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



Eeports on the marine levels have been made by Chalmers and Gold- 

 thwait. Examination of several districts has been made and the writer 

 is convinced that the published figures are far nnder the true summit 

 level. The conspicuous terraces and shore features and gravel bars on 

 the deltas, which have been regarded as initial or summit features, are 

 much inferior. The summit deltas of the streams are far iuland in the 

 deep valle3's and have not been reached or are unrecognized as sealevel 

 deposits. Positive shore features, even in the open valley, have been 

 located by the writer at altitudes above any published figures. 



The tributary valleys on the north side of the Saint Lawrence give no 

 excuse for any question as to glacial w^ater levels. It is mi fortunate that 

 east of the Saguenay (Tadoussac) the north slope of the great valley is 

 so inaccessible and all in forest. The south-fiowing streams must have 

 left good bench-marks of the summit sealevel. Passing up the Batiscau 

 Eiver, on the railroad from Quebec to Lake Saint John, good delta plains 

 are found up to 1,010 feet, and over the height of land near Roberval at 

 more than 1,000 feet. These levels give approximate location for the 

 contour of 1,000 feet. The only features which are not in accord with 

 the map are the terraces of a heavy delta at Sainte Marguerite, some 40 

 miles northwest of Montreal. The theoretic marine level is here al)out 

 880 feet, but the delta plain at the railroad station is 970 feet, with other 

 terraces in view 10 to 15 feet higher. There is some complication here 

 which study will probably explain. 



The north wall of the Saint Lawrence Yalley between Quebec and 

 Tadoussac, especialN in the district of Saint Irenee and Murray Bay, 

 exhibits conspicuous and unmistakable terraces and water lines up to 800 

 to 900 feet, seen from the river steamers. At Murray Bay these standing- 

 water inscriptions were measured with aneroid up to 785 feet, and others 

 appeared in the distance as much as 1 00 feet higher. 



The south (southeast) wall of the valley was examined from River 

 Quelle to Mont Joli, with satisfactory evidence of high-level waters, but 

 without definite measurements. One of the most convincing features is 

 a remarkably extensive delta south of Trois Pistoles, with such extent and 

 relation to the general topography as to rule out glacial waters. , In this 

 great delta the massive clay reaches up to 450 feet, with broad plains at 

 500 feet and higher terraces in distant view, estimated at 200 feet more. 

 The theoretic summit level here by the adjusted isobases is about 715 

 feet (plate 11, figure 1). 



Over the divide, in the southward drainage of Saint John River, is 

 Lake Temiscuata, an expansion of Madawaska River. By the south side 

 of the lake at Cabano station are two heavy gravel bars with altitudes 575 



