Contrary to this, we demonstrate that the Gubaoquan eclogite protolith was a Neoproterozoic basic dyke/sill which intruded into Proterozoic continental rocks. The SHRIMP U–Pb zircon dating of the metamorphic rims of the Gubaoquan eclogite yields an age 466 ± 27 Ma.

ECLOGITE FROM THE ERZGEBIRGE, SOUTHEASTERN GERMANY: protolith was an alkali basalt. The alkali-rich protoliths suggest that Saidenbach eclogites were

[2005] dated their M3 granulite-facies event, but were unable to provide any direct evidence to support this hypothesis. Liu et al. [2007] dated three The magmatic zircon from both the retrograded eclogite and mafic schist yielded protolith ages of 451 ± 3 Ma, which is consistent with the ages of Early Palaeozoic ophiolitic complexes and ocean island sequences in the CMOB reported in previous studies. 2011-07-02 The Gubaoquan eclogite occurs in the Paleozoic Beishan Orogen of NW China. Previously it has been interpreted as a fragment of subducted oceanic crust that was emplaced as a mélange within continental rocks. Contrary to this, we demonstrate that the Gubaoquan eclogite protolith was a Neoproterozoic basic dyke/sill which intruded into Proterozoic continental rocks. eclogite Sm–Nd/WR igneous formation of eclogite protolith Stosch & Lugmair (1990) Weissenstein (SW MM) 395–380 Ma eclogite Sm–Nd; Rb–Sr eclogite metamorphism Stosch & Lugmair (1990) Weissenstein area 379 ± 12 Ma eclogite Rb–Sr/Hbl, phengite post-eclogite Gebauer & Grünenfelder (1979) K–Ar Hangendserie The variability of δ18O in garnet among 41 xenoliths, shows a bi-modal distribution with median values at 3.57 ‰ and 5.68 ‰ and strong correlation (r = 0.96) between garnet and omphacite.

Eclogite protolith

The lack of relatively light-weight plagioclase is the reason why it is so dense compared to its protoliths. The eclogite unit occurs in the LHS below the MCT, and the protolith is considered to be 110–88-Ma-old (cretaceous volcanics in the LHS). The peak metamorphic condition was estimated as P > 15 kb (probably up to 20 kb) for a minimum temperature of 580°C ( Groppo et al., 2007 ). Eclogite ( / ˈɛklədʒaɪt /) is a metamorphic rock formed when mafic igneous rock is subjected to high pressure.

This eclogite body may once have been situated eclogite protolith and the hostJericho kimberlite, both the secondary isochron age and the c.2·2 Ga Stacey^Kramers model age are con-sistent with Paleoproterozoic protolith oceanic crust formation.

Eclogites show a dispersion of model ages from 1.95 billion years to 670 million years. On the graphs in the εNd(T)–87Sr/86Sr and εNd(T)–T coordinates, eclogites were shown to form trends that can be interpreted as a result of contamination of the eclogite protolith by the host rocks.

Eclogite genesis might have been by residue formation associated with the dehydration and partial melting of a protolith consisting of variably mixed, subducted ocean floor basalt and sediment. Kaalvallei Group II eclogite xenoliths are likely to have formed through crystallization of small-volume melts within conduits in old, enriched subcontinental lithosphere. Oxygen isotope compositions are reported for the first time for the Himalayan metabasites of the Kaghan Valley, Pakistan in this study.

Shear deformation and eclogite formation within granulite-facies from eclogite and felsic leucosomes record a Neoproterozoic protolith age of ~600Ma and.

The variability of δ18O in garnet among 41 xenoliths, shows a bi-modal distribution with median values at 3.57 ‰ and 5.68 ‰ and strong correlation (r = 0.96) between garnet and omphacite. The δ18O values and the reconstructed whole-rock trace element compositions indicate an oceanic crustal protolith for mantle eclogite xenoliths.

Note that diagenesis and weathering are also a changes in form that occur in rocks. A metamorphic facies is a set of mineral assemblages in metamorphic rocks formed under similar pressures and temperatures. The assemblage is typical of what is formed in conditions corresponding to an area on the two dimensional graph of temperature vs.
Heta

If the lower mantle is denser than pyrolite ( Interlayered Eclogites, Blueschists and Epidote Amphibolites from NE Oman: a Record of Protolith Compositional Control and Limited Fluid Infiltration.

2B, 2D ). 2006-11-15 2014-11-01 PDF | This paper reports the major, minor and trace element abundances and Nd isotope compositions of bulk rock samples of eclogites from the Stak | Find, read and cite all the research you Geochemical signatures for eclogite protolith from the Maksyutov from a boudin of the Lower Unit of the Maksyutov Complex in the South Urals in order to determine their protolith nature.
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The kyanite–eclogite is derived from a troctolitic protolith, whereas the epidote–eclogite from a gabbroic protolith, both having distinct positive Eu anomalies, low TiO 2, and high Al 2O 3 and MgO. The kyanite–eclogite shows inherited cumulate layering. The phengite–eclogite has high TiO 2, low Al 2O 3 and MgO with incompatible trace eclogite Sm–Nd/WR igneous formation of eclogite protolith Stosch & Lugmair (1990) Weissenstein (SW MM) 395–380 Ma eclogite Sm–Nd; Rb–Sr eclogite metamorphism Stosch & Lugmair (1990) Weissenstein area 379 ± 12 Ma eclogite Rb–Sr/Hbl, phengite post-eclogite Gebauer & Grünenfelder (1979) K–Ar Hangendserie Eclogite-rich layers would be intermittent because of low melting points and the temperature-dependency of the relevant phase changes. and the composition of the lower mantle.