Martínez Cortizas, Antonio and López-Costas, Olalla and Orme, Lisa C. and Mighall, Timothy and Kylander, Malin E. and Bindler, Richard and Gallego-Sala, Angela V. (2019) Holocene atmospheric dust deposition in NW Spain. Holocene, 30 (4). pp. 507-518. ISSN 0959-6836

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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 nutrientpoor 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.

Item Type:	Article
Additional Information:	Cite as: Martínez Cortizas A, López-Costas O, Orme L, et al. Holocene atmospheric dust deposition in NW Spain. The Holocene. 2020;30(4):507-518. doi:10.1177/0959683619875193
Keywords:	dust; Holocene; human activities; NAO; peat records; storminess;
Academic Unit:	Faculty of Social Sciences > Geography Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
Item ID:	13604
Identification Number:	https://doi.org/10.1177/0959683619875193
Depositing User:	Lisa Orme
Date Deposited:	23 Nov 2020 15:38
Journal or Publication Title:	Holocene
Publisher:	SAGE Publications
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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