The temperature of the Icelandic mantle from olivine-spinel aluminum exchange thermometry ...

• Main Authors: Matthews, S, Shorttle, O, Maclennan, J
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: 37 Earth Sciences; 3703 Geochemistry; 3705 Geology; 3706 Geophysics; Iceland
• Online Access: https://dx.doi.org/10.17863/cam.7454; https://www.repository.cam.ac.uk/handle/1810/262197

New crystallization temperatures for four eruptions from the Northern Volcanic Zone of Iceland are determined using olivine-spinel aluminum exchange thermometry. Differences in the olivine crystallization temperatures between these eruptions are consistent with variable extents of cooling during fractional crystallization. However, the crystallization temperatures for Iceland are systematically offset to higher temperatures than equivalent olivine-spinel aluminum exchange crystallization temperatures published for MORB, an effect that cannot be explained by fractional crystallization. The highest observed crystallization temperature in Iceland is 1399 ± 20°C. In order to convert crystallization temperatures to mantle potential temperature, we developed a model of multilithology mantle melting that tracks the thermal evolution of the mantle during isentropic decompression melting. With this model, we explore the controls on the temperature at which primary melts begin to crystallize, as a function of source ...