Dust Deposition and Loess Accretion in New Zealand's South Island: Examining Links between Cold‐Climate Processes and Dust Production

We compared temporal variability in dust and loess accretion in New Zealand's South Island with glacial activity in the central Southern Alps, considered the main mechanism of silt production, in (i) a proximal loess deposit at Barrhill, Rakaia River and (ii) a distal dust record from a peat mire in Central Otago. We applied novel luminescence dating approaches at Barrhill, targeting both polymineral silt and K‐feldspar sand. Results demonstrated loess accretion began from ~8.5 ± 1.7 ka, with accumulation rates increasing by 7 times after ~2 ka, before decreasing toward the present. In the peat record, trace‐element geochemistry was used to distinguish New Zealand‐sourced dust from Australian dust. Like Barrhill, deposition of New Zealand‐sourced dust increased by ~4 times from ~3 ka, while also recording high deposition during the Little Ice Age. Changing dustiness in both records is attributed to climate‐modulated sediment production. At Barrhill, this was linked directly to glacial advances in the Rakaia catchment, while in the more distal peat mire it likely resulted from enhanced periglacial activity. Together, both records demonstrate that dustiness closely tracks glacial variability in the South Island, highlighting potential for further detailed studies of dust production and glacial dynamics from New Zealand's loess.