Oriel College, Staircase 8 Test Pits Archaeological Watching Brief Report

In March 2018, Oxford Archaeology carried out an archaeological watching
brief during the excavation of two small test pits within the existing cellar
below Staircase 8 at Oriel College, Oxford. The work followed on from earlier
test pitting and trenching carried out in 2015 and a borehole transect across
Second Quad which was undertaken in 2017.
During the 2015 works, possible Oxford Clay was encountered at the base of
the stratigraphic sequence, with the lack of overlying gravel suggesting that it
had been truncated by a feature within the projected alignment of the
putative ditch of the primary burh. However, terrace gravel was encountered
in both test pits at approximately the same elevation as the top of the gravel
observed during the borehole transect and the earlier test pits and trenching,
which suggests that the feature encountered during the 2015 works is more
likely to be discrete rather than linear.
No dating evidence was recovered from the fairly homogeneous silty clay
deposits which overlay the gravel, but it is possible that they correspond with
the sequence of medieval occupation observed in the previous phases of
work. As with the earlier observations, no evidence for the post-glacial
brickearth which overlies the gravel terrace was revealed, which may suggest
that these deposits are filling negative features.
In one of the test pits, the silty clay deposit had been truncated by a deposit
of limestone rubble in a sandy gravel matrix which may have represented the
rubble core of an earlier wall, although the extent of this deposit was not
revealed