Geologists' Association. 285 



tlie larger valleys having even in glacial times been completely filled with ice, and 

 deprecated judging of these questions from diagrams, in which the horizontal and 

 vertical scales were different. He repeated that the original large valleys were in his 

 mind of great antiquity, hut all rather due to erosion in some form or other than to 

 any internal disturbances of the strata. They were also to a great extent cut out 

 before the last glacial period. He liad been much gratified to find that, after so many 

 years of opposition, the result of Prof. Gastaldi's mapping of the country on which 

 he had founded his own opinions had been to bring the Professor round to the adop- 

 tion of the same conclusions. 



Mr. Blanford added that in the Neilgherries in India, and in Abyssinia, he had not 

 been able to trace any ice-action whatever, and there also he had not seen any cirques ; 

 and, moreover, there were no lake-basins. He was therefore compelled to connect 

 both lake-basins and cirques with the existence of glaciers. 



Mr. Campbell of Islay, referring to that portion of the paper in which the author 

 alluded to partial subsidence and ilexure to account in some degree for the basins of 

 the alpine lakes, described the Thingvalla lake in Iceland. That hollow is over six 

 miles wide, and for a length of more than twenty miles clearly is the result of fracture 

 and subsidence of the crust formed upon a great lava flood. Mr. Campbell pointed 

 out that the alpine hollows were not like this Icelandic subsidence, and attributed 

 them to erosion, not to subsidence and flexiu'e. Subsequently the author said that he 

 attributed the valleys to erosion. ' 



The President thought that Mr. Bonney's paper as to the formation of these par- 

 ticular lakes had not been answered. It seemed to him that what had been said as to 

 the filling by ice of the valleys with cirques at the sides did not in any wi*y imply 

 that the valleys had been formed by the action of ice. In the case of the Konigsee 

 the vast precipice at the end seemed especially an instance of a cliff that might have 

 existed in preglacial times. lie thought that the author's contention that such pre- 

 cipices could not have been formed by the action of glaciei's was substantiated. At 

 the same time he would not maintain that glaciers could not excavate basins, but 

 denied their power to excavate deep basins with highly inclined sides. He wished 

 that more attention had been paid to the stratigi'aphical features of the rocks in which 

 the lakes were excavated. He cited Mr. Kinahan as having stated that the greatest 

 depths of Loch Lomond coincided in position with faults which could be observed in 

 the surrounding country. lie differed from Prof. Ramsay as to the preponderance of 

 lakes in regions which have been glaciated, and thought they were more closely con- 

 nected with the configuration of hilly countries, which was by no means of necessity 

 connected with glacial erosion. 



Prof. Ramsay doubted the completeness of Mr. Kinahan's observations. As to 

 cliffs surrounding lakes, he by no means thought that they were now in the same con- 

 dition as when the glaciers retired. Sucli clitis were in fact escarpments working back 

 and undergoing constant change. He could not understand any one acquainted with 

 regions that had been glaciated, as, for instance, Labrador, not connecting the prodi- 

 gious number of lakes that prevailed with the action of the ice which once covered 

 the country. The longer axis of the lakes in nearly all instances coincided with the 

 general direction of the flow of the ice ; and by itself alone this circumstance afforded 

 great support to his views. 



Mr. Boiuiey, in reply, pointed out that he had never denied that ice might once 

 have occupied the bottom of cirques, and even have excavated some of the rock- 

 basins. What he wished to maintain was the necessity of drawing a distinction 

 between primary and secondary causes of the configuration of the country. He 

 thought that the operation of secondary causes had been overrated, and wished that 

 more attention should be paid to the circumstances of the particular lakes to which 

 he had called attention. 



Visit of the Geologists' Association to Banbury. — April 14th-17th, 1S73. — 

 Upon the recent visit to Banbury of the Geologists' Association, under the 

 guidance of Prof. John Morris, F.G.S., of University College, London, and Mr. 

 T. Beesley, F.C.S., much valuable instruction was gained by the party. Upon 

 the forenoon of Monday, the 14th, the sections near the town, the Lower 

 Middle Lias of Draper's Road, and the brickyard in Green Lane were inspected, 

 and in the afternoon a more extended excursion was made. At Twyford 

 "Wharf brickyard (Lower Middle Lias), the Ammonttes margaritatus beds, con- 

 sidered by Mr. Beesley (who will be remembered as the author of the "Geology 



