Philadelphia Meeting of Geological Society .— Up ham. 107 
Cambrian and Pre-Cambrian the rocks referred to the Huronian in the 
New Hampshire report'. 
Prof. Emerson, in discussion, remarked that this revision places the 
geological structure in harmony with the results now attained in Mas¬ 
sachusetts on the south. 
The Devonian formations of the southern Appalach ians. C. Willard 
Hayes. Washington, D. C. A. generalized section of the Devonian 
series in the southeastern United States was described. It has an 
upper and very persistent layer, only 8 to 21 inches thick, which is a 
green sandstone, with phosphatic nodules and shreds of volcanic glass, 
feldspars, etc., such as to indicate a volcanic tuff. Below this comes 
black shale, ranging up to 12 feet in thickness, but not always present. 
The next and basal stratum is a ferruginous sandstone or conglomer¬ 
ate, up to 6 feet thick, but sometimes absent, which contains the 
recently discovered irhosphate beds of Tennessee. Various attempts 
have been made to explain the surprising thinness or actual absence of 
the Devonian formations over great areas, as follows: (1) the region 
was a deep sea bottom, lacking sediments ; (2) it was a region of shallow 
waters whose entering streams were without sediments; (3) it was a 
land area : (4) it was a shallow sea without sediments and with swift 
but clear currents, like the Gulf Stream region of the West Indies. 
The speaker believes that such scanty sediments as were distributed 
came in large part in currents from the northeast, and that another 
current came from the southeast and flowed around the Cincinnati 
arch. 
This paper was discussed by Messrs. Langdon, Stevenson, Keith, 
Van Hise, and H. S. Williams, especial attention being directed to 
the relations of the Devonian to the Helderberg limestones in south¬ 
western Virginia. 
Notes on the Relations of the Lower Members of the Coastal Plain 
series in South Cqplina. N‘. H. Darton, Washington, D. C. Until 
about a year ago the geology of South Carolina was known principally 
from the work of Tuomey over fifty years ago. He determined the 
relations of many of the formations of the Coastal Plain area, but 
several very important features were-not ascertained. It is now found 
that the strata classified by Tuomey as the basal members of the 
Eocene are instead of Potomac age, and that this formation extends 
northward beneath the marine Cretaceous marls, of which the edge 
emerges from under the Eocene north of the Wateree river. As was 
suggested by McGee several years ago, a continuous sheet of the Poto¬ 
mac formation lies on the crystalline rocks across South Carolina. 
The entire Coastal Plain series in this state comprises the following- 
formations, in their descending order: Columbia gray sands; Lafayette 
orange-colored loams; Miocene sands and marls; Eocene marls above 
and buhrstone below; Cretaceous marine marls, sands, and clays; and 
the Lower Cretaceous or Jurassic non-marine Potomac sands, sand¬ 
stones, kaolinic arkose, and clays; in which plant remains were observ¬ 
ed at many places. In a deep well at Aiken the full thickness of the 
