Late glacial and Holocene sand drift in northern Götaland and Värmland, Sweden: sediments and ages

Abstract

ABSTRACTThe aeolian deposits of Sweden have received modest attention, despite their usefulness as a palaeoenvironmental archive. Here we present sedimentological information and optically stimulated luminescence (OSL) ages from inland sand dunes in the lowlands of south-central Sweden. Three main lithofacies, each with two subfacies, were identified in the deposits: massive sand, laminated sand and cross-bedded sand. Massive sand was most common and present at all sites, and is largely due to secondary bioturbation when found close to the surface. Other prevalent depositional processes are wind-ripple migration and grain flow. Secondary features include animal burrows and tracks, root traces, infiltration structures and soil profiles. The luminescence ages plot in two different groups, centred in the early and late Holocene, respectively. The primary dune-forming phase occurred in the early Holocene, after local deglaciation and uplift above sea/lake level. However, at some sites, OSL ages suggest a prolonged phase of sand drift, or repeated reworking, long after deglaciation due to locally beneficial conditions. The late Holocene was dominated by reactivation events and sheet sand deposition, which led to the formation of an aeolian mantle.