Geologists working with United Utilities have unearthed rare fossils deep below the surface of east Lancashire, indicating the area was once large marshy swampland.

The beautifully preserved fossils of prehistoric animals and plants were found in rock samples deep under Haslingden, near Rossendale.

They were also found in Bury, Greater Manchester.

The samples were taken along the planned route of an important new section of aqueduct that is being constructed up to 200 metres below ground level in east Lancashire.

READ MORE: Rossendale veteran's perfect send off in Flying Scotsman coffin thanks to funeral director son

The project, known as HARP - the Haweswater Aqueduct Resilience Project - involves building six new pipelines to replace parts of the company’s Haweswater Aqueduct. The hope is to safeguard water supplies in the North West for generations to come.

The relics show a mix of plant and animal species which suggest this part of Lancashire and Greater Manchester was once a marshy swamp before vanishing below sea level and eventually turning into coal.

James Hamnett, an engineering geologist for Jacobs, the company helping to supervise the ground investigations for United Utilities, said they were found in rock about 80m to 170m deep.

“It’s not unusual to find fossils in this part of Lancashire but these are really good quality,” he explained.

Carboniferous fern fossil
Carboniferous fern fossil

“Everyone working on the project is interested in what we discovered, I found myself showing them these fossils and explaining the interesting past they indicated.

“The area between Bury and Haslingden is in the Pennine Coal Measures and Millstone Grit Groups, dating back around 300 million years.

"At various times in the past, the environment varied from marshy swamps and forests in some periods to deep sea in others. Heat and pressure over millions and millions of years turned the remains of these plants, forests, and trees into coal seams.

Possible ammonite fossil
Possible ammonite fossil

"The remains of marine animals on what was once sea bed became fossils and help us to date the age of the rock."

Although not a fossil expert, James believes the fossils include two different Cephalopods (Ammonite and Goniatite), which are fossils of tiny squid-like creatures with tentacles and shells, a Carboniferous Tree fern and a Lepidodendron fossil, which is the tightly packed diamond-shaped leaf scars of an ancient type of Carboniferous tree.

United Utilities’ director of strategic programmes, Neil Gillespie, said: “This is a fascinating glimpse into a world we would otherwise never see. A bit like the project itself. Our new pipeline will be up to hundreds of metres underground and when it’s finished it will itself only leave the occasional marker. It will be an important boost for the region’s water supplies for generations to come,” he added.

Download the LancsLive app for free on iPhone here and Android here.

Have you got news for us? Contact our newsdesk on [email protected].

Get all the latest news, sport and what's on stories sent to your inbox daily with the LancsLive newsletter here.