L. F. Spath—Ammonites from Spitsbergen. 347 
anticlines in which further to the south Cretaceous beds formed the 
crest, while the synclines were occupied by Hocene strata. These 
folds trended from north-east to south-west. It is now shown that 
these folds are markedly asymmetrical with their steep sides generally 
directed south-eastwards. The result is that the strata are not only 
thrown into regular anticlines, but dome structures are numerous. 
Naturally there is also much faulting, but not sufficient to obscure 
the fundamental folding. Perhaps the most striking feature is the 
existence of a remarkable narrow “steep zone”, an extremely 
narrow fold which traverses the Maghara range, and has been traced 
over many kilometres. This will be described in detail by the writer’s 
colleagues in the work now being prepared by them. 
Finally, an indication may be given of the general ‘theoretical 
conceptions which have appeared to arise from the most recent 
studies. The first is the conclusion that the folding which closed 
the Eocene period was north-eastward-south-westward in Sinai, 
changing to an east-west trend in Egypt itself, and perhaps again 
resuming the north-eastward direction in the Libyan Desert, for 
example, in Baharia Oasis. By this folding the deeper-seated 
granitic core was brought either near or to the surface, and may 
subsequently have acted as a buffer against which the already 
slightly folded sedimentary strata were further buckled into 
asymmetric folds under pressures continuing to act from the north- 
west. 
It is noticeable that these pre-Miocene strata both in Sinai and 
HKgypt show no trace of being affected by the series of movements 
which produced the “rift” effects. In the latter the north-west- 
ward trend of the strata is broadly developed between the greater 
fault lines (presumed to be continuous) which border the depression 
of which the Gulf of Suez occupies the centre. These faults have 
been proved with certainty at the base of the Red Sea Hills north- 
ward of lat. 26° N., and also at the feet of Gebel Ataka, near Suez, 
and Genefe, but a great deal of detailed work is still required before 
the continuous nature of the major fault can be established for the 
Egyptian side of the larger Gulf of Suez depression. On the Sinaitic 
side the major fault has been traced in much detail by Barron, Ball, 
Barthoux, and Moon and Sadek. It is hoped later to discuss the 
facts collected in relation to “ Rift” theories. 
On Ammonites from Spitsbergen. 
By Li. F. Spatu, D.Sc., F.G.S. 
(Concluded from p. 305.) 
There appears to be a good deal of variation in the Lower Triassic 
succession of the different parts of Spitsbergen, even between Ice 
Fjord and Bell Sound, at which latter Gyronites nathorsti J. Bohm 
1 This has taken place since this paper was handed in for publication, 
the writer opening a discussion on the subject at the Geological Society 
meeting of 8th June, 1921. 
