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. Glacial formations and drainage features of the Erie and Ohio basins. iguration of the old channel, as shown in fig. 6, will add to the force ofthese considerations. An objection to the northwestward outlet may perhaps seem to bepresented by deposits of gravel which occur along the Allegheny Valleybetween the niouth of French Creek and the mouth of the Clarion. Inseveral places, notabl) at the bends of the river at Brandon, at a point 2miles below Brandon, at Kennerdell, at Blacks (Winter Hill station), andat Emlenton, there are deposits on the face of the gorge extending fromnear the rivers

. Glacial formations and drainage features of the Erie and Ohio basins. iguration of the old channel, as shown in fig. 6, will add to the force ofthese considerations. An objection to the northwestward outlet may perhaps seem to bepresented by deposits of gravel which occur along the Allegheny Valleybetween the niouth of French Creek and the mouth of the Clarion. Inseveral places, notabl) at the bends of the river at Brandon, at a point 2miles below Brandon, at Kennerdell, at Blacks (Winter Hill station), andat Emlenton, there are deposits on the face of the gorge extending fromnear the rivers Stock Photo
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The Reading Room / Alamy Stock Photo

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2AGE9TF

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7.1 MB (571.1 KB Compressed download)

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1286 x 1943 px | 21.8 x 32.9 cm | 8.6 x 13 inches | 150dpi

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. Glacial formations and drainage features of the Erie and Ohio basins. iguration of the old channel, as shown in fig. 6, will add to the force ofthese considerations. An objection to the northwestward outlet may perhaps seem to bepresented by deposits of gravel which occur along the Allegheny Valleybetween the niouth of French Creek and the mouth of the Clarion. Inseveral places, notabl) at the bends of the river at Brandon, at a point 2miles below Brandon, at Kennerdell, at Blacks (Winter Hill station), andat Emlenton, there are deposits on the face of the gorge extending fromnear the rivers edge up to heights of 200 to 300 feet or more above thestream. The occurrence of this gravel at low levels can not be accountedfor by creeping or landslides, since in some places, notably at Kenneidelland 2 miles below Brandon, the gravels show clearly by their situation andbedding that they have not been disturbed since the stream deposited them.We are not, however, reduced to the one interpretation that the valley had U. S. GEOLOGICAL SURVEY MONOGRAPH XLI PL. VIII. Prom Second Geological Survey orPennaylvaJiiaRejiorHn. PL 18.1880J.E LESLEY, State Geologist. OLD MIDDLE ALLEGHENY DRAINAGE SYSTEM. 137 been opened to its present depth and had southward drainage before thebeginning of the glacial period. These gravels are in every observedcase situated on sloping points on the inner curves of sharp bends in theriver. At such places a stream works outward as well as downward, therebeing erosion on the outer curve and liability of deposition on the innercurve. It is to be expected, therefore, on the hypothesis that the streamhas greatly deepened its channel since the ice invasion, that such depositsshould be present, and these deposits do not, it is thought, necessarilyoppose the hypothesis of former northwestward drainage, nor that of greaterosion since the beginning of the Glacial epoch. Concerning the line of discharge for the Middle Allegheny from nearMeadville to the Lake Erie

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