Holywell cliff fall caused by 'fault in rocks'

A beach cave collapsed due a "fault in the rocks", a geologist has said.

The collapse at the historical landmark Holywell cave in Holywell Bay, Newquay, is thought to have occurred overnight on Saturday.

The cave, also known as St Cuthbert's Cave, on the southern cliffs of Kelsey Head featured in the BBC's Poldark series and was known for its multi-coloured rocks.

Geologist Paul Foster described the fault as "a double-edged sword" since it had caused the colourful rocks but had ultimately led to the cave's collapse, which he warned may not be over.

Foster said the rocks were about 350 million years old and lay underneath a mountain range.

He said "all of the rocks were squashed and folded" and were metamorphosed from mud to slate, which is when he said the fault would have developed.

The geologist described a fault as a line within the rock where there had been movement and the rocks on the fault line could become "fractured and broken".

He said: "One side has moved upward, the other side has moved downwards, so it's a joint in the rocks where there has been movement."

"In this case, those breaks have allowed the calcite into the rock which formed all of the minerals on the side of the cave to start with, but it also formed the weakness which has weakened the rocks and caused it to collapse, so it's sort of a double-edged sword."

The area was cordoned off on Sunday and lifeguard warning signs remained at the scene on Wednesday.

Foster said the area was still "very dangerous".

"There are two main hazards, the first being screed pile has lots of gaps in it, and you could fall down into one of those gaps.

"The second is the collapse might not be over and there might be further collapses at the top around the coast path."

Lee Griffin, surf instructor and vice chair of the Holywell Bay Surf Life Saving Club, said everybody was "really gutted about it".

"It's quite upsetting for a lot of people, it's part of the beach, it's part of the DNA of Holywell Bay," he added.

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