1880. | of the Atlantic States. - 709 
shore line these beds of conglomerate thin out and pass into the 
finer, off-shore deposits; associated with the conglomerate we also 
find an abundance of footprints, rain-drop impressions, etc. On 
the western margin of the same area these proofs of shore condi- 
tions are wanting. If this is a river, or a narrow estuary deposit 
we should expect to find somewhat similar strata on each side of 
the valley, and that the material forming the rocks should become 
coarser as we go northward, which as the’ geological surveys 
show is not the case; then, too, what river with floods and ice- 
rafts spread out the Triassic beds in New Jersey, which extend in 
one unbroken area far into Virginia, with the same structural 
peculiarities as are found in the Connecticut valley but reversed in 
their relative position. 
ince my essay on the Physical History of the Triassic Forma- 
tion was written, an interesting and valuable paper on the “ Meso- 
zoic Formation of Virginia”! has been published by M. O. J. 
Heinrich, in which many facts are given that have a direct bear- 
ing on the question of the former extent of the Triassic forma- 
tion. The map accompanying this essay gives the position of the 
detached areas of Triassic rocks in Virginia and North Carolina, 
together with the dip of the beds, and suggests very strongly 
that the separate patches were once united. This conclusion pre- 
sented itself to Mr. Heinrich also, as on page 23 of his paper we 
read, “the destruction of a connection formerly existing between 
all the Mesozoic deposits along the Atlantic States might, there- 
fore, be attributed to a slow, an unequal rising of the Eozoic 
‘rocks after the deposition of the former upon the uneven floor of 
the latter, noticed in the anticlinal of the latter, and producing an 
unequal denudation of the Mesozoic deposits.” In the carefully- 
Prepared section of the Richmond coal basin, published with this 
Paper, we find a rapidly-alternatiug series of sandstones, shales 
and coal, 1518 feet thick, including a coarse conglomerate thirty- 
Six feet thick at the bottom of the series. This section shows 
that the conditions at the time of the deposition of these beds 
Was not unlike those now prevailing at the northern end of the 
Bay of Fundy, where the Tantra marshes are forming. 
Another paper on the “ Mesozoic of Virginia,” by Prof. Wm. 
M. Fontaine, published in the American Fournal of Science about 
a year since? contains much interesting and valuable matter, but 
1 Transactions Amer. Inst. Mining Engineers, 1878. 
* Amer. Four, Sci., January, 1879. - 
