 | | Journal (article/letter/editorial) | | nepheline-syenite pegmatites at Pegmatite Peak, Bearpaw Mts, Montana A. R. Chakhmouradian and R. H. Mitchell...1999 Summary The pegmatites at Pegmatite Peak (Bearpaw Mts., Montana) crystallized from an evolved fraction...minerals evolved from manganoan ilmenite to ferroan pyrophanite, and have relatively low Nb contents (_< 0.9...[chevkinite-(Ce)]. Strontiochevkinite from Pegmatite Peak is compositionally similar to the type material...yon Pegmatite Peak, Bearpaw Mrs., Montana Die Pegmatite yon Pegmatite Peak (Bearpaw Mts., Montana) sind |  | | Journal (article/letter/editorial) | | alkaline pegmatites from Gordon Butte, Crazy Mountains (Montana, USA): comparisons between potassic and sodic...Springer-Verlag 2002 Abstract At Gordon Butte (Crazy Mountains, Montana), agpaitic nepheline±syenite pegmatites intrude...malignites and nepheline microsyenites). All pegmatite veins are composed predominantly of potassium...Alkaline igneous rocks of central and western Montana (USA) exhibit great petrographic diversity, and are...Alkaline parageneses of dierent provenance from Montana have been shown to contain a variety of rare minerals |  | | Conference Paper/Abstract | | associated alkaline rocks from Gordon Butte, Crazy Mountains (Montana) Roger H. Mitchell (Lakehead University)...Alkaline igneous rocks of central and western Montana (U.S.A.) exhibit a great petrographic diversity...Alkaline parageneses of different provenance from Montana have been shown to contain a variety of rare minerals...Mitchell 1999). Igneous lithologies of the Crazy Mountains area include a subalkaline series (gabbro-diorite-granite)...assemblages from the Gordon Butte area, northern Crazy Mountains. At Gordon Butte, four major intrusive series |  | | | | Geological Survey, 956 National Center, Reston, VA 20192, USA 4 Camborne School of Mines, School of Geography,...presented of chevkinite-group minerals from Canada, USA, Guatemala, Norway, Scotland, Italy and India. The...IMA-approved) include perrierite-(La) found in a syenitic pegmatite from Bjørkedalen, Oslofjord, Norway (Segalstad...perrierite-(Ca) perrierite-(Ca) 7 8 Pegmatitic Bearpaw Mts, Montana Burley Farm, Virginia Bjørkedalen, Norway...East Antarctica nepheline syenite granitoid pegmatite syenite cutting gneisses strontio-chevkinite |  | Liferovich, R. P., Mitchell, R. H., Zozulya, D. R., Shpachenko, A. K. (2006) Paragenesis and composition of banalsite, stronalsite, and their solid solution in nepheline syenite and ultramafic alkaline rocks. The Canadian Mineralogist, 44 (4) 929-942 doi:10.2113/gscanmin.44.4.929 | Journal (article/letter/editorial) | | natrolite, tephroite, jacobsite, alleghanyite, pyrophanite, Mn-rich biotite, andradite, harmotome, and apatite...Mitchell & Liferovich (2004) on the ecandrewsite–pyrophanite solid-solution series. The major nepheline syenite...the Mn-rich minerals, kupletskite and zincian pyrophanite (Mitchell & Liferovich 2004), indicating that...(UK), and Tony Nikischer (Excalibur Mineral Corp., USA) for providing stronalsite and banalsite samples...nepheline-syenite pegmatites at Pegmatite Peak, Bearpaw Mts., Montana. Mineral. Petrol. 67, 85-110. Chakhmouradian |  | Macdonald, Ray, Bagiński, Bogusław, Belkin, Harvey E., Stachowicz, Marcin (2019) Composition, paragenesis, and alteration of the chevkinite group of minerals. American Mineralogist, 104 (3) 348-369 doi:10.2138/am-2019-6772 | Journal (article/letter/editorial) | | site of an Fe-rich chevkinite-(Ce) from Mianning County, Sichuan, China, was given 2+ 2+ by Yang et al...inter alia, of perrierite-(Ce) from the Bearpaw Mountains, Montana, U.S.A. (0.35–1.18 apfu; Chakhmouradian...may be an artifact arising from Ti uncorrected for peak interference. Figure 9. La vs.Y plot to show that...described, from a fenitised granite in the Ilmen Mountains, southern Urals, Russia, a phase that they named...cross-cutting a phlogopite-olivine rock in the Ilmen Mountains (Popov et al. 2001). It is an unusual member of |  | | Journal (article/letter/editorial) | | boundary zone of a pegmatite vein and MA MEPB37C from the core of the same pegmatite. The most abundant...designated Amph2 (Fig. 2a, b, c, d). In CE P the pegmatite, minor amounts of amphibole similar to Amph2 in...mineral) were used. Counting time was 10 to 30 s on peak (and half-time on each of the 2 background positions)...wollastonite (Si K, Ca K), Al2O3 (Al K), pyrophanite (Ti K, Mn K), Fe metal (Fe K), MgO (Mg K)...were used. Counting times varied from 13 seconds on peak and 6.5 seconds on the two background positions |  | Ahijado, A., Casillas, R., Nagy, G., Fernández, C. (2005) Sr-rich minerals in a carbonatite skarn, Fuerteventura, Canary Islands (Spain) Mineralogy and Petrology, 84 (1) 107-127 doi:10.1007/s00710-005-0074-8 | Journal (article/letter/editorial) | | differential discriminator was used to avoid the PK III peak. The following standards were used: glasses from...large (up to 2 cm) K-feldspar, phlogopite and pyrophanite crystals appear as relicts within a heterogeneous...carbonatites (i.e. phlogopite, K-feldspar and pyrophanite). The main phases that usually carry Sr in carbonatites...nepheline-syenite pegmatites at Pegmatite Peak, Bearpaw Mts, Montana. Mineral Petrol 67: 85–110 Deer...Semail Ophiolite in the Dibba Zone, Northern Oman Mountains. In: Peters TJ, Nicolas A, Coleman RG (eds) Ophiolite |  | | Journal (article/letter/editorial) | | incompatible and volatile elements in late-magmatic, pegmatite and postmagmatic mineral parageneses. These substitutions...data than using single-LREE standards. However, peak profiles used for the analytical lines were established...data), Khibina (incl. our data), Afrikanda, Bearpaw Mountains, Gordon Butte, Eden Lake, Ilı́maussaq, Inagli...usually being found in evolved nepheline syenite pegmatite segregations with zeolite-rich axial zones and...and apparently did not separate into discrete pegmatite bodies and hydrothermal veins. Our observations |  | Krmíček, Lukáš, Cempírek, Jan, Havlín, Aleš, Přichystal, Antonín, Houzar, Stanislav, Krmíčková, Michaela, Gadas, Petr (2011) Mineralogy and petrogenesis of a Ba–Ti–Zr-rich peralkaline dyke from Šebkovice (Czech Republic): Recognition of the most lamproitic Variscan intrusion. Lithos, 121 (1) 74-86 doi:10.1016/j.lithos.2010.10.005 | Journal (article/letter/editorial) | | A few contacts between the dyke and an older pegmatite have been found. The dyke is at least 200 m long...each background corresponded to the one half of the peak counting time. The following standards were used...features were observed at the contact with the host pegmatite (Fig. 2a and b). The very fine-grained margin shows...by medium-grained, mineralogically primitive pegmatite intruded by the very fine-grained border zone facies...xenotime-(Y) and allanite-(Ce) were found in the pegmatite. 4.2. Whole-rock composition The Šebkovice dyke |  | | Journal (article/letter/editorial) | | Microscope (Thermo Fisher Scientific, Waltham, MA, USA) coupled with an INCA Energy 250 EDS microanalysis...microprobe (JEOL USA, Peabody, MA, USA) with five wavelength dispersive spectrometers (JEOL USA, Peabody, MA...MA, USA), also located at the Scientific and Technological Centres of the University of Barcelona. Operating...counting time was 10 s peak and 10 s background except for Ce, La, Ba (20 s peak and 20 s background),... and Na and F (30 s peak and 30 s background). The acquisition method used was two background measurements |  | | Journal (article/letter/editorial) | | nepheline syenite at Bratthagen, Norway, and Pegmatite Peak, Montana (Lumpkin et al., 1997; Chakhmouradian and...rock types include syenitic, nephelinesyenitic pegmatite, phonolite and lamprophyre dykes. The magmatic...zircono-silicates, and Ti-based oxides such as loparite, pyrophanite, murataite and landauite (Portnov et al., 198l;...using EDS spectrnm-stripping techniques. However, peak profiles used for the analytical X-ray lines were...peralkaline pegmatites at Gordon Butte and Pegmatite Peak in Montana (Mitchell and Chakhmouradian, submitted) |
|
