Investigating the Impact of Concrete Driven Piles on the Archaeological Record Using Soil Micromorphology: Three Case Studies from the Netherlands

Abstract

In this paper we present the results of field tests into the impact of driven concrete piles on three archaeological sites in the Netherlands. The field tests were done in two different types of archaeological sites. Two locations in the northern part of the Netherlands (Kenwerd and Groot Wetsinge) were artificial mounds or terps, where new buildings were going to be constructed using driven piles. The third location was Voorburg in the western part of the country, where the impact of pilings from the 1950s were studied. We analysed soil which was in direct contact with the piles, and soil at a distance from the pile surface.

The tests show remarkable results. Visible effects of piling in sand were downdrag of sediments along with the pile, disturbance of structure by local displacements, or liquefaction. In clay, some disturbance of structure, compression of pores, and damage to carbonized material was observed. Additionally, piles may promote the formation of pyrite in the directly adjacent peat. In a large number of samples taken from soil directly adjacent to a pile, no disturbance was observed. We did not observe any impact further than six to eight cm from the pile surface.

These results indicate that the impact of piling in fine sediments is smaller than is generally assumed. However, as the number of observations in the present study is relatively small, the results need to be corroborated by more field tests. In future, planners need to consider the direct effects piles have on the surrounding soil as well as the possibility of excavations.     

TAPHONOMIC OBSERVATIONS OF ARCHAEOLOGICAL WHEAT PHYTOLITHS FROM NEOLITHIC ÇATALHÖYÜK,TURKEY, AND THE USE OF CONJOINED PHYTOLITH SIZE AS AN INDICATOR OF WATER AVAILABILITY*

An investigation of wheat husk phytoliths from a midden deposit at Neolithic Çatalhöyük provided the opportunity to investigate the impact of taphonomic processes on conjoined phytolith size. Wheat husk phytoliths from a possible crop processing deposit were examined using three methods. The results indicate that the size of conjoined forms decreases significantly as a result of laboratory extraction and slide preparation. Observations of the phytolith layer in thin section show some of the depositional and post‐depositional processes affecting phytolith size. These results indicate that these taphonomic factors need further investigation before conjoined phytolith size can be used to infer past water availability and agricultural practices.     

Joined-Up Archaeology at Old Scatness,Shetland: Thin Section Analysis of the Site and Hinterland

Abstract

Excavations on the multi-period settlement at Old Scatness, Shetland have uncovered a number of Iron Age structures with compacted, floor-like layers. Thin section analysis was undertaken in order to investigate and compare the characteristics of these layers. The investigation also draws on earlier analyses of the Iron Age agricultural soil around the settlement and the midden deposits that accumulated within the settlement, to create a 'joined-up' analysis which considers the way material from the settlement was used and then recycled as fertiliser for the fields. Peat was collected from the nearby uplands and was used for fuel and possibly also for flooring. It is suggested that organic-rich floors from the structures were periodically removed and the material was spread onto the fields as fertilisers. More organic-rich material may have been used selectively for fertiliser, while the less organic peat ash was allowed to accumulate in middens. Several of the structures may have functioned as byres, which suggests a prehistoric plaggen system.