Ba-Fe titanates in peralkaline granite of the Ilímaussaq Complex, South Greenland
MAŁGORZATA CEGIEŁKA1,2,*, BOGUSŁAW BAGIŃSKI1, RAY MACDONALD1,3, BEATA MARCINIAK-MALISZEWSKA1 and MARCIN STACHOWICZ1
1 Department of Geochemistry, Mineralogy and Petrology, Faculty of Geology, University of Warsaw, 02-089 Warsaw, Poland.
E-mails: B.Baginski1@uw.edu.pl; marcin.stachowicz@chem.uw.edu.pl; b.maliszewska@uw.edu.pl
2 Institute of Geological Sciences, Polish Academy of Sciences, Research Centre in Warsaw, Twarda 51/55, 00-818 Warsaw, Poland.
E-mail: m.cegielka@twarda.pan.pl
3 Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
E-mail: raymacdonald186@gmail.com
* Corresponding author: E-mail: m.cegielka@twarda.pan.pl ABSTRACT:
Cegiełka, M., Bagiński, B., Macdonald, R., Marciniak-Maliszewska, B. and Stachowicz, M. 2021. Ba-Fe tita- nates in peralkaline granite of the Ilímaussaq Complex, South Greenland. Acta Geologica Polonica, XX (X), xxx−xxx.
A peralkaline granite of the Ilímaussaq Complex, South Greenland, contains the rare mineral henrymeye rite [(Ba0.92Na0.05Ca0.03)1.0(Ti6.87Fe2+1.04Nb0.03)7.9O16], a low-Fe Ba titanate [(Ba0.74Ca0.02Na0.05)0.8 (Ti4.9oFe2+0.15 Nb0.04)5.1O11], and an unidentified Ba titanosilicate. Both titanates show the coupled substitution 2Na+ + Si4+
→ Ba2+ + Ti4+. The minerals are present as tiny crystals fringing ilmenite inclusions in an amphibole crystal and are thought to have formed during the hydrothermal stage of the granite’s evolution.
Key words: Ilímaussaq peralkaline granite; Henrymeyerite; Low-Fe Ba Titanate.
INTRODUCTION
Henrymeyerite [Ba(Ti4+Fe2+)8O16] is a member of the priderite group of the hollandite supergroup of minerals (Biagioni et al. 2013). From its first recogni- tion in a mineralised vug in a carbonatite vein of the Kovdor alkaline ultramafic complex, Russia (Mitchell et al. 2000), it has been recorded in a few further local- ities, including the Crazy Mountains, Montana, USA (Chakhmouradian and Mitchell 2002), the Khibiny Massif, Kola Peninsula, Russia (Mikhailova et al.
2007), and Šebkovice, Czech Republic (Krmíček et al. 2011). However, as noted by Mitchell et al. (2000), some pre-2000 reports have typically referred to it under such names as Ba-Fe hollandite-type titanates (Mitchell and Bergman 1991) or Ba-Fe-hollandite
(Platt 1994; Chakhmouradian and Mitchell 1999).
So far as we know, henrymeyerite has been found only in silica-undersaturated parageneses. In this pa- per, we describe it in a peralkaline granite from the Ilímaussaq complex, South Greenland, where it is associated with what appears to be the most Fe-poor Ba titanate yet reported. It is also closely associated with a Ba titanosilicate with an unusually high Ti/Si ratio (~3) which we still have not identified. This note provides compositional data on all three phases.
GEOLOGICAL SETTING
Dated at 1161 ± 5 Ma (Krumrei et al. 2006), the complex, situated within the Younger Gardar south-
ern rift zone (Upton 2013), is one of the youngest in the Gardar Igneous Province. The pressure of em- placement has been estimated as c. 1 kbar (Marks et al. 2003). The complex comprises three separate in- trusions (Nielsen and Steenfelt 1978; Steenfelt 1981).
In order of emplacement these intrusions are: (1) An augite syenite stock with an ovoidal plan measuring c. 19 × 9 km. The syenites are slightly silica-under- saturated, with nepheline as a minor component.
(2) Quartz syenites and peralkaline granites cropping out over an area of c.16 km2 in the highest parts of the complex. (3) Silica-undersaturated syenites (pu- laskites, foyaites and sodalite foyaite) that occupy the greater part of the exposed complex. These crys- tallized consecutively downwards and form the roof zone to the third intrusion. The peralkaline granite is holocrystalline, porphyritic and massive without any visible orientation of crystals. The dominant mineral is subhedral perthitic feldspar (54 modal %; 2–4 mm).
The potassic feldspar composes 26% of the granite;
the bulk composition is Or98.43Ab1.57. The sodic feld- spar, making up 29% of the granite, is albite with an average composition of Ab99.52Or0.41An0.07. Both types of feldspar contain aegirine inclusions ranging in size from 5 to 30 μm. These are probably the cause of the remarkable green colour of the rock. Anhedral quartz, often showing undulose extinction, forms over 35% of the granite, the grain size ranging from 60 μm to 5 mm. Amphiboles are the most abundant mafic minerals (8 modal %), forming large (40 μm to 6 mm) crystals with a zonation ranging from deep red- dish-brown, katophoritic cores to dark bluish-green, arfvedsonitic margins. Commonly it is replaced by aegirine. Aenigmatite occurs as deep-brown anhedral crystals, up to 3 mm in size, commonly mantled by aegirine, titanite and fluorite; the average formula is (Na3.94Ca0.08)4.02Ti1.93(Fe2+10.10Mn0.20)10.30Si11.73O40. Our sample of the granite contains the following accessory minerals, which total ~1 modal %: aegir- ine, astrophyllite, britholite-(Ce), catapleiite, chevki- nite-(Ce), ekanite, elpidite, fluorite, henrymeyerite, Fe-poor Ba-titanate, ilmenite, leucosphenite, loren- zenite, monazite-(Ce), narsarsukite, neptunite, pec- tolite, pyrochlore, thorite, titanite, zircon, and five unidentified phases. Fluorite is the most abundant accessory mineral, comprising ~0.2 modal % of the whole-rock.
ANALYTICAL METHODS
Our sample was collected from a loose block in the River Dyrnaes. From its intense green colour
and mineralogy, the sample is undoubtedly from the Ilímaussaq peralkaline granite, the so-called Green Granite (Table 1). Mineral analyses were made on a single thin section of the granite, which was initially studied with polarized light microscope NIKON ECLIPSE LV100 POL, equipped with a high-preci- sion automatic stage. Both plane and crossed polar- ized light images of minerals and textures present in the granite were acquired. Quantitative element distribution maps and point analyses were acquired using a Zeiss Σigma™ VP FE (field emission) – SEM equipped with new generation SDD-type two EDS (XFlash 6|10™) detectors produced by Bruker.
Analyses carried out under operating conditions of acceleration voltage of 30 kV and a 120 μm aperture.
Mineral compositions were determined at the Inter- Institution Laboratory of Microanalysis of Minerals and Synthetic Substances (Faculty of Geology, University of Warsaw), using a Cameca SXFiveFE electron probe micro analyser (EPMA) equipped with five wavelength dispersive spectrometers (WDS). The operating conditions of the electron mi- croprobe were: 15 kV accelerating voltage, 6–20 nA probe current and focused or defocused (3–10 μm in diameter) electron beam. The φ(ρZ) correction model (X-PHI in the electron microprobe software) developed by Merlet (1994) was used for corrections.
All the standards, lines etc. used are listed in the Appendices to Tables 2 and 3. Due to changes in the analysis conditions, applied in order to acquire data of highest possible quality, the detection limits in the Appendices are expressed as ranges instead of exact values. The locations of the analysed spots are shown in the Supplementary Material (Fig. S1) – available only in the online version.
wt.% ppm ppm ppm
SiO2 73.35 Ba 51 Th 29.8 Ho 4.53
TiO2 0.21 Be 24 U 7.7 Er 12.3
Al2O3 10.85 Co 36.5 V <8 Tm 1.67 Fe2O3* 4.38 Cs 2.50 W 558 Yb 10.16
MnO 0.09 Ga 35.6 Zr 572 Lu 1.39
MgO 0.04 Hf 14.7 La 174 Y 142
CaO 0.52 Nb 140 Ce 341
Na2O 4.55 Ni <20 Pr 37.6
K2O 4.84 Rb 454 Nd 138
P2O5 0.02 Sc <1 Sm 24.6
LOI 0.8 Sn 10.0 Eu 1.31
TOT/C 0.14 Sr 20.2 Gd 21.7
Total 99.79 Ta 13.1 Dy 21.3
Table 1. Chemical composition of the Green Granite. Fe2O3* – all Fe as Fe3+.
Henrymeyerite Fe-poor Ba titanate
1 2 3 6 9 11 19 21 27 31
Anal. no. IL-379 IL-380 IL-381 IL-407 IL-410 IL-417 IL-389 IL-392 IL-399 IL-404
BaO 17.65 17.25 17.07 16.94 18.28 18.72 20.03 20.36 20.63 25.86
CaO 0.14 0.10 0.04 0.74 0.13 0.14 bd bd bd bd
Na2O 0.27 0.33 0.34 0.18 bd bd 0.03 0.15 0.37 0.03
K2O bd 0.04 0.04 0.03 bd 0.03 bd 0.03 0.03 0.03
La2O3 0.37 0.38 0.38 0.35 0.38 0.38 0.43 0.39 0.41 0.40
Ce2O3 0.33 0.39 0.33 0.53 0.26 0.27 0.46 0.35 0.40 0.43
TiO2 70.18 69.98 69.81 69.04 71.50 71.06 75.88 75.70 73.70 71.84
FeO* 9.40 9.17 9.49 9.49 9.29 10.08 1.10 1.52 1.38 2.73
MnO bd 0.08 0.09 0.07 bd 0.05 bd 0.07 0.07 bd
MgO bd bd bd bd bd bd bd bd bd bd
Nb2O5 0.61 0.96 0.46 1.63 bd bd 1.09 1.03 1.16 0.19
SiO2 0.59 0.93 1.10 0.29 bd bd 0.10 0.22 1.13 0.07
Total 99.54 99.61 99.15 99.29 99.84 100.73 99.12 99.82 99.28 101.58
Formula on the basis of 16 oxygens
Ba 0.900 0.875 0.869 0.868 0.932 0.953 0.692 0.700 0.714 0.919
Ca 0.020 0.014 0.006 0.104 0.018 0.019 0.000 0.000 0.000 0.000
Na 0.068 0.083 0.086 0.046 0.000 0.000 0.005 0.026 0.063 0.005
K 0.000 0.007 0.007 0.005 0.000 0.005 0.000 0.003 0.003 0.003
La 0.018 0.018 0.018 0.017 0.018 0.018 0.014 0.013 0.013 0.013
Ce 0.016 0.018 0.016 0.025 0.012 0.013 0.015 0.011 0.013 0.014
Ti 6.865 6.814 6.817 6.789 6.996 6.939 5.028 4.996 4.895 4.898
Fe2+ 1.023 0.993 1.031 1.038 1.011 1.095 0.081 0.112 0.102 0.207
Mn 0.000 0.009 0.010 0.008 0.000 0.005 0.000 0.005 0.005 0.000
Mg 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
Nb 0.036 0.056 0.027 0.096 0.000 0.000 0.043 0.041 0.046 0.008
Si 0.077 0.120 0.143 0.038 0.000 0.000 0.009 0.019 0.100 0.006
Σ cations 9.02 9.01 9.03 9.03 8.99 9.05 5.89 5.93 5.96 6.07
Table 2. Representative compositions of Ba-Fe titanates (in wt.%). FeO* – all Fe as Fe2+; bd – below detection.
1 2 3 4 5 6 7
Anal. no. Il-382 IL-383 IL-384 IL-391 IL-398 IL-401 IL-456
Na2O 0.11 2.80 0.08 4.51 1.91 1.53 0.05
CaO 0.44 0.06 bd bd bd bd 0.08
BaO 27.56 28.44 30.12 17.88 22.03 25.25 20.17
La2O3 0.29 0.24 0.30 0.23 0.27 0.32 0.25
Ce2O3 0.40 0.31 0.71 bd 0.37 0.54 0.42
Al2O3 0.08 0.08 bd bd bd bd bd
TiO2 48.19 46.92 55.17 47.17 46.75 52.27 49.09
FeO* 7.06 3.19 2.23 13.04 11.71 4.89 15.54
MnO 0.23 0.11 0.14 1.85 1.10 0.46 1.47
MgO bd bd bd bd bd bd bd
Nb2O5 3.51 2.67 0.89 1.10 1.01 1.05 1.27
SiO2 11.25 14.25 9.51 13.45 11.83 10.59 8.25
Cl 1.52 1.40 1.09 1.26 1.16 1.11
Sum 99.12 100.59 100.55 100.32 98.24 98.06 97.70
O ≡ Cl 0.35 0.32 0.25 0.29 0.27 0.25
Total 99.12 100.24 100.23 100.07 97.95 97.79 97.45
Table 3. Compositions of unidentified Ba titanosilicate (in wt.%). FeO*– all Fe as Fe2+; bd – below detection; blank – not determined.
Prior to the EBSD examination, the sample was additionally polished (using a vibrating polisher) for 8 hours in a diamond suspension with a grain di- ameter of 1/4 micron. The sample was covered with a 4.3 nm carbon layer for better surface discharge EBSD patterns were collected with a Zeiss Auriga electron microscope equipped with a Bruker e − FlashHR+ detector with integrated ARGUS imaging device. The sample was tilted to 70° using the dedi- cated stage (tilt about sample X axis) for an optimal EBSD signal, while the detector tilt angle was 1.25°
and sample to detector distance of 15.66 mm. The ex- periment was carried out using an electron beam with energy of 15 keV. Image tilt correction was used on the Zeiss SmartSEM software and no image rotation was applied. A single EBSD pattern of 400 × 300 resolution was recorded from the 0.39 × 0.39 mi- crometer area during 300 ms. The system was cali- brated in Bruker ESPRIT 2. The pattern centre (PC), in Bruker fractional coordinates, was measured as:
PCx = 0.489, PCy = 0.237 with a pattern aspect ratio of 1.33 (width/height), detector distance 15.45 mm.
OCCURRENCE OF HENRYMEYERITE AND ASSOCIATED MINERALS
Textural details of the henrymeyerite, Fe-poor Ba titanate and unidentified Ba titanosilicate are shown in Text-fig. 2. Three grains of ilmenite (Text-fig. 1), the largest of which is ~340×60 μm in size, are en- closed in an arfvedsonite crystal. The ilmenites ap- pear to have been partially resorbed and then mantled by a layer of lorenzenite ~10–30 μm thick (Text- fig. 2A). The lorenzenite was in turn mantled by a thin layer of astrophyllite, varying in width from 5 to 20 μm, which sent thin branches into the arfvedsonite.
Neptunite is intergrown with, and patchily replaces, the lorenzenite (Text-fig. 2B). The Ba titanates locally form little clusters fringing the ilmenite grains (Text- fig. 2C). They are mainly acicular, up to 10 μm long, but also form small patches. In Text-fig. 2D, an un- identified Ba titanosilicate accompanies the titanate.
MINERAL COMPOSITIONS
Ba titanates
There are two compositional varieties (Table 2;
Supplementary Table S1a). One is a Ba-Fe titanate, with the average formula (n = 17) [(Ba0.92Na0.05Ca0.03)1.0
(Ti6.87Fe2+1.04Nb0.03)7.9O16]. This is henrymeyerite (Mitchell et al. 2000). The main component in the A site is Ba (0.79–0.97 a.p.f.u.), with lesser amounts of Ca (0.01–0.07 a.p.f.u.) and Na (b.d.–0.12 a.p.f.u.).
La+Ce contents are in the range 0.02–0.04 a.p.f.u..
Titanium dominates the M site (6.67–7.01 a.p.f.u.), with significant amounts of Fe (0.96–1.11 a.p.f.u.) and
Text-fig. 1. BSE image of ilmenite (ilm) inclusions in arfvedsonite (arf), showing the zones of replacement. Abbreviations: lrn – lo- renzenite; ast – astrophyllite; nep – neptunite; bft – Ba-Fe titanates.
Text-fig. 2. A – BSE image showing the mantles of lorenzenite (lrn) and astrophyllite (ast) on ilmenite (ilm) located withing arfvedsonite crystal (arf). Henrymeyerite and Fe-poor Ba titanate form clusters (bft) of bright crystals at the edges of the ilmenite. Boxes mark the positions of (B), (C) and (D). B – Neptunite (nep) intergrown with lorenzenite and also patchily replacing it (difficult to discern at the contrast used here). C – Cluster of henrymeyerite (hrm) and Fe-poor Ba titanate (Fe-poor bft). D – Cluster of henrymeyerite (hrm) and an
unidentified Ba titanosilicate (uni).
in some analyses Nb (bd–0.10 a.p.f.u.). The close ap- proach to the ideal formula suggests that the Fe is pres- ent dominantly as Fe2+, with a very little proportion of the hexatitanate end-member, BaFe3+2Ti6O16. The entry of Na and Si into the phase may be represented by the substitution 2Na+ + Si4+ → Ba2+ + Ti4+ (Text- fig. 2A).
The second variety in the Green Granite has a much lower Fe content (1.10–2.85 wt.% FeO*, where FeO* is all Fe as Fe2+) (Table 2, Appendix to Table 2). Mitchell and Vladykin (1993) reported
an Fe-poor Ba titanate forming reaction mantles on magnetite in aegirine-potassium feldspar sy- enites from the Little Murun complex, Yakutia, Russia, and suggested that its formula was (Ba,K) (Ti,Fe)5O11. On the basis of 11 oxygens, the formula of the Green Granite phase can be written (n = 19):
[(Ba0.74Ca0.02Na0.05)0.8(Ti4.9oFe2+0.15Nb0.04)5.1O11], comparable to the Little Murun phase but with lower Fe/Ti ratios, 0.02–0.05 as opposed to 0.05–0.19 and with no replacement of Ba by K. These appear to be the lowest Fe/Ti ratios yet recorded in a natural Ba-Fe titanate. A subset of crystals, brighter on BSE images, have higher Si and Na contents, suggesting perhaps a substitution 2Na+ + Si4+ →Ba2+ + Ti4+, as in henrymeyerite (Text-fig. 3). The nature of the de- ficiency in the A site is uncertain but may reflect the presence of vacancies. The phase is potentially a new mineral – and although its small size (≤10 μm) and the fact that it is intergrown with henrymeyerite has made a structural determination very difficult – we managed to acquire EBSD data shown in Text-fig. 4.
Unidentified Ba-Ti-Fe silicate
The unidentified phase associated with the Ba tita- nates (Table 3) has some compositional affinities with baotite, Ba4Ti8Si4O28Cl, but there are critical differ- ences. On the basis of 16 cations pfu, there are major deficiencies in Ba (plus Na, K, Ca and REE: 1.9–3.8 a.p.f.u.) and Si (1.9–3.2 a.p.f.u.), and a large excess of Ti (plus Fe, Nb, Mn: 9.2–12.3 a.p.f.u.). The Cl values (0.10–0.59 a.p.f.u.) are far below the stoichiometric 1 a.p.f.u. for baotite. The analyses are very variable;
e.g. TiO2 varies from 46.75 to 55.17 wt.%, FeO* from 2.23 to 15.54 wt.%, and Nb2O5 from 0.89 to 3.51 wt.%.
Text-fig. 3. Plots of (Na++Si4+) against (Ba2++Ti4+) for henryme ye- rite (white circles) and Fe-poor Ba titanate (grey circles). Analyses were based on 16 oxygens (henrymeyerite) and 11 oxygens (Fe-
poor Ba titanate). Data source – Supplementary Table S1a.
Text-fig. 4. A representative EBSD pattern from area no. 402 (A) and corresponding simulated pattern of Ba2Ti3Nb4O18 phase with indexed Kikuchi lines (B) that are also visible on the experimental pattern.
The nature of this phase is enigmatic. It is un- likely to be a result of analytical problems: it was analyzed in the same runs as henrymeyerite, which gave satisfactory results. It may have formed by the breakdown of the low-Fe Ba titanate: e.g., BaTi5O11 + Si4+ + 2O2- → BaTi3SiO9 + 2TiO2, but rutile has not been identified. At this stage we refer to it simply as an unidentified Ba titanosilicate.
A diffraction pattern from polished thin sections around areas 385, 392 and 402 for which, among others compositional analysis indicated low Fe (see Supplementary Table S1a) was captured for Electron Backscatter Diffraction (EBSD) analysis.
For the identification of the barium titanium ox- ide phase, the crystal structure of BaTi5O11 phase, (Tillmanns 1969), crystallizing in a monoclinic system, space group P21/n was downloaded from Inorganic Crystal Structure database (ICSD no 26174), and uploaded to the ESPRIT software data- base to be included in EBSD patterns identification.
The collected patterns were compared to theoretical, simulated Kikuchi lines generated by the Esprit soft- ware. No match to the known BaTi5O11 (Tillmanns 1969) crystal structure was found in the analyzed ar- eas of the sample. Further search was initiated for any phases containing oxygen, titanium and any other elements. A very good match (Text-fig. 4B) of the ex- perimentally registered Kikuchi lines was found with a phase of the formula Ba2Ti3Nb4O18 crystallizing in the monoclinic system, space group P21/c (Gasperin 1984). It is plausible that the studied barium titanate of formula BaTi5O11 has a new and yet unknown crystal structure or its chemical formula is different, where the end-member is Ba2Ti7O18.
FORMATION OF THE BA TITANATES
Our ongoing studies of the textural relationships in the Green Granite indicate that the accessory min- erals formed over a range of conditions, from early- to late-magmatic and hydrothermal. A continuous transition from melt to fluid resulted in extensive autometasomatism and hydrothermal overprints.
Early mineral assemblages were therefore partially replaced to various extents by late-magmatic phases formed from a volatile-saturated melt and then by secondary minerals from hydrothermal fluids during a late deuteric stage.
Given their occurrence as fringes of tiny crys- tals on ilmenite grains, the Ba titanates are prob- ably of hydrothermal origin. A hydrothermal or- igin was reported for the type henrymeyerite by
Mitchell et al. (2000). Similarly, Chakmouradian and Mitchell (1999) recorded Ba titanate forming, with ilmenite, rims on rutile in nepheline syenite pegmatites at Pegmatite Peak, Bearpaw Mountains, Montana, ascribing it to late-stage deuteric alteration.
Chakmouradian and Mitchell (2002) found Ba-Fe ti- tanates formed by deuteric alteration of nepheline syenites from the Crazy Mountains, Montana. In the Šebkovice dyke, Czech Republic, henrymeyerite occurs in aggregates in late-stage titanite veinlets (Krmíček et al. 2011). The phase BaTi5O11 has also been synthesized experimentally. Using as start- ing materials barium acetate [(Ba(CH3COO)2] and tetrabutyl titanate [Ti(C4H9O)4], and with NaOH as a pH-adjusting agent in the aqueous precursor, Li et al.
(2019) synthesized BaTi5O11 nanocrystals at 280°C in 20 h. The Green Granite occurrence is entirely consistent with these natural and experimental par- ageneses.
A significant problem in attempting to estimate the crystallization conditions of the titanates is the petrographic complexity of the granite. For exam- ple, our sample contains 26 accessory minerals, each potentially able to provide information on their con- ditions of formation. Here we comment briefly on certain parameters. Marks et al. (2003) proposed, on the basis of phase equilibria, that the formation of the accessories in the peralkaline granite of the Gardar Puklen complex formed at temperatures as low as 300 °C with progressive increases in fO2. For exam- ple, aegirine replaced arfvedsonite an T<300 °C and at an fO2 above the hematite-magnetite (HM) buffer.
For the Green Granite, that temperature estimate is consistent with the 280 °C found during synthesis of BaTi5O11 (Li et al. 2019). The oxidized conditions are not, however, reflected in the Fe3+-poor nature of the henrymeyerite inferred in this study.
Mineral formation in the later stages of the Green Granite took place in the presence of fluids.
Konnerup-Madsen and Rose-Hansen (1984) showed that fluid inclusions in quartz in the granite were en- tirely aqueous, with salinities from about 2 to 64 wt.%.
Melt water contents are more difficult to estimate.
In experimental studies of pantellerites, Scaillet and Macdonald (2003) and Di Carlo et al. (2010) showed that there is a positive correlation between CaO in amphibole and melt water content. Applying the rela- tionship to the Green Granite is hampered by the fact that the arfvedsonites show a range of CaO contents, 0.5–2.0 wt.% (our unpublished data). That range, how- ever, indicates a maximum water content of ~2 wt.%;
such a low value suggests that the melt had partially degassed at the time of titanate crystallization.
Acknowledgements
We thank Adam Pieczka and Bruno Scaillet for very helpful journal reviews. Special thanks to Brian G. J. Upton for provid- ing us with the samples. We also thank Paula Sierpień for help with conversion of the figures. This research was funded by the Faculty of Geology KGMiP grant 501 D-113 01 113 01 00.
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Manuscript submitted: 18th January 2021 Revised version accepted: 25th June 2021
APPENDIX (to Table 2)
15 nA beam current. focused beam (to Table 2)
Element Line Crystal Standard Detection limit (wt.%)
Ba Lα LLIF BaSO4 0.137–0.182
Ca Kα LPET wollastonite 0.012
Na Kα TAP sodalite 0.039–0.047
K Kα LPET orthoclase 0.016–0.018
La Lα LPET LaPO4 0.050–0.053
Ce Lα LPET CePO4 0.001–0.007
Ti Kα LLIF TiO2 0.049–0.067
Fe Kα LLIF hematite 0.053–0.065
Mn Kα LLIF rhodonite 0.049–0.053
Mg Kα LTAP MgO 0.014
Nb Lα LPET Nb metal 0.052–0.059
Si Kα TAP wollastonite 0.020–0.022
APPENDIX (to Tables 3)
10–15 nA beam current. focused beam (to Table 3)
Element Line Crystal Standard Detection limit (wt.%)
Na Kα TAP sodalite 0.044–0.062
Ca Kα LPET wollastonite 0.013–0.015
Ba Lα LLIF BaSO4 0.171–0.230
La Lα LPET LaPO4 0.052–0.064
Ce Lα LPET CePO4 0.003–0.007
Al Kα TAP orthoclase 0.029–0.036
Ti Kα LLIF TiO2 0.062–0.080
Fe Kα LLIF hematite 0.064–0.077
Mn Kα LLIF rhodonite 0.051–0.063
Mg Kα LTAP MgO 0.015
Nb Lα LPET Nb metal 0.058–0.073
Si Kα TAP wollastonite 0.021–0.026
Cl Kα LPET sodalite 0.020–0.023
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Analysi
s no. IL-379 IL-380 IL-381 IL-386 IL-406 IL-407 IL-408 IL-409 IL-410 IL-411 IL-417 IL-418 IL-419 IL-420 IL-422 IL-423 IL-424 Wt.%
BaO 17.65 17.25 17.07 18.69 17.84 16.94 18.53 18.03 18.28 18.36 18.72 17.38 18.53 17.99 18.90 18.75 18.42
CaO 0.14 0.10 0.04 0.06 0.08 0.74 0.08 0.24 0.13 0.21 0.14 0.18 0.22 0.51 0.13 0.44 0.27
Na2O 0.27 0.33 0.34 0.05 bd 0.18 bd 0.10 bd 0.46 bd 0.49 0.21 0.32 0.05 0.10 0.30
K2O bd 0.04 0.04 bd 0.03 0.03 0.06 0.04 bd 0.06 0.03 0.03 0.03 0.03 bd 0.03 0.03
La2O3 0.37 0.38 0.38 0.36 0.42 0.35 0.39 0.38 0.38 0.37 0.38 0.37 0.39 0.37 0.41 0.37 0.41 Ce2O3 0.33 0.39 0.33 0.16 0.36 0.53 0.36 0.38 0.26 0.25 0.27 0.19 0.23 0.24 bd 0.14 0.15 TiO2 70.18 69.98 69.81 72.40 70.01 69.04 70.83 70.00 71.50 69.34 71.06 68.88 71.06 70.09 70.64 69.17 68.55 FeO* 9.40 9.17 9.49 9.02 10.03 9.49 9.79 9.43 9.29 9.86 10.08 8.95 9.58 9.66 10.10 9.76 9.47
MnO bd 0.08 0.09 0.06 0.07 0.07 0.05 bd bd bd 0.05 bd 0.05 0.05 bd 0.06 bd
MgO bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd
Nb2O5 0.61 0.96 0.46 bd bd 1.63 bd 0.58 bd 0.11 bd 0.18 0.30 1.25 bd 0.55 1.07
SiO2 0.59 0.93 1.10 bd bd 0.29 bd 0.13 bd 1.23 bd 2.56 0.11 0.68 0.08 0.22 0.42
Total 99.54 99.61 99.15 100.80 98.84 99.29 100.09 99.31 99.84 100.25 100.73 99.21 100.71 101.19 100.31 99.59 99.09
Ba 0.900 0.875 0.869 0.944 0.923 0.868 0.948 0.927 0.932 0.933 0.953 0.877 0.941 0.906 0.966 0.968 0.953 Ca 0.020 0.014 0.006 0.008 0.011 0.104 0.011 0.034 0.018 0.029 0.019 0.025 0.031 0.070 0.018 0.062 0.038 Na 0.068 0.083 0.086 0.012 0.000 0.046 0.000 0.025 0.000 0.116 0.000 0.122 0.053 0.080 0.013 0.026 0.077 K 0.000 0.007 0.007 0.000 0.005 0.005 0.010 0.007 0.000 0.010 0.005 0.005 0.005 0.005 0.000 0.005 0.005 La 0.018 0.018 0.018 0.017 0.020 0.017 0.019 0.018 0.018 0.018 0.018 0.018 0.019 0.018 0.020 0.018 0.020 Ce 0.016 0.018 0.016 0.008 0.017 0.025 0.017 0.018 0.012 0.012 0.013 0.009 0.011 0.011 0.000 0.007 0.007 Ti 6.865 6.814 6.817 7.013 6.946 6.789 6.954 6.907 6.996 6.763 6.939 6.672 6.920 6.770 6.929 6.848 6.805 Fe2+ 1.023 0.993 1.031 0.972 1.107 1.038 1.069 1.035 1.011 1.069 1.095 0.964 1.037 1.038 1.102 1.075 1.045 Mn 0.000 0.009 0.010 0.007 0.008 0.008 0.006 0.000 0.000 0.000 0.005 0.000 0.005 0.005 0.000 0.007 0.000 Mg 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Nb 0.036 0.056 0.027 0.000 0.000 0.096 0.000 0.034 0.000 0.006 0.000 0.010 0.018 0.073 0.000 0.033 0.064 Si 0.077 0.120 0.143 0.000 0.000 0.038 0.000 0.017 0.000 0.160 0.000 0.330 0.014 0.087 0.010 0.029 0.055
Σ cations 9.02 9.01 9.03 8.98 9.04 9.03 9.03 9.02 8.99 9.12 9.05 9.03 9.05 9.06 9.06 9.08 9.07
FeO*, all Fe as Fe2+. bd, below detection. Blank, not determined. Al and V below detection in all analyses.
Formula on the basis of 16 oxygens
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Analysi
s no. IL-385 IL-389 IL-390 IL-392 IL-393 IL-394 IL-395 IL-396 IL-397 IL-399 IL-400 IL-402 IL-403 IL-404 IL-405 IL-413 IL-414 IL-415 IL-421 Wt.%
BaO 20.48 20.03 20.19 20.36 20.14 24.32 24.88 19.76 19.86 20.63 19.86 20.62 20.21 25.86 24.81 20.87 19.57 19.80 23.22
CaO bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd 0.09 2.28 1.26 bd
Na2O 0.03 0.03 0.07 0.15 0.11 0.54 0.33 0.06 0.05 0.37 1.15 0.09 0.11 0.03 bd 0.07 0.28 0.08 1.58
K2O bd bd bd 0.03 bd bd bd bd bd 0.03 0.05 0.06 bd 0.03 0.04 bd 0.04 0.03 bd
La2O3 0.40 0.43 0.41 0.39 0.39 0.40 0.39 0.43 0.38 0.41 0.32 0.42 0.40 0.40 0.36 0.40 0.38 0.38 0.38
Ce2O3 0.43 0.46 0.26 0.35 0.22 0.58 0.43 0.38 0.29 0.40 0.54 0.27 0.39 0.43 0.51 0.39 0.23 0.34 0.35
TiO2 75.96 75.88 75.13 75.70 72.90 71.40 71.73 74.46 73.58 73.70 72.35 74.32 75.30 71.84 71.10 76.85 73.37 73.96 69.64
FeO* 1.29 1.10 2.49 1.52 3.02 2.61 2.85 1.89 2.66 1.38 1.25 1.69 1.55 2.73 2.69 1.41 2.05 1.93 2.28
MnO bd bd 0.15 0.07 0.19 0.12 0.11 0.15 0.22 0.07 bd 0.08 bd bd bd bd 0.12 0.07 0.09
MgO bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd bd
Nb2O5 1.10 1.09 1.23 1.03 1.16 0.80 0.99 1.09 1.25 1.16 1.10 1.07 0.19 0.19 0.55 1.09 1.07 1.12 0.82
SiO2 0.04 0.10 0.17 0.22 0.53 1.04 0.61 0.13 0.41 1.13 2.56 0.59 0.37 0.07 0.24 0.15 0.58 0.42 3.54
Total 99.73 99.12 100.10 99.82 98.66 101.81 102.32 98.35 98.70 99.28 99.18 99.21 98.52 101.58 100.30 101.32 99.97 99.39 101.90
Ba 0.705 0.692 0.695 0.700 0.706 0.851 0.871 0.690 0.693 0.714 0.682 0.716 0.703 0.919 0.888 0.708 0.673 0.685 0.796 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.008 0.214 0.119 0.000 Na 0.005 0.005 0.012 0.026 0.019 0.093 0.057 0.010 0.009 0.063 0.195 0.015 0.019 0.005 0.000 0.012 0.048 0.014 0.268 K 0.000 0.000 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.003 0.006 0.007 0.000 0.003 0.005 0.000 0.004 0.003 0.000 La 0.013 0.014 0.013 0.013 0.013 0.013 0.013 0.014 0.012 0.013 0.010 0.014 0.013 0.013 0.012 0.013 0.012 0.012 0.012 Ce 0.014 0.015 0.008 0.011 0.007 0.019 0.014 0.012 0.009 0.013 0.017 0.009 0.013 0.014 0.017 0.012 0.007 0.011 0.011 Ti 5.020 5.028 4.960 4.996 4.901 4.792 4.815 4.990 4.928 4.895 4.764 4.948 5.025 4.898 4.880 5.003 4.844 4.909 4.581 Fe2+ 0.095 0.081 0.183 0.112 0.226 0.195 0.213 0.141 0.198 0.102 0.092 0.125 0.115 0.207 0.205 0.102 0.151 0.142 0.167 Mn 0.000 0.000 0.011 0.005 0.014 0.009 0.008 0.011 0.017 0.005 0.000 0.006 0.000 0.000 0.000 0.000 0.009 0.005 0.007 Mg 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Nb 0.044 0.043 0.049 0.041 0.047 0.032 0.040 0.044 0.050 0.046 0.044 0.043 0.008 0.008 0.023 0.043 0.042 0.045 0.032 Si 0.004 0.009 0.015 0.019 0.047 0.093 0.054 0.012 0.037 0.100 0.224 0.052 0.033 0.006 0.022 0.013 0.051 0.037 0.310
Σ cations 5.90 5.89 5.95 5.93 5.98 6.10 6.09 5.92 5.95 5.96 6.03 5.93 5.93 6.07 6.05 5.91 6.06 5.98 6.18
FeO*, all Fe as Fe2+. bd, below detection. Blank, not determined. Al and V below detection in all analyses.
Formula on the basis of 11 oxygens
1 2 3 4 5 6 7 8 9 10 11 12 Anal. no. IL-438 IL-439 IL-441 IL-442 IL-444 IL-445 IL-448 IL-449 IL-450 IL-451 IL-454 IL-455 wt%
Nb2O5 0.95 1.16 1.16 1.07 0.99 0.85 0.94 0.69 0.92 1.18 0.98 0.77 Ta2O5 0.38 0.38 0.31 0.41 0.36 0.37 0.34 0.36 0.36 0.37 0.40 0.36 SiO2 36.24 36.11 36.11 36.17 35.43 36.52 36.13 35.72 35.77 37.01 35.36 35.48 TiO2 45.15 44.60 45.32 44.90 46.22 44.58 45.41 45.74 44.93 43.66 45.75 46.06
Al2O3 bd 0.19 0.18 0.09 bd 0.13 0.06 bd bd bd bd bd
La2O3 0.26 0.27 0.26 0.26 0.28 0.28 0.27 0.28 0.28 0.26 0.31 0.26 Ce2O3 0.11 0.14 0.14 0.17 0.16 0.10 0.13 0.18 0.11 0.15 0.15 0.10
CaO 0.05 0.06 0.07 0.04 0.04 bd 0.04 bd 0.05 0.04 0.06 bd
MnO 0.06 bd 0.06 bd 0.05 bd bd bd 0.05 0.06 bd bd
FeO* 1.32 1.39 1.30 1.09 0.85 1.04 1.70 1.21 1.07 2.11 1.09 0.90
Na2O 16.49 16.31 16.10 16.67 17.03 17.21 16.40 16.22 16.59 16.35 17.01 17.69
K2O 0.11 0.12 0.15 0.12 0.05 0.19 0.27 0.22 0.19 0.40 0.08 0.12
Total 101.12 100.73 101.16 100.99 101.46 101.27 101.69 100.62 100.32 101.59 101.19 101.74
Nb 0.024 0.030 0.030 0.027 0.025 0.022 0.024 0.018 0.024 0.030 0.025 0.020 Ta 0.006 0.006 0.005 0.006 0.006 0.006 0.005 0.006 0.006 0.006 0.006 0.006 Si 2.045 2.046 2.034 2.046 1.999 2.064 2.034 2.032 2.036 2.087 2.001 2.004 Ti 1.916 1.900 1.920 1.910 1.962 1.895 1.922 1.957 1.924 1.852 1.947 1.956 Al 0.000 0.013 0.012 0.006 0.000 0.009 0.004 0.000 0.000 0.000 0.000 0.000 La 0.005 0.006 0.005 0.005 0.006 0.006 0.006 0.006 0.006 0.005 0.006 0.005 Ce 0.002 0.003 0.003 0.004 0.003 0.002 0.003 0.004 0.002 0.003 0.003 0.002 Ca 0.050 0.060 0.070 0.040 0.040 0.000 0.040 0.000 0.050 0.040 0.060 0.000 Mn 0.003 0.000 0.003 0.000 0.002 0.000 0.000 0.000 0.002 0.003 0.000 0.000 Fe2+ 0.062 0.066 0.061 0.051 0.040 0.049 0.080 0.057 0.051 0.099 0.052 0.042 Na 1.805 1.792 1.758 1.829 1.863 1.886 1.790 1.789 1.831 1.788 1.866 1.937 K 0.008 0.009 0.011 0.009 0.004 0.014 0.019 0.016 0.014 0.029 0.006 0.009
Σ cations 5.93 5.93 5.91 5.93 5.95 5.95 5.93 5.88 5.95 5.94 5.97 5.98 Formulae on the basis of 9 oxygens
FeO*, all Fe as Fe2+. bd, below detection.
