HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Deciphering Degassing and Source Effects in Cl Isotopes in Melt Inclusions: The Possible Role of Amphibole in the Magma Source of Stromboli (Aeolian Island Arc)

Abstract : Chlorine isotopes have emerged as a new geochemical tool over the past 15 years. Most of the data consist of bulk rock data, with a minority carried out in situ on melt inclusions using secondary ion mass spectrometry. More data are necessary to understand the relationship between δ 37 Cl measured in melt inclusions and that in bulk rocks from the same volcanic center. Here we have analyzed a suite of melt inclusions entrapped in olivine Fo 63-85 , as well as some from clinopyroxene crystals, from a single hand-sample from the Vancori unit of Stromboli, Aeolian Islands. The 27 selected melt inclusions have major element compositions ranging from high potassium alkali basalt to evolved shoshonite. Their δ 37 Cl vary from −2.6 ± 0.1‰ to +1.2 ± 0.2‰, a far larger range than for Stromboli bulk rocks. In this dataset, the δ 37 Cl variation in melt inclusions is not related to Cl degassing, or to fractional crystallization. Instead, correlations between δ 37 Cl and S/Cl, K 2 O and trace element ratios suggest mixing of two Cl endmembers with distinct δ 37 Cl signatures. A first endmember is characterized by high potassium alkali basalt compositions, high Ba/La (∼28), high S/Cl, and high δ 37 Cl (>1‰), confirming the influence in the mantle source of an aqueous fluid and providing a new constraint on its composition: that it derives from the breakdown of amphibole. The second endmember has a more evolved composition, high La/Yb, low S/Cl, and low δ 37 Cl (<−2‰), identifying the influence of a solute-rich component derived from subducted sediments. The δ 37 Cl data thus help refine the two sources initially identified from bulk rock studies and δ 37 Cl proves to be a potential tracer for amphibole.
Document type :
Journal articles
Complete list of metadata

https://hal.uca.fr/hal-03561197
Contributor : Sylvaine Jouhannel Connect in order to contact the contributor
Submitted on : Tuesday, February 8, 2022 - 10:00:28 AM
Last modification on : Thursday, February 10, 2022 - 3:35:15 AM
Long-term archiving on: : Monday, May 9, 2022 - 6:23:07 PM

File

Frontiers in Earth Science 202...
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Anne-Sophie Bouvier, Estelle Rose-Koga, Alexis Chapuis. Deciphering Degassing and Source Effects in Cl Isotopes in Melt Inclusions: The Possible Role of Amphibole in the Magma Source of Stromboli (Aeolian Island Arc). Frontiers in Earth Science, Frontiers Media, 2022, 9, ⟨10.3389/feart.2021.793259⟩. ⟨hal-03561197⟩

Share

Metrics

Record views

44

Files downloads

31