On the age of the red sandstone formation of Vermont
American Journal of Science
I HAVE lately been examining a tract of the Calciferous sandrock which lies on the boundary line between Canada and Vermont on Missisquodi Bay. The rock is exposed here in long parallel ridges, over an area of eight or nine miles in length and from one to three in width. On the east side of the exposure there is a ridge of greyish sandstone which I traced south across the boundary line, after crossing which it soon becomes interstratified with thick beds of rock of a chocolate red or brown
... e red or brown color. It is here the typical red sandrock formation of Prof. Adams. Hearing that Dr. G. M. Hall aind Rev. J. D. Perry of Swanton had discovered trilobites near this place I called upon them a~d they kindly co!1ducted me t~ the loca~ity. It is above two rules south of the hne and one mlle or a httle more east of the Highgate Springs. The individual fossils are abundant in the red sandstone but I could find only two species, a small Theca and a Oonocephalites. Of the latter we found only the head but the specimens are very numerous and some of them wen preserved. The species resembles Bradley's 0. minutus but is a. little larger and I think quite distinct therefrom. It is a true primordial type and if we are to be guided at all by PalreontoIogy we cannot regard this rock as lying at the toJ> of the Lower Silurian but at the very base of Barrande's Second Fauna if not indeed a little lower. It is therefore not the Medina Sandstone but a formation somewhere near the horizon of the Potsdam. This accords exactly with conclusion drawn from the evidence afforded by the fossils discovered by our survey at Quebec last year.