Principles and Practice of Investigating Buried Adobe Features with Ground-Penetrating Radar

Because so many ancestral populations, at various times, have lived within the constraints of earthen architectural technology, it has significant representation in building traditions across large temporal and geographic expanses. Adobe, known also as dagga, ferey, cob, and by other names, is a variant in which clays and other sediments are combined with organic materials and formulated into discrete construction components, often in communities of practice for which adobe recipes, preparation, and application are integral to daily intersections of home and community. For archaeologists, community partners, and interested publics who wish to learn more about it, a large portion of this architectural culture is no longer visible above the surface but is accessible through archaeology. Yet low impact sampling, such as probing and test excavation, rarely reveals adobe features. Ground-penetrating radar (GPR) allows a tantalizing and non-invasive perspective on subsurface adobe features; increasingly there is a buried structural landscape emerging at sites where adobe architecture prevailed. The case studies presented here from 18th and 19th century sites in central and southern California serve as a guide for further survey.