392 
The Geological Survey of England and Wales. 
glomerate which forms the base of the Gault seems to correspond to 
the Carstone of the Isle of Wight, which has again been correlated 
with the Folkestone Beds. The suggestion, therefore, made long 
ago, that a portion of the Folkestone Beds should be included in the 
Upper Cretaceous group receives support. In the Weymouth 
peninsula the principal alterations relate to the mapping of the sub- 
divisions of the Chalk as far westward as they are recognisable, and 
in the tracing of subdivisions of the Corallian rocks which are locally 
developed near Weymouth. The numerous faults of the area have 
also been followed with a minuteness of detail which was impossible 
on the old one-inch map. An interesting result has been obtained 
from this work. The faults and foldings of the strata, though nearly 
all agreeing in direction, were found to have been formed at two 
different periods, the one set affecting the Oolitic rocks, but passing 
under the Upper Ci’etaceous strata without disturbing them, the 
other breaking through both Oolitic and Cretaceous rocks alike. 
The older movements took place between the deposition of the 
Upper and Lower Cretaceous strata, while the later set were 
obviously contemporaneous with the Isle of Wight and Isle of Pur- 
beck monoclines, which are believed to be of Miocene age. In more 
than one case faults of the later age cross obliquely the older lines 
of fracture, producing a complication which could only be worked out 
on the large-scale map. The break at the base of the Gault mentioned 
above seems to have been due to the faulting and upheaving of the 
rocks during the first of these periods of disturbance. It becomes 
here a most pronounced unconformability, and the Gault, with a 
thin conglomerate at its base, passes over the edges of the Wealden, 
Purbeck, and Kimmeridgian rocks in rapid succession. 
In the country around Bedford important changes have been 
made in the maps. The Oxford Clay is now known to cover a large 
area of Great Oolite to the north-west of Bedford. In the original 
survey this clay seems to have been taken as part of the Boulder 
Clay by which it is generally covered, the underlying Kellaways 
Sands having been also taken as drift. But the detailed mapping 
of the drifts of the district has enabled Mr. Cameron to make the 
correction. Another improvement in the map is the mapping of the 
Cornbrash over areas where it was formerly supposed to be absent. 
This bed has now been ascertained to have a continuous range from 
the coast of Dorsetshire to Yorkshire. A smaller but not unim- 
portant alteration relates to the exposures of clay beneath the Great 
Oolite near Olney. These were formerly considered to be Lias ; but 
Mr. H. B. Woodward has now shown that, although Upper Lias is 
present at no great depth, the strata laid bare at the surface are the 
Upper Estuarine Clays of the Great Oolite series. 
Triassic . — Advantage has been taken of the prosecution of the 
Drift Survey across the salt districts of Cheshire and Staffordshire 
to obtain much additional information regarding the Triassic rocks, 
especially with reference to their industrial aspects. Mr. C. E. 
de Ranee has collected 208 sections of the salt-deposits at Northwich, 
Middlewich, Winsford and Lawton. He has likewise reduced some 
