A rock in a hard place : European use of dolerite in Tasmania

Abstract

Despite being more prevalent in Tasmania than elsewhere, dolerite found relatively limited use by early European settlers. Dolerite was used in foundations, basements and retaining walls, but was difficult to shape and at least in the first half of the colonial century, highly unfashionable both in colour and texture, although acceptable for industrial buildings and rural outbuildings. Later in the nineteenth century, quarried stones of uniform colour were used to build some notable churches as well as basements for buildings of other materials. There was a progression during the three decades before the First World War from use of stones of varied size to a preference for stones of regular appearance; after which dolerite was largely replaced by concrete. For much of the twentieth century, dolerite was chiefly crushed for road metal, concrete aggregate or railway ballast, with occasional use in formal building. Towards the end of that period, it returned to building in decorative features, and to engineering practice as filling for gabions and in massive assemblies of boulders. This overview traces the use of dolerite in Tasmania from early colonial times to present-day practices in fashionable architecture and as a structural building material.