xenolith

Citing recent evidence from deep crust-mantle sections exhumed in orogenic belts as well as crustal and mantle xenoliths brought to the surface by volcanic activity, geologists investigate the boundary between the lower crust of Earth and the underlying mantle.

Zhi, "Iron and magnesium isotopic compositions of peridotite xenoliths from Eastern China," Geochimica et Cosmochimica Acta, vol.

The presence of the granite xenoliths in the doleritic rock suggests that the latter is younger.

The Bogan Brook Granodiorite is a medium to dark grey, fine- to medium-grained, equigranular biotite or hornblende-biotite granodiorite displaying a weak fabric and containing numerous xenoliths and enclaves of paragneiss or migmatized paragneiss (Fig.

Diamond-bearing eclogite xenoliths * Cat's-eye calcite from Pakistan * Large chatoyant Brazilian emerald * Nonbeadcultured pearls from Strombus gigas * Purple scapolite * Synthetic star sapphire with diffusion-induced colour and star * Partially filled blue chalcedony * Presumably oiled ruby * Inclusions in synthetic star sapphire * Diamond slices * Large Namibian demantoid * Nephrite from British Columbia * Baroque cultured pearls * Ruby from Namya, Myanmar * Rock Creek sapphire update * Unusual tourmaline necklace * Conference reports.

It was described from ultramafic xenoliths in carbonatites (Gaspar, 1992) and kimberlites (McGetehin et al., 1970; Aoki et al., 1976), found to be associated with antigorite in serpentinites (Trommsdorff and Evans, 1980; SanchezVizcaino et al., 2005) and also occurs in metadunite (Dymek et al., 1988), in several garnet peridotites from ultrahigh-pressure (UHP) metamorphic terranes (Yang et al., 1993; Okay, 1994; Zhang et al., 1995; Yang, 2003), in metagabbros (Scambelluri and Rampone, 1999) and in a garnet-rich rock from the Kokchetav UHP metamorphic terrane of northern Kazakhstan (Muko et al., 2001).

* the research of deep-seated xenoliths evacuated from great depths.

The PC[O.sub.2] at the Qatruyeh may have been raised by the assimilation of dolomitic-marble host rock by iron-rich hydrothermal fluids, as is evidenced by the presence of carbonate xenoliths in the magnetite ore.

The likely presence of meta-dolerite xenoliths in Sydney region diatremes is also extremely low, as is the possibility of such material being in the older known palaeochannel remnants such as at Newington and Newtown.

He discusses the impact of meteors, the geology of shield areas and their associated rocks and minerals, pegmatite and pegmatite minerals, early minerals and rocks associated with the formation of the atmosphere, unusual minerals linked to early limestone-like rocks, greenstone belts and their connection to the earth's gold deposits, marble and quartz, and xenoliths in igneous granite.

This is highly encouraging as NEV027 only just intersected the top of the intrusive complex with several large Chim Formation clasts (fragments) incorporated within the porphyry groundmass (as xenoliths).

Instead of melting and being transported to the surface as a melt, the diamonds are carried to the surface in large pieces of mantle rock known as xenoliths.

Recognizable in the tunnel walls were xenoliths of black tourmaline, as are typical of pegmatites.