W. M. Fontaine—Primordial Strata of Virginia. 421 
it is mixed with more or less clayey matters. Its sharp angu- 
lar condition shows that it has not been moved far. Large 
boulders of the metamorphosed quartzite occurring in No. (4) 
are found in it. 
South Branch, about 500 yards wide. Here the strata are not 
exposed. This space was occupied entirely, or in great part, 
by the shales overlying the Potsdam strata. No very reliable 
the Calciferous strata, which are found immediately on the west 
side of the stream. Here, at the town of Waynesboro, we have 
the following succession of strata, in which the dip is again high, 
viz: 60° to the southeast: first, purplish slaty shales, 50 feet; then 
dark gray, argillaceous limestone of earthy texture, 5 feet; next, 
greenish slaty shales, 15 feet; then dull purple, calcareous shales, 
feet; next, very fissile, yellowish, calcareous shales, 40 feet. 
poch. 
ane of the Valley, the Auroral, or No. II, of the Messrs. 
gers. 
_It will be seen by a comparison of this section with that 
given at Balcony Falls, that the thickness of Nos. (5) and (6) 
in the section here is much greater than that estimated for 
their equivalent, No. (9), in that section. A disparity, no 
doubt, exists, though probably not to such an extent as it thus 
appears to do, since I have under-estimated rather than over- 
estimated the thickness of (9). Still there remains the fact that 
the proportion of shaly matter in the entire group at Rockfish 
p has greatly increased. This may be due to the nature 
of the shores of the Primordial sea, which, as we have seen, 
were probably composed of the fine chloritic argillites of the 
ue Ridge. What could have been the source of the immense 
paneled of kaolin found here and everywhere in the Primor- 
ial strata, and what caused the almost total freedom of such 
kaolin rocks from iron, forms an interesting problem. 
The following section represents the junction of No. (1) of 
the series with the argillites of the Blue Ridge, as seen in the 
