Mantle and Crustal Effects on the Geochemistry of Proterozoic Dikes and Sills in Sweden

Patchett, P. Jonathan; Lehnert, Kerstin; Rehkämper, Mark; Sieber, G.

doi:10.1093/petrology/35.4.1095

Cited by 44 publications

(30 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Normalizing values are after Sun and McDonough (1989) Fig. 5 a YTC (Y = Y + Zr, Ti=TiO 2 %×100, C = Cr) ternary diagram (after Davies et al 1979) for the mafic dykes explain the negative Nb anomaly observed in the studied dykes: (1) subduction-related enrichment of lithospheric mantle (Kepezhinskas et al 1997) and (2) chemical interaction between lithospheric mantle and asthenosphere-derived magma having incompatible elements but little Nb (Arndt and Christensen 1992;Patchett et al 1994). High La/Nb (1.21-3.00) ratios of mafic dykes suggest in support of the first possibility as the cause for Nb anomalies in the present samples.…”

Section: Geochemical Characteristics and Magma Typementioning

confidence: 99%

جيوكيمياء القواطع المافية في أجزاء من معقدة سينغابوم الجرانيتية: الأصل الصخري والوضع التكتونى

2010

View full text Add to dashboard Cite

Singhbhum granitoid complex has been intruded by numerous mafic dykes trending in different directions. The studied dykes were originated from subalkaline magma, ranging in composition from basalt through basaltic-andesite to andesite. In the present work, the studied dykes are divided into two groups on the bases of abundance of SiO 2 , MgO, Al 2 O 3 , Ni, and Cr. The first one has higher Mg# than that of group II. These dykes have enriched incompatible trace element patterns. These are particularly enriched in the light rare earth elements and large ion lithophile elements with depleted high field strength elements (Nb, P, Ti). High Ba/Nb and Sr/P ratios of present mafic dykes are the indications of subduction signature. The geochemical characters of the back arc extension basalt tectonic setting is suggested for the studied dykes. Higher PM-normalized Th/Nb, Rb/Nb, and Ba/Nb ratios of studied samples support their non-plume source.

show abstract

Section: Geochemical Characteristics and Magma Typementioning

confidence: 99%

جيوكيمياء القواطع المافية في أجزاء من معقدة سينغابوم الجرانيتية: الأصل الصخري والوضع التكتونى

2010

View full text Add to dashboard Cite

show abstract

“…The presence of mafic and felsic rocks that share geochemical characteristics suggests that AFC processes, rather than crustal anatexis, played a more significant role in the petrogenesis of these rocks. The isotopic composition of the most primitive rocks in the Kigluaik pluton are close to "bulk earth" and thus could be interpreted as being derived from either an enriched mantle source or from contaminated, depleted asthenospheric mantle [e.g., Patchett et al, 1994]. Below, we compare the composition of the rocks from the mafic root to other plutons 3.…”

Section: Mafic Rootmentioning

confidence: 99%

Potassic mafic magmatism in the Kigluaik gneiss dome, northern Alaska: A geochemical study of arc magmatism in an extensional tectonic setting

Amato¹,

Wright²

1997

J. Geophys. Res.

View full text Add to dashboard Cite

“…On the ε Nd (T)-Nb/Nb* diagram (Fig. 9d), one can see a negative correlation between these parameters, i.e., a ε Nd (T) decrease is accompanied by the weakening of Nb anomaly, which also disagrees with the above model (Patchett et al, 1994).…”

Section: Discussionmentioning

confidence: 74%

Late Paleoproterozoic basites of the northern Baikal area: composition and melt sources

Donskaya

Гладкочуб

Shokhonova

et al. 2014

Russian Geology and Geophysics

View full text Add to dashboard Cite

We present results of isotope-geochemical studies of Late Paleoproterozoic basites from intrusions located in different parts of a dike swarm traceable for more than 200 km within the Baikal marginal salient of the Siberian craton basement (northern Baikal area). The basites of the southern (Khibelen site) and northern (Chaya site) parts of the dike swarm show both similarity and difference in their sources and formation conditions. For example, the Khibelen basites correspond in chemical composition to basalts and trachybasalts, and the Chaya basites, to basalts and andesite-basalts. Based on petrographic and petrochemical data, the basites of both sites can be referred to as medium-alkali (subalkalic) series. All analyzed basites show distinct negative Nb-Ta and Ti anomalies on element spidergrams, negative ε Nd (t) values, and indicative geochemical ratios Th/Nb pm , La/Nb pm , and La/Sm n > 1. All this points to the formation of basites of both sites from mantle sources contaminated with continental crust. Contamination might have occurred in intermediate magma chambers localized in crust. Differentiated basic varieties of both sites resulted from fractionation of clinopyroxene. For the Khibelen basites, the mantle source (probably, with geochemical parameters close to those of IAB) might have been initially contaminated with middle-crust rocks and then, with lower/upper-crust material. The source of the Chaya basites was probably produced during the interaction of mantle components similar in composition to IAB and N-MORB with a crustal component. The performed studies testify to the heterogeneous composition of the upper mantle beneath different sites of the Siberian craton basement.

show abstract

Mantle and Crustal Effects on the Geochemistry of Proterozoic Dikes and Sills in Sweden

Cited by 44 publications

References 0 publications

جيوكيمياء القواطع المافية في أجزاء من معقدة سينغابوم الجرانيتية: الأصل الصخري والوضع التكتونى

جيوكيمياء القواطع المافية في أجزاء من معقدة سينغابوم الجرانيتية: الأصل الصخري والوضع التكتونى

Potassic mafic magmatism in the Kigluaik gneiss dome, northern Alaska: A geochemical study of arc magmatism in an extensional tectonic setting

Late Paleoproterozoic basites of the northern Baikal area: composition and melt sources

Contact Info

Product

Resources

About