DEFORMATIONS. 55 



Spencer found them all substantially horizontal from the Ohio line nearly 

 up to Port Huron, but west of this place they all begin to rise northward. 

 The profile on an east-and-west line from Imlay to Port Huron shows 

 the following heights for the several beaches : Leipsic beach at Imlay, 

 849 feet; Belmore beach near Summit, 770 feet; Arkona beach near 

 Goodells, 697 feet ; Forest beach five miles west of Port Huron, 665 feet, 

 and lake Huron, 581 feet. On a north-and-south line from Imlay through 

 Ubly and Verona Mills, crossing the heads of the outlets, the heights are 

 as follows : Leipsic beach at Imlay, 849 feet ; Belmore on col east of 

 Ubly, 800 feet ; Arkona, not known ; Forest one mile north of Verona 

 Mills, 775 feet, and lake Huron, 581 feet. On the east-and-west line the 

 vertical intervals between the beaches are, in descending order, 79, 73, 32, 

 and 84 feet, while on the north-and-south line they are approximately 

 50 feet for the first, 25 feet for the second and third combined, and 195 feet 

 for the last. The second and third combined on the east and-west line 

 are about 105 feet. On the north-and-south line the distances are about 

 50 miles for the first, 7 miles for the second and third combined, and 16 

 miles for the last. On the east-and-west line the distances are 16, 5, 41, 

 and 6 miles. In its horizontal part the Leipsic beach from Ypsilanti to 

 Fort Wayne averages (from Spencer and Gilbert's measurements) about 

 785 feet altitude, so that its level at Imlay represents a northward rise of 

 something like 60 feet from Ypsilanti or some point north of there. 

 Treating the other beaches in the same way, we find that the Belmore 

 rises about 35 feet to Emmet from horizontality somewhere north of 

 Ypsilanti and about 67 feet in all to the col at Ubly, and that the Forest, 

 which seems to be horizontal to Port Huron, rises thence 110 feet to 

 Verona Mills. 



The supposition of a local northward uplift springing from some point 

 north of Ypsilanti and occurring after all the beaches were made does not 

 account for all the facts. It might account for the deformation of the 

 Leipsic and Belmore beaches, but not so clearly for the two below. If 

 the axis of a low local anticlinal uplift were west of Imlay and its strike 

 ran about northeast and southwest, the Leipsic beach, lying the farther 

 west, would rise upon its flank sooner, while the Belmore would begin 

 to rise at a point farther north, producing substantially the effect found ; 

 but from what little is known of the Arkona, it seems improbable that 

 this idea applies to it, and it obviously fails for the Forest. It seems clear 

 that there was a subsidence affecting the north end of the thumb some 

 time after the Belmore beach and before the Forest. It is not known how 

 this ma}' have been related to the Arkona. The Forest beach rises from 

 near Port Huron gradually and with fair uniformity for some distance, 

 but more rapidly in the last ten miles toward Verona Mills, apparently 



VIII— Bull. Geol. Soc. Am., Vol. 8, 1896 



