Plume-Associated Ultramafic Magmas of Phanerozoic Age

Herzberg, Claude; O’Hara, M. J.

doi:10.1093/petrology/43.10.1857

Cited by 439 publications

(432 citation statements)

References 102 publications

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“…We assume olivine crystallization occurs at near atmospheric pressure. At high pressures within the melting regime, the model of Toplis [2005] is similar to that of Herzberg and O'Hara [2002]; pressure effects on K D will be examined below. The temperature at which olivine crystallizes, which is required in the Toplis K D , is calculated from the method of Beattie [1993], also discussed below.…”

Section: Calculation Of Parental Magmamentioning

confidence: 99%

“…(b) Illustration showing the method for computing primary magma composition of the lavas in Figure 1a. Red lines indicate FeO and MgO contents of accumulated fractional melts of depleted peridotite at the melt fractions F shown [Herzberg and O'Hara, 2002]. Green arrows illustrate the approximate range of instantaneous fractional melts that, when mixed together, produce the accumulated fractional melts.…”

Section: Calculation Of Parental Magmamentioning

confidence: 99%

“…Crosses in white circles indicate primary magmas formed at the same melt fractions as those given in Figure 2. MgO contents do not change much with decompression because dT/dP of isopleths of MgO in partial melts of peridotite approximately parallel the adiabatic gradient [Herzberg and O'Hara, 2002] (but see small changes in Appendix A for fertile peridotite). Black, red, and blue circles are whole rock and glass data from Figure 1a.…”

Section: Calculation Of Parental Magmamentioning

confidence: 99%

“…The derivation of a primary magma solely by reconstruction from observed rocks is not a welldefined procedure and this has led to considerable divergence of opinion on the nature of primary magmas. Following Herzberg and O'Hara [2002], we supplement reconstruction of parental magmas with forward calculations of mantle melting to constrain primary magma compositions. A detailed example is given as a tutorial in Appendix A.…”

Section: Introductionmentioning

confidence: 99%

“…Both methods give the same results (Appendix A), and the solutions reported by Herzberg and O'Hara [2002] will be used here. Results for major elements are not significantly affected by including a small trapped melt fraction within a residual porosity.…”

Section: Introductionmentioning

confidence: 99%

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Temperatures in ambient mantle and plumes: Constraints from basalts, picrites, and komatiites

Herzberg

Asimow

Arndt

et al. 2007

Geochem Geophys Geosyst

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639

449

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International audienceSeveral methods have been developed to assess the thermal state of the mantle below oceanic ridges, islands, and plateaus, on the basis of the petrology and geochemistry of erupted lavas. One leads to the conclusion that mantle potential temperature (i.e., TP) of ambient mantle below oceanic ridges is 1430°C, the same as Hawaii. Another has ridges with a large range in ambient mantle potential temperature (i.e., TP = 1300–1570°C), comparable in some cases to hot spots (Klein and Langmuir, 1987; Langmuir et al., 1992). A third has uniformly low temperatures for ambient mantle below ridges, ∼1300°C, with localized 250°C anomalies associated with mantle plumes. All methods involve assumptions and uncertainties that we critically evaluate. A new evaluation is made of parental magma compositions that would crystallize olivines with the maximum forsterite contents observed in lava flows. These are generally in good agreement with primary magma compositions calculated using the mass balance method of Herzberg and O'Hara (2002), and differences reflect the well-known effects of fractional crystallization. Results of primary magma compositions we obtain for mid-ocean ridge basalts and various oceanic islands and plateaus generally favor the third type of model but with ambient mantle potential temperatures in the range 1280–1400°C and thermal anomalies that can be 200–300°C above this background. Our results are consistent with the plume model

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Section: Calculation Of Parental Magmamentioning

confidence: 99%

Section: Calculation Of Parental Magmamentioning

confidence: 99%

Section: Calculation Of Parental Magmamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Temperatures in ambient mantle and plumes: Constraints from basalts, picrites, and komatiites

Herzberg

Asimow

Arndt

et al. 2007

Geochem Geophys Geosyst

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639

449

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Calculation of water-bearing primary basalt and estimation of source mantle conditions beneath arcs: PRIMACALC2 model for WINDOWS

Kimura

Ariskin²

2014

Geochem. Geophys. Geosyst.

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We present a new method for estimating the composition of water-bearing primary arc basalt and its source mantle conditions. The PRIMACALC2 model uses a thermodynamic fractional crystallization model COMAGMAT3.72 and runs with an Excel macro to examine the mantle equilibrium and trace element calculations of a primary basalt. COMAGMAT3.72 calculates magma fractionation in 0-10 kb at various compositions, pressure, oxygen fugacity, and water content, but is only applicable for forward calculations. PRI-MACALC2 first calculates the provisional composition of a primary basalt from an observed magma. The basalt composition is then calculated by COMAGMAT3.72 for crystallization. Differences in elemental concentrations between observed and the closest-match calculated magmas are then adjusted in the primary basalt. Further iteration continues until the calculated magma composition converges with the observed magma, resulting in the primary basalt composition. Once the fitting is satisfied, back calculations of trace elements are made using stepwise addition of fractionated minerals. Mantle equilibrium of the primary basalt is tested using the Fo-NiO relationship of olivine in equilibrium with the primary basalt, and thus with the source mantle. Source mantle pressure, temperature, and degree of melting are estimated using petrogenetic grids based on experimental data obtained in anhydrous systems. Mantle melting temperature in a hydrous system is computed by adjusting T with a parameterization for a water-bearing system. PRIMA-CALC2 can be used either in dry or water-bearing arc magmas and is also applicable to mid-ocean ridge basalts and nonalkalic ocean island basalts.

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Trace element mass balance in hydrous adiabatic mantle melting: The Hydrous Adiabatic Mantle Melting Simulator version 1 (HAMMS1)

Kimura

Kawabata

2014

Geochem Geophys Geosyst

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A numerical mass balance calculation model for the adiabatic melting of a dry to hydrous peridotite has been programmed in order to simulate the trace element compositions of basalts from midocean ridges, back-arc basins, ocean islands, and large igneous provinces. The Excel spreadsheet-based calculator, Hydrous Adiabatic Mantle Melting Simulator version 1 (HAMMS1) uses (1) a thermodynamic model of fractional adiabatic melting of mantle peridotite, with (2) the parameterized experimental melting relationships of primitive to depleted mantle sources in terms of pressure, temperature, water content, and degree of partial melting. The trace element composition of the model basalt is calculated from the accumulated incremental melts within the adiabatic melting regime, with consideration for source depletion. The mineralogic mode in the primitive to depleted source mantle in adiabat is calculated using parameterized experimental results. Partition coefficients of the trace elements of mantle minerals are parameterized to melt temperature mostly from a lattice strain model and are tested using the latest compilations of experimental results. The parameters that control the composition of trace elements in the model are as follows: (1) mantle potential temperature, (2) water content in the source mantle, (3) depth of termination of adiabatic melting, and (4) source mantle depletion. HAMMS1 enables us to obtain the above controlling parameters using Monte Carlo fitting calculations and by comparing the calculated basalt compositions to primary basalt compositions. Additionally, HAMMS1 compares melting parameters with a major element model, which uses petrogenetic grids formulated from experimental results, thus providing better constraints on the source conditions.

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Plume-Associated Ultramafic Magmas of Phanerozoic Age

Cited by 439 publications

References 102 publications

Temperatures in ambient mantle and plumes: Constraints from basalts, picrites, and komatiites

Temperatures in ambient mantle and plumes: Constraints from basalts, picrites, and komatiites

Calculation of water-bearing primary basalt and estimation of source mantle conditions beneath arcs: PRIMACALC2 model for WINDOWS

Trace element mass balance in hydrous adiabatic mantle melting: The Hydrous Adiabatic Mantle Melting Simulator version 1 (HAMMS1)

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