File:The Quarterly journal of the Geological Society of London (12734028493).jpg

396 J. G. G00DCHILD ON THE CARBONIFEROUS CONGLOMERATES
less conglomeratic, and subordinate beds of limestone, which are
similar in lithological character to those in the Ash-Fell sections.
Some sandstones about the middle of this series may be seen in
the railway-cutting in the village of Shap.
" c." The Sandstone series is succeeded by a variable thickness of
limestone, which cannot be less than 500 or 600 feet near Ash Fell.
The beds are not usually so pure as those of the upper series

but
this lower group is nowhere split up by beds of sandstone or shale.
Near the base it becomes thinner-bedded and passes down by almost
insensible gradations into the next series.
" d." This group in its upper part consists of shales, with thin
impure limestones here and there containing grains of quartz, and
passes down through calcareous beds of a more decidedly conglo-
meratic character into a series of apple-green quartz conglomerates
and chocolate and grey shales.
These, in their turn, are succeeded without any clear line of de-
marcation by the Drift-like series of red conglomerates, sandstones,
and shales which forms the lower part of the Carboniferous base-
ment-beds here, and has always been considered the equivalent of
the Upper Old Red of other parts of the kingdom.
This basement-series is exceedingly variable in thickness and
mineral character

and, so far as it has yet been proved, it seems to
be mainly composed of locally derived materials.
These are the beds which are seen at intervals along the northern
border of the Lake-district between the Silurian rocks and the lime-
stone scars of the Carboniferous series. They are very well exposed
in Birk Beck, between Tebay and Shap Wells.
Between Poola Bridge, at the foot of Ullswater, and the village of
Dacre are thick masses of roughly stratified conglomerates belonging
to this basement-series. It is these beds which form the striking
conical hills known as Great Mell Fell and Little Mell Fell, as well
as others of the same outline between the foot of Ullswater and the
outcrop of the Carboniferous Limestone to the north.
A thickness of several hundred feet of limestone belonging to
group " c " comes on above the conglomerates in the river-Eamont
sections north of Ullswater

and it is not until we reach Yanwath,
about two miles to the south of Penrith, that we find the Ash-Fell
beds in full force.
Groups u b," " c," and "cZ" form much of the valley-ground
skirting the north-eastern border of the Lake-district

and the
generally north-easterly dip of the beds causes these lower groups
to pass beneath the higher members of the Carboniferous series and
the Permian rocks up to the great lines of disturbance at the foot of
the Pennine escarpment, where they are again thrown up to the
surface by faults which have several thousand feet of downthrow
on the south side.
About a mile and a half to the east of Ash Fell a north-easterly
line of disturbance cuts off the Ash-Fell beds on the east, and throws
in limestones belonging to the series " a ."
The strike of the beds on the western side of the faults