Environmental change has affected all societies throughout history, and by understanding the ways in which past peoples have both caused these changes and responded to their effects, archaeologists can provide guidance for modern societies struggling with similar environmental challenges.  Iceland is a particularly good place to investigate the human dynamics of environmental change. No humans lived on the island until the late 9th century CE, which makes it easy to compare the environmental impacts before and after settlement. This project investigates how settlement organization, agriculture, and social relationships changed during the medieval period, as erosion and deforestation were in the process of irreversibly altering Iceland’s landscapes and ecosystems. 

The specific goals of the research were to identify, date, and determine the size of abandoned marginal medieval settlements in the region of Hegranes, in Skagafjordur, North Iceland, and to determine how their settlement history correlates with environmental changes. To achieve these goals, systematic survey, coring, and excavation were carried out at seventeen sites around Hegranes, which is an island between two rivers at the mouth of the fjord (see map). Iceland’s history of volcanic eruptions has left identifiable layers of ash (tephra) in the soil that are easily assigned to known dates in the field, and so coring revealed not only the presence and spatial area of medieval settlements, but also the date of those settlements. By comparing the depth of soil with the presence of tephra layers, sequences of soil erosion, sediment deposition, and wetland development were also determined and recorded from the cores (see photo).

Test excavations at the marginal settlements targeted the oldest deposits within middens (primarily composed of ash, charcoal, and animal bones) as determined from the coring survey. Limited finds were retrieved: primarily animal bones, as well as some iron objects and a small number of decorative carved bone pieces (see photo). Soil samples were taken from all layers, and have been processed to determine the plants that were growing at the time, and to retrieve charred barley seeds for radiocarbon dating. Environmental soil profiles were placed to characterize erosion at a distance from human habitation, and to provide samples for loss-on-ignition analysis (a procedure that measures the change in mass after all organic material is burnt away) to characterize the process of wetland formation near and distant from the settlements (see photo).

At some sites habitation was short-lived, while at others, settlement appears to have been ongoing for many decades or longer, perhaps in multiple phases.  In all cases, people did not live at the sites past ca. 1104 CE. While some of these sites may have been early farms, others are likely to have served as activity areas associated with existing large farms, perhaps for charcoal or peat production or for the acquisition of other wild resources. Between the 12th and early 20th centuries, the sites were used as farm infrastructure, likely involved in herding or maintenance of livestock. In other words, around the late 11th and early 12th centuries, the outlying areas of Hegranes ceased to be used for permanent settlement, but continued or even increased in importance as part of seasonal or day-to-day management of large farms.

The overall landscape of Hegranes has been subject to significant erosion and landscape change over the course of its history. The region has experienced two significant periods of erosion: during the medieval period, and after the 18th century. Erosion events primarily occurred after habitation at the sites had ceased, and may not be directly related to changes in use at the sites. The presence of wetland very close to the majority of marginal sites suggests that the formation of wetlands may have had at least as much, if not more, to do with the change in the way these sites were used than did erosion per se. Analysis of the results from wetland loss-on-ignition is ongoing, but preliminary results suggest that areas closest to the sites have consistently supported greater quantities of mire vegetation than areas farther from the sites, showing that the people who lived at the settlements probably did so in part to gather wetland resources.

Broader impacts. This research strongly supported international collaboration, and has provided opportunities for graduate (MA and PhD) as well as undergraduate scholars to learn the methods and practices of archaeology and to gain experience in international issues of environmental change, social change, colonization, and social inequality. Locally in Iceland, the project has helped to raise awareness of the importance of archaeological remains in the landscape. In a broader social context, analysis of trade-offs between sustainability and inequality suggests thoughtful, alternative strategies to mitigate degradation without increasing poverty and human suffering. Specifically, the project shows how infrastructure shapes human responses to environmental change, suggesting ways that modern infrastructures can be constructed and modified to encourage more sustainable practices.

Last Modified: 11/17/2017
Modified by: Kathryn A Catlin