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With few exceptions in which dating is implied by indirect association with adjacent settlements or incorporation of diagnostic artefacts in upcast sediment, individual qanats have proven very difficult to date. This absence of a chronological framework hampers both our understanding of technology transfer, as well as the study of local settlement and landscape evolution and the temporal correlation of land use with climatic and palaeoenvironmental data. However, surface shaft mounds potentially contain a sequence of upcast deposits collected periodically from the tunnel, starting with initial construction and persisting until the last maintenance episode, less any material lost by surface erosion. The sedimentary nature of the upcast lends itself to the application of luminescence dating to determine the burial age, in particular, using the techniques based on optically stimulated luminescence. We examine the results produced by two recent dating studies where luminescence techniques were applied to two qanat systems with the aim of building a chronostratigraphy for the deposits within their upcast mounds. These studies show that the extent to which a complete record of the deposition since initial construction survives may differ between qanat systems, and even shaft mounds within the same system. Providing there is a close coupling of luminescence and sedimentological analysis in the testing of qanat mounds, these formative studies suggest that there are good prospects for introducing a valuable tool in the study of various types of hydraulic feature where upcast has been preserved and guidance regarding further fieldwork is provided.

Terracing is found widely in the Mediterranean and in other hilly and mountainous regions of the world. Yet while archaeological attention to these ‘mundane’ landscape features has grown, they remain understudied, particularly in Northern Europe. Here, the authors present a multidisciplinary study of terraces in the Breamish Valley, Northumberland. The results date their construction to the Early to Middle Bronze Age, when they were built by cutting back the hillside, stone clearance and wall construction. Environmental evidence points to their use for cereal cultivation. The authors suggest that the construction and use of these terraces formed part of an Early to Middle Bronze Age agricultural intensification, which may have been both demographically and culturally driven.

Abstract. Being the most common human-created landforms, terrace construction has resulted in an extensive perturbation of the land surface. However, our mechanistic understanding of soil organic carbon (SOC) (de-)stabilization mechanisms and the persistence of SOC stored in terraced soils is far from complete. Here we explored the factors controlling SOC stability and the temperature sensitivity (Q10) of abandoned prehistoric agricultural terrace soils in NE England using soil fractionation and temperature-sensitive incubation combined with terrace soil burial-age measurements. Results showed that although buried terrace soils contained 1.7 times more unprotected SOC (i.e., coarse particulate organic carbon) than non-terraced soils at comparable soil depths, a significantly lower potential soil respiration was observed relative to a control (non-terraced) profile. This suggests that the burial of former topsoil due to terracing provided a mechanism for stabilizing SOC. Furthermore, we observed a shift in SOC fraction composition from particulate organic C towards mineral-protected C with increasing burial age. This clear shift to more processed recalcitrant SOC with soil burial age also contributes to SOC stability in terraced soils. Temperature sensitivity incubations revealed that the dominant controls on Q10 depend on the terrace soil burial age. At relatively younger ages of soil burial, the reduction in substrate availability due to SOC mineral protection with aging attenuates the intrinsic Q10 of SOC decomposition. However, as terrace soil becomes older, SOC stocks in deep buried horizons are characterized by a higher temperature sensitivity, potentially resulting from the poor SOC quality (i.e., soil C:N ratio). In conclusion, terracing in our study site has stabilized SOC as a result of soil burial during terrace construction. The depth–age patterns of Q10 and SOC fraction composition of terraced soils observed in our study site differ from those seen in non-terraced soils, and this has implications when assessing the effects of climate warming and terrace abandonment on the terrestrial C cycle.