|Ultramafic and mafic rocks from the Garret Transform Fault near 13 degree 30'S on the East Pacific Rise: Igneous petrology|
Hébert, R.; Bideau, D.; Hekinian, R. (1983). Ultramafic and mafic rocks from the Garret Transform Fault near 13 degree 30'S on the East Pacific Rise: Igneous petrology. Earth Planet. Sci. Lett. 65(1): 107-125
In: Earth and Planetary Science Letters. Elsevier: Amsterdam. ISSN 0012-821X, more
Igneous rocks; Petrology; ISE, East Pacific Rise [Marine Regions]; Marine
|Authors|| || Top |
- Hébert, R.
- Bideau, D.
- Hekinian, R.
Serpertinized peridotites, metagabbros and fresh basaltic rocks were dredged from the Garret Transform Fault near 13 degree S on the East Pacific Rise. Two dredge hauls taken on the northern wall (from about 3100-3600 m) consisted of aphyric and picritic basalts; while peridotites, gabbros and moderately phyric basalts were recovered in a single dredge located near the deepest part (4616-4820 m) of the transform valley. Well preserved igneous textures and mineralogical assemblages enabled differentiation between tectonites (including harzburgites and clinopyrozene-bearing harzburgites) and cumulates (consisting of plagioclase-dunite, troctolies, olivine-gabbros and ilmenite-gabbros). The harzburgites are likely to represent deep-seated peridoties left after extraction of basaltic melt during upper mantle partial melting of a lherzolite. The ultramafic cumulates underwent some deformation and show textural and mineralogical evidences which suggest formation at a minimum depth corresponding to the very lower crust.