The Greer Lake leucogranite, Manitoba, and the origin of lepidolite-subtype granitic pegmatites

Černý, Petr; Masau, Morgan; Goad, Bruce E.; Ferreira, Karen

doi:10.1016/j.lithos.2003.11.003

Cited by 48 publications

(8 citation statements)

References 22 publications

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“…THE classification, petrogenetic interpretation and the diagnosis of the metallogenic potential of granitic pegmatites is based on the parageneses of accessory minerals, on the relation with the regional geological context (Č erný, 1991;Č erný and Ercit, 2005 and references therein) and, in addition, on the chemistry of the main rock-forming and accessory minerals, notably the columbite group (Č erný, 1989a), zircon, tourmaline group and garnet group. A considerable number of studies deal with the chemistry of Kfeldspar and muscovite for classification and exploration purposes and as an aid to understanding the crystallization processes in pegmatites (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…A considerable number of studies deal with the chemistry of Kfeldspar and muscovite for classification and exploration purposes and as an aid to understanding the crystallization processes in pegmatites (e.g. Č erný, 1989b;Morteani and Graup, 1989;Larsen, 2002). In comparison, studies of the chemistry of pegmatite quartz are relatively rare (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Petrogenetic significance of LA-ICP-MS trace-element data on quartz from the Borborema Pegmatite Province, northeast Brazil

et al. 2011

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Quartz from different zones within five granitic pegmatites of the rare-element class from the Borborema Pegmatite Province in northeast Brazil were analysed for fourteen trace elements using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The concentrations of Li (6À150 ppm), B (1À9 ppm) and Ge (1À23 ppm) in quartz show a positive correlation with Al (30À770 ppm). The concentrations of these elements increase from the border zone to the quartz core of pegmatites of the spodumene or lepidolite subtypes. The Ge concentrations in the quartz core are the highest so far reported in igneous quartz. In the less evolved pegmatites of the beryl-columbite subtype, the Al, Li, B, and Ge concentrations in quartz from all zones remain at the same level as the border and wall zones. The Ti concentrations in quartz from the core of the more evolved pegmatites are below 3 ppm (with Al >250 ppm), contrasting with 7À25 ppm (with Al <280 ppm) in samples from the border and wall zones of the less evolved and more evolved pegmatites. The concentrations of Al, Li, B, Ge, and Ti in quartz are therefore confirmed as good indicators of the degree of magma fractionation and analyses of pegmatite quartz cores can be used for exploration purposes to distinguish pegmatites with high metallogenic potential. Atoms of Li and Al are incorporated into quartz such that Li/Al ranges between 0.75 and 1.0. This suggests a coupled substitution of the form Si 4+ $ (Li + + Al 3+ ). The other elements analysed either showed an erratic distribution (e.g. Be and P) or were below the respective limits of detection (Na, K, Rb, Ca, Sr, Mn, Fe) in most samples.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Petrogenetic significance of LA-ICP-MS trace-element data on quartz from the Borborema Pegmatite Province, northeast Brazil

et al. 2011

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“…This author proposes that these features are due to partial melting of metamorphic protoliths leaving REE-rich accessory minerals in the residua, to progressive REE-depletion of the differentiating melts by crystallization of some minerals (e.g., monazite, xenotime, apatite, garnet) and to a change in the oxidation state of europium. Complex variable chondrite-normalized REE patterns in pegmatites have been documented by several authors (e.g., [74][75][76][77][78][79][80]). As a possible explanation for the REE-patterns of the studied pegmatites, we suggest that late-magmatic to post-magmatic (hydrothermal) processes, and interaction with external metamorphic fluids, affected the studied bodies and probably remobilized some rare earth elements to produce the complex variable patterns.…”

Section: Discussionmentioning

confidence: 99%

Barren and Li–Sn–Ta Mineralized Pegmatites from NW Spain (Central Galicia): A Comparative Study of Their Mineralogy, Geochemistry, and Wallrock Metasomatism

et al. 2019

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In Central Galicia, there are occurrences of barren and Li–Sn–Ta-bearing pegmatites hosted by metasedimentary rocks. A number of common and contrasting features between Panceiros pegmatites (barren) and Li–Sn–Ta mineralized Presqueira pegmatite are established in this study. K-feldspar and muscovite have the same trace elements (Rb, Cs, P, Zn, and Ba), but the mineralized one has the highest Rb and Cs and the lowest P contents. The barren bodies show fluorapatite and eosphorite–childrenite replacing early silicates. The mineralized body has primary phosphates (fluorapatite and montebrasite), a metasomatic paragenesis (fluorapatite and goyazite) replacing early silicates, and a late hydrothermal assemblage (vivianite and messelite). Ta–Nb oxides from the Presqueira body show a trend from columbite-(Fe) to tantalite-(Fe) and tapiolite-(Fe). In this body, the Li-aluminosilicate textures support primary crystallization of petalite that was partially transformed into Spodumene + Quartz (SQI) during cooling, and into myrmekite during a Na-metasomatism stage. As a result of both processes, spodumene formed. The geochemical study supports magmatic differentiation increasing from the neighboring granites to the Li–Sn–Ta mineralized pegmatite. In both barren and mineralized bodies, the pegmatite-derived fluids that migrated into the wallrock were enriched in B, F, Li, Rb, and Cs and, moreover, in Sn, Zn, and As.

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“…On the primitive mantle normalized spider diagram, compared with granite, the pegmatites show positive in Rb, U, and P anomalies, and negative anomalies of Ba, Sr, Zr, and Ti (Figure 5b). The positive in Rb, U, and P anomalies in the pegmatites is ascribed to their high incompatible properties, i.e., they do not favor crystallization of their individual (accessory) minerals at the early magmatic stage [85][86][87][88]. The depletion in Ba and Sr in the pegmatite can be ascribed to feldspar fractionation in the two-mica monzogranites [89], whereas depletion in Ti and Zr is the result of early-crystallized ferromagnesian minerals (biotite and Fe-Ti oxides) fractionation and zircon fractionation, respectively [77,90].…”

Section: Relationship Between the Pegmatites And Granitesmentioning

confidence: 99%

Geochemical Contrasts between Late Triassic Rb-Rich and Barren Pegmatites from Ningshan Pegmatite District, South Qinling Orogen, China: Implications for Petrogenesis and Rare Metal Exploration

et al. 2020

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The Ningshan pegmatite district in the South Qinling Orogen hosts numerous Rb-(Be) mineralized pegmatites. In this study, whole-rock geochemistry, mineral geochemistry, and zircon U–Pb isotopes of the Rb-rich and barren pegmatites were determined. The barren pegmatites consist mainly of muscovite, microcline, albite, quartz, and garnet, whereas the Rb-rich pegmatites are mainly composed of muscovite, albite, quartz, and beryl, with minor chrysoberyl, cassiterite and columbite-group mineral. The muscovite and albite are the main Rb-bearing minerals. The U–Pb zircon dating of the Rb-rich and barren pegmatites yielding an age of 212–203 Ma, which is similar to that of the neighboring two-mica monzogranites distributed in the Ningshan area. Compared with the two-mica monzogranites, geochemical features, such as the Zr/Hf, Rb/Sr and Nb/Ta ratios and trace element contents indicated that the Rb-rich and barren pegmatites derived from fractionation of the two-mica monzogranites. In combination, the current and previous results suggest that the fractionation of the two-mica monzogranites caused the generation of the affinitive residual melts that, finally, crystallized to form the pegmatites. Compared to those from the barren pegmatites, the apatite from the Rb-rich pegmatites have higher MnO (14.51–19.12 wt.%) and Cl (0.12–0.16 wt.%) contents and lower F/Cl rartios (20–29). We conclude that these differences reflect unique geochemical signatures, and the geochemical composition of the apatite can be used as exploration guidance for rare metal-rich pegmatites.

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The Greer Lake leucogranite, Manitoba, and the origin of lepidolite-subtype granitic pegmatites

Cited by 48 publications

References 22 publications

Petrogenetic significance of LA-ICP-MS trace-element data on quartz from the Borborema Pegmatite Province, northeast Brazil

Petrogenetic significance of LA-ICP-MS trace-element data on quartz from the Borborema Pegmatite Province, northeast Brazil

Barren and Li–Sn–Ta Mineralized Pegmatites from NW Spain (Central Galicia): A Comparative Study of Their Mineralogy, Geochemistry, and Wallrock Metasomatism

Geochemical Contrasts between Late Triassic Rb-Rich and Barren Pegmatites from Ningshan Pegmatite District, South Qinling Orogen, China: Implications for Petrogenesis and Rare Metal Exploration

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