[ 313 ] 



XXVII. Proceedings of Learned Societies, 



GEOLOGICAL SOCIETY. 

 [Continued from p. 231.] 



April 3rd, 1895.— Dr. Henry Woodward, F.R.S., President, 



in the Chair. 



^HE following communications were read : — 



-*- 1. ' Physical Features and Geology of Mauritius.' By Major 



H. de Haga Haig, E.E., F.G.S. 



The greater part of the surface of Mauritius is composed of a 

 volcanic breccia ; here and there lava-streams occur in the sections 

 exposed in ravines, and sometimes on the surface. The commonest 

 lavas are dolerites. 



In at least two places, sedimentary rocks occur at considerable 

 elevations ; in the Black River Mountains at a height of about 

 1200 feet a clay-slate is found, and near Midlands in the Grand 

 Port group of mountains a chloritic schist is found at an elevation 

 of about 1700 feet, forming the hill of La Selle ; the schist is much 

 contorted, but seems to have a general dip to the south or south- 

 east. 



Evidence of recent elevation of the island is furnished by masses 

 of coral-reef and beach coral-rock standing at heights of 40 feet 

 above sea-level in the south, 12 feet in the north, and 7 feet on the 

 islands situated on the bank extending to the north-east. 



The author gives full details of the physical geography of the 

 island, including the nature and composition of the mountain- 

 ranges, the depth of the ravines, the occurrence of caverns in the 

 lavas, and the character of the coral-reef surrounding the island. 

 Information is furnished concerning the neighbouring islands, and 

 reference made to the possible former existence of an extensive 

 tract of land at no great distance from Mauritius. 



2. ' On a Comparison of the Permian Freshwater Lamelli- 

 branchiata from Russia with those from the Karoo Formation 

 of Africa/ By Dr. Wladimir Amalitsky, Professor of Geology in 

 Warsaw University. 



3. ' Ice-plough Furrows of a Glacial Period.' By W. S. Gresley, 

 Esq., F.G.S. 



The furrows described in the paper occur in Coal-Measures 

 of North-west Leicestershire. The author considers that they were 

 formed about the time of the Glacial Period by floating ice. 



Phil. Mag. S. 5. Vol. 40. No. 244. Sept. 1895. Y 



