236 The American Geologist. October, i896 
These conclusiouH obviously point to the cause of the oscillating re- 
cession HS neither local nor terresti-ial, but (;iiniatic and hence of astro- 
nomic orif^in. Thus the nature of the cause of the Ice Age is apparently 
disclosed by evidence drawn directly from observations on the drift. 
This subject, which in a different phase has l)een V)riefly considered ))y 
Woodworth in the last Am. Geologist (p. 1(57), will be discussed more 
fully at a future time. 
The moraines here described were shown on a colored map. Other 
maps, illustrating portions of the themes of this and the preceding pa- 
per, have been given by Mr. Taylor in another very valuable paper, en- 
titled " A Short History of the Great Lakes," in recent numbers of the 
Inland Educator (vol. n, pp. 101-103, 1.38-145, and 216 223, March, 
April, and May, 189G), published at Terre Haute, Indiana. 
35. The Operations of tlie Geological Survey of the State of New 
York. James Hall. 
36. The Eocene Stages of Georgia. Gilbert D. Harris. The north- 
ern border of the Eocene of Georgia was indicated more correctly by 
White's map in 1849 than on maps of subsequent date; but the hand- 
books published by White, Stephenson, Henderson, and others, contain 
little reliable information on this subject. Lyell did some good work 
along the Savannah river, and properly referred the exposure at Shell 
Bluff to a horizon not far from the Claiborne. The mapping of the sub- 
divisions of the Eocene in southwestern Georgia by Spencer, in 1891, 
must have been somewhat hasty, since it is now ascertained that nearly, 
if not quite, all the area he includes in his map as middle and upper 
Eocene is occupied })y Vicksburg beds. 
During the past summer the author has traced the Midway stage 
from the Chattahoochee river to Putnam, Marion county. The Lignitic 
stage seems not to be fossiliferous east of the Chattahoochee. The 
Lower Claiborne is represented by siliceous ledges seen at quarries two 
miles east of Ft. Gaines, where it is fossiliferous: in the central part of 
the state it is unfossiliferous and consists of whitish sands: on the Sa- 
vannah it is marly and sometimes indurated, as at Shell Bluff. 
The Vicksburg beds are enormously developed in southwestern Geor- 
gia, their northern limit i)assing four miles east of Ft. Gaines, five miles 
north of Cuthbert. one or two miles west of Anderson ville, two miles 
south of Perry, past West Lake and Sandersvilie, and thence probably 
southeast to Screven county, though from Sandersvilie eastward Prof. 
Harris has not personally studied this stage. A remarkable outlier of 
Vicksburg rock is found twelve miles north of Fort Valley, at Rich 
Hill, Crawford county. The southern limits of this stage are still not 
well defined, esi^ecially in the southeastern part of the state. 
37. Tlte Origin and Age of the Gypsum Deposits in Kansas. G. P. 
Grimsley. The gypsum beds of Kansas, mapped during the past sum- 
mer for the University Geological Survey of the state, outcrop in a belt 
of varying width extending diagonally across the state in a northeast to 
southwest direction. They cover an area about 180 miles long, grad- 
uallv widening toward the south: its width is 10 miles at the north, 20 
