Geoarchaeological investigations of harbours of the 12th and 13th cent. along the Hever Estuary (North Frisia) starting at the trading settlement of Rungholt - RUNGHOLT -

点击翻译按钮获取中文摘要

The coasts of North Frisia which, during High and Late Middle Ages, were subject to both land reclamation measures and several catastrophic storm surges, represent a highly dynamic natural and cultural landscape (UNESCO World Natural Heritage since 2009). Especially for the 12th and 13th cent., when the coastline lay further west than today, only little knowledge exists on coastal palaeogeographies on the one hand and on the localization and structure of harbours on the other. Although there is some historic, cartographic and archaeological evidence regarding harbour sites, detailed geoarchaeological data on their position and how they were embedded in the palaeoenvironment are still missing until this day. This is mostly because large parts of the former marshland got lost within the course of storm surges, especially during the 1st Grote Mandränke in 1362, and because working in tidal flat areas is complicated. The main objectives of the RUNGHOLT project thus are to localize, reconstruct and evaluate harbour sites of the 12th and 13th cent. in the wadden zone along the Hever Estuary near Husum which has to be regarded as transport and development axis. We plan to carry out studies in three areas. The high-medieval marshland around Rungholt (Hallig Südfall) and the Trendermarsch (Nordstrand), located in todays wadden sea due to storm-related ingressions, as well as the marshland around the Mildeburg (Rantrum), which has not undergone substantial changes since the High Middle Ages, allow reconstructing palaeoenvironmental changes, for instance caused by sea level fluctuations and flood events. Together with complex man-environment interactions, the effects of these changes on the spatio-temporal structure of settlements and harbours can be exemplarily documented along a west-east transect within the context of land reclamation measures and considering tidal differences. Within the RUNGHOLT project, this is the first time that systematic geoarchaeological studies by means of vibracoring, borehole geophysics and geophysical surveys are planned to be realized in tidal flats. The methodological focus lies on multi proxy analyses of sediments for example by magnetic susceptibility measurements, geochemical analyses of (earth) alkaline and heavy metals, the determination of isotope concentrations and microfossil analyses. Dendrochronologic studies, radiocarbon dating and relative age estimation using amino acid racemization will yield geochronostratigraphic information. The RUNGHOLT project is based on an interdisciplinary co-operation between the universities of Mainz and Kiel integrating the Geophysical Central Project of PP 1630. Principal investigators (PIs) have longtime experience in historic-geographical and geoarchaeological research on coasts and harbours. The RUNGHOLT project was harmonized with the North Sea project of PIs Jöns and Segschneider on trading terps and Geest fringe fortifications to achieve maximum synergies.