76 TJie America?i 'Geologist. Febiiuuy, i898 
"The view expressed by the section is that there was a practically 
conformable deposition of sediments, against and over the Archaean 
area of the Adirondack mountains, from early Cambrian times up to the 
close of the deposition of the sediment forming the Utica shale, except 
in the case of the unconformity by non-deposition between the Potsdam 
and the Chazy. The writer has seen the deposition contact of the Utica 
shale, against the granite, on the eastern side of the Adirondack moun- 
tains, in Essex county. New York, and takes that as the upper line of 
the ideal section, although he has little doubt that the formations over- 
lying the Utica shale, even through the Silurian, were deposited against 
and over the Archaean of the Adirondacks and subsequently removed 
by denudation." 
Lately a somewhat different view regarding the relation of 
the sedimentary covering to the underlying crystallines has 
been advanced by J. F. Kemp.* 
A careful study of the topography and geology of the otit- 
liers in the eastern Adirondacks led Mr. Kemp to the con- 
clusion that the Palaeozoic rocks^ — Potsdam sandstone and 
Calciferous limestone at present, and also Trenton and Utica 
beds formerly, as Mr. Kemp supposes — were deposited in pre- 
existing valleys, which had been formed when, in the early 
Cambrian, the Adirondack hight -of-land must have been sub- 
jected to the ordinary processes of erosion and land sculpture. 
Mr. Kemp admits that faulting no doubt plays a considerable 
part in many of the outliers, but, at the same time, calls atten- 
tion to the fact that some of the present streams, connected 
with the outliers show often very low gradients for Adiron- 
dack creeks and appear to be near local base levels. It is sup- 
posed that the post-palaeozoic erosion, as well as the great 
ice-sheet, were active in clearing the valleys of the Cambrian 
and Ordovician sediments, and in reducing them to their pre- 
Cambrian gradients. 
Special attention is also called in Mr. Kemp's interesting 
paper to the outlier of Palseozoic rocks at Wellstown, on the 
Sacandaga river. f As this remarkable outlier, which consists 
of Potsdam, Calciferous, Trenton and Utica beds, lies directly 
in the path of the current which produced the parallel arrange- 
*J. F. Kemp. Physiography of the eastern Adirondacks in the 
Cambrian and Ordovician times. Bull. Geol. Soc. Am., Vol. VIII, p. 
408, 1896, and J. F. Kemp. The Pre-Cambrian Topography of the 
Eastern Adirondacks, read at the Washington meeting of the Geol. 
Soc. Amer. ; Abstract in Jour. Geol., Vol. V, No. i, p. loi, 1897. 
tSee the map: Am. Geol., Vol. XIX, No. 6, pi. XXII. 
