The site is thought to have been run by the military
The finds includes a roman altar, timber-framed buildings, shoes, coins and pottery.
Historians from Manchester University's archaeology unit are logging the discovery and there are plans to place the artefacts in local museums.
The site dates back to the first century and is believed to have been a large-scale industrial settlement.
'Complex site'
Project officer Peter Connelly said: "The quantity and quality of the finds suggests that this site was run by the Roman military rather than the local Romano-Britons.
"The size and complexity of the site is astounding and has shown us how much salt working was going on at the time."
As well as the industrial works, there is also a domestic area and the remains of a roman road.
One of the larger finds is a Roman altar which it is hoped will eventually go on public display.
Mr Connelly said: "What we have is the base of an altar so it has no inscriptions on it, but it is similar to pieces found all over Britain.
"Once we have finished recording the site, the finds will be handed over to the local council and hopefully some of the larger artefacts will end up in local museums."
The site is owned by Bellway Homes which is funding the archaeological project and will build new homes there whene the historians have finished their work.