32 P. B. TAYLOR — CORRELATION OF BEACHES AND MORAINES. 



" thumb " and the Saginaw valley in Michigan * The '' thumb " is that 

 part of the state which projects northward between Saginaw bay on the 

 west and the south end of lake Huron on the east.f 



Our previous knowledge concerning the Pleistocene formations of 

 these areas may be epitomized as follows : 



Professor T. C. Chamberlin's map in his report on the " Terminal 

 Moraine of the Second Glacial Epoch "J shows the great Saginaw-Erie 

 interlobate moraine of northeastern Indiana and southeastern Michigan 

 projected hypothetically northward well toward the end of the thumb. 

 Another great interlobate, which may be called the Saginaw-Michigan, 

 is also shown on the extreme west of the Saginaw valley, but no other 

 moraines are recorded within these areas. His latest map, issued in the 

 recent edition of James Geikie's " Great Ice Age " (opposite page 727), 

 shows only one additional moraine. It belongs to the Saginaw glacier, 

 and lies mostly south of the valle} T , only a small part of it falling within 

 the area here under consideration. 



With respect to beaches, the only observations recorded are those of 

 Dr J. W. Spencer.§ Beaches had been recognized at points farther south 

 near Ypsilanti b}^ Professor Alexander Winchell several years before,|| 

 but so far as known he did not trace any of them northward to the area 

 here considered. Spencer had traced an extensive series of beaches in 

 Ontario and had named the body of water that made them lake Warren, 

 and later Warren water and Warren gulf, supposing it to have been 

 marine.^ He supposed this lake to extend almost without limit to the 

 north and northeast and' to overspread the basins of all the Great Lakes ; 

 and he supposed further that the same waters had formerly stood at still 

 higher levels, much higher than the highest beaches which he had traced 

 continuously in Ontario. Beginning near the Ohio-Michigan state line 

 west of Toledo, to which Gilbert had previously traced several beaches 

 from Ohio,** Spencer followed four beaches northeastward to a line pass- 

 ing nearly due west from Port Huron. He found that the three lower 

 beaches of this series corresponded very closely with three similar beaches 



* After this paper was read at the Buffalo meeting, ten days more were spent exploring on the 

 "thumb." A few additions have been made in consequence, and the interpretation of the phe- 

 nomena has been slightly altered in one or two instances. This will explain some slight points 

 of difference which appear between this print and the abstract published in the American Geol- 

 ogist for October, 1896, pp. 233 and 234. 



t Mr G. K. Gilbert spent some time in this part of Michigan in the early part of June, but after 

 working a few days on these beaches he was called east, and at his suggestion the work was taken 

 up by the writer. Due acknowledgment is here made of the free use of Mr Gilbert's notes. 



J Third Annual Report U. S. Geological Survey, 1881-1882 ; maps opposite pages 2:4 and 222. 



§"High L,evel Shores in the Region of the Great L,akes and their Deformation," by J. W. 

 Spencer, Am. Jour. Sci., vol. xli, March, 1891. 



|| " Geology of Washtenaw County," by A. Winchell, 1881. 



^Science, vol. xi, p. 49, Jan. 27, 1888 ; Proc. Am. Assoc. Adv. Sci., vol. xxxvii, 18S8, pp. 198, 199. 



** Geological Survey of Ohio, vol. 1, chap, xxi, 1871, by G. K. Gilbert, beginning at page 357. 



