408 
THE LAST DECADE. 
fact that the dehris of the upper dales has been removed and deposited 
at a lower level of several hundred feet, all point to this agency as 
the grand feature of their formation. He ventures an opinion that 
the origin of the dales is due to a series of inequalities or synclinals 
of the surface shown by the fact that the beds of chalk repeatedly 
dip in different directions, though the general dip of the mass is 
towards the south-east. This paper was followed, in 1885, by one 
read by Mr. J. R. Mortimer, who endeavoured to demonstrate that 
the valleys were due in the first instance and in a great measure 
to cracks or fissures caused by the elevation of the beds of chalk 
into dry land, and that since the commencement of that eleva- 
tion those gaping cracks have been widened and acted upon by 
sub-marine, sub-jerial, and all the denuding and abraiding forces 
of nature, some of which are still at work. Mr. Mortimer cites 
a number of instances in which faults have been proved to exist 
at the bottom of the dale, for example, that of Thixendale, Backdale, 
Fairydale, and near Wharram Station. The contortions in the chalk 
at Flamborough Head were described by Mr, James W. Davis, in a 
paper explanatory of photographs issued to the Society in the same 
year. The contortions which are exhibited in the cliffs at Staple 
Nook, a small bay in the Bempton Cliffs, extend about 300 yards, and 
are more than 400 feet in height. The strata are bent and doubled 
into a series of anticlinals and synclinals, and in one place are broken 
and faulted. The action causing these contortions probably took 
place long after the deposition of the chalk when it had become hard 
and consolidated, the pressure in all probability having been applied 
laterally. In 1882, the Rev. Mr. Cole contributed a paper on the 
White Chalk, in which he contests the opinion that the chalk was 
deposited in an area forming a deep sea. Europe, before the deposition 
of the chalk, which extends over a Jarge part of its surface, had 
certainly attained a continental form, and it is probable that a slight 
depression of the surface allowed the waters of the Atlantic to pour 
over its central portion. The constant flow eastward of a stream, 
similar to the Gulf Stream, would supply an enormous quantity of 
foraminifera, which, by their decay, aided by the disintegration of 
coral reefs, caused the accumulation of calcareous sediment known 
