STRATIGRAPHIC SUMMARY. 607 



the Asophellus homfreyi zone of the Atlantic coast, and the Tre- 

 madoc of England. By overlap this formation rests as a basal 

 sandstone upon the crystallines. South of the Adirondacks, the 

 Saratoga series of basal sands, limestones and dolomites (Neely- 

 town limestones), rests upon the Precambric, and represents the 

 highest upper Cambric. From it the name Saratogan is generally 

 applied to the uppermost Cambric of the interior and western 

 region. The lower portion of the Hudson River shale series carries 

 the Dictynomena flabelliforme fauna of the upper Cambric of the 

 Atlantic, this portion being known as the Schaghticoke shale. 



In New Jersey the base of the Cambric is the Hardiston quartz- 

 ite, which carries the Olenellus fauna. It is succeeded by the 

 Kittatinny limestone which ranges in age from Lower Cambric at 

 the base, to Lower Ordovicic at the top. In central Pennsylvania, 

 in the Cumberland valley, the Reading quartzite and the Cumber- 

 land limestone are the approximate equivalents of the New Jersey 

 formations. Southeastward of this in Lancaster County and ad- 

 joining districts the series apparently begins somewhat higher up. 

 The base is the Chickies (Chiques) quartzite of Lower Cambric 

 age and this is succeeded by the York shale and the Lancaster lime- 

 stone, the latter still carrying the Olenellus fauna in its basal 

 portion. 



On the Pennsylvania-Maryland border, the following section is 

 given by Stose :^ 



SUPERFORMATION. 



Beekmantownian. 

 Upper Cambric. 



Conococheague limestone 1^635 ft. 



Middle Cambric. 



Elbrook formation 3,ooo ft. 



Waynesboro formation 1,250 ft. 



Lower Cambric. 



Tomstown limestone 1,000 ft. 



Antietam sandstone 500 ft. 



''Journal of Geology, XIV., p. 201 ; XVI., p. 698. See also Keith, Harper's 

 Ferry Folio. 



