Cubic Fe-bearing majorite synthesized at 18-25 GPa and 1000 °C: implications for element transport, subducted slab rheology and diamond formation.

ABSTRACT: The chemistry and mineralogy of slabs subducted into lower mantle control slab rheology and impact the deep volatile cycle. It is known that the metamorphism of little-altered oceanic crust results in eclogite rocks with subequal proportions of garnet and clinopyroxene. With increasing pressure, these minerals react to stabilize pyrope-rich tetragonal majoritic garnet. However, some eclogites contain higher proportions of omphacitic clinopyroxene, caused by Na- and Si-rich metasomatism on the ocean floor or during subduction. The mineralogy of such eclogites is expected to evolve differently. Here, we discuss the results of the crystallization products of omphacitic glass at ~ 18 and ~ 25 GPa and 1000 °C to simulate P-T regimes of cold subduction. The full characterization of the recovered

SUBMITTER: Stagno V 

PROVIDER: S-EPMC10516933 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature