Geology Site Account

Temporary exposure of fossiliferous deposits during road excavations. Further excavations in the vicinity could yield further fossils.

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Site description

During excavations for the second stage of the Waterworks Corner road improvement scheme in 1974, a large log of fossilised wood was found in the London Clay at a depth of about 4 metres (12 feet). The log was encrusted by selenite crystals and contained distinctive shipworm borings. Around the log the brown/pale grey London Clay was altered to an intense blue colour.

Fossilised logs from the London Clay are nearly always infested with holes made by the shipworm teredo which tells us that these logs had been floating in the sub-tropical sea for some considerable time before sinking. The shipworm is a wood-boring mollusc that is still common in tropical seas today and, as its name suggests, was the scourge of early timber ships. The London Clay sea was in existence about 50 million years ago and the coastline is thought to have been similar to present day Malaysia and Indonesia with extensive mangrove swamps. Large amounts of vegetation would have been floating down rivers and out to sea.

The log was presented by the contractors to the Passmore Edwards Museum in Stratford on 2nd April 1974 and it was displayed for several years in the main museum building in Romford Road. It is reported to have been illustrated in a local newspaper. Following closure of the museum the log is now in storage with the rest of the Essex Field Clubs collection.