334 Obituary—M. René Fourtau. 
uplands (Ardennes). Relation of topography to geological structure ; 
the northern lowlands a Paleozoic platform covered by Cretaceous 
and ‘Tertiary; the Namur Basin a Devono-Carboniferous 
synclinorium; the Ardennes also a Devono-Carboniferous 
synclinorium with a Silurian ridge on the north and Cambrian 
“ massifs? on the south. ‘Geological history of the country ; pre- 
Devonian rocks; the great Devonian transgression. The late 
Carboniferous (Armorican or Hercynian) folding. The Ardennes— 
London ridge and its influence on Mesozoic and Tertiary strati- 
graphy. The Cretaceous transgression. The Anglo-Franco-Belgian 
Basin of Eocene times. Pliocene: Diestian and Lenham Beds. 
Tectonics — three great epochs of folding; late Silurian, late 
Carboniferous (Armorican), Cretaceo-Tertiary (Alpine). The Brabant 
stable block and its influence on Armorican folding. Some notes on 
the districts to be visited. 
“Possible causes of Mountain Folding.” By A. J. Bull, M.Sc., 
F.Inst.P., F.G.S8. 
Salient features of the earth’s crust, the lines of folded mountains 
bordered by large regions of no compression. Occasional evidence 
of tension. Fjords. Fissure eruptions. 
Explanations of folding by (a) the assumption that the earth is 
cooling, (b) periodic contraction of the earth due to molecular 
rearrangement, (c) penetration of oceanic water into the crust, (d) 
loading of the crust by terrigenous deposits and other hypotheses. 
Difficulties of accepting some of these explanations. 
Other factors to be considered. Radio-active content of rocks. 
Isostatic adjustment. Strength of the crust. Crustal tides. 
Probable condition of the earth’s interior. Heterogeneous com- 
position of crust. Suggested explanation of folding as being due to 
underdrag of crust by convective currents in the asthenosphere, 
produced by local heating and expansion, enhanced possibly by 
changes of crystalline form in the cooler parts. 
OBITUARY. 
M. Rene Fourtau. 
By the death of M. René Fourtau, paleontological science has 
sustained a severe, and in some respects, irreparable loss. Born on 
26th February, 1867, he was mainly educated at the College of 
St. Caprais, Agen. He came to Egypt in 1888, and was associated 
with the railway administration for some years, being for a while 
in control of boring operations undertaken in the Delta in connexion 
with bridge construction. He early became interested in the 
problems of Egyptian geology, and came into contact with leading 
paleontological authorities, such as M. de Loriol, 
When the Geological Survey of Egypt was founded in 1896, 
