With several members of the Yorkshire branch we set of from
the centre of Settle on what was
to be a pleasant summer day. We first visited Langcliffe Quarry, where Paul
Wyre told us about the
lime industry and in particular the substantial remains of a Hoffman Kiln. This
type of lime kiln mass
produced qicklime (CaO), using a continuous burn process to heat the limestone.
The structure is huge
and Steve Darlington is shown in the photo below preparing to take a photograph.
The Hoffman lime kiln with Steve Darlington.
This is the photograph that Steve took, which shows just how
large the kiln is. A number of chamber
entrances may be seen.
Steve's photo.
Alan Diggles then showed us outcrops next to Dry Rigg Quarry.
In this vicinity, the rocks are of
Silurian age, which form one of a series of inliers along the North Craven Fault.
Inspecting the Silurian rocks.
Excellent examples of flute casts can be found in the turbidite succession.
Alan Diggles shows us the flute casts.
The steeply dipping Silurian beds are capped unconformably by
Carboniferous limestone, as shown
in the photograph below.
Dry Rigg Quarry
We then went to the third location where we had a quick look
at Malham Tarn, which exists
in a predominantly limestone area because it is underlain by slaty Silurian
rock similar to that
at Dry Rigg Quarry.
Malham Tarn
Walking along the outflow from Malham Tarn, we found that it
disappears at a place known
appropriately as Water Sinks. This point marks the approximate edge of the North
Craven fault
and the underlying rock becomes Great Scar Limestone.
Water Sinks
We followed the dried out course of the outflow which can carry water in very wet periods.
Watlowes
The day ended at Malham Cove. After having a look at the limestone
pavement that tops it,
we descended and observed the cliff, which had been formed by the outflow in
glacial times.
The river here is not the Malham Tarn outflow.
Malham Cove
Written by Mike Woods. Photographs by Mike Woods and Steve Darlington.