Assimilation of the Plutonic Roots of the Andean Arc Controls Variations in U-series Disequilibria at Volcan Llaima, Chile

DSpace/Manakin Repository

Assimilation of the Plutonic Roots of the Andean Arc Controls Variations in U-series Disequilibria at Volcan Llaima, Chile

Citable link to this page

 

 
Title: Assimilation of the Plutonic Roots of the Andean Arc Controls Variations in U-series Disequilibria at Volcan Llaima, Chile
Author: Reubi, O.; Bourdon, B.; Dungan, M.A.; Koornneef, J.M.; Sellés, D.; Langmuir, Charles H.; Aciego, S.

Note: Order does not necessarily reflect citation order of authors.

Citation: Reubi, O., B. Bourdon, M.A. Dungan, J.M. Koornneef, D. Sellés, C.H. Langmuir, and S. Aciego. 2011. Assimilation of the plutonic roots of the Andean arc controls variations in U-series disequilibria at Volcan Llaima, Chile. Earth and Planetary Science Letters 303 (1-2): 37-47.
Access Status: Full text of the requested work is not available in DASH at this time (“dark deposit”). For more information on dark deposits, see our FAQ.
Full Text & Related Files:
Abstract: U-series disequilibria provide important constraints on the processes and time scales of melt production, differentiation, and transport in subduction settings. Such constraints, which are essential for understanding the chemical evolution of the continental crust, are conventionally based on the assumption that the U-series disequilibria measured in mafic lavas are produced during mantle metasomatism and melting, and that intracrustal differentiation and assimilation have limited impacts. Here we show that mantle-derived U-series disequilibria in mafic lavas erupted at Volcán Llaima, Chile are significantly diminished by assimilation of plutonic rocks forming Llaima's subvolcanic basement. This contamination process is extremely subtle in terms of “classical” indicators of crustal assimilation like Sr, Nd or Pb isotopes because it is a manifestation of assimilative recycling of the plutonic roots of the arc. This process results in variations in U-series disequilibria and incompatible trace element ratios that are significant compared to regional and global variability in arc magmas. Furthermore, it yields linear correlations between U-series excesses and incompatible trace element ratios that are generally interpreted as slab-fluid indicators and chronometers, or tracers of sediment recycling in subduction zone. Cannibalization of ancestral magmas by ascending melts warrants careful evaluation when considering the components and chemical fluxes in subduction zones. Linear arrays defined by activity ratios of U-series nuclides with different half-lives may be the most reliable indicators of assimilative recycling of ancestral intrusive magmas.
Published Version: doi:10.1016/j.epsl.2010.12.018
Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:32116901
Downloads of this work:

Show full Dublin Core record

This item appears in the following Collection(s)

 
 

Search DASH


Advanced Search
 
 

Submitters