Dating archaeological sites is often challenging due to a poor preservation of datable organic materials (bone, plant material, …), especially in the dry and acidic environment of the coversand area in northern Belgium. When organic remains are preserved, their association with the human activities is not always clear: charcoal, for instance, may result from wildfires. In addition, different types of organic materials can be subject to dating problems such as an old wood effect (calcined bone, charcoal) or reservoir effect (human and animal bone, food residue). Pottery is one of the most common finds on archaeological sites and it is the direct outcome of human activities. In Belgium and other parts of NW Europe, from the Neolithic to the Merovingian period (ca. 5000 BC – 800 AD), plant material was often added as temper to pottery clays to enhance the vessels’ strength. In many cases, charred remains of these plant additives are preserved inside the pottery and can be used for AMS 14C dating. The possibilities of this dating method are however underexplored.
ORG-ID aims to broaden the dating potential for archaeological sites in Belgium and adjacent areas with the AMS 14C dating of plant temper material preserved in pottery. The first objective is to identify which plant species have been used as temper in Neolithic, Iron Age, Roman and Merovingian pottery from the study area. This is an important first step, as only terrestrial plants provide reliable radiocarbon dates, whereas dates on aquatic plants may be subject to a reservoir effect. The second objective is to set up a protocol for the extraction and chemical pre-treatment of plant temper prior to AMS 14C dating. The third objective is to evaluate the reliability of the obtained dates by comparing them to other dates on (organic) materials from the same archaeological sites.