Poster Number 158
See more from this Division: Topical Sessions
See more from this Session: Whole Earth Systems Science: New Perspectives on the “Rock Cycle” from the Deep Earth to the Atmosphere to Life (Posters)
Abstract:
Experiments were conducted at the 10 MN (1,000 ton) LVP in 13-ID-D, GSECARS, APS. A 3mm TEL beamline modified assembly was used in all experiments - a Re furnace with lanthanum chromite insulating sleeve, alumina or MgO end caps and graphite capsule. Starting materials are fine powder, packed into the capsule. X-ray windows are a slit in the Re furnace and alumina or graphite plugs in the lanthanum chromite. MgO was used as a diffraction pressure standard. Runs were pressurized to 400, 600, 650 and 700 tons, and diffraction data were collected at temperature intervals between 1700 °C and 2400 °C.
Preliminary results for peridotite suggest the liquidus at 22 GPa occurs at 2350 °C, with ferropericlase as the liquidus phase. For Allende, Mg,Fe perovskite is the liquidus phase above 21 GPa and 2050 °C. A shallow perovskite liquidus slope, steep ferropericlase slope is consistent with deeper, hotter magma ocean. The ferropericlase slope may be very steep, and become the liquidus phase above 25 GPa. In a magma ocean crystallizing from the bottom up, this scenario may not crystallize enough perovskite to drive an oxidation pump of the mantle.
See more from this Division: Topical Sessions
See more from this Session: Whole Earth Systems Science: New Perspectives on the “Rock Cycle” from the Deep Earth to the Atmosphere to Life (Posters)