. Jefferson, Berkeley, and Morgan counties, by Grimsley, assistant geologist. White, state geologist. is seen on a number ofhills at 800 feet to west of Doe Gully and southwest ofHansrote in western part of Morgan County. It is found atvarious places along the Potomac Valley, as on the hills westof Sleepy Creek, at 600 feet and also one mile east of that is seen south of Big Run and also in a series of hills south ofCherry Run at 600 feet. North of Soho, the 500-foot ridge prob-ably is this plain, and at south end of Ferrel Ridge, the levelis 600 feet. It stands at 500-foot l
. Jefferson, Berkeley, and Morgan counties, by Grimsley, assistant geologist. White, state geologist. is seen on a number ofhills at 800 feet to west of Doe Gully and southwest ofHansrote in western part of Morgan County. It is found atvarious places along the Potomac Valley, as on the hills westof Sleepy Creek, at 600 feet and also one mile east of that is seen south of Big Run and also in a series of hills south ofCherry Run at 600 feet. North of Soho, the 500-foot ridge prob-ably is this plain, and at south end of Ferrel Ridge, the levelis 600 feet. It stands at 500-foot level on the hills in the bendof Back Creek, north of Hedgesville road. It is seen at severalplaces south of Hedgesville at 600 feet and north of Nipetownat the same level. Around Martinsburg, it is marked by the500-foot hills, and the same across the valley to Harpers Ferryand the Shenandoah River. DEVELOPMENT OF STREAM VALLEYS. The rivers on an uplifted sea plain or on a peneplain passthrough i cycle of developmenl similar to that of the landforms. By analogy, this cycle is compared with the life history. WEST VIRGINIA GEOLOGICAL SURVEY. 49 of organisms passing from the period of infancy throughadolescence, maturity, to old age and death. In the earlier life of the stream as it cuts its way down-ward, the valley slope is steep. Erosion is rapid through thesofter rocks while the more resistant layers withstand the cut-ting force and remain for a time as projecting layers overwhich the water pours in rapids or falls, and the river is in itsperiod of infancy passing into the period of adolescence. Theriver is now eroding its channel deeper and deeper, and butlittle from side to side. As the valley floor approaches more nearly the level of itsoutlet, the current becomes less swift, the projecting ledges ofthe falls are brought to the general grade of the stream. Theriver can not now cut its channel downward as rapidly as be-fore and it increases the erosion laterally, widening the
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeology, bookyear1916
