Interpretative trajectories towards the understanding of negative features using Terraco das Laranjeiras Bronze Age site as a case study

In prehistoric sites, the most common features identified by archaeologists are negative ones, such as pits, postholes, hearths, sunken hut, and among others. However, interpretations are not easy, and some researchers prefer not to reflect upon them, classifying them as rubbish pits while other researchers argue that these structures have other functions. This paper describes and discusses different types of negative structures and how archaeobotanical studies can guide their interpretations. In order to exemplify this problem results from the Terraco Laranjeiras will be discussed. This Middle Bronze Age site is located in the Sabor Valley (NE Portugal), where different types of negative features are the only archaeological evidence of human occupation. Some of these features were initially interpreted as storage pits, and the plant remains as the result of such activities. However, the archaeobotanical analyses compared with ethnographic examples led to a different interpretation. The results from this research show that wild taxa are more common than cultivated taxa and that the majority of the plant remains are chaff and weed seeds rather than cereal grains. To conclude, the carpological remains - the abundance of chaff fragments and weeds - are probably by-products from an early cereal processing stage (e.g. threshing), these findings suggest that the site was used for processing cereal and not necessarily for storing it.