Isotopic and trace element compositions of upper mantle and lower crustal xenoliths, Cima volcanic field, California: Implications for evolution of the subcontinental lithospheric mantle

The origin and mantle dynamics of the Quaternary intraplate sodic and potassic volcanism in northeast China have long been intensely debated. We present a high-resolution, three-dimensional (3-D) crust and upper-mantle S-wave velocity (Vs) model of northeast China by combining ambient noise and earthquake two-plane wave tomography based on unprecedented regional dense seismic arrays. Our seismic images highlight a strong correlation between the basalt geochemistry and upper-mantle seismic velocity structure: Sodic volcanoes are all characterized by prominent low seismic velocities in the uppermost mantle, while potassic volcanoes still possess a normal but thin upper-mantle “lid” depicted by high seismic velocities. Combined with previous petrological and geochemical research findings, we propose that the rarely erupted Quaternary potassic volcanism in northeast China results from the interaction between asthenospheric low-degree melts and the overlying subcontinental lithospheric mantle. In contrast, the more widespread Quaternary sodic volcanism in this region is predominantly sourced from the upwelling asthenosphere without significant overprinting from the subcontinental lithospheric mantle.

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Oxidation state of Paleozoic subcontinental lithospheric mantle below the Pali Aike volcanic field in southernmost Patagonia

Lithos ◽

10.1016/j.lithos.2008.02.009 ◽

2008 ◽

Vol 105 (1-2) ◽

pp. 98-110 ◽

Cited By ~ 25

Author(s):

Jian Wang ◽

Keiko H. Hattori ◽

Jianping Li ◽

Charles R. Stern

Keyword(s):

Oxidation State ◽

Lithospheric Mantle ◽

Volcanic Field ◽

Subcontinental Lithospheric Mantle

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The petrogenesis of tholeiitic diabases in eastern Parnaíba Basin: evidence for geochemical heterogeneities in the subcontinental lithospheric mantle in NE Brazil

Brazilian Journal of Geology ◽

10.1590/2317-4889201720160041 ◽

2017 ◽

Vol 47 (1) ◽

pp. 109-126 ◽

Cited By ~ 6

Author(s):

Adriano Guilherme da Silva ◽

Cícera Neysi de Almeida ◽

Sérgio de Castro Valente ◽

Leonardo Fonseca Borghi de Almeida

Keyword(s):

Trace Element ◽

Fractional Crystallization ◽

Lithospheric Mantle ◽

Sedimentary Basin ◽

Sedimentary Rocks ◽

Geochemical Modelling ◽

Subcontinental Lithospheric Mantle ◽

Tectonic Events ◽

Tholeiitic Magmatism ◽

Parnaíba Basin

ABSTRACT: The sedimentary rocks within the Paleozoic Parnaiba basin in NE Brazil were intruded by voluminous tholeiitic diabase sills and covered by coeval basaltic flows. This paper presents lithogeochemical data of borehole samples obtained from wells located in the eastern portion of the Parnaiba basin. The diabases are subalkaline tholeiitc rocks comprising three high-TiO2 and three low-TiO2 suites that are unrelated by differentiation processes. Fractional crystallization of olivine and augite was the predominantly evolutionary processes within individual high- and low-TiO2 suites as depicted by trace element geochemical modelling, exception being made for one low-TiO2 suite that evolved by AFC. Parental compositions for both low- and high-TiO2 suites are related with variably enriched, spinel harzburgitic sources likely to represent the heterogeneous subcontinental lithospheric mantle underneath the sedimentary basin. The geochemical provinciality of the Parnaiba tholeiitic magmatism seems unrelated with the Transbrasiliano Lineament but may be due to lithospheric mantle amalgamation and remobilization occurred during previous tectonic events.

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