Introduction
We were invited to evaluate the geoarchaeology of a site at Johnny Ball Lane, Bristol, to help the excavating archaeologists, both in understanding the origins of the deposits and in assessing the archaeological potential of the site.
Background
The bedrock of the area was known to be Quartzitic Sandstone of the Carboniferous, Millstone Grit Series and we found the soils on the site to be typical brown earths which are well drained fine loamy soils often over rock. The site lay on a south east facing slope within an urbanised area of Bristol to the north of the River Avon.
The site is situated in the area of a former hospital cemetery and post medieval cottages. The cottages had been built upon level terraces that been built by cut and fill methods, where the underlying sloping bedrock was cut into to form steps with the rest of the terrace formed from made ground.
At the time of our visit the site was undergoing redevelopment and a large trench had been dug across the site and it was in this trench that we able to examine deposits exposed in the sides.
Findings
We examined one section of made ground which was thought by the excavating archaeologists to be a possible garden soil. We found this deposit to be made from mainly domestic and not industrial debris, in well defined layers, with no evidence of mixing between these layers.
Conclusions
From our investigations, were we able to tell the excavating archaeologists, that the deposit we examined was not a garden soil, but a series of dumped materials that had occurred over a short space of time. The deposits had built up quickly and had then been sealed by the building of the cottages preventing mixing between the layers and preserving the deposits.