The importance of water to oceanic mantle melting regimes

@article{Asimow2003TheIO,
  title={The importance of water to oceanic mantle melting regimes},
  author={Paul D. Asimow and Charles H. Langmuir},
  journal={Nature},
  year={2003},
  volume={421},
  pages={815-820}
}
The formation of basaltic crust at mid-ocean ridges and ocean islands provides a window into the compositional and thermal state of the Earth's upper mantle. But the interpretation of geochemical and crustal-thickness data in terms of magma source parameters depends on our understanding of the melting, melt-extraction and differentiation processes that intervene between the magma source and the crust. Much of the quantitative theory developed to model these processes has neglected the role of… 

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References

SHOWING 1-10 OF 44 REFERENCES
Melt Generation at Very Slow-Spreading Oceanic Ridges: Constraints from Geochemical and Geophysical Data
We show that there is a strong and consistent correlation between geochemical and geophysical estimates of the amount of melt generated in the mantle beneath oceanic ridges. This correlation holds
Geochemical constraints on initial and final depths of melting beneath mid-ocean ridges
The comparison of the composition and volume of mid-ocean ridge basalts to predicted values inferred from experimental and theoretical studies is one of the primary tools for mapping thermal
Effects of the melting regime on the composition of the oceanic crust
The physical form of the melting regime and the mechanisms of melt extraction influence the composition of magmas erupted at ocean ridges. We investigate aspects of this relationship, beginning with
Low degree melting under the Southwest Indian Ridge: the roles of mantle temperature, conductive cooling and wet melting
Abstract Both low mantle temperatures and conductive cooling have been suggested as the cause of the atypically thin oceanic crust and the incompatible element enrichment characteristic of very
Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt
TLDR
It is demonstrated that basalts associated with mantle plume components containing subducted lithosphere—‘enriched-mantle’ or ‘EM-type’ basalts—contain less water than those associated with a common mantle source.
Global correlations of ocean ridge basalt chemistry with axial depth and crustal thickness
Regional averages of the major element chemistry of ocean ridge basalts, corrected for low-pressure fractionation, correlate with regional averages of axial depth for the global system of ocean
Water in the oceanic upper mantle: implications for rheology
Abstract The influence of water on the dynamics of the oceanic upper mantle is re-evaluated based on recent experimental constraints on the solubility of water in mantle minerals and earlier
Not So Hot "Hot Spots" in the Oceanic Mantle
TLDR
Some so-called hot spots might be melting anomalies unrelated to abnormally high mantle temperature or thermal plumes, which would lower the melting temperature of the hot spot mantle and thereby reconcile its high degree of melting with the lack of a mantle temperature anomaly.
Calculation of Peridotite Partial Melting from Thermodynamic Models of Minerals and Melts, IV. Adiabatic Decompression and the Composition and Mean Properties of Mid-ocean Ridge Basalts
Composition, mean pressure, mean melt fraction, and crustal thickness of model mid-ocean ridge basalts (MORBs) are calculated using MELTS. Polybaric, isentropic batch and fractional melts from ranges
The role of water in the petrogenesis of Mariana trough magmas
Most variations in composition among primitive basalts from the Mariana back-arc trough can be explained by melting mixtures of an NMORB-type mantle source and an H_2O-rich component, provided the
...
1
2
3
4
5
...