PIdiKilioii >'^trr(nii /'iidci/. 251 



for il. This form of stream piracy is less froquently soon in stroains whiili 

 iirc .•ii»i(roximatoly o<iual in sizt>. Wlioro suoli cases occur it is pnihaliic 

 that one stream does not cause tlie |)irMcy by lateral pianation more than 

 the otlier, l)ut they may he mutually lesponsihle. In any case the stream 

 whicli is deeper accpiires the drainage of tlie other. Since tiiis type of 

 piracy talies place on acc(»unt of lateral planation. usually hy the major 

 more mature stream, it is here proposed that this tyix' of stream piracy 

 Ik' called planation piracy. 



A Tyiilcdl Cane of Planation stream Piraci/. 



Location and Gco(/rai)liy.— The area which affords a typical example of 

 planation stream piracy lies mainly in southern Monroe County, Indiana. 

 .V topographic map of the locality accompanies this paper. The area as 

 iMai>i)ed laps somewhat over into Lawrence County. Some seven square 

 miles are included in the mapped area, the larger part of which lies in T. 

 7 X.. K. 1 W. The portion of the area in Lawrence County lies in the next 

 township to the south. A small portion of the mapped area is included in 

 the extreme southeastern part of the Bloomington Quadrangle area. The 

 case of piracy is about two and one-half miles east of Harrodshurg station 

 and just south of the little village of Fairfax. The area is some twelve 

 to fourteen miles south of P.loomlngton. 



The area is cut by the intreiu^hed valley of Salt Creek. The valley on 

 approaching the area from the north makes an abrupt turn to the west and 

 northwest, and then again turns to the south when within three-fourths 

 of a mile of Harrodshurg station. It leaves the area trending in a 

 southeasterly direction. The.se abrupt turns in the valley of Salt Creek 

 have given rise to an upland mass of land partly surrounded by Salt 

 Creek valley. The individual drainage of the upland is by rather minor 

 streams, chief among which are Upper and Lower Cut-off creeks. These 

 streams are not more than two miles in length. Clear Creek which heads 

 near Bloomington enters Siilt Cx'eek near the southwest corner of the 

 mapped area. 



The area is rather sparsely .settled and most of the steeper slopes are 

 wooded. The gently rolling upland area and the broad valley of Salt Creek 

 are under cultivation, but no part of the area is attractive from the stand- 

 point of agriculture. 



Topof/raphj/ and Relief. — The topography is shown specifically upon the 

 accompanying topographic map which has been prepared to show the out- 

 standing topographic features and their relationships. The area has a max- 

 imum relief of slightly over 250 feet, extending from the valley of Salt 

 Creek which has an elevation of about HOO feet to the higher parts of the 

 upland which reach an elevation of 750 feet or slightly more above sea 

 level. Towards the east side this maximum relief of 250 feet is attained 

 immediately between the valley and the upland. The chief topographic 

 feature is the deeply cut. but flat-bottomed valley of Salt Creek. This valley 

 ranges in width from al)out one-fourth of a mile to a mile. In places this 

 valley is flanked by terraces which are from 10 to 40 feet in height above 

 the i)resent flood-plain. For the most part the upland rises abruptly from 

 the valley floor with an ascent varying from 125 to 250 feet. The upland 



