I I 8 AUTHORS' ABSTRACTS 



have been obtained from a large kame-like ridge near Smith's Falls 

 at a height above sea of 440 feet, the skeleton being reached in the 

 excavation at a point 50 feet from the outer zone of the ridge. This- 

 elevation is nearly 200 feet above the present level of Lake Ontario. 

 The indications of submergence, as seen along the sides of the Mont- 

 real mountain, are clear at elevations from 220 to 750 feet or nearly 

 to the summit. Similar high level beaches are found along the slopes 

 of the mountain ranges in eastern Quebec to a height of nearly, or in 

 places quite 1000 feet, so that it may be considered as fairly well 

 established by the latest evidence that this portion of Canada was sub- 

 merged, subsequent to the glacial period, to a depth of at least 1000 

 to 1200 feet. All the high level beaches in the St. Lawrence and 

 Ottawa valleys front directly to the open estuary of the St. Lawrence 

 River, and there were, in so far as can now be seen, no barriers to 

 interrupt the inland spread of the sea between that river and the upper 

 great lakes. The submergence mentioned would carry these waters 

 over the height of land in nearly every part of the Ottawa basin and 

 support the view now put forward that the clays which are found on 

 most of the portages at the highest levels are marine. It is probable 

 also on this theory that the Erie clays, which are very similar in char- 

 acter to those of the lower Ottawa, and unconformable to the over- 

 lying series, are the true equivalents of the Leda clays of the eastern 

 area, though this point requires further detailed examination before 

 the exact relations of the fresh water deposits of this part of Canada to 

 the underlying clays can be completely established. 



Note on an Area of Compressed Structure in Western Indiana. By 

 Geo. H. Ashley. 



As is well-known, the rocks of Illinois, most of Indiana, and part 

 of Kentucky form a basin with gently dipping slopes, and where local 

 evidences of stress are- observed they usually indicate tension. Thus 

 the faults are commonly tension or normal faults, and the joints are 

 perpendicular and open. Recently several local areas of disturbance 

 have been observed and this note is intended to call attention to one 

 of these. In this case the evidence of considerable tangential pres- 

 sure is seen in (1) overthrust or pressure faults, (2) coal beds com- 

 pressed laterally until they become several times their original thick- 

 ness ; (3) in place of perpendicular open joints, confined to the coal 



