SECTIONAL TRANSACTIONS.— C. 547 



sufficiently well defined by the isogams to permit the conclusion that the embavment 

 IS a gully approximately 70 yards wide and with a possible depth of 150 to 200 feet 

 from the surface. A bore in this neighbourhood shows 114 feet of drift. So far the 

 gravitational survey is in agreement with the facts known from boring and presented 

 in diagrammatic form in the map in the Glasgow Memoir. This map shows north of 

 Drumry a deep branch of the buried Kelvin valley stretching east and west. The 

 isogam map, however, suggests the conclusion that the valley running from the east 

 takes a right-angled bend to the south, while in the crook of the bend a westward- 

 pointing bay has been formed. Owing to the unsuitable nature of the country 

 north-west of Drumry there is no gravitational information available as to the 

 westward extension of the buried valley, though there is mining evidence, one mil© 

 west of Drumry, that the drift reaches 140 feet below O.D. If such an extension 

 exists, the results so far obtained by the Eotvos balance indicate that it will be at a 

 considerably higher level than the floor of the valley in the Drumry bend. 



Dr. G. Slater. — The Structure of the Drumlins on the Southern Shore of 

 Lake Ontario, New York State, 1924. 



The central-western part of New York State, south of L. Ontario, contains the 

 finest development of drumlins in the United States. Within an area of 5,000 square 

 miles there are at least 10,000 drumlin-crests, 6,000 of which are indicated on the 

 fifteen topograpliical maps of the area. Scores of these drumlins are a mile in length, 

 but only two exceed an elevation of 200 feet, the average height of -thirty-one of the 

 highest being 150 feet. The drumlins radiate from the south-eastern shore of the 

 lake, and attain their greatest development in the adjacent low Ontario plain. 



The sections which display the structure to best advantage extend from Sodus 

 Point to Oswego, a distance of 28 miles. Of the score of drumlins in this stretch of 

 shore-line, eleven are of especial interest. As a rule a lower ' core ' of boulder clay 

 is overlain by stoneless clays, loams, boulder clay and occasionally lenticles of sand, 

 showing ' concentric-bedding.' The drumlins are therefore composite in character' 

 the two facies of deposits representing progressive stages of construction. The 

 genesis of the structure appears to be as follows : In each of the drumlins the stranding 

 of the lower boulder clay, of roche-moutonnee outline, led to a local pressure gradient 

 and the plastering of later material over, and against, the flanks of the ' core,' movement 

 being along thrust-planes. The area between the flanks of adjacent drumlins 

 functioned as a zone of tension. This structure agrees with the principles of glacial 

 tectonics described by the author at previous meetings (Brit. Ass. 1924, '26, '27). 

 The expenses of this investigation were defrayed by a grant from the Sladen Trustees," 

 1924, for which the author expresses his thanks. 



Mr. G. Ross. — Glacial Phenomena in the Douglas Valley. 



Recent survey work in the Dojglas Valley and the adjacent ground has in the 

 main confirmed the work of the earlier investigators in this region. It has further 

 shown that the oldest glacial deposits, the shelly boulder clay of the western, and the 

 Highland boulder clay of the north-western parts of the area are overlain by the 

 Southern Upland Drift. 



The carry of the erratics of Cairn Table Sandstone, Spango Granite, and 

 Crawford John essexite show the main Southern Upland ice-movement to have been 

 north and north-east in this region. Subsequently the direction of this ice-movement 

 was determined by the grade of the Douglas Valley. 



The trend of glacial striae within the valley and of glacial drainage channels alon" 

 its sides indicate the existence of a valley glacier originating in the wide amphitheatre 

 bounded by the heights extending from Cairn Table to Spango Hill. 



The fluvio-glacial deposits of the Douglas Valley are due probably to deposition 

 by melt-waters along the margins of the shrunken valley glacier at a late stace in its 

 <lissolution, when drainage into the Clyde Valley was still blocked by ice. 



Mr. J. B. Simpson. — The Valley Glaciation of Loch Lomond. 



In the Loch Lomond district the terminal moraine of a large valley glacier has been 

 traced b\' the writer almost continuously for fourteen miles, from Auchineck west- 



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