Bulletin - New York State Museum . district aremore steeply inclined to the south than are the earlier water levelsbetween New York and Albany. The reversed direction of tilt-ing of the land to the south which has since taken place wouldproduce the observed discordance if the land were tilted moreand more to the north while the glacial lake advanced northwardin the face of the retreating ice sheet. Evidence from the northern face of Covey hill [see pi. 25]. Asis shown in more detail in ilie report on the Mooers quadrangle,the northern face of Covey hill is a critical field for the study ofwate
Bulletin - New York State Museum . district aremore steeply inclined to the south than are the earlier water levelsbetween New York and Albany. The reversed direction of tilt-ing of the land to the south which has since taken place wouldproduce the observed discordance if the land were tilted moreand more to the north while the glacial lake advanced northwardin the face of the retreating ice sheet. Evidence from the northern face of Covey hill [see pi. 25]. Asis shown in more detail in ilie report on the Mooers quadrangle,the northern face of Covey hill is a critical field for the study ofwater levels in the upper St Lawrence valley. Mr Gilbert appearsto have been the first to perceive this point and was I believe thefirst to make critical though unpublished observations on thisinteresting locality. Covey hill and the Gulf are localities atwhirli most lines of evidence presented in this paper come to afocus; hence the various features which are there presented willbe found often under sepai-ate headings in this O > 4-1 oo GO 0) bX) pO O) ANCIENT WATER LEVELS OF CHAMPLAIN-HUDSON VALLEYS 163 As regards the position of the ice front on the northern flankof the hill, it should be stated that as noted by Mr Gilbert thehighest well defined and clearly demonstrable beach along thisline is at 450 feet above sea level. But above this beach occurs asuccession of rude terraces with coarse and often rather angularblocks from just above the 450 foot line to about 570 feet. Someof these are lines strikingly level for long distances; yet otherparts of this system are inclined. All of them and particularlythe highest show considerable cutting into the till cover of thehill. A till cliff is conspicuous at a number of localities on thenorth side of Covey hill near the 570 foot level according to myaneroid readings. Waterworn pebbles and characteristic beachwall structure are apparently absent. Mr Gilbert according tohis notes in his search for beaches ruled all these high
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
