THE 
JOURNAL OF GEOLOGY: 
YOLY- AUG OST 1807 
MORAINES OF RECESSION AND THEIR SIGNIF- 
([GANCE-IN-GLACIAL THEORY: 
CONTENTS. 
Introduction. 
Value of the Cincinnati-Mackinac moraine series as a basis of interpretation. 
Known periodic oscillations of climate. 
Theoretical effect of precessional oscillations of climate upon the ice-sheet 
Character of the glacial oscillations as revealed by the drift. 
Probable rate of ice-sheet motion. 
Englacial transportation and deposition. 
Probable duration of the periods of glacial oscillation. 
Superposition of the oscillation upon a greater and much longer climatic 
variation. 
Summary. 
INTRODUCTION. 
The principal facts which form the basis of this paper were 
presented in an article read before the joint session of the 
Geological Society of: America and Section E of the American 
Association for the Advancement of Science at Buffalo in 
August 1896.2, They may be briefly summarized as follows: 
During parts of the seasons of 1893, 1895 and 1896 the writer 
explored the eastern coast of Michigan southward from Mack- 
* An abstract of this paper was read before the Geological Society of America at 
Washington, December 31, 1896. 
2*Glacial Succession in Eastern Michigan.’ Abstract in Am. Geol. for October 
1896, p. 234. 
WOls Ven NO. 5: 421 
