(PDF) Mineral chemistry of monazite-(Nd), xenotime-(Y), …
The studied mineralized lamprophyre dyke in Abu Rusheid area is trending NNW-SSE, and occurs within Abu Rusheid mineralized shear zone, measuring 0.2 - 1.0 m in width …
Petrology, mineral chemistry and geochemistry of …
The biotite in the apatite inclusion rich assemblage (camptonite) is essentially phlogopite and has a very narrow range of compositional variation (Mg#: 0.70–0.83). This …
Lamprophyre
Lamprophyre is a group of ultrapotassic, igneous rocks that consist of phenocrysts of mica - particularly biotite or phlogopite - and amphibole, such as pargasite or hornblende.
A Post-Caledonian Ultrabasic Biotite Lamprophyre Dyke …
Large plates of biotite are the most abundant porphyritic constituent. Phenocrysts of carbonate-chlorite pseudomorphs after olivine are less common, but it is sometimes difficult to distinguish …
Antecrysts and their effect on rock compositions: The …
Lamprophyre intrusions are frequent in the northeast of the Catalonian Coastal Ranges. ... pseudomorphed olivine and accessory biotite, analcime, apatite, calcite, chlorite …
Lamprophyre
Minettes (biotite-orthoclase) and spessartite (amphibole-orthoclase) lamprophyre dykes are reported from the Above Rocks granodiorite in Jamaica. Jackson et al. (1998) ^ report that the …
Lamprophyres, lamproites and related rocks as tracers to …
The Thanewasna lamprophyre has a characteristic porphyritic texture, dominated by phenocrysts of biotite and microphenocrysts of amphibole and clinopyroxene that are set in a groundmass …
Lamprophyres
A minette is a porphyritic alkaline igneous rock dominated by essential biotite and potassic feldspar, often with augite and plagioclase present as accessories within the groundmass. Spessartites: From Spessart mountains east of …
Mineral textures of olivine minette and their significance for
In this paper we present mineral textures of an olivine minette dyke with relatively well preserved primary phases. It comes from the western part of the Moldanubian Zone, …
The nature and origin of lamprophyres: some definitions, …
Important characteristics common to all members of this extremely heterogeneous group are suggested to include their intrusion at a late stage in any igneous event, the …
Lamprophyre
Major minerals include biotite, amphibole, and pyroxene, with clinopyroxene and olivine sometimes present. The groundmass of the lamprophyre is either feldspar or foids. …
Lamprophyre | Properties, Composition and Formation
Classification of lamprophyres has had several revisions andso much argument within the geology. Modern naming has been derived from anattempt some genetic parameters of lamprphyre genesis.This has, by and large,dispensed with the previous provincial names of lamprophyre species, …
The nature and origin of lamprophyres: some definitions, distinctions
At least four lamprophyre subgroups may be recognised; these are quite distinct in petrology, chemistry, paragenesis and petrogenesis although individual members of each …
A note on the origin of Clinopyroxene megacrysts from …
Biotite composition from the megacrystic suite and phenocrystic phase of Udiripikonda lamprophyre are essentially confined to the primary biotite field (see also Figure 5B; Nachit et …
The "Lamprophyre Clan" Revisited
The lamprophyre clan includes minor intrusive rocks (see Fig. 1) like kimberlites, orangeites, lamproites and lamprophyres (calc-alkaline, alkaline, ultramafic). These rocks are generally …
Structure of lamprophyres: a discriminant marker for …
Millimetre-thick films of biotite, ... dip direction and dip of lamprophyre dyke walls; 9: trajectory, dip direction, and dip of D4 mylonitic to stylolitic foliation; trend and plunge of stretching lineation …
Lamprophyre
Lamprophyre is defined as a type of porphyritic dyke rock characterized by phenocrysts of solely mafic minerals, such as biotite or amphibole, with feldspars and/or feldspathoids limited to the …
A late Eocene lamprophyre-carbonatite association in the SE …
We recently identified an Eocene basin—the Wase Basin—in the west Yunnan and west Sichuan lamprophyre provinces (Guo et al., 2005), SE Tibet. The basin fill contains a …
Lamprophyres, lamproites and related rocks as …
Lamprophyres, lamproites and related rock types (e.g. kimberlites, orangeites and shoshonites) represent mantle-derived, volatile-rich rocks situated both in craton and off-craton settings that are genetically linked with individual phases of the …
The nature and origin of lamprophyres: some definitions, distinctions
Thealkaline lamprophyre subgroup is considered in detail: new definitions ofcamptonite andmonchiquite are proposed which are believed to reconcile majority usage …
Lamprophyre
Lamprophyre is an unusual group of dark, igneous rocks, which due to their chemical composition belong to the alkali rocks. The name "lamprophyre" comes from the Greek and means "bright" …
Nature and origin of calc-alkaline lamprophyres: …
Calc-alkaline lamprophyres are porphyritic dyke-rocks, richer in amphibole, biotite, ultramark elements (Mg, Cr, Ni) and incompatible elements (K, F, P, Rb, Sr, Zn, Nb, Ba, REE, Th, U) than other rocks of comparable colour index …
Lamprophyre
They are dark-colored rocks containing essential biotite (or Fe-rich phlogopite) and/or amphibole, with clinopyroxene and olivine, and in the cases of alnöite and polzenite, melilite. Feldspars …
Photomicrographs of the lamprophyres. (A) …
Here, we report petrology, geochemistry and zircon U-Pb geochronology data for the lamprophyre of the Weishan REE deposit in order to develop constraints for the d... ... rock consists of 15%...