New Zealand Heritage Properties archaeologist Natasha Phillips said the items could relate to a timber yard dating from about the 1860s to 1870s, and a tannery that was known to be in the area in the late 1880s, but might have been in operation earlier.
Features uncovered included a type of track way made completely of wood.
"The only metal we are finding is the nails that they used to put it together."
This ran alongside a hard pad of clay topped with cobble stones, which was perhaps created for something very heavy to sit on or be rotated around, she said.
"So we are not sure if it relates to the track way but it would be quite neat if it was actually for the same purpose."
A sample of wood was being investigated to see what type of wood was used at the site, to understand what types of wood were being used, and whether it was locally sourced or from further abroad.
A feature revealed about a metre below surface was a dark layer of material spread around a large area .
"It was possibly related to the tannery that was on the site here."
The mulch might have been used to soak up waste products from the tannery, she said.
A timber causeway near the track was possibly used for crossing or walking over.
"But it also might be related to whatever heavy vehicle, or wagon they were using to take along the track way."
The timber laid on the causeway was very roughly worked.
"They really just chopped of most of the branches and then just laid them down on top of really hard clay, and then they put cobbled stone on top."
The items revealed at the site were being carefully recorded before being removed, she said.
