188 H. L. FAIRCHILD POST-GLACIAL UPLIFT OF N. E. AMERICA 



gence or^ conversely, the height of the subsequent uplift and the limits of 

 the affected area have not been determined. In recent years there has 

 been a tendency to minimize the diastrophic movement and even to deny 

 its occurrence along the south border of the glaciated territory ; but Pro- 

 fessor Shaler believed that Marthas Vineyard had been submerged 300 feet 

 and Mount Desert 1,300 feet, and several eminent geologists have found 

 abundant and positive proof of Pleistocene submergence of the lower 

 Hudson Valley and New Jersey (see number 81 of the bibliographic list, 

 page 288). The radical difference^of opinion on a subject open to direct 

 observation is a problem in psychology. 



Canadian geologists have- recorded many localities of marine fossils at 

 high altitudes in the Saint Lawrence and Ottawa valleys and eastward, 

 Avith the other attendant evidences of standing water. Similar evidence 

 is abundant in ISTew England, but at less altitude. This proof of deep 

 submergence while the Labradorian ice-sheet was passing off led the 

 earlier geologists to overemphasize the w^ork of floating ice and icebergs 

 in the explanation of glacial phenomena. The later recognition that 

 most glacial features are the effects of land ice has resulted in the com- 

 parative neglect, es]3ecially by geologists of the United States, of the fact 

 of deep marine submergence. AVith emphasis on direct glaciation, we 

 have neglected the observations of the "diluvialists" and "icebergists" 

 and have minimized the effects of oceanic waters. However, it must be 

 admitted that in the deep marine waters of the valleys of Canada and New 

 England the students of half a century ago had good basis for the theory 

 of iceberg agency. 



In the recent examination of eastern Canada and New England^ the 

 study has been systematically extended from an area in which the post- 

 Glacial uplift had been well determined. The Hudson, Champlain, Saint 

 Lawrence, and Connecticut valleys hold a clear record of the earliest and 

 deepest sealevel waters and afford a long base-line for the extension of the 

 isobases. In the Hudson-Champlain depression is inscribed a record of 

 Pleistocene history for all the time during which the waning Labradorian 

 glacier lay on any part of the United States. On this meridian the tilted 

 uplift has been determined as over 800 feet on the north boundary of 

 Vermont. The results of previous study are on record in papers numbers 

 81 to 85 (see bibliography), but the detailed description of the critical 

 features in New York is awaiting publication by the New York State 

 Museum. 



2 The Avriter makes si'ateful ackno\vleflc:m(mt of financial niVl from llie research ftiud 

 of the Americau Associatiou for the Advaucemeut of Science. 



