Advocate for US Science
Importance: Thermodynamic modeling of tuite, a high pressure phosphate mineral in some sublithospheric diamonds, shows that it is only stable in the very rare, coldest slabs and not typical slabs. This subduction difficulty in normal slabs provides an partial explanation for how phospohorous has reamines concentrated at Earth's surface where.it is essential for life.
Importance: The Mg and Fe isotopic composition of ferropericlase in sublithospheric diamonds from the Juina Brazil locality are used to propose a new model for forming sublithospheric diamonds from pockets of hydrated mantle surrounded by ahydrous mantle at depths near the top of the lower mantle.
Importance: Are there isotopic signatures that remain in Earth's mantle from the time of accretion? This paper uses the mass independant composition of potassium and mass balance arguments to estimate a proto-Earth composition that occasionally appears in some deep-seated igneous rocks suh as ocean island basalts.
Importance: Why does Bermuda, a mantle-plume-free volcano built lt on oceanic lithosphere even exist? This paper provides isotopic data to hypothesize that melting of this metasomatized mantle created by the supercontinent cycle was triggered by the arrival of the Farallon slab to the eastern North American margin in the late Cenozoic.