Holocene atmospheric dust deposition in NW Spain

Antonio Martínez Cortizas* (Corresponding Author), Olalla López-Costas, Lisa Orme, Tim Mighall, Malin E. Kylander, Richard Bindler, Angela Gallego-Sala

*Corresponding author for this work

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Abstract

Atmospheric dust plays an important role in terrestrial and marine ecosystems, particularly those that are nutrient limited. Despite that most dust originates from arid and semi-arid regions, recent research has shown that past dust events may have been involved in boosting productivity in nutrient-poor peatlands. We investigated dust deposition in a mid-latitude, raised bog, which is surrounded by a complex geology (paragneiss/schist, granite, quartzite and granodiorite). As proxies for dust fluxes, we used accumulation rates of trace (Ti, Zr, Rb, Sr and Y) as well as major (K and Ca) lithogenic elements. The oldest, largest dust deposition event occurred between ~8.6 and ~7.4 ka BP, peaking at ~8.1 ka BP (most probably the 8.2 ka BP event). The event had a large impact on the evolution of the mire, which subsequently transitioned from a fen into a raised bog in ~1500 years. From ~6.7 to ~4.0 ka BP, fluxes were very low, coeval with mid-Holocene forest stability and maximum extent. In the late Holocene, after ~4.0 ka BP, dust events became more prevalent with relatively major deposition at ~3.2–2.5, ~1.4 ka BP and ~0.35–0.05 ka BP, and minor peaks at ~4.0–3.7, ~1.7, ~1.10–0.95 ka BP and ~0.74–0.58 ka BP. Strontium fluxes display a similar pattern between ~11 and ~6.7 ka BP but then became decoupled from the other elements from the mid Holocene onwards. This seems to be a specific signal of the granodiorite batholith, which has an Sr anomaly. The reconstructed variations in dust fluxes bear a strong climatic imprint, probably related to storminess controlled by North Atlantic Oscillation conditions. Complex interactions also arise because of increased pressure from human activities.
Original languageEnglish
Pages (from-to)507-518
Number of pages11
JournalThe Holocene
Volume30
Issue number4
Early online date18 Sep 2019
DOIs
Publication statusPublished - 1 Apr 2020

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Keywords

  • peat records
  • dust
  • Holocene
  • storminess
  • NAO
  • human activities
  • PEAT BOG
  • GREAT BOG
  • STORE MOSSE
  • IBERIAN PENINSULA
  • NORTH-ATLANTIC OSCILLATION
  • TRACE-ELEMENTS
  • PB
  • TIERRA-DEL-FUEGO
  • SOIL-EROSION
  • CLIMATE

ASJC Scopus subject areas

  • Earth-Surface Processes
  • Archaeology
  • Global and Planetary Change
  • Palaeontology
  • Ecology

Cite this

Martínez Cortizas, A., López-Costas, O., Orme, L., Mighall, T., Kylander, M. E., Bindler, R., & Gallego-Sala, A. (2020). Holocene atmospheric dust deposition in NW Spain. The Holocene, 30(4), 507-518. https://doi.org/10.1177/0959683619875193