HELSTON HISTORY

CLIFF EROSION AT PORTHLEVEN

Over the last 25 years the track continuing from Loe Bar Road at Tye Rock to Loe Bar itself has suffered from severe erosion.

During the late 1970`s the track was cut at the point where the last car on the right can be seen. Access to Loe Bar from Porthleven is now only achievable by footpath.

According to our eminent local Geomorphologist, Dave Davies, "the lower cliffs are predominately of periglacial "Head" - a gelifluction deposit formed during fluvial-glacial periods when the short warm summers melted the frozen permafrost covering the tundra of Cornwall and it then flowed slowly down slopes to infill Cornish valleys and over the top of cliffs. It's unconsolidated and uncemented and so easily eroded". This makes the whole area extremely susceptible to erosion of the lower cliffs by wave action from below, whilst surface water penetration causes `slumping` of the overlaying material.

The cliffs are now eroding at an alarming rate along this small stretch of coast.

The fence posts in the photograph below are situated to prevent the unwary `walker` from falling over the cliff edge at the point where the top vehicle in the above photo can be seen when it was taken in 1973.

The old track can just be made out as the straight line just below the posts.

The photograph below is taken from the end of the track nearest Loe Bar from Porthleven and is looking back at Tye Rock itself.

During the 1970`s "TYE ROCK" (Granite Building in centre) was a small hotel with a swimming pool located on the edge of the cliff. The white `pavillion` looking building is located on the edge of what was the swimming pool. Unfortunately, the cliff erosion has taken part of the pool over the cliff.

The photograph gives us an excellent illustration of the lower slate overlaid with the very soft fluvial deposits. Note how the cliff has eroded back in a semi-circular fashion, cutting into the soft sand and mud.

Photo added 19th Feb 2008

Only a few hundred metres from Loe Bar can be found one of the last WWII anti-invasion structures left along this section of the coast. Unfortunately, this TYPE 24 Pillbox is suffering from the same cliff erosion problem. The photograph below was taken looking up from the beach below and illustrates how the slate under concrete base of the pillbox is being eroded away.

At Porthleven itself drastic action by Cornwall County Council in the form of a substantial sea defence wall means that many of the threatend properties are now relatively safe! However, many are still affected by the spray from winter gale waves!

Copyright Graham G Matthews 2003