234 Geological Society : — 



surface was described as consisting of nearly unfossilifcous Post- 

 tertiary deposits, immediately beneath which is an unstratified marine 

 deposit containing a great abundance of fossils, among which are 

 species of Ostrea, Pecten, and Cidaris (?). Below this deposit is a 

 succession of strata, repeated several times in the hills ; and at the 

 bottom of the series in each case is a bed of gypsum. The spaces 

 between the recurrent series are filled up with conglomerates. Be- 

 neath the gypseous series is a formation of compact limestone, which 

 rises to a height of about 1500 feet both north and south of the 

 plain of Kazirun ; its beds dip 25°, and their strike is from N.E. to 

 S.W. The author mentioned the occurrence in a gypsum quarry 

 near Kazirun of three long cylinders from 6 to 10 feet in diameter, 

 composed of the same material as the surrounding rock. He also 

 stated that he had examined several caverns in the neighbouring 

 mountains, and also the great cave at Shahpoor, but without dis- 

 covering any organic remains. 



April 9th, 1873.— His Grace the Duke of Argyll, K.T., F.R.S., 



President, in the Chair. 



The following communications were read : — 



1. " Lakes of the North-eastern Alps, and their bearing on the 

 Glacier-erosion Theory." By the Rev. T. G. Bonney, M.A., F.G.S. 



The purpose of this paper was to test, by the Lakes of the Salz- 

 kammergut and neighbourhood, the theory of the erosion of lake- 

 basins by glaciers, which has been advanced by Professor Ramsay. 

 The author premised : — 



(1) That an extensive glacier could not exist without a consider- 

 able area to supply it. 



(2) That under no circumstances could a glacier excavate a cliff 

 of considerable height (say 1000 feet) approximately vertical. 



(3) That owing to the proximity of the regions, a theory of ex- 

 cavation which applied to the Western and Central Alps ought to be 

 applicable also to the Eastern Alps. 



He then proceeded to examine a number of lakes in detail. 



The Konigsee lies in a remarkably deep, steep-sided valley, ter- 

 minated by a cirque, with cliffs full a thousand feet high, and has 

 no large supply-area behind. 



The Hallstadtersee is similarly situated, has a cirque at the 

 head, and two lateral valleys nearly at right angles to the lake, up 

 which arms of it have formerly extended. These are not likely to 

 have furnished glaciers which could have excavated the lake ; and 

 above the cirque there is no large supply-area. 



The Gosauthal consists of lake-basins separated by valleys of river- 

 erosion. 



The Fuschelsee and Wolfgangersee, on the south side of the 

 Schafberg, are separated by a narrow sharp ridge of hills, incapable 

 of nourishing glaciers large enough to grind them out ; there are 

 no signs of glaciers from other directions having eroded them. 



The Mondsee and Attersee (once one lake) on the north lie 

 under the steep cliffs of the Schafberg, which could not have nou- 

 rished a large glacier ; and the ridge of the Schafberg is too sharp 



