Characterising mine wastes as archaeological landscapes

Abstract

Industrial-scale metal mining has long been a feature of developing economies. Processing ores to recover minerals has generated large quantities of waste rock, tailings and contaminants. Mining-related deposits, along with associated soil and water geochemistry, river modifications and other environmental changes, are a product of the nature, scale and intensity of past operations. These artefacts of historical mining create anthropogenic landscapes that extend far beyond individual sites due to the dispersal of mine waste by rivers and pose enduring threats to human and ecosystem health. Their presence and significance, however, are often overlooked by heritage and environmental managers. To be acknowledged as artefacts of the historical mining industry, landscape features must be identified and characterised with reference to the human activities that triggered their formation. This requires an interdisciplinary approach that incorporates anthropogenic landscape change at a regional scale. In this paper, we integrate archaeological, geomorphological and geochemical evidence to identify and analyse mining-related changes to the Loddon River valley in Victoria, Australia. Nineteenth-century gold mining caused extensive erosion of creeks and gullies and mobilised sediments that filled channels and spread over floodplains. In addition, tailing deposits concentrated arsenic at levels significantly above environmental background conditions. Recognising these legacies of historical mining is vital to understanding mining heritage and to managing healthy rivers, environments and communities.