CBA SMA\SMA 1998.PDF - Council for British Archaeology

including small round pits filled with dark soil and burnt
flint, covered the gravel terrace, as in the adjacent
excavation of EX1 in 1995 (SMA 1996,23-4 and Fig 13).
As was the case with previous excavation on the floodplain,
bucket-width trenches were dug along the sides of the area
to a depth of 1.2 m to provide a preview of the stratigraphy
within the palaeochannel. The alluvial deposits were then
machined down to the first occupation horizon. No dense
concentrations of finds were revealed, but there was a
general scatter of artefacts at this level as well as a single
shallow pit. Finds on the surface of the horizon were
individually numbered and 3-dimensionally plotted and a
sample trench, 2 m wide, was dug by hand through the
horizon, but produced no further finds.
Two-thirds of the alluvial deposits were then machined
down to a second occupation horizon, which had a very thin
spread of charcoal across it, within which a burnt mound
deposit some 3 m in diameter was found, consisting of in
situ burnt soil overlain by a layer of charcoal and burnt flint.
Scattered around the bumt mound was burnt flint but no
other finds or features. Sample 2 m squares were excavated
across the surface but there were no further finds. This was
the only buried soil horizon so far encountered that could be
traced over a large area, due to the charcoal staining on its
surface. This charcoal implies extensive burning, possibly
accidental but more likely connected to the burnt mounds
and burnt flint pits adjacent on the gravel terrace. A further
charcoal-stained horizon had been found in an evaluation
trench, but on machine stripping this proved to be a very
localised and sterile deposit.
One third of the alluvial area was then machined down to
the surface of an orange clay deposit which overlay the peat
in this area. Several vertical timbers were found protruding
from the surface of the clay, but none of these were worked,
and some of them forked into smaller branches in the peat
below, suggesting that they were trees that had fallen over
and sunk into the soft deposits in shallow water.
The orange clay was then removed by machine, as was the
underlying peat. No artefacts were found, and the character
of the peat clearly indicated reedswamp deposits of early
post-glacial date.
Excavation of the floodplain and former Thames
channel - EX3
This was the third area to be excavated running from the
gravel terrace across the alluvial floodplain into the former
channel of the river Thames. Area EX1, excavated in 1995,
contained in situ knapping scatters dating to the Neolithic
and the Early Bronze Age, including an Early Neolithic
activity area where leaf-shaped arrowheads were
manufactured. Area EX2, which ran parallel to EX1, was
excavated in 1996. Although an occupation horizon was
identified, no lumpping clusters were found. However, part
Oxfordshire
of a Neolithic Peterborough ware vessel and an early Bronze
Age urn were found.
An area of 0.58 ha was stripped for EX3 in the same manner
as in EX1 and EX2. Bucket-width guide trenches were
excavated along the west and east of the area to provide a
preview of the stratigraphy. An occupation horizon was
found within the alluvium and the area was stripped to this
level. Patches of burnt flints and two struck flint clusters
were found, one of them containing in excess of 1000 struck
flints. Overall, however, the activity was at a much lower
density than that found in EX1. Several tree holes were also
identified at this level.
Two-thirds of the area was then machined down again to
look for further occupation horizons but none was found,
though a perforated antler mattock of possible Mesolithic
date was found. Machining was continued through the
underlying peat layer, which was sterile.
At the north end of the site, part of the former Thames
channel was excavated. Lying on the edge of the first phase
of the charmel was a mass of small branches, many of which
were beaver-gnawed - characteristic teeth-marks were
found on the ends of the branches - and it is likely that this
is the remains of a beaver lodge or dam, better preserved
than those found in EX1 in 1995. Unlike Area EX1,
however, where struck flint and pottery was found in
amongst the beaver-gnawed timbers, only a single struck
flint was found in the channel in EX3.
A second phase of the channel was just clipped by the
excavation. Most of the disarticulated skeleton of a cow was
found at the edge of this phase of the channel, along with a
little pottery.
Northern Access Road
A length of 165 m of the route of a new access road was
subject to archaeological investigation. The road corridor
was crossed by several ditches running on a north-easterly
aligmnent, which correspond to cropmark ditches belonging
to the Late Bronze Age enclosure system visible on this area
of gravel terrace.
At the east end the road corridor ran across a former channel
of the Cress Brook. The channel proved to slope down very
gently; no concentrations of finds were recovered from the
channel edge and no waterlogged deposits were
encountered. Probing further east suggested that the
palaeochannel continued to be shallow all the way across at
this point.
Watching Brief on the former Thames channel
Watching brief was carried out during August and
September, 1997. Isolated finds of human and animal bone,
pottery, struck flints and wooden objects were made within
the channel deposits, including a circular pebble macehead'
of probable Mesolithic date. Although no structures on the
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