(Table 2) Chlorine geochemistry and mineralogy of altered oceanic crust samples


Bulk chlorine concentrations and chlorine stable isotope compositions were determined for hydrothermally altered basalt (extrusive lavas and sheeted dikes) and gabbro samples (n = 50) from seven DSDP/ODP/IODP drill sites. These altered oceanic crust (AOC) samples span a range of crustal ages, tectonic settings, alteration type, and crustal depth. Bulk chlorine concentrations range from =~0.5 per mil) are associated with areas of higher amphibole content. This observation is consistent with theoretical calculations that estimate amphibole should be enriched in 37Cl compared to co-existing fluid. Negative to near zero d37Cl values are found in areas dominated by clay minerals. Chlorine geochemistry is a rough indicator of metamorphic grade and mineralogy. AOC is a major Cl host in the subducting oceanic lithospheric slab. Here we show that bulk chlorine concentrations are ~3 times higher than previous estimates resulting in a greater contribution of Cl to the mantle.

Supplement to: Barnes, Jaime D; Cisneros, Miguel (2012): Mineralogical control on the chlorine isotope composition of altered oceanic crust. Chemical Geology, 326-327, 51-60

DOI https://doi.org/10.1594/PANGAEA.812212
Related Identifier IsSupplementTo https://doi.org/10.1016/j.chemgeo.2012.07.022
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.812212
Creator Barnes, Jaime D; Cisneros, Miguel ORCID logo
Publisher PANGAEA
Publication Year 2012
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 293 data points
Discipline Earth System Research
Spatial Coverage (-101.525W, -32.724S, 156.360E, 36.879N); North Atlantic/VALLEY; North Atlantic/CONT RISE; South Indian Ridge, South Indian Ocean; North Pacific Ocean
Temporal Coverage Begin 1974-06-17T00:00:00Z
Temporal Coverage End 2002-11-23T03:45:00Z