:{7!) 



silts over the old bed rock lloor is iiiurii dcrpci- than a normal stiram of 

 its si/c should have ]M)ss(>sscd. Willi tlic l.clicadiu- of this aiKirnt drain- 

 age in the earlier staj^es of successive pirac.x the drainage reinaiiiiiij.' 

 would not he ahle to retain as low a jxnuliont as the previous lari,'er nioi-e 

 vijr<u-ous drainajic. 'i'lie result would ho iiKsradalieu <d' the valley. If this 

 is a cornu't interpretation, the fact that the present valle.v of I'due I{i\'er 

 is ;>() feet heh>\v the old valle.v flat is not altop'ther a residt of erosion down- 

 ward of its hod since the stream adjustments have lieen made. A>,'ain this 

 aK^cradation of the lower pjirt of the valle.v will aid in explaining the ex- 

 cei»tionall.v low .uradient of the old nortliwestwardly flowiufr stream as de- 

 lerniined hy the relative elevations of the renniaids of the yradation j.lain. 

 At I'.orden it is To,", feet and in the iireserved lowei' portions it is T:;(l feet 

 where it is lowest. This would be a gradient of less than live feet to the 

 Mdle. 



The I'otiHliiil Fiifiirc of Miuhhi Fork of Silrcr <'n<k. 



When one realizes that the lari^er j.art of .Muddy Fork of Silver ("reek 

 has been made at the expense of the I'.lue iCiver drainage systenl. and that 



tiie last annexation was rel.ntively recent, one nnist in(pure whether the 

 flrainage adjustments are yet c<implete. It needs little nioic than casual 

 observation to note that the piracy is fai' fi'oni complete in the Pekin- 

 Horden rofjion. The tiny stream shown on the topojiraphic map in the 

 southeast corner of socfion .".0 was really the latest accession. This was 

 a mere wash leadin.g to the northwest before the Monon Railroad was built 

 through tlie old col. The cut necessary for a more gradual descent into 

 the Silver Creek system allowed the wash to send its waters into the 



