452 PLEISTOCENE OF INDIANA AND MICHIGAN. 



ridges which separate three or four small lakes from Lake Huron. This sandy belt terminates 

 near Grace Harbor, beyond which cliffs freshly eroded by the present lake extend northwest 

 and west to Cheboygan lighthouse. This part of the shore was seen only at Greens Landing, 

 where only a narrow strip of the Nipissing bench remains. It seems probable that the Nipissing 

 beach has been cut away by the present lake in much of this interval. A mile east of the 

 Cheboygan lighthouse the beach turns inland and runs southwest to Cheboygan River. A 

 great sandy flat, the west half of which is swampy, stretches 4 miles east from Cheboygan 

 At Cheboygan the Nipissing shore line makes a considerable excursion inland, forming an 

 irregular strait reaching through to the head of Little Traverse Bay. It extends up Cheboygan 

 and Black rivers to or very nearly to Black Lake. This lake appears to stand almost exactly 

 at the level of the beach, but the precise relationship has not been determined. The waters 

 of Lake Huron at the time of the Nipissing Great Lakes extended as a narrow strait into the 

 basin of Mullet Lake, around which the Nipissing beach is strong, mainly as a cut bench with a 

 lake cliff back of it and light sandy ridges below. From the west side of the lake a narrow, 

 swampy trough extends 5 miles northwest toward Douglas Lake. Up this the waters at that 

 time extended for several miles. 



Again contracting to a narrow strait, the waters extended up Indian River to Burt Lake, 

 and around its steep shores the Nipissing beach is nearly everywhere distinct though not strong. 

 Extending westward over a great swamp these waters filled the basins of Pickerel and Crooked 

 lakes and passed through to Little Traverse Bay. At Conway the strait was a little more 

 than a mile wide, but it broadened to 2 miles at Kegomic. The relatively great strength and 

 sharpness of this beach on the shores of these small lakes indicate a relatively long pause of 

 the waters at this level. 



About a mile south of Cheboygan on the east side of the river many fossil shells were found 

 a little below the level of the Nipissing beach. The following forms were identified by W. H. 

 Dall, two or three others being too fragmentary for certain recognition: Sphserium striatinum 

 Lamarck, Unio luteolus Lamarck, Limnsea elodis Say, and Goniobasis depygis Say. 



In the western part of Cheboygan the Nipissing beach is a wide sandy bench with a cliff 

 10 or 15 feet high at its back. It weakens considerably southward in the narrow passage to 

 Mullet Lake, but is still distinct. Between Cheboygan and Mackinaw City the Nipissing beach 

 is a bench carrying strong, gravelly, and sandy beach ridges, backed by a lake cliff 10 to 40 

 feet high and in one or two places 70 or 80 feet high. The Michigan Central Railroad follows 

 the beach rather closely and lies most of the way on its bench. The present lake has cut 

 heavily into this shore and at Lakeside has cut back to the Nipissing beach. At Freedom the 

 beach is composed of heavy sandy and gravelly ridges. A mile south of Mackinaw City it is a 

 wave-cut bench and bluff. 



Islands. — The shores of Bois Blanc Island are rather low, but the interior rises above the 

 level of the Nipissing beach, which encircles it about a mile inland. It has not been explored 

 above the Nipissing level, but it certainly rises high enough to record the Fort Brady and 

 probably the Battlefield beaches, though perhaps not high enough to record any of the upper 

 Algonquin group. The Nipissing beach is well developed on Round Island as heavy gravel 

 ridges and a low cliff. 



On Mackinac Island the Nipissing beach is well developed on the northwest part and 

 at the southeast end in the vicinity of the village. (See PL XXLX, O.) On the east side of 

 the island and on the southwest side along the line of the great cliffs the beach has been almost 

 entirely cut away. From Robinsons Folly to the Episcopal Church the beach is a strongly 

 cut bench with a cliff 40 to 70 feet high at its back. Gravelly beach ridges run at the base of the 

 cliff, but the drift is thin over the bedrock and the ridges are rather faint. The Mission House 

 is on the highest beach ridge at that point and the wave-cut notch is just back of the hotel at a 

 slightly higher level. This notch runs along the base of the bluff back of the Island House, 

 the public school, and the Marquette Monument. This beach is cut away below Arch Rock. 

 (See PI. XXX.) 



