The role of African dust in the formation of Quaternary soils on Mallorca, Spain and implications for the genesis of Red Mediterranean soils

Authors

Daniel R. Muhs, U.S. Geological SurveyFollow
James Budahn, U.S. Geological Survey
Anna Avila, Universitat Autònoma de Barcelona
Gary Skipp, U.S. Geological SurveyFollow
Joshua Freeman, U.S. Geological Survey
DeAnna Patterson, ATA Services, Inc., Lakewood, CO

Document Type

Article

Date of this Version

2010

Citation

Quaternary Science Reviews 29 (2010) 2518e2543

doi:10.1016/j.quascirev.2010.04.013

Comments

U.S. government work

Abstract

African dust additions explain the origin of terra rossa soils that are common on the carbonate-platform island of Mallorca, Spain. Mineralogical and geochemical analyses indicate that Quaternary carbonate eolianites on Mallorca have a very high purity, usually composed of more than 90% carbonate minerals (calcite, dolomite, and aragonite). In contrast, terra rossa soils developed on these eolianites have lower carbonate contents and contain higher concentrations of quartz and other silicates. Analyses of immobile trace elements indicate that the non-carbonate fractions of the eolianites have distinctive Zr/Hf, La/Yb, Cr/Sc and Th/Ta values that differ from the superjacent terra rossa soils. These observations indicate that even if suf!cient dissolution of the eolianite had taken place to create the soils by residual accumulation, immobile element ratios in the soils require an external source. However, Zr/Hf, La/Yb, Cr/Sc and Th/Ta values in the soils fall within the range of values for these element ratios in African dust collected on Barbados and mainland Spain. We conclude that the silicate fractions of terra rossa soils on Mallorca are derived mainly, though not wholly, from far-traveled African dust, and this process may explain the origin of other terra rossa soils found in southern Europe.