375 



Md.iiisliiiciit of the i-cuioii. It lies lu-lwccii Ihr ;iii<l Icii miles l.;ick rrmii llic 

 jrciicral sciirp. Muddy Fork of J'.iuc IJivcr (lows wcst-soiitliwcsi i»;isl 

 I'l'kiii, and as a Ki"i'*l«'<l stream is oiilircly in ilic I\nolistoiic rocks. .Miidd.N 

 Fork of Silver Creek Hows soutlieast, and is clianicterized i»y n hariied 

 dr;iina;H' iiatteni. Tliis draiiia.ue is almost wliolly in tiie Kiiol)sloiie rocks, 

 (tidy tlie loiij,'. toii},Mie-like. inter-stream tracts S(M) feet or more in elc\a- 



tion are capix'd iiy tiie Ilarrodsiiur.ir. Tlic slojies are steep and w led. ami 



are ((iiite ciiaracteristir (d' Knolistone t(ipo,i,'rapliy w liei-e it is in a mncli 

 disst'cted condition due to minor sticam development. 'I'lie uplands iic- 

 twoen Pekin and .Martinslniri; liaxc a t.\pical surface exi>ression of tlic 

 overlyin,!? Harrodslturj;. Tlie inter-stream tract east of .Marrinslmrt: readies 

 an elevation of about 950 feet, and is expressive of a renniani of the uplifted 

 Tertiary peneplain, heiiifi capix'd Ity Tertiary fiiavels and sand. 



The valley of Muddy Fork of P,lue Itiver at I'ekin has an elevaticm of 7(»(i 

 feet, and .seems to he in a graded comlition. In the next fifteen miles tiie 

 valley descends 100 feet, beiujj approximately at an elevation of <;u(> feet at 

 Frederick^bur};. Drainage from apiiroximately forty sipiare miles Hows 

 past Pekin. Muddy Fork of Silver ("reek heads in a niunher of steeii ravines 

 a short distance southeast of Pekin. These ravines are sharply trenched 

 below the general level of the upland. Starting from an elevation of T.'U) 

 feet in a broad, valley-like sag. a mere gravel and silt terrace above Blue 

 River valley at Old Pekin. marking the lowest part of the divide be- 

 tween the two stream systejiis. one may make a rapid descent into Muddy 

 Fork of Silver Creek. A descent of 1(K) feet is attained in the first nnle. and 

 within one and one-half miles the elevati(m is down to GOO 

 feet. This is the elevation of Blue River fifteen miles below Pekin. At 

 Borden the valley of Muddy Fork of Silver Creek is down to an elevation 

 of 560 feet. The stream here has dcAeloped a fairly wide, flat valley and 

 is in a graded condition. 



The barbed drainage pattern of Muddy Fm'k of Silver Crei'k is a result of 

 stream piracy. The parent stream of the present Muddy Fork of Silver 

 Creek was a small stream flowing down the eastern face of the Knobstone 

 scarp vei'y similar to numerous others of the pre.sent time. Back-slope 

 streams of the cuesta flowed westward from the crest of the escarpment. 

 The position of the parent stream of INIuddy Fork of Silver Creek does 

 not appear to have been more favorably located for its development of head- 

 ward erosion than many streams of the pre.sent along the escarpment. ISut 

 for s<mie reason it has succeeded in capturing practically the entire stream 

 system of a large tributary that formerly flowed northwest and emptieil 

 into Blue River at Pekin. It would appear that after having once broken 

 through the divide near the crest of the escarpment ftirther capture of the 

 lower tributaries followed in relatively (piick succession. 



The drainage direction of the tributaries t)f Muddy Fork of Silver Creek 

 coming in from the south between Borden and Broom Hill suggest that a 

 single stream flowed to the northwest one time through sections i;>. 12 and 

 into section 1. and that this unit of drainage has been broken Tip by the 



