Allegany County . interesting example is found iu Braddock Eun, of theWills Creek system. The period of lower level which permitted Town Creek to carvesuch a wide, evenly-floored valley, gave Wills Creek similar oppor-tunity. At that time, however, Braddock Kun did not pursue itspresent course northeast from Allegany Grove, but ran eastward tojoin Wills Creek or perhaps the Potomac, after cutting across Wills^lountain through a gap now seen about one mile northeast of Alle-gany Grove. The present valley between Piney and Will; mountains 4-t THE PHYSIOGRAPHY OF ALLEGANY COUNTY is but the succes
Allegany County . interesting example is found iu Braddock Eun, of theWills Creek system. The period of lower level which permitted Town Creek to carvesuch a wide, evenly-floored valley, gave Wills Creek similar oppor-tunity. At that time, however, Braddock Kun did not pursue itspresent course northeast from Allegany Grove, but ran eastward tojoin Wills Creek or perhaps the Potomac, after cutting across Wills^lountain through a gap now seen about one mile northeast of Alle-gany Grove. The present valley between Piney and Will; mountains 4-t THE PHYSIOGRAPHY OF ALLEGANY COUNTY is but the successor of a \wder valley which in those days had beenworn out on the same yielding, soluble limestones and shales that aiefound there as valley-makers to-day. This former valley was due tothe work of two small streams, one (b) flowing northward emptiedinto Wills Creek just where it turned to cross Wills Mountain, theother (a) flowing southward joined Braddock Kun near where it alsocrossed the same sandstone Fk;. !,.—Drainaije about Cumberland, on Shenandoah Plain. .\t that time, both AVills Creek and Braddock Run were smallerthan they are to-day; still Wills Creek must have been the larger, andtherefore the more powerful, even then, for it had in addition toJennings Bun a considerable tributary from the north. The streamarrangement at this time was as shown in Fig. 2. When the eleva-tion occurred, as a result of which both Town Creek and Wills Creekdeepened their channels, the two streams a and b also went to work GEOLOGICAL SURVEY 45 with renewed vigor. These two tributaries were limited in theirrates of down-cutting bv the rates at which their two main streams,Wills Creek and Braddock Run, could reduce their channels. Thesuperior power of Wills Creek, due to its greater size, would soonbecome apparent, and as a result, b would have the advantage of alower outlet than a. This advantage possessed by h resulted in thegradual but continual shortening of a by th
Size: 1389px × 1799px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectf, booksubjectgeology
