377 



trciicliiiK'iit is not less th:iii L'fH* I'cct. Kcimiaiit!? of llio firjulatioii pliiiii iiic 

 perfectly preserved on both sides of the present intrenched valley to the 

 northwest of Borden. The renmiints iire more extensive farther up the 

 stream where the piracy occun-ed at successively later periods. Finally the 

 whole of the old valley is se(>n f(.r a sfrelch of about three-fourths nnle in 

 section ;!0 slretchin.ir southeast from old Tekin. Old Pekin is built on tiie 

 Hlue Kivei- lllarfein,(')f it. (See Fi.mu-c 2, ::. and 4. i This iMirtion of the 



If n 



wi<l 



IS til 



e. as wi 

 made by a slrca 

 incd an area of 

 f P.iue Kiver drai 



It vallci 

 iparabh 



app 



old valley is more than o 

 the Muddy Fork of Blue Rivei 

 size to this Fork of lilue Rive 

 square miles while that of .Mud 

 40 .square miles. 



The few tributaries of the old drainage course yet remaininji are shallow 

 streams. The hirgest one comes in from the south. It is not discornahly 

 below the ohl valley flat in the northeast one-quarter of section ?,!. (See Fig. 

 4). On approaching Pdue River it is trenched broadly into the old alluvial 

 dejiosits. and enters Pdue River accordantly. The small tributaries from 

 the north have scarcely been able to transport their load across the old 

 \alley Hat. and haxc the apiiearaiicc of having slightly aggraded the old 

 valley flat where they debouch upon it. 



Fi^. 2. — Viow of llio old valley wliirc it j.. 

 IMiio River ne.ir Pckiii. View takpii from tlic n 

 Sec. 31. Old Pokin in tho distance. 



,f tlio Mnddy Fork 

 II tlie northern half 



The divide between the iiicscMl streams on the old valley flat southeast 

 of Old Pekin is only ::(» feet above the valley of Pdue Kiver. The old valley- 

 flat ju-ojeets above the valley or Blue Kiver as a terrace. It api^ears that 

 P.lue Kiver has cut its valley down something like 30 feet since the stream 

 adjustment has taken place, but such is proliably not the case. It is evident 



