282 THE CAMBRIAN. [bull. 81, 



Feet. 



(3) Shaly limestone in massive layers; argillaceous shales interbedded in the 



layers 380 



(4) Calcareous, argillaceous shales, in massive layers, with interbedded arena- 



ceous limestones below, and passing into an argillaceous shale above.. . 240 



(5) Dark, argillaceous, and arenaceous shales becoming fissile in places; occa- 



sional layers of a hard, gritty limestone 1 or 2 inches thick occur at 

 various horizons. Near the summit of this section Hyolithes americanus, 

 Microdi8cu8 pulchellus, Olenellus asajihoides, and Conocoryphe trilineaia occur 

 near the roadside. This is the trilobite bed from which the original 



specimens described by Dr. Emmons were obtained 370 



The section to this point gives a total of 2,000 feet, and is considered 

 Division A of the section. 



(6) Compact, steel-gray, massive-bedded argillaceo-argillaceous shale, breaking 



into irregular fragments, and weathering a rust-brown color 2,200 



At a point 1,300 feet up in this I found Stenotheca rugosa, Hyolithes amer- 

 icanu8, and fragments of Olenellus asaphoides. At 2, 100 feet up fragments 

 of Olenellus occur in a stratum of calciferous shale. 



(7) Massive beds of a thinly banded, cherty, and argillaceous rock, capped by 



a band of calciferous sandrock 400 



(8) Argillaceous shale, more or less arenaceous and calcareous throughout its 



extent 2,400 



(9) Calciferous sandrock, light colored, weathering to a reddish brown, crum- 



bling sandy rock. This is embedded in a calcareo-argillaceous rock, that 

 breaks into angular fragments of a shaly character. The only fossils ob- 

 served were Obolella crassa, Hyolithes, fragments of Olenellus, on the 

 decomposed surfaces of the more calciferous layers 900 



(10) Argillaceous and arenaceous shales, much like those of Nos. 8 and 9, with 



bands of bluish gray, evenly bedded, and conglomerate limestone carry- 

 ing fossils. As shown in the section, this division appears to have a thick- 

 ness of 4,500 feet ; but it is assumed that there is much repetition by 

 faulting, so that it is given a thickness of 2,250 feet 2, 250 



The combined thickness of the section to this point is 10,750 feet. Its 

 continuity is here broken by a fault, that brings the rocks of the Hud- 

 son (!) terrane against it and between it and the purple and green slates 

 that form a large portion of the Cambrian section east of the rocks of 

 the Hudson (!) terrane. The section is again taken up on the east side 

 of Salem Village, at the base of the green and purple slates and inter- 

 bedded limestones, carrying characteristic Lower Cambrian fossils of 

 the Olenellus fauna. 



Feet. 



(11) Green, purple, and higher up, gray and dark shales and slates and inter- 



bedded limestones, in very thin layers 2, 500 



(12) Nonfossiliferons green and purple slates 2,150 



In the township of Hampton to the north, the green and purple slates 

 appear to have a thickness of 4,300 feet; and 2 miles north of that point 

 there are over 5,000 feet of these beds, if no repetition occurs. 



The lower portion of this division is characterized by the Olenellus 

 fauna in association with some other species that indicate the Middle 

 Cambrian zone. The entire thickness of the lower and upper divisions, 

 according to the section, is 15,350 feet. 



(13) Above the green and purple slate belt is a series of greenish, schistose, 



hydro- mica slates, estimated to have a thickness of 3,700 feet. They are 

 not fottsiliferous, and appear to pass beneath the limestones characterized 



