White Limestones of Sussex County, X. J. — Nason. 165 
the publications cited. Along anticlinal axes one side may be 
wholly white limestone, while the other may be part blue and 
part white, both the latter having the same dip and strike, as 
is shown in one instance in the Rudeville quarries, and simi- 
lar facts have been observed elsewhere. 
3. Conformability with quartzite. The blue limestone has 
been shown (loc, cit.) to contain Obolella crassa, and is there- 
fore referred to the Lower Cambrian. The quartzite. which 
generally underlies the limestones of the region, contains 
abundant remains of Olenellus and other fossils, and its age 
is thus positively determined to be Lower Cambrian. 
Wherever studied, both the white and blue limestones are 
found to be conformable with and above this fossiliferous 
quartzite or sandstone; and therefore they cannot be of Arch- 
wan aye. A good illustration of this may be seen in Hardis- 
tonville, where the graphitic fossiliferous quartzite in contact 
with the granite is conformably overlaid with a coarsely crys- 
talline graphitic limestone which gradually passes out into a 
fossiliferous blue limestone overlying the same quartzite. The 
white limestone is continuous with that of the region and is 
everywhere filled with intrusives. 
These relations are diagrammatically represented in the ad- 
joining figure. The sandstone being less affected by meta- 
morphic action than the limestones, retains its fossiliferous 
contents up to the line of contact with the dike. 
Fig. i. Effects of a granite dike on Cambrian limestone and sandstone, 
Hardistonville, N. J. 
4. Unconformability with the gneiss. In spite of the fact 
that there is apparent conformability with the franklinite and 
zinc beds of Franklin Furnace, the conformability is only ap- 
