GLACIAL LAKE WARREN. 393 



on the south side of the river nearly to Petersburg. Thence it runs north and, to a point 4 miles 

 west of Dundee, is a fairly strong beach ridge of sandy gravel. About 3 miles farther north it 

 turns northeastward and enters Washtenaw County in sec. 33, Milan Township. 



Washtenaw and Wayne counties. — From this point the course of the beach can be readily 

 followed on the Survey's topographic maps of the Ann Arbor, Ypsilanti, Romulus, Wayne, 

 Detroit, and Rochester quadrangles to a point 2 miles northeast of Washington, Macomb 

 County. It does not itself appear prominently on the maps but its course is nearly identical 

 with that of the 680-foot contour. Commonly it lies just above this line, but in places a little. 

 below it. From west of Dundee to 1 J miles north of Azalia it is represented only by low irregular 

 patches of sand. North of Azalia, however, it becomes more definite, running along the front 

 of a gravelly delta plain belonging to Saline River. A low bluff stands at its back and a wide 

 plain of fine sand stretches in its front to the southeast and east. 



The weakness of the beach in this stretch is probably due to the wide shallows which lay 

 in front of it. In the Ann Arbor quadrangle an offshore bar of Lake Warren extends from 

 Oakville southward past London with an altitude of 670 to 675 feet, or somewhat higher than 

 the Wayne beach 1 to lh miles farther east and a little lower than the average of the main 

 Warren beach. 



From Saline River northeast to Whittaker the beach is broken and not well developed. 

 East of Whittaker a sandy bar runs south about 2 miles toward Oakville, as if to join the offshore 

 bar at that place. Between Whittaker and Belleville the beach is fairly well developed along 

 the front of an older delta of Huron River. Through most of the interval from Canton to Faim- 

 ington Junction it is a well-formed beach ridge of gravel and follows close along the west side 

 of the contour of 680 feet. 



Oakland and Macomb counties. — The Warren beach bends more than a mile southeast in 

 eastern Southfield Township on account of the broad low ridge of the Detroit interlobate moraine, 

 but turns again sharply northeast and north as it leaves the Detroit quadrangle. The beach 

 is well developed as a strong gravel ridge through most of the interval from Southfield to where 

 it passes out of the Rochester quadrangle 2 miles northeast of Washington. It is a particularly 

 strong gravelly ridge a mile northwest and north of Utica along the front of an older delta of 

 Clinton River. 



The Warren beach has an altitude of about 687 feet in the extreme northeast corner of 

 the Rochester quadrangle. From this point it runs northeast, passing \\ miles north of Ray 

 Center, to the northeast corner of Ray Township where it turns a little south of east and runs 

 to a point a mile south of Lenox. 



In this interval the Warren beach is not so strongly developed as in some other parts. 

 Through Ray and Lenox townships it consists generally of a rather lightly formed pair of grav- 

 elly ridges. At Lenox, in common with the Whittlesey and Arkona beaches, the Warren beach 

 turns sharply north and in turning grows surprisingly faint (hi fact almost disappears) for 1J 

 miles. In this gap the ridge is not replaced by a wave-cut bench; the ground is a little stony 

 but offers no other suggestion of a shore line. 



St. Clair County.- — From a mile above the Grand Trunk Railway bridge over Belle River 

 the beach runs nearly straight north-northeast to near Abbottsford. Through Wales and Clyde 

 townships it is strong and for much of the way stands well above the country at its back, as well 

 as above that in front. For a mile or two south of Pine River it is 20 to 25 feet high. Toward 

 Abbottsford it forks into three broad, sand}^, branch ridges which diverge for a mile or two 

 toward the north and northeast. 



This great barrier beach shuts off a considerable bay behind it, but was not formed until the 

 lake had existed for some tune. This fact is established by the existence of a bay-shore beach 

 back of the main ridge. From sec. 34, Wales Township, a very much lighter gravelly shore 

 line runs north at the same level as the main ridge and a hah mile back of it. In sec. 10 it is 

 broken and offset on a patch of stony ground, but resumes its course half a mile farther west 

 and runs northeast and then north, passing just east of Goodells and Abbottsford stations to 

 Mill Creek, north of which it turns east and dies out on the sandy plain. 



