EHG6041 - Trial trenching - Thing's Va Broch, near Thurso

Archaeological trial trenches were excavated by ORCA in 2017 at the broch site of Thing’s Va and the nearby cairn, west of Thurso, Caithness, commissioned by the Caithness Broch Project (CBP). The trial trenches were located in order to ground-truth a number of anomalies identified in a geophysical survey carried out by ORCA in August 2017 (see EHG6040). The results of the fieldwork both varied by both nature and location. In Trenches 1 and 2, located to the northeast of the broch itself no archaeological evidence was observed to confirm the geophysics findings. It was considered that the geophysical anomalies may reflect the presence of clumps of iron pan in the subsoil, although it was possible they may be a result of ephemeral activities undertaken at this location that only left signatures in the soil rather than archaeological remains. Trench 3, placed over the cairn in the arable field to the southeast of the broch, was located due to the strong magnetic responses of a kind that tend to indicate burnt mounds and domestic occupation. The excavation revealed the top of a stone structure. The strong magnetic responses, the structural element and the presence of a small burn shown on the 1st OS map all point towards an interpretation of the ‘cairn’ as a burnt mound rather than a funerary monument, although it is possible that the mound may be some other kind of ‘domestic’ building, perhaps even related to the broch. The lack of definite structural form or diagnostic small find evidence from any of the trenches meant that the features could not be placed within a definite period and more extensive excavation would be required to address this. Thus the assumption that any of these features are related to the broch, a possible Bronze Age burnt mound, or Norse activity, remained to be proven. It was proposed that geophysical survey in the ploughed field south of the broch (which was not possible due to the field being under crop at the time of the original survey) would complete a full circuit of survey around the broch. This would identify the potential presence / absence of a related extramural settlement. Field-walking was planned over ploughed fields around the broch in early 2018, which could identify datable finds. <1>