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.
1988: Explosive interaction of magma with ground water: insights from xenoliths
and geothermal drillings.
The diamonds are produced either by mining the rock, which contains the xenoliths
or by mining the soils and sediments that formed as the diamond-bearing rock weathered away.
Power law olivine crystal size distributions in lithospheric mantle xenoliths
Unit G is composed of sparsely to moderately porphyritic basalt, with gabbroid xenoliths
, plagioclase glomerocrysts and olivine microphenocrysts.
Megacrysts and/or mafic xenoliths
are usually absent but clustering of clinopyroxene microphenocrysts is relatively frequent.
Pellet-rich tuffistic (volcaniclastic) serpentine kimberlite breccia occupies the southern fissure appendage of the pipe which is extremely rich in mantle xenocrysts, megacrysts and xenoliths
On your way to the lake, look for xenoliths
--fragments of ancient dark rock that have been "absorbed' over time into the now dominant granite.
The emplacement of the volcanic edifice affected the marllimestone rhythmite and oncolitic limestones, promoting in situ mineralogical changes as well as the genesis of white carbonate clasts incorporated into the phreatomagmatic breccia and xenoliths
in the lamproites.
Mesozoic A-Type Granitoids and Xenoliths
in the Lujiang-Zongyang Area, Anhui Province: Significance in Post-Collisional Magmatic Evolution.