4.3 The surrounding feature
The next feature Holwerda describes is the surrounding feature of the primary mound period (F3, fig.6). At a depth of 1.5 m below the top of the mound, thus at the level of the old surface, a ‘burnt strip’ was found with a circumference of about 10 m. In all likelihood, the burnt feature Holwerda describes was an orange-reddish discolouration typical for soil features in the region (Fontijn & Van der Linde in prep). In this case we are dealing with a trench under the foot of the primary barrow. At some places the outer edges of the ditch are said to have been lined with charcoal, creating two concentric circles 60 cm apart. That it really was charcoal is supported by one of the barrows at nearby Vaassen, where tumulus III also had a 3 m long stretch of charcoal in the fill of the ditch (cf. Lanting & Van der Waals 1971, fig.9). These charcoal stretches give us the approximate width of the ditch. The depth of the feature is not mentioned.
The lines of charcoal probably represent the outer sides of superficially charred posts or burnt wickerwork running in between posts. Holwerda also mentions that at regular intervals, the soil was burnt more intensely than in other places. In our opinion this may indicate that posts had stood in this trench, as these would show a different discolouration than the fill of the ditch. Palisaded ditches are commonly found around Neolithic barrows in the region (cf. Vaassen, tumulus I and III, Lanting & Van der Waals 1971; or Emst Hertekamp, tumulus 5, Holwerda 1910, 8-9).
Holwerda’s description and reconstruction of the barrow is, however, not without problems. The trench would have had posts which stood upright, creating a wooden cylinder, not much unlike the reconstruction suggested by Modderman (1984, 57; for a similar reconstruction see Lawson 2007, 168). That the barrow represents the remains of a collapsed house or roof (Holwerda 1908, 16) can be refuted since the area within the palisaded trench would have been filled in with sods and sand. Whether or not the palisaded trench would have been pulled out before the barrow was erected is still subject to debate (cf. Lanting 2008, 62). Either way a barrow was built on top of the grave.