Luminescence dating illuminates soil evolution

Abstract

Understanding soil chronology and evolution processes is fundamental for forecasting soil development and implementing effective conservation and management strategies. However, traditional quantitative methods that rely on radiogenic isotopic dating of secondary soil components (such as humus and pedogenic carbonates) often yield unreliable results due to soil's nature as an open system, where elemental cycling can substantially alter age signatures. This review presents an alternative perspective on soil evolution by examining common soil mineral grains, such as quartz and feldspar, using luminescence dating techniques, which determine the last time sediments were exposed to light. Over the past two decades, advances in single-grain luminescence dating have empowered the method's capacity to analyze dynamic, mixed soil systems. This review introduces the principles of luminescence dating and outlines its diverse applications across soil types. We list and explain indicators for quantifying soil mixing, methodologies for dating soils of varying disturbance degrees, and their application in reconstructing soil-landscape evolution processes. Finally, we highlight the advantages, challenges, and future directions for luminescence dating in soil evolution research. We conclude that luminescence dating holds significant promise as a tool for investigating soil evolution over time scales ranging from decades to millennia.