Melting in the Earth's deep upper mantle caused by carbon dioxide
Top Cited Papers
- 1 March 2006
- journal article
- letter
- Published by Springer Science and Business Media LLC in Nature
- Vol. 440 (7084), 659-662
- https://doi.org/10.1038/nature04612
Abstract
The onset of partial melting beneath mid-ocean ridges governs the cycling of highly incompatible elements from the mantle to the crust1, the flux of key volatiles (such as CO2, He and Ar)1,2 and the rheological properties of the upper mantle3. Geophysical observations4,5,6 indicate that melting beneath ridges begins at depths approaching 300 km, but the cause of this melting has remained unclear. Here we determine the solidus of carbonated peridotite from 3 to 10 GPa and demonstrate that melting beneath ridges may occur at depths up to 330 km, producing 0.03–0.3% carbonatite liquid. We argue that these melts promote recrystallization and realignment of the mineral matrix, which may explain the geophysical observations. Extraction of incipient carbonatite melts from deep within the oceanic mantle produces an abundant source of metasomatic fluids and a vast mantle residue depleted in highly incompatible elements and fractionated in key parent-daughter elements. We infer that carbon, helium, argon and highly incompatible heat-producing elements (such as uranium, thorium and potassium) are efficiently scavenged from depths of ∼ 200–330 km in the upper mantle.Keywords
This publication has 32 references indexed in Scilit:
- Deep structure and seismic anisotropy beneath the East Pacific RiseEarth and Planetary Science Letters, 2005
- Hydrogen partition coefficients between nominally anhydrous minerals and basaltic meltsGeophysical Research Letters, 2004
- Carbon dioxide cycling and implications for climate on ancient EarthJournal of Geophysical Research, 2001
- Mantle solidus: Experimental constraints and the effects of peridotite compositionGeochemistry, Geophysics, Geosystems, 2000
- Ultrafast mantle impregnation by carbonatite meltsGeology, 2000
- Water and carbon in the Earth´s mantlePhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1996
- Melting phase relations of an anhydrous mid‐ocean ridge basalt from 3 to 20 GPa: Implications for the behavior of subducted oceanic crust in the mantleJournal of Geophysical Research, 1994
- Distribution and evolution of carbon and nitrogen in EarthEarth and Planetary Science Letters, 1993
- The volatiles record of a “popping” rock from the Mid-Atlantic Ridge at 14°N: chemical and isotopic composition of gas trapped in the vesiclesEarth and Planetary Science Letters, 1991
- The solidus of carbonated, fertile peridotiteEarth and Planetary Science Letters, 1989