M4 Smart Motorway (Junctions 3–12), Berkshire and Buckinghamshire Archaeological Evaluation, Excavation and Watching Brief Report

Archaeological work during the M4 Junction 3–12 Smart Motorway scheme
included a series of watching briefs, five evaluations and two excavations. The
watching briefs and three of the evaluations did not uncover archaeological
finds or features, but discoveries during the evaluations at Compound 3
(Hurst) and Compound 8 (Datchet), both in Berkshire, led to area excavation
of these sites.
At Compound 3, a multi-phased middle Iron Age settlement enclosure was
discovered that included 10 roundhouses, 21 pits and other features. One of
the roundhouses had complex entrance features and an internal post-ring. A
complete quern stone is the most exceptional find on the site.
The sequence at Compound 8 began with a middle Bronze Age waterhole that
contained a partially dismembered cattle burial. The waterhole was recut and
large Deverel-Rimbury pottery sherds were placed in the lowest fill, which
were found alongside late Bronze Age pottery. Most of the features on the site
dated to the late Bronze Age, including a long rectangular structure (a possible
longhouse) measuring 11m by 4m. Postholes and beamslots associated with
the rectangular structure contained burnt flint. Five radiocarbon dates were
taken from the structure, and three further dates were obtained from late
Bronze Age features. The radiocarbon dates all returned very similar results,
suggesting a probably short-lived settlement dating to the decades around c
1000 cal BC. Other late Bronze Age features included a series of waterholes, a
possible roundhouse, a possible enclosure, a cremation deposit, and a series
of pits including one containing a large quantity of burnt flint that may have
been the remains of a burnt mound. A probable recut Roman trackway was
discovered that might be related to the system known nearby at Agar’s Plough.
One of the recuts contained early/middle Anglo-Saxon pottery suggesting the
feature remained open into this period.