VOL. XVI.(3) |. EXCURSION—MALVERN HILLS 
action exhibited by the exposure near at hand.* 
In the quarries of the hills are gneisses of many 
types, the most striking being parallel banding of 
granite in diorite. The rock-pressure which ori- 
ginated this structure, combined with chemical 
changes also, generated new minerals, the most 
important being black mica, white mica, and silky 
mica, with secondary quartz and felspar. A good 
example of a banded gneiss (granite in diorite) 
was shown in a quarry at The Wyche, and it 
was seen that this gneiss passed without a break 
into a mixture of granite and diorite in which there 
is no parallel structure. On the ridge above, Dr 
Callaway called attention to an augen-gneiss 
formed out of granite only, the ‘‘eyes” in the 
rock being merely cores of granite which had 
resisted the shearing force which had produced 
foliation in the rock surrounding the cores. In 
the latter part of the Carboniferous Epoch the 
Malvern crystalline rock-mass was affected by a 
force from the east, which thrust it laterally over 
the Silurian strata that lie along the western base 
of the ridge, and bent them backwards, so that 
they now appear to dip below the Archzan. 
The overthrust Silurian, consisting of Lower 
Wenlock Shale, is shown in the western slope 
below The Wyche. The country to the west of 
the Malvern ridge at its northern end consists 
of Silurian strata, mainly composed of limestones 
and shales. The limestones resisted the forces 
of denudation better than the shales, and formed 
upstanding ridges running parallel to the Malvern 
range—that is, north and south. Eastward, the 
Liassic and Triassic strata occupying the valley of 
the Severn are brought into contact with the 
Malvern mass by a great downthrow fault, while 
the Malvern ridge in its turn is faulted against the 
Silurian rocks lying to the west. 
Mr C. Upton, whilst not assuming the pos- 
session of any special knowledge on the subject, 
asked whether it might not have been possible 
for the pressure, to which reference had been 
made, to have come from the west rather than 
the east. Having listened to what Dr. Callaway 
had said respecting the bending of one formation 
Se. 
| SEVEN SPRINGS 
LECKHAMPTON HILL 
N. W WaLVERN HILLS 
INFERIOR 
fi} 
OOLITE 
| UPPER LIAS 
MIDOLE LIAS 
CHELTENHAM 
BERROW HILL 
217 
-- datum 
LOWER LIAS 
I ayy 
Ordnanee- 
RHATIC 
KEUPER 
ARCHEAN 
over another, it occurred to him that perhaps as much might be said 
in favour of pressure from the west as from the east. 
1 The reader is referred forsfurther information on the Malvern rocks to Dr. C. 
Callaway’s papers :—Quart. Journ. Geol. Soc., vol. xlix (1893), pp. 398-425; ézd, vol. 
xlv (1889), pp. 475-503; 62d, vol. xliii (1887), pp. 525-536; Proc. Cotteswold Nat. F.C., 
vol. xii., pt. 3 (1898), pp. 239-247; Proc. Liverpool Geol. Soc,, 1895-96, p. 453. [Ep.] 
