474 



PLEISTOCENE OF INDIANA AND MICHIGAN. 



Figure 10.— Map of distributaries, gravelly river bars, the St. Clair esker, 

 and other features near St. Clair, Mich. The river occupied both sides 

 of the esker, but the space between the esker and the Canadian bank 

 of the river is not now swampy and shows evidence of such occupation 

 only in the gravelly bars south of St. Clair. 



moraine range in width from nearly half a 

 mile to only a few rods. The divided old 

 river bed south of St. Clair, though resem- 

 bling a pair of distributary channels, is not 

 in reality of that nature. (See pp. 476-478.) 



CHANNELS. 



The distributary channels north of St. 

 Clair were made at a higher stage of the lake 

 waters than that which made the old river 

 bed in the village, and the streams that made 

 them were shorter lived. They lie in the 

 eastern part of St. Clair Township and run 

 southwesterly to Pine River. Measured by 

 aneroid barometer their heads where they 

 start on the crest of the moraine are 630 to 

 635 feet above sea level, the moraine crest 

 being 5 to 10 feet higher. 



The largest channel starts in southwest 

 sec. 6 (east tier of sections), 1 St. Clair Town- 

 ship, and runs southwest through sees. 7 

 (east tier), 12, 13, 14, and 23, ending along 

 the east side of sec. 22. It is nearly half a 

 mile wide and is slightly swampy in some 

 parts. It has a thin black soil, with scat- 

 tered patches of sand and gravel. Toward 

 its lower end it is floored with gravel across 

 its whole width, and it bears two or three 

 conspicuous gravel ridges which were depos- 

 ited as bars where the current slackened in 

 the Pine River valley. These gravels are 

 best developed in southwest sec. 14 and 

 northwest sec. 23. A prominent gravel bar 

 is crossed by the diagonal road which runs 

 southeast through sec. 23, less than a quar- 

 ter of a mile east of the northwest corner. 

 Some well-marked banks 5 to 10 feet high 

 along the sides of this channel are in fact 

 residual ridges forming barriers between it 

 and other channels on either side. They 

 are one-quarter to one-half mile wide, are 

 composed of stony clay or till, and are simply 

 parts of the original moraine which remained 

 after the distributary streams had done their 

 work. 



Another channel starts in northeast sec. 

 7 (east tier) and runs southwest through sees. 

 13, 24, 23, and 26. It is like the channel 

 just described, except that it is only half as 

 wide and runs about a mile farther south- 

 west. It is gravelly toward its lower end 



1 St. Clair Township is irregular, being made to include a tier of sections east of the regular boundary. 



