A. F. Foerste — Fossil localities in the early Paleozoics. 435 



Aet. LIX. — New fossil localities in the early Paleozoics of 

 Pennsylvania, New Jersey and Vermont, with remarks on 

 the close similarity of the lithologic features of these Paleo- 

 zoics ; by Aug. F. Foerste. 



[Published by permission of G. K. Gilbert, Chief Geologist IT. S. Geological 



Survey.] 



The general distribution and succession of the paleozoic 

 rocks of J^ew Jersey, east of the Kittatinny Mountains and 

 west of the Green Pond Mountain ranges and of the more 

 southern part of the Triassic area, were clearly understood by 

 the former State geologist George H. Cook and his assistants, 

 at an early date. The folding to which this territory had been 

 subjected was too simple, structurally, not to be easily unrav- 

 elled. Immediately below a great conglomerate series on the 

 eastern side of the Kittatinny Mountains, now known as the 

 Oneida conglomerate, lay a great mass of sandy shales, or slates, 

 constituting the Hudson River shale horizon. Below this was 

 a great thickness of limestones, generally whitish in color, 

 from which fossils were known at an horizon, lithologically 

 somewhat distinct. This horizon consisted of a bluish, at 

 times dark blue limestone, at the very top of the limestone 

 group, just underneath the shales, and almost always contained 

 fossils. To find fossils at this horizon it is only necessary to 

 follow the trend of the formation and to keep a sharp look- 

 out. The fossils aro often small, but were early identified as 

 Trenton. The white, often magnesian, limestones beneath, 

 composing almost all of the limestone series were clearly sepa- 

 rable from the Trenton horizon, as a Magnesian series. No 

 fossils were found and so their age was properly left a little in- 

 definite, except as regards their pre-Trenton character. Beneath 

 the limestones, a sandstone belt of moderate thickness was 

 known to be almost universally present. As sandstones at the 

 base of the paleozoic series were then understood, it was possi- 

 ble to interpret this basal sandstone only as Potsdam, a litho- 

 logical interpretation, which since has lost its value. Beneath 

 this sandstone occurred crystalline rocks, white limestone, 

 gneisses, massive granites, and dykes, but except in northern 

 Sussex county, no igneous rocks were known to penetrate the 

 paleozoic series, and even there such penetration was limited 

 to certain dike rocks, with limited contact metainorphism. 

 These rocks were called Archaean. Some who are at present 

 working in this field suspect that a part of these rocks will 

 have to be eventually classed as Algonkian but that is a new 



