188 
Ransome. Members-at-large of the Council, 
Bailey Willis, A. H. Brooks, W. Lindgren, G. 
O. Smith, T. W. Stanton. 
The address of the retiring president, Mr. 
Whitman Cross, on ‘ The Development of Syste- 
matic Petrography in the Nineteenth Century’ 
was delivered in connection with this meeting. 
AT the 108th regular meeting, held January 
9, 1901, the following papers were presented : 
N. H. DARTON: Comparison of Stratigraphy of 
the Black Hills with that of the Front Range of 
the Rocky Mountains. 
After several years of detailed investigation 
of the stratigraphy of the Black Hills in South 
Dakota and Wyoming, a preliminary examina- 
tion has recently been made of the region south- 
west to and along the front ranges of the Rocky 
Mountains across Wyoming and Colorado. The 
Black Hills are due to a local expansion of a 
branch of the Laramie range, but the connection 
underlies a country in great part covered by 
Tertiary deposits. In the vicinity of Hartville, 
about 125 miles southwest of the Black Hills, 
there is a local uplift on this line, affording ex- 
tensive exposures of formations from the crys- 
talline schists part way up the Mesozoic col- 
umn. The stratigraphy is here very similar 
to that of the Black Hills, and all the principal 
formations from Lower Cretaceous sandstones 
to the Lower Carboniferous limestone can be 
distinctly recognized. Along the flanks of the 
Laramie range, and southward into Colorado, 
the formations present considerable change, 
but numerous features of close relationship were 
observed. In the fine sections at Morrison, 
west of Denver, there was found an extension 
of the Purple (Minnekahta) limestone of the 
Black Hills, having precisely similar strati- 
graphic relations in the Red beds, and containing 
some of the same Permian fossil, although these 
are scarce and not well preserved. The lime- 
stone was traced south for a considerable dis- 
tance and found to merge into a sandy bed 
which was finally lost in the great mass of 
coarse red deposits in the vicinity of the Gar- 
den of the Gods. Its very distinct occurrence 
at Morrison affords the means for a precise cor- 
relation with the Black Hills region. The 
underlying mass of coarse sandstone lying 
SCIENCE. 
[N.S. Vou. XIII. No. 318. 
against the crystalline rocks represent portions 
or perhaps all the Carboniferous formations 
of the Black Hills. The Red beds overlying 
this Minnekahta limestone at Morrison are 
gypsiferous shales similar to those of the Red 
Valley encircling the Black Hills. The Morri- 
son formation lying next above, is, as previous 
observers have pointed out, the equivalent of 
the Alantosaurus (Beulah) shales and the marine 
Jurassic which was traced as far south’as the 
Hartville region, is lacking in the Morrison 
section. The lower Cretaceous sandstone in 
the Black Hills has not been recognized in 
Colorado. The Benton formation presents the 
same three divisions through the Black Hills 
region as were determined by Gilbert in south- 
ern Colorado. In the valley of the Purgatoire 
in southern Colorado the Red bed series are 
represented by red sandstones of moderate 
coarseness, in the upper bed of which was dis- 
covered a bone of a Bolodont which is thought 
to be of Triassic age. The overlying series of 
gypsum, limestone, and shale yielded no fossils, 
but probably comprises a representative of the 
Morrison formation, for its upper part it least 
has all the characteristic features of the Alanto- 
saurus shale. It is overlain by so-called Da- 
kota sandstone. 
ALFRED H. Brooks and ARTHUR J. COLLIER: 
Glacial Phenomena of the Seward Peninsula. 
The Seward Peninsula, stretching out toward 
the Siberian coast from northwestern Alaska, 
separates the Arctic Ocean from Bering Sea. 
It consists, topographically, of low, rounded 
hills whose gentle slopes are often broken by 
well-marked benches. Above this upland, rise 
three notable mountain masses. The Kiglow- 
aik range, whose highest peaks reach an ele- 
vation of 4,500 feet, is a rugged mountain mass 
lying some 80 miles north of Nome. To the 
northeast of this range is another mountain 
mass, which, extending to the northeastward 
for some 80 miles, sweeps around the head- 
waters of Fish River, and joins the mountains 
east of Golofnuin Bay. The York Mountains, 
the third mountain mass, extend inland from 
Cape York. 
In this region there is no evidence of general 
glaciation. In fact, there is positive proof 
