Flint, shells and sand found in the mud in the Tyne show it originated not from the North East but from the Thames, brought to Newcastle in ships’ ballast.
Lining the river bed for 15 miles from the old Dunston Coal Staithes to the mouth of the river Tyne, the silt from the Thames is a hidden by-product of the golden age of coal.
Drawing on research carried out by Dr Peter Wright, a Visiting Fellow in History, Classics and Archaeology at Newcastle University, geologists at Newcastle say the flint, shells and sand that are typical of the chalky rocks on which London is built are one of many geological legacies left behind by the industrial revolution.
“In the 18th Century, over 2000 ships a year were arriving in Newcastle and up to 90% of these were carrying ballast,” explains Dr Martin Cooke, a lecturer in the School of Civil Engineering and Geosciences at Newcastle University.
“Unlike most ports in the UK, the Tyne tended to export high volume, heavy goods such as coal but the majority of ships arriving back in Newcastle did not bring cargo with them, or only very small quantities compared to the coal they were taking away.
“So they would head south to London, weighed down with coal but then face the problem of how to get back up North with an empty boat? A light boat is an unstable boat so they needed something to weigh them down and what they used as ballast was Thames dredgings."
How ballast changed the geology of the Tyne
The ballast was dumped, for a fee, on the banks of the Tyne in Ballast Hills and Ballast quays that were run as businesses. These ballast hills were located as far up as Dunston and as far inland as the Newcastle Town Moor. The sand from these ballast hills was used as a raw material in the local glass industry while the ballast hills were used to form the banks of the Tyne and as infill on the land.
However, unscrupulous captains would dump the ballast directly into the river and it was this that caused the river to silt up. By the 1800s there were four clear islands in the Tyne comprising solely of ballast.
“It’s one of a number of geological oddities that we have been left with in the North East as a result of our industrial past,” says Dr Cooke.
“At Tynemouth, for example, the beach is littered with boulders - comprised of high grade metamorphic rocks such as gneiss and amphibolite - that were brought over from Norway, transported in the boats’ ballast for the same reason as the Thames dredgings.”
New Earth Sciences degree
How geology shaped our industry and how it in turn changed our geology will be a key research area for students starting Newcastle University’s new Earth Sciences degree in September.
Led by Professor David Manning and Dr Cooke, the course marks a revival for geology at Newcastle University, reflecting an increased demand nationally for the subject.
“Students studying Earth, Marine and Environmental Sciences dropped from approximately 5000 a year in 1999 to 3500 a year in 2013,” explains Dr Cooke.
“We now find ourselves in a situation where there is a major shortage of geologists and a growing need for them.”
Newcastle has continued to teach geology modules as part of other degree programmes but the new Earth Sciences degree will bring them back together. At the same time, the aim is to move away from the traditional geology degree, says Dr Cooke, and focus instead on environmental contamination and engineering geology.
“Engineering is one of Newcastle’s key strengths so it makes sense to focus on this important part of geology,” says Dr Cooke.
“Vital to answering key questions we face today, such as the debate around fracking or where to build a new housing estate, all civil engineering projects start with the same question - “Will the ground support the engineering?” It’s geologists we need to answer that question.
“Our research expertise in Geomatics and geological engineering here at Newcastle University is world class and the aim of the Earth Sciences degree is to bring through a new generation of engineering geologists and environmental consultants in this economically and socially important field.”
published on: 10 June 2015