Enriched component of the proto-Icelandic mantle plume revealed in alkaline Tertiary lavas from East Greenland.

Stefan Bernstein, Charles Kent Brooks, Ole Stecher

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Alkaline ultramafic lavas in north East Greenland were contemporaneous with Tertiary tholeiitic flood basalts in East Greenland. The alkaline lavas are enriched in light rare earth elements (REEs) and Ti and Nb, but depleted in Rb, Ba, K, Th, and P. The flood basalts have trace element profiles similar to those of the alkaline lavas. These features are not caused by fractional crystallization or crustal contamination and are thus regarded as inherited from the mantle source. The trace element profiles and Sr and Nd isotopic compositions of the flood basalts are shown to be consistent with a simple model, in which 5%–10% alkaline melt is mixed into normal-mid-ocean ridge basalt. This alkaline melt has a composition reflecting low-degree melting at high pressures of incompatible element– enriched mantle. In areas where only deep melting occurred, this enriched melt component reached the surface in an essentially undiluted form. Elsewhere, under the rift axis, it mixed with asthenospheric melts, resulting in the typical enriched characteristics of East Greenland flood basalts. The presence of pronounced negative P anomalies in modern Iceland lavas suggests this to be a long-term feature of the Iceland mantle plume.
OriginalsprogEngelsk
TidsskriftGeology
Vol/bind29
Udgave nummer9
Sider (fra-til)859-862
Antal sider4
ISSN0091-7613
DOI
StatusUdgivet - 2001
Udgivet eksterntJa

Citer dette

Bernstein, Stefan ; Brooks, Charles Kent ; Stecher, Ole. / Enriched component of the proto-Icelandic mantle plume revealed in alkaline Tertiary lavas from East Greenland. I: Geology. 2001 ; Bind 29, Nr. 9. s. 859-862.
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title = "Enriched component of the proto-Icelandic mantle plume revealed in alkaline Tertiary lavas from East Greenland.",
abstract = "Alkaline ultramafic lavas in north East Greenland were contemporaneous with Tertiary tholeiitic flood basalts in East Greenland. The alkaline lavas are enriched in light rare earth elements (REEs) and Ti and Nb, but depleted in Rb, Ba, K, Th, and P. The flood basalts have trace element profiles similar to those of the alkaline lavas. These features are not caused by fractional crystallization or crustal contamination and are thus regarded as inherited from the mantle source. The trace element profiles and Sr and Nd isotopic compositions of the flood basalts are shown to be consistent with a simple model, in which 5{\%}–10{\%} alkaline melt is mixed into normal-mid-ocean ridge basalt. This alkaline melt has a composition reflecting low-degree melting at high pressures of incompatible element– enriched mantle. In areas where only deep melting occurred, this enriched melt component reached the surface in an essentially undiluted form. Elsewhere, under the rift axis, it mixed with asthenospheric melts, resulting in the typical enriched characteristics of East Greenland flood basalts. The presence of pronounced negative P anomalies in modern Iceland lavas suggests this to be a long-term feature of the Iceland mantle plume.",
keywords = "flood basalt, alkaline ultramafic lava, -pressure melting, magma mixing",
author = "Stefan Bernstein and Brooks, {Charles Kent} and Ole Stecher",
year = "2001",
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language = "English",
volume = "29",
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Enriched component of the proto-Icelandic mantle plume revealed in alkaline Tertiary lavas from East Greenland. / Bernstein, Stefan; Brooks, Charles Kent; Stecher, Ole.

I: Geology, Bind 29, Nr. 9, 2001, s. 859-862.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Enriched component of the proto-Icelandic mantle plume revealed in alkaline Tertiary lavas from East Greenland.

AU - Bernstein, Stefan

AU - Brooks, Charles Kent

AU - Stecher, Ole

PY - 2001

Y1 - 2001

N2 - Alkaline ultramafic lavas in north East Greenland were contemporaneous with Tertiary tholeiitic flood basalts in East Greenland. The alkaline lavas are enriched in light rare earth elements (REEs) and Ti and Nb, but depleted in Rb, Ba, K, Th, and P. The flood basalts have trace element profiles similar to those of the alkaline lavas. These features are not caused by fractional crystallization or crustal contamination and are thus regarded as inherited from the mantle source. The trace element profiles and Sr and Nd isotopic compositions of the flood basalts are shown to be consistent with a simple model, in which 5%–10% alkaline melt is mixed into normal-mid-ocean ridge basalt. This alkaline melt has a composition reflecting low-degree melting at high pressures of incompatible element– enriched mantle. In areas where only deep melting occurred, this enriched melt component reached the surface in an essentially undiluted form. Elsewhere, under the rift axis, it mixed with asthenospheric melts, resulting in the typical enriched characteristics of East Greenland flood basalts. The presence of pronounced negative P anomalies in modern Iceland lavas suggests this to be a long-term feature of the Iceland mantle plume.

AB - Alkaline ultramafic lavas in north East Greenland were contemporaneous with Tertiary tholeiitic flood basalts in East Greenland. The alkaline lavas are enriched in light rare earth elements (REEs) and Ti and Nb, but depleted in Rb, Ba, K, Th, and P. The flood basalts have trace element profiles similar to those of the alkaline lavas. These features are not caused by fractional crystallization or crustal contamination and are thus regarded as inherited from the mantle source. The trace element profiles and Sr and Nd isotopic compositions of the flood basalts are shown to be consistent with a simple model, in which 5%–10% alkaline melt is mixed into normal-mid-ocean ridge basalt. This alkaline melt has a composition reflecting low-degree melting at high pressures of incompatible element– enriched mantle. In areas where only deep melting occurred, this enriched melt component reached the surface in an essentially undiluted form. Elsewhere, under the rift axis, it mixed with asthenospheric melts, resulting in the typical enriched characteristics of East Greenland flood basalts. The presence of pronounced negative P anomalies in modern Iceland lavas suggests this to be a long-term feature of the Iceland mantle plume.

KW - flood basalt

KW - alkaline ultramafic lava

KW - -pressure melting

KW - magma mixing

U2 - 10.1130/0091-7613(2001)029<0859:ECOTPI>2.0.CO;2

DO - 10.1130/0091-7613(2001)029<0859:ECOTPI>2.0.CO;2

M3 - Journal article

VL - 29

SP - 859

EP - 862

JO - Geology

JF - Geology

SN - 0091-7613

IS - 9

ER -