High water content of arc magmas recorded in cumulates from subduction zone lower crust
Abstract:
We report secondary ion mass spectrometry measurements of volatile (H2O, F, P, S, Cl) abundances in lower-crustal cumulate minerals from the Kohistan paleo-arc (NW Pakistan), and determine H2O abundances of melts from which the cumulates crystallized. Pyroxenes retained magmatic H2O abundances and record damp (less than 1% wt.% H2O) to hydrous (up to 10 wt.% H2O) primitive melts. Subsequent crystal fractionation led to formation of super-hydrous melts with approximately 12–20 wt.% H2O, predicted petrologically yet virtually absent from the melt inclusion record. Porphyry copper deposits are likely a natural eventuality of fluid exsolution from super-hydrous melts, corroborating a growing body of evidence.
How to cite this dataset:
Urann, B. M., Le Roux, V., Jagoutz, O., Müntener, O., Behn, M. D., Chin, E. J., 2022. High water content of arc magmas recorded in cumulates from subduction zone lower crust, Version 1.0. Interdisciplinary Earth Data Alliance (IEDA).
https://doi.org/10.26022/IEDA/112279. Accessed 2024-07-27.
DOI Creation Date:
2022-04-08
Related
Publication(s):
Urann, B., Le Roux, V., Jagoutz, O., Müntener O., Behn, M., Chin, E., High water content of arc magmas recorded in cumulates from subduction zone lower crust: Nature Geoscience (accepted March 2022).
License:
Creative Commons Attribution-ShareAlike 4.0 International [CC-BY-SA-4.0]
Funding source(s):
National Science Foundation:
0841006 National Science Foundation:
0841108 National Science Foundation:
1839128 National Science Foundation:
1855302 National Science Foundation:
1855430 National Science Foundation:
2126559Keyword(s):
Coverage Scope: Regional (Continents, Oceans)
Geographic Location: Chilas and Jijal Complexes, Kohistan Paleo-arc, NW Pakistan
User Contributed Keyword(s):
volatiles, arc magmas, Kohistan
Data Available On:
2022-05-01