504 I. O. Russell — Glacial Records in the Nevja;r~k System. 



always found to be a coarse conglomerate or breccia. This 

 deposit lias been brought to the surface in several instances by 

 faults and its character is well known. Coarse conglomerates 

 occur especially on the east border of the Connecticut Valley 

 area and on the west border of the !S"ew York- Virginia area 

 and the detached areas in Virginia and North Carolina which 

 fall in line with it. The beds are not continuous, but occur as 

 local deposits. Where the coarse material is thickest, it grades 

 into fine material both along the strike, that is along the shores 

 against which it was deposited, and in a direction at right angles 

 to the shore. Toward the center of the area of deposition, the 

 coarse beds become fine and overlap or interdigitate, with fine 

 off-shore sediments. As the upheaval of the system has not 

 been uniform, erosion has cut far deeper in certain localities 

 than at others. Thus, in northern Xew Jersey the Xewark 

 rocks are known to be not less than three or four thousand feet 

 thick, while in the prolongation of the same area in Maryland, 

 the thickness is certainly much less. The present base-level of 

 erosion has cut deeper into the system at the south than at the 

 north ; yet all along the ancient shore, joining the two ex- 

 tremes, coarse deposits occur from time to time. The evidence 

 points definitely to the conclusion that coarse deposits occur at 

 all horizons from the bottom of the system up to the highest 

 beds that now remain. If these beds are glacial deposits, then 

 glaciers must have existed throughout the deposition of the 

 system. 



The coarse deposits along portions of the borders of the vari- 

 ous Xewark areas are always of local origin. They are not 

 heterogeneous accumulations gathered from a broad area, as 

 might be expected if they are of glacial origin, but have 

 been derived from terranes in the immediate vicinity of 

 where they now occur. The material forming the large bowl- 

 ders in particular, may invariably be found in situ, near at hand. 



Xo contortion of the fine sediments adjacent to or interstrat- 

 ified with the coarse deposits have been observed, such as 

 would result from the extension of glaciers into the basins in 

 which the fine sediments had been accumulated, or from the 

 superposition or moraines upon them. On the contrary, the 

 phenomena noted at many localities are fully explained on the 

 assumption that the strata both coarse and fine, were deposited 

 contemporaneously as water-laid beds. 



The fine deposits intimately associated and even interstrati- 

 fied with the coarse deposits, are frequently ripple-marked, 

 sun-cracked, and contain rain-drop impressions and the foot- 

 prints of animals, at many horizons ; thus showing conclusive- 

 ly, that the water bodies in which the strata were spread out 

 were shallow. There is, therefore, no reason why glaciers 



