STREAM-CAPTURE IN MICHIGAN 333 



Mississippi at Turnbull's Island, as shown on the eight-sheet map 

 of the alluvial valley of the Mississippi. The Red may have run 

 right to the Gulf at one time until the meandering Mississippi bit 

 into the valley and carried off the waters. In time of drought, the 

 Red discharges into the Mississippi, but in flood season it discharges 

 partly into the Atchafalaya which runs into the Gulf. Bayous at 

 Turnbuh's Island indicate a possible westward meandering in the 

 Mississippi sufficient to produce such a result. In the same way 

 Bayou Mafon appears to have once discharged into the Tensas, and 

 so into the Red, while Lake Mafon would seem to indicate that the 

 Mississippi had cut into the river and captured it at that place. 

 Eastward cutting in the Mississippi may then have carried the 

 river away from Bayou Majon, so that that stream now discharges 

 through its old channel. Were it not for the extreme flatness of 

 the Mississippi flood-plain, these streams would probably have con- 

 tinued to run into the Mississippi even after its withdrawal from 

 the scene of capture. The silting up of the ends of the cut-offs seems 

 on that faint grade to have been sufficient to return the streams to. 

 their old courses. 



An example of capture from neighboring streams is that of the 

 capture of the upper waters of Beaverdam Creek by the Shenandoah 

 at Snickers Gap, as described by Bailey Wilhs; or the well-known 

 capture of the upper Chattahoochee by the Savannah on the bound- 

 ary between Georgia and South Carolina. 



In the National Geographic Magazine, June, 1896, p. 189, in 

 an article entitled "The Seine, the Meuse, and the MoseUe, " Pro- 

 fessor Davis describes the capture of the Ste. Austreberte by the Seine, 

 which, swinging past Quevillon and St. Martin, cuts into the bluffs 

 bordering the upland at Duclair. The Ste. Austreberte is diverted 

 from its previous course across the spur marked by the Foret de 

 Jumieges. The same writer describes a similar case on the Marne. 



The Huron River exhibits the latter type of capture. During 

 its youth it maintained a course, across what had been but recently 

 the floor of a glacial-marginal lake, wdth strict propriety. Its tribu- 

 taries flowed to the southeastward for the same reason as did the 

 master-stream, and entered the Huron at a slight angle. The 

 moment that the powerful Huron began swinging from side to side, 



