Shell mound formation and materialisation: The mid-late Holocene coastal archaeology of Wathayn, Australia and Janaba Bay, Farasan Island

Abstract

Archaeologists use empirical observations of the material remains of past people’s actions to generate explanatory narratives, and through these they impact the lives of indigenous and contemporary people in complex ways. For example, archaeologists identify material indicators of increasing social complexity and use these to create sequences of socio-economic change that at times differ from indigenous accounts of the past. Shell mounds are one such set of indicators with their appearance and physical properties interpreted as the consequence of historical human action. Studies of shell mounds at local scales emphasise the palaeoeconomics of past communities, while globally deposition of shells in mounds during the mid-late Holocene indicates resource intensification and/or new forms of ceremonial activities, both indicating increased social complexity. However, several factors exist that complicate the interpretation of shell mounds in these ways. Differing research objectives, methodologies and reporting standards mean few mounds outside of isolated research projects can be directly compared. As shell mound formation is still poorly understood, it remains uncertain how shell mounds from different places should be compared and narratives of socio-economic change assessed. This study therefore refocuses attention away from palaeoeconomics to the history of formation of shell mounds by presenting new comparative geomorphological and sedimentological data from two regions with very different histories: Weipa, Australia and the Farasan Islands, Saudi Arabia. Comparative analysis of shell mound composition, fragmentation, form, and accumulation rates highlight similarities despite the different cultural and environmental contexts of the two case studies. These similarities suggest that the size and form of shell deposits reflect ongoing changes in deposit composition unrelated to human actions in the past. Shell deposits are shown to be composed of mobile sediments whose contemporary composition and form is not easily related to past human behaviour. This complicates interpretative narratives of increasing social complexity, suggesting the need to consider alternative ontologies for understanding landscape formation that move beyond natural and cultural dichotomies.