The Dry Fall at Malham Cove

The geology in short

Malham Cove is a relict waterfall. The cliff is a near-vertical face of Great Scar Limestone, laid down in a shallow tropical sea around 330 million years ago in the Carboniferous. It was not lifted into a cliff by earth movement — it was cut by water. Meltwater from retreating ice sheets poured over this lip in enormous volume, and the plunge pool at the base undercut the rock until the fall retreated upstream, leaving the dry face you see now.

The water that carved it no longer comes this way. It sinks into the ground at Malham Tarn, nearly four kilometres north, and travels through a cave system to emerge at Aire Head springs south of the village. The river is still there. It is simply underground.

What to observe

Stand at the base of the cliff and look at the rock, not the view. The limestone is bedded — laid down in horizontal layers you can count like a stack of pages. Those beds are cut by two sets of vertical joints at roughly right angles, and it is the joints that do the work.

Climb to the pavement on top, reached by the stepped path on the eastern side. The pavement is a bare limestone surface split by those joints into blocks called clints, separated by fissures called grykes. It is a karst surface: rainwater, slightly acidic from dissolved carbon dioxide, has been widening the joints for thousands of years.

Logging tasks

To log this EarthCache, send answers to the four questions below through the message centre. Do not put the answers in your log. A photograph of yourself or your GPS at the cliff top, showing the pavement, is welcome but not required.

1. At the pavement edge nearest the cliff lip, measure the width of the widest gryke you can safely reach across. Give it in centimetres and say how you measured it.
2. Count the visible beds in the cliff face from base to lip. They are not all the same thickness. State the number, and the approximate thickness of the thickest bed you can see.
3. Grykes vary in depth. Explain in one or two sentences why grykes at the cliff edge tend to be deeper and wider than grykes further back from the lip.
4. Describe the colour and texture of the limestone where people walk. Why is this different from the freshly broken rock inside a gryke?

Access and safety

• The stepped path up the eastern side is steep and has about four hundred steps. It is not a scramble, but it is not a stroll either.
• The pavement is a protected feature inside a Site of Special Scientific Interest. Walk on the clints, not in the grykes, and keep to the waymarked route.
• The cliff edge is unfenced at the top. There are no barriers and the drop is real.
• The lower slope below the cliff collects loose rock after frost. Do not linger directly beneath the face in winter.

After the find

Gordale Scar is twenty minutes north-east: a collapsed cave system forming a ravine with two waterfalls, and a completely different chapter of the same geological story. Malham Tarn, where the water that carved the cove now sinks underground, is an hour further on foot.