Abstract
The mineral composition of oceanic crust is a function of pressure and temperature and thus changes as a slab of crust descends a subduction zone. A knowledge of the mineralogy of subducted material would provide important constraints on its geophysical characteristics. We have sought, by means of high pressure laboratory experiments (in the pressure range 4.6–18 GPa) on a synthetic mix with the composition of mid-ocean ridge basalt (MORB), to determine the sequence of mineralogical changes. We find that at 1,200°C, solid solution of pyroxene in garnet begins around 10 GPa, and increases substantially between 12 and 15 GPa. Complete transformation of eclogite to garnetite is achieved at 15 GPa. The garnetite has a zero-pressure density of 3.76 g cm−3 and accordingly would be denser than the surrounding mantle throughout its stability field, which extends to depths of ˜600 km. If subducted to greater depths, garnetite may transform to perovskitite.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Green, D. H., Hibberson, W. O. & Jaques, A. L. in The Earth: Its Origin, Structure and Evolution (ed. McElhinny, M. W.) 265–299 (Academic, London, 1979).
Sekine, T. & Ringwood, A. E. Phys. Earth planet. Inter. (in the press).
Irifune, T. & Hibberson, W. O. High Temp. High Press. (submitted).
Ringwood, A. E. Earth planet. Sci. Lett. 2, 255–263 (1967).
Liu, L. Phys. Earth planet. Inter. 23, 262–267 (1980).
Ringwood, A. E. J. Geol. 90, 611–643 (1982).
Irifune, T., Sekine, T., Ringwood, A. E. & Hibberson, W. O. Earth planet. Sci. Lett. (submitted).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sekine, T., Irifune, T., Ringwood, A. et al. High-pressure transformation of eclogite to garnetite in subducted oceanic crust. Nature 319, 584–586 (1986). https://doi.org/10.1038/319584a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/319584a0
This article is cited by
-
Granites and thermal structures in the lithosphere
Geologische Rundschau (1987)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.