Temperature dependence of pedogenic magnetic mineral formation in loess deposits

Abstract

Loess sequences provide some of the most important continental records of climatic change, and various pedogenesis proxies from Chinese loess deposits have provided humidity records for the Miocene through Holocene. Amongst these proxies, magnetic properties have often been used to reconstruct paleoprecipitation; however, an increasing number of studies have recognized that magnetic records from loess deposits are also influenced by temperature and hence they can be used to reconstruct paleotemperatures. In the present study, the magnetic characteristics of modern loessic soils and loessic paleosols from five regions spanning a broad climatic gradient were studied to investigate the temperature dependence of the pedogenic production of magnetic minerals. The results indicate that the magnetic characteristics are dependent on the temperature of particularly season, rather than mean annual temperature in temperate region. The findings can potentially provide insights into changes in climatic seasonality on geological timescales.