Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-08-20
The Geological Section.

c. K. Gilbert, United States geological sur
vey. read paper on 'Post-glacial Anticlina
Ridges Near Ripley, N Y, aud near Caledonia
n. " in which he said:
At the Buffalo meeting I presented to tn,
association an account of postglacisl anticlina
northwestern Ohio. The ridges are small
having width Of few rods and
height of a few feet, the maximum
height observed being sixteen feet In
northern New York they are constituted
of Trenton limestone in northwestern Ohio Of
Deyonian shale. They are chiefly or entirely
within areas thiniy covered by till overlaid BY
laminated lacustrine clay Of the Champlaiu
epoch.
At Buffalo expressed the opinion that the
phenomena are superficial, basing that infer
ence on the narrowness of the ridges. am
now able to sustain the inference by re.
porting section which extends well toward
the base of the disturbances. The locality
was first mentioned by James Hall in the
geology Of the fourth district of New York.
Near Ripley the shore Of Lake Erie
presents cliff toward the lake. and this cliff,
about forty feet in height, exhibits ridge in
section. The amount of disturbance and the
width of the disturbed area diminish from the
top Of the cliff to the base at SO rapid rate al
to indicate that the disturbance extends but q
few feet below the water level.
Mr.. Z. X. Howell reported to me the occur
renee of similar pheno mena at Lime Rock,
between the towns of Caledonia and LIE Roy,
n. Y, and l afterward visited the locality,
great number of small anticlinal ridges
are there to be seen and they are post.
glacial but they differ in type from those pre-
viously described, and they probably differ in
origin. They run. as q rule, parallel with one
another and with the strike Of the strata The
anticiinals are usually unsymmetric and the
disturbed rock is greatly fractured.
The ridges are much nearer together than
<1,.ga nT >tl,1
carboniferous limestone and beneath II are
shales Of the Salina group. A few miles to the
north ward the drill has discovered bed Of salt
in these shales. The theory advanced in explana-
ton Is that salt and gypsum are being removed
from the shales somewhat rapidly by under
ground water. that the superjacent corniforous
limestone sinks in large masses, and that the
ridges are the superficial phenomena of the
partings of these blocks. 4 large spring issu-
ing from the limestone IL exporting annually
more than 10000 cubic feet Of salt and gyp-
sum.
Following are the papers listed for tomor-
rows session of the section:
Fossil Tracks in the Triassic Of York County,
Pa, A. Warner; Eve minutes.
'New Footprints Of the Connecticut Valley, /"
n. N. Mitievier; ten minutes.
1.-The Plantbearing Deposits of the American
Tries, Lester +. Ward; twenty minutes.
"A Reply to Prof. Marsh's Note ON Nesozoic
Mammaia," Henry F. Osborn; twelve miuutes
Purposes and Methods of Geologic Corre-
iation by Means Of Fossil Plants" Lester r..
Ward: thirty minutes.
Exhibition of Certain Bones Of HeRalouyx
Not Before Known" James r. SaAord; ave
minutes.
'.On the Probable Evidence Of a Seooud
Drittiess Area in the Mississippi Basin, r. d.
Salisbury; fifteen minutes.
The Cincinnati Ice Dome," Frank Leysrett;
ten minutes.
1.-The Structure of thu Ouchit. yrrHN .,
Arkansas" Leon g. Griswold: fifteen minutss.
The Relations Of the Archean and the Aleou
khan in the Northwest" G. r. Van Rise; twenty
minutes.
Results Of Well Boring at Rochester. n.
l., Herman I. Fairchild; ten minutes.