scispace - formally typeset
Search or ask a question
Topic

Incompatible element

About: Incompatible element is a research topic. Over the lifetime, 2420 publications have been published within this topic receiving 154052 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: The Halberstadt high-Nb basalts are derived from spinel peridotite mantle source regions, which both require garnet and amphibole as metasomatic residual phases as discussed by the authors.

102 citations

Journal ArticleDOI
19 Mar 1981-Nature
TL;DR: In this paper, a model in which the mantle contains chemical heterogeneities of many sizes which are less depleted in incompatible elements than the surrounding mantle was proposed, and the entire mantle is slowly mixed by convection.
Abstract: Neodymium and strontium isotopic data from rocks can be satisfied by a model in which the mantle contains chemical heterogeneities of many sizes which are less depleted in incompatible elements than the surrounding mantle, and in which the entire mantle is slowly mixed by convection.

102 citations

Journal ArticleDOI
TL;DR: The amphibolite source is inferred to be subduction-enriched metabasalt that underplated the crust during pre-Mesozoic subduction as discussed by the authors, which can be modeled by melting of meta-basalt enriched in incompatible elements.
Abstract: Potassium-rich volcanic rocks of the shoshonite suite are common features of postorogenic extensional settings inboard from subduction zones. Various petrogenetic processes and tectonic settings have been proposed for their origin. Early Miocene volcanic rocks of Limnos, part of the northeast Aegean shoshonite belt, show distinctive geochemical features that allow their petrogenesis to be well constrained. The rocks are principally trachyandesites and dacites. Very strong fractionation of light and middle rare earth elements (REEs), similar to that found in adakites, is inconsistent with a mantle source, but it can be modeled by melting of meta-basalt enriched in incompatible elements. A comparison with experimental melting of metabasaltic amphibolite requires small degrees of dehydration melting of amphibole, plagioclase, clinopyroxene, and minor garnet at a temperature >950 °C. Melting was triggered by mantle-derived magma, evidenced by repetitive zoning in clinopyroxene with Cr-rich cores. Nd and Sm isotopes suggest that some of this magma was similar to lamproite found elsewhere in this shoshonite belt and some was of asthenospheric origin. The amphibolite source is inferred to be subduction-enriched metabasalt that underplated the crust during pre-Mesozoic subduction. The regional trigger for dehydration melting was upwelling of asthenosphere as a result of slab detachment. The geochemistry and radiogenic isotopes of other shoshonitic rocks in the northeastern Aegean suggest a similar origin, but with higher degrees of partial melting of base-of-crust metabasaltic amphibolite. Similar processes appear likely for shoshonitic magmatism in some postcollisional settings elsewhere.

101 citations

Journal ArticleDOI
TL;DR: In this article, a suite of alkali basalts from the Massif Central, in France, has been determined using a semi-quantitative approach, showing that the source of the basalts could be produced by rather high degrees of partial melting (such as 10 or 15%) of the metasomatically enriched mantle mantle.

101 citations

Journal ArticleDOI
TL;DR: This article used the geochemistry of primitive mafic lavas from the Rungwe volcanic province (southwestern Tanzania) to infer the source mineralogy and melting history, and showed that these mafics can be interpreted as a series of low-percentage melts of CO2-rich peridotite at pressures that span the garnet-spinel transition.
Abstract: This paper uses the geochemistry of primitive mafic lavas from the Rungwe volcanic province (southwestern Tanzania) to infer the source mineralogy and melting history. Post-Miocene mafic lavas from Rungwe include alkali basalts, basanites, nephelinites and picrites with up to 18.9 wt% MgO; nephelinites (>13.5% normative nepheline) are restricted to Kiejo volcano in the southern portion of the province. Rungwe lavas differ from most Western Rift volcanics in that they are not unusually potassic (K2O/Na2O ca. 0.40). Sparsely phyric mafic lavas contain phenocrysts and xenocrysts of plagioclase (An82–90), clinopyroxene (4.5–9.5 wt% Al2O3), and olivine (Fo79–88); one basanite contains a 1 mm xenocryst of apatite included in magnesian clinopyroxene. All samples have high abundances of incompatible elements (e.g., 0.7–2.2 wt% P2O5) and are enriched in REE relative to HFSE (Hf, Zr, Ti, Y), Cs, Ba, and K. Some incompatible element ratios are constant throughout the Rungwe suite (e.g., Zr/Nb, Sr/Ce, K/Rb), but other ratios are extremely variable and exceed the range measured in global Ocean Island Basalts (OIB) (e.g., Ba/Nb, Sm/Zr, La/Nb, Pb/Ce, Nb/U). The range in degree of silica saturation, and its excellent correlation with P2O5/Al2O3, indicate that the Rungwe suite records variable degrees of melting. Variations of individual incompatible trace element abundances in nephelinite and basanite samples suggest that the source contains metasomatic amphibole, ilmenite, apatite, and zircon. The Rungwe suite is interpreted as a series of low-percentage melts of CO2-rich peridotite at pressures that span the garnet-spinel transition. A geochemical comparison of Rungwe samples to lavas from other Western Rift volcanic centers requires that the source mineralogy varies along the rift axis, although each province is underlain by metasomatized peridotite. The incompatible trace element signatures of Western Rift lavas indicate that the source area is typically homogeneous on the scale of individual volcanoes, although lavas from each volcano reflect a range in degree of melting. Significantly, volcanoes with distinct geochemistry are always separated by major rift faults, suggesting that volcanic and tectonic surface features may correspond to metasomatic provinces within the subcontinental lithospheric mantle.

101 citations


Network Information
Related Topics (5)
Metamorphism
18.3K papers, 655.8K citations
94% related
Continental crust
11.1K papers, 677.5K citations
94% related
Basalt
18.6K papers, 805.1K citations
93% related
Mantle (geology)
26.1K papers, 1.3M citations
92% related
Zircon
23.7K papers, 786.6K citations
92% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20237
202216
202157
202056
201960
201851