Minette (a type of lamprophyre), from Jáchymov in the Czech Republic
Lamprophyres (from Ancient Greek λαμπρός (lamprós) 'bright', and φύρω (phúrō) 'to mix') are uncommon, small-volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks, and small intrusions. They are alkaline silica-undersaturated mafic or ultramafic rocks with high magnesium oxide, >3% potassium oxide, high sodium oxide, and high nickel and chromium.
Lamprophyres occur throughout all geologic eras. Archaean examples are commonly associated with lode gold deposits. Cenozoic examples include magnesian rocks in Mexico and South America, and young ultramafic lamprophyres from Gympie in Australia with 18.5% MgO at ~250 Ma.
rock Lamproite – Mantle rock expulsed to the surface in volcanic pipes Lamprophyre – Ultrapotassic igneous rocks – An ultramafic, ultrapotassic intrusive...
considered "ultramafic". Ultrapotassic, ultramafic igneous rocks such as lamprophyre, lamproite and kimberlite are known to have reached the surface of the...
dikes or sills consist either of phonolite, tinguaite, lamprophyre micromalignite, lamprophyre micromelteigite, or carbonatite. The Beemerville Alkaline...
otherwise inaccessible mantle. Basalts, kimberlites, lamproites and lamprophyres, which have their source in the upper mantle, often contain fragments...
equivalent, rhyolite. Biotite is an essential phenocryst in some varieties of lamprophyre. Biotite is occasionally found in large cleavable crystals, especially...
occurrences are as masses adjacent to ultramafic intrusives, associated with lamprophyre dikes and as large crystals in pegmatites. It commonly occurs as a detrital...
microdiamonds in the island arc of Japan are found in a type of rock called lamprophyre. Kimberlites can be found in narrow (1 to 4 meters) dikes and sills,...
red denotes a pyrite-chalcopyrite ore body, green is a gabbro diabase, lamprophyre and quartz porphyry dike, and light tan is the Supraore sequence of the...
Line district, in kimberlite in the Iron Mountain district, Wyoming, in lamprophyre at Cedar Mountain in Wyoming, and in numerous anthills and outcrops of...
volcanic breccia and black dikes of igneous rock called minette, a type of lamprophyre. It is the erosional remnant of the throat of a volcano, and the volcanic...
phenocryst and groundmass phase within ultrapotassic igneous rocks such as lamprophyre, kimberlite, lamproite, and other deeply sourced ultramafic or high-magnesian...
proposed, but differences in chemistry mean this remains uncertain. Lamprophyre dykes of Late Permian age are found throughout Orkney. Glacial striation...
volcanic rocks associated with this rise are tholeiitic lavas and intrusive lamprophyre sheets, which form a volcanic basement, on average, 50 m (160 ft) below...
begins by determining if the rock is ultramafic, a carbonatite, or a lamprophyre. An ultramafic rock contains more than 90% of iron- and magnesium-rich...
kimberlites in Colorado, from the Bishop Conglomerate and in a Tertiary age lamprophyre at Cedar Mountain in Wyoming. A variety of pyrope from Macon County,...
in ultrapotassic igneous rocks such as kimberlites, carbonatites, and lamprophyre, owing to the unusual magma genesis of these rocks.[citation needed]...
continental crust above upwelling mafic magma, such as at rift zones. Lamprophyres and melilitic rocks Kimberlite Lamproite Orangeite (see Group II kimberlite)...
forms. Other rock types present include: alkali basalt, nephelinite, lamprophyre, and carbonatite. Mantle xenoliths have been described from Kachchh (northwestern...
orthogneisses. On the west face of Broad Peak and the south spur of K2, lamprophyre dikes, which consist of clinopyroxene and biotite-porphyritic vogesites...
Siluro-Devonian Calc-Alkaline Dyke Suite' seen at Scalasaig and Balnahard. Lamprophyre dykes, assigned to the same suite are also frequently seen intruding...
Several varieties of carbonatite are present in the area as well as lamprophyre, ijolite and other highly alkalic rocks. It is the type locality for...
greater than 90% amphiboles, which have a feldspar groundmass, may be lamprophyres. Metamorphic rocks composed primarily of amphibole, plagioclase, with...
diorites, lamprophyres, alkali-syenites and rhyolites. The parent gabbroic magma is shown to have given rise in sequence to diorites, lamprophyres and alkali-syenites...
Variscan orogeny. The Karkonosze Granite is intruded by somewhat younger lamprophyre dykes. A NW-SE to WNW-ESE oriented strike-slip fault —the Intra-Sudetic...
and they seem to bear a complementary relationship to certain types of lamprophyre dikes. Though nowhere very common they have a wide distribution with...
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