How big a pit was 10067?

 

When the A344 was lifted in 2013–14, Wessex Archaeology examined what was left beneath the road bed. Seven and a half metres north of the Heel Stone they found a feature, 10067, surviving 0.06 m deep, three finger widths. It took some skill to notice it at all, and there was not a lot to record. Powell et al. interpreted it as a shallow tree-throw hollow.

The interesting question is not what survives but what was cut. Nobody digs a hole six centimetres deep. Whatever 10067 was, what was found is the very bottom of it, and how big a pit it was depends entirely on how far below the contemporary ground surface that bottom sits.

Hawley's photograph, 10067 is the dark mark just this side of the motor car

10067 is marked with a dark mark this side of the Heelstone

The road makes that hard to establish. Until it was tarmacked in 1935, a chalk road was maintained by scarifying, watering and rolling. That takes out the ruts and gives a remarkably smooth surface, at the cost of removing chalk each time, so roads of this kind sank slowly. The early photographs show a dark patch where 10067 lies — a soft spot in the road surface, which is what you would expect from a deep feature with looser fill compacting under traffic. The looser top surface was removed before the road was tarmacked taking it down to a firm surface. On top of all that, the corridor was machine-stripped for the watching brief. The surface Powell recorded from is not the surface 10067 was dug from.

The 2013 excavation - 10067 is marked with the metal stakes, note the section revealed at the bank.

Levels

Two Ordnance Survey benchmarks are cut into the Heel Stone. The lower one is a broad arrow with the levelled bar above it, about 0.1 m above the turf, published at 100.70 m OD. Pitts tied his 1979–80 levels to it, so his sections can be read directly against the stone.

That gives a run of comparable figures for the entrance zone:

• Pit 97 — about 1 m deep, base 1.60 m below the mark, so about 99.1 m OD. Pitts's fig. 7 is contoured in centimetres below the benchmark, which is why this one is solid.
• Heel Stone ditch — cut about 0.8 m into the chalk, base just touching below 99 m (Pitts fig. 8).
• Avenue ditches — 0.75–0.80 m deep, base near 99 m, and consistent between the Vatchers, Pitts and Powell.

Three features, two campaigns, all bottoming out around the same horizon.

Pitt's Fig. 7 - Stonehole 97

Pitt's Fig. 8  Heelstone Ditch - note 99m OD mark

Pitt's Fig. 13 - Avenue Ditch - note 99m OD mark

Click to enlarge.

Where 10067 sits

Not, unfortunately, from the published levels. Powell's GPS heights do not reconcile with the earlier work. He records the natural at the edge of the Heel Stone ditch, inside the road-line, at 102.13 m — that is 1.43 m above a benchmark cut just above ground level at the stone a few metres away. It is not merely an offset, it is the wrong way round: the road ran below the ground at the stone, not above it. Powell notes the inconsistency and leaves it unresolved. So do I.

Which leaves the photographs. The verge in my photograph of the stripped corridor shows the old road in section with the turf line above it, and the perimeter fence for scale — standard chain-link, probably1.8 m. Reading the drop against that, the surface Powell was working from lies something like 1.2 m below the turf beside the Heel Stone, so around 99.4–99.5 m OD. The base of 10067, a further 0.06 m down, comes out somewhere in the region of 99.3–99.4 m.

That is a reconstruction from photographs, not a survey, and it is worth a couple of tens of centimetres either way. But it is enough for the point. The base of 10067 sits close to the level at which Pit 97, the Heel Stone ditch and the Avenue ditches all stop. And it was cut from a surface a metre or so above where it was found, which makes it a substantial pit rather than a scrape.

So what was it?

I am not going to claim it is definitely a stone-hole. The evidence will not carry that, and even if we knew the actual OD of the surface it was found in, and the archive might be able to reveal that, we would still only be able to improve its comparison to the other pits.

But a pit of that size, seven and a half metres north of the Heel Stone, bottoming at much the same depth as 97, is not obviously a tree throw either. It sits in a zone already full of holes nobody can explain: 97, B, C, the A holes, the Heel Stone's own ditch. Stones put up and taken away? The Heel Stone shifted about like a pawn from one hole to the next? Whatever was going on here, 10067 and the other holes deserve deeper scrutiny.