EHG5636 - Evaluation - Main Street, Portmahomack

An archaeological evaluation was undertaken by Avon Archaeology (Highland) in 2022 in accordance with the requirements of planning consent in advance of groundworks for a house and associated development at a site located immediately SW of Sanford, Main Street, Portmahomack. The evaluation was designed to establish the presence or absence of significant buried archaeology within the footprint of the development area, in particular deposits, features or finds associated with the Tarbat early medieval monastic site, a scheduled monument whose boundary is located c 75m to the SE. Each of the three trenches revealed a broadly similar sequence of deposits dominated by windblown sands in excess of 2m deep, which extend below the depth of the proposed house build FFL (c 7.2m OD). The most complete sequence of deposits was revealed in Trench 1 where the stratification was dominated by episodes of clean windblown sands that were interbedded with at least three layers reflecting archaeological activity. The most recent archaeological activity was represented by the accumulation of a large midden deposit of marine mussel shell overlain by clean windblown sand. The shell midden overlay further clean windblown sand that in turn overlay a second archaeological midden deposit, which consisted of a spread of charcoal, a concretion of burnt and crushed marine mollusc shells and animal bones. The earliest archaeological horizon was represented by a thick layer of darker sand revealed towards the base of the trench sequence, which is suggested to reflect a period when the site was under cultivation, the darker colouration a product of manuring, either animal or perhaps seaweed. A broadly similar but less complete sequence of archaeological deposits was recorded in Trenches 2 and 3. The sequence of deposits identified on the site illustrate a dynamic sequence of deposition that has fluctuated between episodes of natural windblown sands and deposits associated with human activity, the earliest of which is suggested to reflect the development of a cultivation soil through manuring. The subsequent accumulation of at least two midden deposits suggests a foreshore location outside the focus of associated settlement where marine foodstuffs were processed or, more likely, where domestic refuse was deposited. The chronology of the phases of activity identified in Trenches 1 and 3 remains uncertain due to an absence of stratified finds. However, there are strong similarities between deposits 106/107 and 303 and medieval midden deposits recorded in 2005 by Farrell at Toughs Yard (see MHG54023), some 50m to the NE of the present site – this similarity suggests that the midden deposits revealed in Trenches 1 and 3 are also quite possibly of medieval date. In conclusion, the evidence recorded during the evaluation is considered to have significant archaeological research potential, which justifies more complete understanding. <1> The results of the subsequent PERD stage analysis and reporting work confirmed that the Sanford Portmahomack site contains a series of significant and stratified archaeological deposits preserved within a deep sequence of windblown sands. The AMS radiocarbon determination provided by charred plant material recovered from midden deposit 106/107 in Evaluation Trench 1 confirms that the activity identified includes anthropogenic deposits associated with medieval activity during the late 13th to early 14th century. The radiocarbon determination indicates that the formation of midden deposits 106/107 and 303 can be assigned to Period 4B of the Portmahomack Medieval Township (Carver et al 2016, Chapter 7), a period when the fishing settlement appears to have gradually expanded and the utilisation of marine resources, both fish and marine molluscs, became increasingly important both for subsistence and for wider trade (ibid). The deposits identified and sampled from the site and reported on by specialists provide significant new evidence relating to medieval settlement-related activity at Portmahomack and the subsistence strategies and agricultural base of its medieval inhabitants, in particular involving arable cultivation, marine fishing, animal husbandry and the utilisation of marine foreshore resources. The evidence produced by the PERD analysis work has confirmed the significant archaeological potential and importance of buried deposits preserved on the site, as identified during the preceding evaluation stage – further archaeological deposits of equal or greater importance can be expected to be revealed during the groundwork stage for future development of the site. <2>