow shale, 
Apulia and Sherburne shales, and Cazenovia group.* 
This division of rocks underlies the Catskill division, without being separated by any very 
obvious line of demarkation in the First Geological District. The rocks of these divisions 
graduate into each other in their characters in the First district, and have been described in 
former geological reports as the Catskill mountain series.! In other parts of the State, where 
fossil remains abound in these rocks, the line of demarkation is more easily recognized. The 
rocks of the Erie division form the base, and a part of the mass of the Catskill mountains. 
They also occupy the top of a part of the Helderberg mountains. They range from the 
Delaware river, near Carpenter’s point, along the west side of the Mamakating valley! to 
Kingston; thence on the west side of the Hudson valley nearly north, at a distance of a few 
miles from the Hudson to the south line of Albany county, whence they bear away to the 
northwest on the Helderberg mountains, at a higher level than in other parts of their range ; 
and finally westward, along the southern side of the Mohawk valley, and occupy most of 
the south part of the Stale between the Erie canal and Pennsylvania. 
The rocks of this division consist of sandstones distinctly stratified, often fissile, and 
highly indurated, of grey, greenish grey, olive, black and brown colors, called by many 
persons greywacke \; and of slates and shales of similar colors. 
The Erie division in the First Geological District, consists of the following groups, viz : 
1. Ithaca and Chemung group. 
2. Hamilton group. 
3. Marcellus shales. 
The Portage group, Genesee shales and Tully limestone, of the Erie division, if they 
exist in the First district, have not been recognized as distinct strata. 
Some of the rocks of the Erie division are upturned at a high angle southwest, west and 
northwest of Catskill, near where a fracture parallel to the main axis of disturbance crosses 
the Kaaterskill and Catskill creeks ; and also near Port Jervis, on the Delaware ; and thence 
by Cuddebackville to Red bridge and Ellenville, where another axis of disturbance crosses 
the Delaware and extends through the Mamakating valley. The dip, except in these and 
* Final Report of Third District, by L. Vanuxem, p. 150. 
t Vide Geological Reports of New-York, 1840, p. 527 ; 1841, p. 77. 
t The Delaware and Hudson canal passes through this valley. 
4 Third, greywacke of Prof. A. Eaton. 
