scholarly journals Mantle Source Heterogeneity Inferred from Olivine-Hosted Melt Inclusions

2020 ◽  
Author(s):  
Mischa Böhnke ◽  
Felix Genske ◽  
Andreas Stracke
Keyword(s):  
Mantle Source ◽  
Melt Inclusions ◽  
Source Heterogeneity

scholarly journals Investigating ocean island mantle source heterogeneity with boron isotopes in melt inclusions

2019 ◽  
Vol 508 ◽  
pp. 97-108 ◽  
Author(s):  
K.J. Walowski ◽  
L.A. Kirstein ◽  
J.C.M. De Hoog ◽  
T.R. Elliott ◽  
I.P. Savov ◽  
...  
Keyword(s):  
Mantle Source ◽  
Melt Inclusions ◽  
Boron Isotopes ◽  
Ocean Island ◽  
Source Heterogeneity

Mantle source heterogeneity for South Tyrrhenian magmas revealed by Pb isotopes and halogen contents of olivine-hosted melt inclusions

2012 ◽  
Vol 334 ◽  
pp. 266-279 ◽  
Author(s):  
Estelle F. Rose-Koga ◽  
Kenneth T. Koga ◽  
Pierre Schiano ◽  
Marion Le Voyer ◽  
Nobumichi Shimizu ◽  
...  
Keyword(s):  
Mantle Source ◽  
Melt Inclusions ◽  
Pb Isotopes ◽  
Source Heterogeneity

Sulfide mantle source heterogeneity recorded in basaltic lavas from the Azores

2020 ◽  
Vol 268 ◽  
pp. 422-445 ◽  
Author(s):  
Christopher L. Waters ◽  
James M.D. Day ◽  
Shizuko Watanabe ◽  
Kaan Sayit ◽  
Vittorio Zanon ◽  
...  
Keyword(s):  
Mantle Source ◽  
Source Heterogeneity ◽  
Basaltic Lavas

scholarly journals Constraining Mantle Heterogeneity beneath the South China Sea: A New Perspective on Magma Water Content

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 410 ◽  
Author(s):  
Wei Wang ◽  
Fengyou Chu ◽  
Xichang Wu ◽  
Zhenggang Li ◽  
Ling Chen ◽  
...  
Keyword(s):  
South China Sea ◽  
Water Content ◽  
South China ◽  
Mantle Source ◽  
Melt Inclusions ◽  
The South China Sea ◽  
Spreading Ridge ◽  
Mantle Heterogeneity ◽  
The South ◽  
China Sea

The nature of upper mantle is important to understand the evolution of the South China Sea (SCS); thus, we need better constrains on its mantle heterogeneity. Magma water concentration is a good indicator, but few data have been reported. However, the rarity of glass and melt inclusions and the special genesis for phenocrysts in SCS basalts present challenges to analyzing magmatic water content. Therefore, it is possible to estimate the water variations through the characteristics of partial melting and magma crystallization. We evaluated variations in Fe depletion, degree of melt fractions, and mantle source composition along the fossil spreading ridge (FSR) using SCS basalt data from published papers. We found that lava from the FSR 116.2° E, FSR 117.7° E, and non-FSR regions can be considered normal lava with normal water content; in contrast, lava from the FSR 117° E-carbonatite and 114.9–115.0° E basalts have higher water content and show evidence of strong Fe depletion during the fractional crystallization after elimination of the effects of plagioclase oversaturation. The enriched water in the 117° E-carbonatite basalts is contained in carbonated silicate melts, and that in the 114.9–115.0° E basalts results from mantle contamination with the lower continental crust. The lava from the 117° E-normal basalt has much lower water content because of the lesser influence of the Hainan plume. Therefore, there must be a mantle source compositional transition area between the southwestern and eastern sub-basins of the SCS, which have different mantle evolution histories. The mantle in the west is more affected by contamination with continental materials, while that in the east is more affected by the Hainan mantle plume.

Comparative Geothermometry in High-Mg Magmas from the Etendeka Province and Constraints on their Mantle Source

2019 ◽  
Vol 60 (12) ◽  
pp. 2509-2528
Author(s):  
Zhiguo Cheng ◽  
Tong Hou ◽  
Jakob K Keiding ◽  
Ilya V Veksler ◽  
Vadim S Kamenetsky ◽  
...  
Keyword(s):  
Trace Element ◽  
Mantle Source ◽  
Melt Inclusions ◽  
Relative Proportion ◽  
Flood Basalt ◽  
Reliable Estimate ◽  
Thermal Plume ◽  
Continental Flood Basalt ◽  
Rock Composition ◽  
Liquidus Temperatures

Abstract There is still debate whether Large Igneous Provinces (LIPs) are caused by high mantle temperatures induced by thermal plumes or by other factors that enhance melt production from the mantle. A prerequisite for assessing the thermal plume model is a reliable estimate of liquidus temperatures of the magmas produced, preferably based on more than one method of geothermometry. The study reported here compares multiple geothermometers for the Etendeka LIP, which is among the largest Phanerozoic examples and one that shows several features suggestive of a plume origin (continental flood basalt province linked via an age-progressive volcanic ridge to an active hotspot). Magnesium (Mg)-rich magmas emplaced as dikes in NW Namibia are the most primitive rocks known from this province and are thus best suited to determine the composition and melting conditions of their mantle source. Earlier studies of the Etendeka Mg-rich dikes reported high liquidus temperatures based on olivine-melt Mg–Fe equilibria. We extend that work to a larger set of samples and compare the results of olivine-melt Mg–Fe thermometry with other methods based on spinel-melt and spinel–olivine equilibria (Al-in-olivine thermometry), as well as olivine-melt trace-element exchange (Sc/Y thermometry and V oxybarometry). All methods used the same starting assumptions of nominally anhydrous melts and a crystallization pressure of 0·5 GPa. Only mineral-melt or mineral-mineral pairs consistent with compositional equilibrium were used for calculating temperatures. The trace-element compositions of olivine are also used to discuss the relative proportion of peridotite and pyroxenite in the mantle source for these magmas. Twelve dike samples were studied, with whole-rock MgO concentrations ranging from 8·4 to 19·4 wt %. Diagnostic element ratios of transition metals in olivine (e.g., Mn/Fe, Mn/Zn, Zn/Fe) indicate a peridotite-dominated mantle source for the magmas, which is consistent with the other indicators based on whole-rock data e.g., 10 000×Zn/Fe, CaO–MgO trend, FeO/MnO and FC3MS (FeO/CaO–3×MgO/SiO2). The temperature variations show a positive correlation with the Fo-content of host olivines, and values from high-Fo olivine agree well with olivine and spinel liquidus temperatures calculated from thermodynamic models of bulk-rock composition. All methods and most samples yielded a temperature range between 1300 °C and 1400 °C. An exceptional few samples returned temperatures below 1300 °C, the minimum being 1193 °C, whereas several samples yielded temperatures above 1400 °C, the upper range being 1420–1440°C, which we consider to be a robust estimate of the maximum liquidus temperatures for the high-Mg magmas studied. The conversion to mantle potential temperatures is complicated by uncertain depth and degree of melting, but the functional relationship between Tp and primary melt MgO contents, using melt inclusions from olivine phenocrysts with of Fo > 90, indicate a Tp range from 1414 to 1525 °C ( 42 °C), which is 100–150°C higher than estimates of ambient upper mantle Tp in the South Atlantic today.

Geochemistry of Lavas from Taal Volcano, Southwestern Luzon, Philippines: Evidence for Multiple Magma Supply Systems and Mantle Source Heterogeneity

1991 ◽  
Vol 32 (3) ◽  
pp. 593-627 ◽  
Author(s):  
A. MIKLIUS ◽  
M. F. J. FLOWER ◽  
J. P. P. HUIJSMANS ◽  
S. B. MUKASA ◽  
P. CASTILLO
Keyword(s):  
Mantle Source ◽  
Taal Volcano ◽  
Magma Supply ◽  
Supply Systems ◽  
Source Heterogeneity
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