# Geochemical processes in the roots of the Azores
magmatic systems

Vittorio Zanon, Nicole Métrich, Claudia d'Oriano

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Vittorio Zanon, Nicole Métrich, Claudia d'Oriano. Geochemical processes in the roots of the Azores magmatic systems. Contributions to Mineralogy and Petrology, 2024, 179, 10.1007/s00410-024-02142-z. insu-05081581

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# Geochemical processes in the roots of the Azores magmatic systems

Vittorio Zanon<fnref n="1" /> Ⓒ · Nicole Métrich<fnref n="2" /> · Claudia D’Oriano<fnref n="3" />

Received: 22 October 2020 / Accepted: 7 May 2024 / Published online: 29 May 2024
© The Author(s) 2024

## Abstract

The Azores archipelago, situated east of the Mid-Atlantic Ridge, comprises volcanic islands arranged along sub-parallel spreading systems and rests on a thick oceanic crust. Magma is supplied directly from the roots of the volcanic systems. Located at or nearby the boundary between the crust and the mantle, they consist of mafic cumulates and mafic mush layers. This work focuses on tephra samples and a submarine lava younger than 40.000 years, collected from both central volcanoes and fissure zones. Our report details a new dataset of major, trace, and volatile elements analysed in glassy melt inclusions trapped in olivine (Fo₇₅.₈–₈₅.₆) which are extracted from cumulative bodies at the vicinity of the crust-mantle boundary. Their compositions cover a range from subalkaline to mildly alkaline basalt, and trachybasalt, which match those of Azores lavas. They registered a chemical evolution through fractional crystallisation of olivine alone, as well as olivine and clinopyroxene, as both the FeO/MgO (1.4–3.1) and CaO/Al₂O₃ (0.4–1.0) ratios of the melt decrease. Incompatible element ratios of Zr (40–352 ppm), Ba (135–612 ppm), and Rb (5–77 ppm), as compared to Nb (5–82 ppm), exhibit variability within a limited but significant range of values. The ranges in the Nb/Zr, Ba/Nb and Rb/Nb ratios recorded by melt inclusions possibly reveal distinct geochemical sources (at least two), and mixing between partial melts as they move upward. The halogen signature is characteristic of the shallow mantle. The majority of melt inclusions show Cl/K ratio (0.06) similar to E-MORB, although some of them are comparable to N-MORB (Cl/K = 0.03). Their F/Nd ratio may achieve a rather high value (27.8).

**Keywords** Azores · Melt inclusions · Basalts · Oceanic islands · Magma ponding

## Introduction

Oceanic islands, situated amidst vast oceans and distant from continents, serve as unique observation points to understand the underlying geological processes. By studying these islands, it is possible to gain valuable insights into the formation of volcanoes, mechanisms of magma storage and ascent, and the evolution of magmatism in oceanic settings at depth. This is due to the fact that rising magma batches frequently contain mafic mineral phases that have been torn

out from the deep cumulate layers, which form the basis of volcanic systems. Mafic minerals can originate from different parental melts, and can have different geochemical histories via different generations of silicate melt inclusions (SMIs) (MacIennan 2008). A basic study of bulk rocks provides only a partial insight into this information.

The Azores archipelago comprises the visible part of volcanic ridges, stretched for several tens of kilometres into the Atlantic Ocean, covering an area of about 52,000 km<fnref n="2" />. These volcanoes started to erupt on a plateau since the late Miocene (e.g., Luis et al. 1998; Cannat et al. 1999; Gente et al. 2003; Silveira et al. 2010). The formation of the volcanic ridges is linked to the movement of oblique transtensional systems, which are characterised by limited spreading over time (Marques et al. 2013). In this tectonic regime, magmas accumulate rather than erupt, resulting in the formation of cumulate layers and crystal mushes. The depth of these bodies, inferred from fluid inclusion studies, has been determined to range between 18 ± 0.31 and 20 ± 0.73 km beneath the islands east of the Mid-Atlantic Ridge (MAR) that are younger than 500 ka (Pico, Faial, Terceira, Graciosa). They

Communicated by Othmar Müntener.

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Vittorio Zanon
Vittorio.VZ.Zanon@azores.gov.pt

<footnote n="1">¹ Instituto de Investigação em Vulcanologia e Avaliação de Riscos (IVAR), Universidade dos Açores, 9501-801 Ponta Delgada, Portugal</footnote>

<footnote n="2">² Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, 75005 Paris, France</footnote>

<footnote n="3">³ Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione di Pisa, 56125 Pisa, Italy</footnote>
have also been confirmed to extend up to 26 ± 0.66 km beneath the 1.9 Ma old island of São Jorge. On the eastern island of São Miguel, located about 400 km east of the MAR, this depth reaches up to 26 ± 0.51 km (Zanon et al. 2023).

In the Azores, olivine- and clinopyroxene-rich basalts with rare plagioclase dominate over evolved magmas such as trachyte, pantellerite, and comendite (Zanon 2015a). These basalts range from sub-aphyric to highly porphyritic and can contain up to 70% olivine. Olivine phenocrysts in these basalts are abundant and contain silicate melt inclusions (SMIs), whose study is crucial for defining both the petrogenetic processes that occur in the primary ponding zone and the conditions of crustal accretion.

The present study, carried out at the archipelago scale, aims to identify the petrogenetic processes that have influenced the geochemical signature of mafic magmas during stalling at the crust-mantle interface. It is based on the study of the geochemistry of SMIs, with particular emphasis on the role of volatiles. The SMIs, preserved as glass, are hosted in rapidly quenched, polyhedral olivine crystals. They belong to products of basaltic cinder cones formed over the last 40,000 years at fissure zones and lateral vents of central volcanoes on six islands east of the MAR (Table 1). They therefore cover a wide time span in the magmatic evolution of the Azores.

## Geological setting

The Azores region in the central North Atlantic comprises nine volcanic islands and seamounts distributed across three plate boundaries and straddling the MAR, which extends at ~N20° (Fig. 1a). Flores and Corvo are located on the North American plate, while all others are located along sub-parallel slow spreading systems oriented along a general N120° direction (e.g., Vogt and Jung 2004; Borges et al. 2007; Hildenbrand et al. 2014; Miranda et al. 2014; Fernandes et al. 2018). These systems, spreading away from Eurasia at rates ranging from 2 ± 1 mm/year (at the Terceira Rift) to 3.5 ± 0.5 mm/yr at the Pico-Faial system to the south, define the diffuse boundary between the Euroasia and Nubia plates (Marques et al. 2013).

The intersection of local N45° to N75° strike-slip faults with the N120° fissure systems (Fig. 1b) served as a pathway for the ascent of poorly developed magmas, which rose rapidly from the deepest magma accumulation zones without further long-term ponding and differentiation in the crust (e.g., Zanon et al. 2020, 2023).

All volcanic systems are currently either inactive or extinct. The only geophysical activity of note is the recurrent seismic swarms along the tectonic systems, including the 2022 São Jorge crisis and the 2023 Terceira crisis.

<table><caption>**Table 1** Sample database</caption><thead><tr><th>island</th><th>sample</th><th>volcanic system</th><th>material</th><th>Age (kyr)</th><th>latitude</th><th>longitude</th></tr></thead><tbody><tr><td rowspan="3">Graciosa</td><td>GRA1</td><td rowspan="3">fissure zone</td><td rowspan="3">tephra</td><td rowspan="3">~50<sup>1</sup></td><td>39° 02.403'</td><td>28° 00.404'</td></tr><tr><td>GRA2</td><td>39° 02.365'</td><td>28° 01.783'</td></tr><tr><td>GRA5</td><td>39° 03.969'</td><td>28° 04.034'</td></tr><tr><td rowspan="2">S. Jorge</td><td>SJ240713b</td><td rowspan="2">fissure zone</td><td rowspan="2">tephra</td><td rowspan="2">&lt;5300<sup>2</sup></td><td>38° 40.301'</td><td>28° 10.352'</td></tr><tr><td>SJ200713b</td><td>38° 39.254'</td><td>28° 5.095'</td></tr><tr><td rowspan="2">Faial</td><td>FYS369s</td><td rowspan="2">fissure zone</td><td rowspan="2">tephra</td><td>CE 1958–59<sup>3</sup></td><td>38° 35.686'</td><td>28° 49.463'</td></tr><tr><td>FYS371s</td><td>≤11<sup>3</sup></td><td>38° 34.858'</td><td>28° 44.591'</td></tr><tr><td rowspan="4">Pico</td><td>PIC66s</td><td rowspan="4">Pico volcano</td><td rowspan="4">tephra</td><td rowspan="4">1–1.5<sup>4</sup></td><td>38° 26.600'</td><td>28° 23.223'</td></tr><tr><td>PIC67s</td><td>38° 29.160'</td><td>28° 19.113'</td></tr><tr><td>PIC68s</td><td>38° 25.821'</td><td>28° 18.154'</td></tr><tr><td>PIC69s</td><td>38° 25.923'</td><td>28° 26.016'</td></tr><tr><td rowspan="3">Terceira</td><td>ZKP6</td><td>Serreta fissure zone</td><td>submarine lava</td><td>CE 1999–2000<sup>5</sup></td><td>38° 47.562'</td><td>27° 28.445'</td></tr><tr><td>TRS24a</td><td rowspan="2">central fissure zone</td><td>tephra</td><td>&gt;43 ka<sup>6</sup></td><td>38° 39.016'</td><td>27° 04.638'</td></tr><tr><td>TRS24b</td><td>tephra</td><td>&gt;43 ka<sup>6</sup></td><td>38° 39.016'</td><td>27° 04.638'</td></tr><tr><td rowspan="3">S. Miguel</td><td>SM0810s</td><td>Água de Pau<br>volcano</td><td>tephra</td><td>1.3–3.0<sup>7</sup></td><td>37° 42.762'</td><td>25° 30.329'</td></tr><tr><td>MFs</td><td rowspan="2">Sete Cidades<br>volcano</td><td rowspan="2">tephra</td><td>10–30<sup>7</sup></td><td>37° 53.351'</td><td>25° 48.390'</td></tr><tr><td>SMG9s</td><td>10–30<sup>7</sup></td><td>37° 53.952'</td><td>25° 47.186'</td></tr></tbody></table>

– Basic description of samples and coordinates of collection sites. References for reported ages are: (1) Larrea et al. (2014); (2) Madeira (1998); 3) Zanon and Frezzotti (2013); (4) Nunes (1999); (5) Zanon and Pimentel (2015); (6) Calvert et al. (2006); (7) Moore (1990)
<figure><img src="image_3.png" /><figcaption>**Fig. 1** Geographical location of the Azores, digital elevation model of the islands considered in this study and sampling sites. Panel (a) shows the location of the archipelago in the Atlantic Ocean. Panel (b) shows a bathymetric model of the Azores region and the main tectonic elements. The thick yellow line marks the Terceira Rift (TR), which is the northern boundary of the region, and the East–West Azores Fracture Zone transform fault (EAFZ). Thinner red lines mark</figcaption></figure>

the São Jorge and Faial-Pico spreading systems. The thick segmented black line is the Mid-Atlantic Ridge. Panel (c) shows sampling sites on the islands of São Miguel, Terceira, Pico-Faial, Graciosa and São Jorge. In these maps, blue triangles indicate the sampling sites at fissure zones, while yellow dots are at central volcanoes. Dashed lines represent fissure zones, and blue dashed lines are the main faults. Names indicate the location of central volcanoes referred in this paper
## Samples collection

We examined tephra samples and a submarine lava less than 40,000 years old, collected from the central volcanoes and fissure zones of six islands of the Azores archipelago, located east of the MAR. The samples were collected from the Pico-Faial and São Jorge fissure zones and the Terceira Rift which runs from the southwest to the northeast of the islands (as depicted in Fig. 1b). A sample over 800 ka old from the eastern segment of the São Jorge fissure zone (Marques et al. 2018) was included for comparison. As a whole, geochemical analyses were performed on 142 SMIs from 18 samples (Table 1).

In summary, we studied basaltic tephra from: (1) well-preserved Holocene cinder cones formed along fissure systems (11 samples; blue triangles in Fig. 1b). These samples include submarine lava, erupted during the 1998–2000 eruption off the coasts of Terceira; (2) lateral vents located along transtensive faults (7 samples; yellow dots in Fig. 1b) at the central volcanoes of Água de Pau and Sete Cidades on São Miguel Island, and at the central volcano of Pico. The remaining central volcanoes in the archipelago erupted lavas that were either too evolved or aphyric to be considered.

## Analytical procedures

SMIs were found in polyhedral olivine ranging in size from 2 to 0.5 mm in diameter. These crystals were handpicked from the 0.25–1.00 cm grain size, after sieving samples of tephra fallouts, which included sandy (0.63 mm) to glassy lapilli (3.5 cm) deposits. These small-sized samples were specifically collected from explosive products to reduce the likelihood of post-entrapment chemical exchange between the trapped melt and the host crystal. SMIs were analysed for major, minor and trace elements, as well as sulfur and halogens (141 and 99 analyses) and water content (121 measurements), using a combination of vibrational microspectroscopy, electron microprobe and laser ablation inductively coupled mass spectrometry.

Fourier Transform Infrared (FT-IR) spectroscopy was used to measure the water concentration on double polished SMIs. A Nicolet Magna-IR 550 spectrometer, equipped with a Globar source, a liquid nitrogen cooled MCT/A detector and an X-KBr beam splitter was used at the Institut de Physique du Globe de Paris (France). Concentrations were calculated according to the Beer-Lambert's law: $H_2O (wt.\%) = [(100 \cdot A \cdot M)/(\varepsilon \cdot \rho \cdot e)]$, where A is the absorbance at the peak (measured after subtraction of the baseline extrapolated from the base of the peak),

M the molar mass (g·mol⁻¹), ε the molar absorptivity (L·mol⁻¹·cm⁻¹), e the thickness measured under an optical microscope (cm), and ρ the glass density (g·cm⁻³), calculated following Lange and Carmichael (1990). The total dissolved water ($H_2O_{mol} + OH^−$) was derived from the broadband at 3535 cm⁻¹, using an absorption coefficient of 62.8 L·mol⁻¹·cm⁻¹ (Mercier et al. 2010). The thickness of the inclusions was measured using an electronic crystal thickness gauge (Supplementary Table 1), with relative errors estimated to be <10% for $H_2O$. All FT-IR spectra showed the characteristic bands of carbonate between 1610 and 1345 cm⁻¹. However, the amount of $CO_2$ (both that diffused from the melt into the bubble, and that still dissolved in the glass) was not determined.

Electron microprobe analysis was used to determine the major element compositions in SMIs and hosting olivines using a Cameca SXFive electron microprobe (Camparis, Paris, France). Glasses were analysed using a defocused beam (Ø = 10 µm) at 10 nA and counting times varying from 10 to 25 s. Three to four analytical spots were analysed, depending on the inclusion size. Concentrations of S, F, Cl and P were determined during dedicated analytical sessions using a 30 nA defocused beam (Ø = 15 µm) and counting times of 240 s at the peak. Fluorine, in particular, was analysed by coupling LTAP and TAP crystals. The relative errors are <5% for F at the level of 0.04 wt.%, <4% for Cl at the level of 0.02 wt.%, <3% for S and <6% for P, <5% for $K_2O$ and <3% for the other major elements. The accuracy of F (2495 ± 272 ppm, N = 12) was checked against the glass standard CF-A47 (2270 ± 10 ppm); and Cl (286 ± 17 ppm) and S (1419 ± 33 ppm, N = 14) against the international standard VG2 (303 ± 10 ppm Cl; 1450 ± 30 ppm S at 1σ; N > 100; Métrich et al. 2014). To calculate the melt-olivine equilibrium, the host olivine was analysed (3 analytical spots) around each SMI, at 15 keV and 20 nA, using a focused beam and counting times from 10 to 20 s on the peak. Accuracy was checked against the San Carlos Olivine international standard. The relative errors are <7% for Ni and Mn, <5% for Fe and Ca, and <1% for Si and Mg. The detection limits for trace elements are as low as 18 ppm in olivine and 16 ppm in spinel. To calculate the redox state, olivine-spinel pairs were analysed for major element composition at 20 keV and 10 nA for 10 s (Wan et al. 2008). Trace elements in olivine (Cr, Al, Mn, Ni, Ca, Co) and spinel (Si, Mn, Co, Ni) were measured at 20 keV using a beam current of 300 nA for 30–40 s and 120 s (Supplementary Table 2). The error is better than 2% for olivine and spinel.

The trace element composition was determined by laser ablation associated with an inductively coupled plasma mass spectrometer (ICP-MS) at the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Palermo Section (Italy). The laser, a GeoLasPro 193 nm excimer system, equipped with an Agilent 7500ce quadrupole ICP-MS, operated at 10 Hz,

<figure><img src="image_4.png" /></figure>
with a spot size of 24–32 µm, associated with a fluence of 14 and 15 J·cm⁻², and He fluxes of 800–820 ml·min⁻¹ in the ablation cell. Thirty-five trace elements were measured in peak-hopping mode with a dwell time of 10 ms. The entire analysis took 2 min for each spot, including 1 min for background acquisition. Plasma conditions were adjusted to a ThO/Th ratio of less than 1% so that no further oxide corrections were required. NIST SRM 612 was measured as an external standard at the beginning and the end of each analysis session (20–30 spot analyses). ⁴³Ca was used as the internal standard for the geochemical reference materials. For SMIs, we used CaO wt.% measured by electron microprobe. Raw data of major and trace element compositions are presented in Supplementary Table 1. Data were collected in time-resolved graphics mode to check for any compositional heterogeneity that may be present in the sample at the scale of the laser sampling and to check for interelement fractionation. The data were processed using the GLITTER program (Van Achterbergh et al. 2001). Accuracy was checked by repeated measurements of BCR-2G basaltic reference glass from the USGS (Jenner and O'Neill 2012), during each analysis session (Supplementary Table 3).

## Data description

### Sample characteristics

The samples collected are proximal tephra fallouts containing juvenile porphyritic to hypocrystalline and holohyaline

clasts as well as loose olivine and pyroxene crystals. The content of crystals is within the range of 20–40 vol.%. Fragments of the submarine lava are poorly porphyritic (~15–18 vol.%) with euhedral to skeletal clinopyroxene, olivine and plagioclase in the mineral assemblage. The groundmass ranges from vitrophyric to intersertal.

Studied olivines in these samples are typically either euhedral (polyhedral) or subhedral (Ø ≤ 2 mm). Additionally, megacrysts measuring up to 4 mm, are a common feature in the products of Pico and Sete Cidades volcanoes. These have been discovered dispersed or accumulated in discontinuous layers or lenses, resulting from the disruption of consolidated crystal mushes, due to the ascent of magma along tectonic discontinuities (Zanon et al. 2020). Furthermore, glomeroporphyritic aggregates incorporating pyroxenes and oxides have been occasionally found in lavas (Fig. 2a).

### Silicate-melt inclusions and their host crystals

This study examines SMIs found in ~10% of olivine crystals with compositions ranging from Fo₇₅.₈ to Fo₈₅.₆, as reported in Supplementary Table 2. Chemical core-rim profiles of some crystals from Pico, São Jorge, and São Miguel demonstrate the absence of any zoning (Supplementary Fig. 1).

We followed the practises for selection, preparation and analysis guidelines for SMIs as recommended by Rose-Koga et al. (2021). SMIs are either isolated or form minor clusters (Fig. 2b). The inclusions are transparent with a diameter

<figure><img src="image_5.png" /><figcaption>**Fig. 2** Photomicrographs of representative studied lava samples and SMIs. **a** Highly porphyritic lava from the north coast of Pico volcano. All crystals present are olvines. A large euhedral twinned crystal is present in the upper right corner. Other crystals of different sizes form aggregates. **b** Large clinopyroxenes in the lava from the west coast of Sete Cidades volcano, São Miguel Island. These large crystals show patchy zoning. **c** A cluster of SMIs of variable size hosted in olivines from São Miguel Island. **d** Partially exposed melt inclusion from Faial Island, containing a fluid bubble and a sulfide globule</figcaption></figure>
larger than 20 µm and there are no signs of fractures or deprecitation. The majority of them have a tiny shrinkage bubble that represents approximately 2–5% of the total inclusion volume and a small sulfide globule (Fig. 2c). Any potential post-entrapment modifications were corrected using the Petrolog3 program (Danyushevsky and Plechov 2011) with the following inputs:

- The equilibrium condition between liquid and the host olivine has been computed using the model of Herzberg and O’Hara (2002). Temperatures have been corrected for the effect of olivine liquidus depression due to water content dissolved in SMIs, using the equation $dT(^{\circ}C) = 74.403H_2O (\text{wt.}\%)^{0.352}$ (Falloon and Danyushevsky 2000). This correction enables calculations under hydrous conditions using models developed for anhydrous conditions only;

- The $Fe^{2+}/Fe^{3+}$ ratio of the melt that was calculated from the compositions of spinel and olivine pairs using the equation:

$$ \frac{Fe^{2+}}{Fe^{3+}} = aFo(\text{mol}\%) + b \quad (\text{Danyushevsky and Sobolev 1996}), $$ where *a* and *b* are the coefficients of the interpolation line of $Fe^{2+}/Fe^{3+}$ from spinel composition versus Fo (mol%) in olivine (Supplementary Table 2);

The original $FeO_t$ of the trapped melt has been calculated by intercepting the $FeO_t-MgO$ linear data regression in bulk rocks obtained from literature data for every volcanic system (GEOROC database http://georoc.mpch-mainz.gwdg.de/georoc/), with the trend created by the SMIs of each sample. On average, SMIs display 32% depletion in iron, regardless of their size. Two individual inclusions from São Jorge experienced a loss of 38%. In Terceira volcanic systems, SMIs exhibit a continuous trend of iron depletion, with a maximum of 41%. Fe gain was observed in 14% of SMIs from Faial (up to 23%) and in most SMIs from Graciosa (up to 27%).

The calculated PEC varies from 2 to 5% in all islands, except in São Miguel, where it is 10%. Trace element compositions were calculated using the CaO content (internal standard) after the correction for PEC. Corrected major and trace element compositions are presented in Table 2 and all figures in this article. It is important to note that all subsequent data presentation and discussion are exclusively to the corrected compositions.

The $D_{Ca}^{ol-liqu}$ was also computed using the CaO content of olivine and PEC-corrected SMIs. Of these values, 95% of them fall between 0.021 and 0.029 (Fig. 3d), in good agreement with literature data on olivine-liquid pairs found in basaltic liquids (e.g., Leeman and Scheidegger 1977; Beattie 1994). These values, which are characteristic of both MORB and oceanic basalts (Gavrilenko et al. 2016) indicate equilibrium conditions between the SMIs and their host. Roughly

9% of the values, represented by São Jorge data are <0.021 while ~20% of the data (Pico and São Miguel) are >0.029. Values from São Jorge, which show a reduced Fo content, are positively correlated with PEC. Therefore, the low partition coefficients might be an artefact of the calculation. The other data, especially those from Pico volcano, show a large variability in CaO (0.30–0.49 wt.%) associated with high Fo content (~85–88%).

SMIs exhibit a dominant compositional range from basalt to trachybasalt, with a few tephrite exceptions (Fig. 3a). They are mostly alkaline, except for some inclusions from Terceira, Graciosa and Pico, which display a sub-alkaline affinity. Their alkalinity is highly pronounced, except for a few inclusions from Terceira, Graciosa and Pico, which show a sub-alkaline affinity. The major and trace element compositions of the SMIs are in the bulk rocks domain and are considered to be representative of the erupted magmas and the mafic lavas of the Azores archipelago, based on the GEOROC database (Supplementary Figs. 2 and 3).

The SMIs exhibit a wide spectrum of $CaO/Al_2O_3$ and $FeO/MgO$ major element compositions (Fig. 3b), while their MgO content varies from 11.6 to 4.4 wt.% (Table 2). The most evolved compositions are found in samples from São Jorge, Graciosa, Terceira and Faial islands (Fig. 3b). The decrease of $CaO/Al_2O_3$ ratios suggests clinopyroxene fractionation, alongside olivine (Fig. 3c). A reduction in Sc, Ni, and Co concentrations, with a simultaneous increase in Nb from 4 to 82 ppm, provides further evidence supporting this interpretation (Supplementary Fig. 3).

The least evolved compositions ($CaO/Al_2O_3$=0.77–0.99; $FeO/MgO$ = 1.04–1.31) are from the pyroclastic deposits from the central volcanoes in the islands of Pico and São Miguel, and are trapped in forsterite-rich olivine (Fo = 82–85 mol.%). These inclusions also show the highest contents of $TiO_2$, and $FeO_t$ and the lowest concentration of $Na_2O$ and $Al_2O_3$ (Supplementary Fig. 2). They record a large range of Nb concentrations for a narrow range of transition elements as marked by the grey field in Supplementary Fig. 3.

The content of High Field-Strength Elements (HFSE: Zr, Nb, Hf, Ta), U, Th, the Rare Earth Elements (REE: La → Lu) and most of the Large-Ion Lithophile Elements (LILE: Ba, K, Rb, Cs) is positively correlated with each other. There is no evidence of Eu anomaly in the studied compositions. Spider diagrams of SMIs show similar trace element patterns, with each other, as well as fractionated REE, enrichment in LILE, and HFSE relative to the Primordial Mantle (McDonough and Sun 1995). Specifically, the SMIs from São Miguel exhibit the highest degree of enrichment in incompatible elements and are also the least evolved compared to the other samples. The sub-alkaline samples from Terceira are the most depleted in incompatible elements, despite they are more evolved than the SMIs
<table><caption>Table 2 Melt inclusions data</caption><thead><tr><th></th><th>D.L. %</th><th>GRA 1-1</th><th>GRA 1-2b</th><th>GRA 1-2c</th><th>GRA 1-3</th><th>GRA 1-4b</th><th>GRA 1-4c</th><th>GRA 1-5</th><th>GRA 1-6</th><th>GRA 1-7a</th><th>GRA 1-7b</th><th>GRA 1-9</th><th>GRA 1-10a</th><th>GRA 1-10b</th><th>GRA 1-11b</th><th>GRA 2-1a</th></tr></thead><tbody><tr><td>PEC</td><td>7.7</td><td>3.62</td><td>3.58</td><td>2.53</td><td>3.46</td><td>1.1</td><td>-1.09</td><td>4.49</td><td>2.38</td><td>2.56</td><td>5.31</td><td>10.56</td><td>14.61</td><td>6.79</td><td>5.86</td></tr><tr><td>%</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Fo</td><td>82.1</td><td>80.7</td><td>80.6</td><td>78.9</td><td>80.9</td><td>80.7</td><td>80.3</td><td>81.3</td><td>80.2</td><td>80.2</td><td>80.7</td><td>83.6</td><td>85.0</td><td>81.1</td><td>80.5</td></tr><tr><td>%</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>0.13</td><td>46.1</td><td>46.2</td><td>48.5</td><td>48.2</td><td>46.9</td><td>47.6</td><td>48.7</td><td>46.4</td><td>47.1</td><td>46.5</td><td>46.0</td><td>44.9</td><td>44.5</td><td>43.8</td><td>56.0</td></tr><tr><td>TiO<sub>2</sub></td><td>0.10</td><td>2.66</td><td>3.41</td><td>2.13</td><td>2.88</td><td>3.15</td><td>3.08</td><td>2.95</td><td>3.27</td><td>3.52</td><td>3.55</td><td>3.54</td><td>3.25</td><td>2.98</td><td>4.05</td><td>3.66</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>0.06</td><td>16.2</td><td>16.4</td><td>16.8</td><td>16.1</td><td>16.0</td><td>15.7</td><td>17.4</td><td>16.3</td><td>16.8</td><td>17.6</td><td>16.3</td><td>15.2</td><td>14.6</td><td>14.7</td><td>15.8</td></tr><tr><td>FeO<sub>1</sub></td><td>0.11</td><td>11.1</td><td>10.7</td><td>10.1</td><td>11.2</td><td>10.7</td><td>10.2</td><td>8.9</td><td>10.9</td><td>10.5</td><td>10.8</td><td>11.3</td><td>11.1</td><td>11.3</td><td>12.3</td><td>11.3</td></tr><tr><td>MnO</td><td>0.11</td><td>0.15</td><td>0.16</td><td>0.17</td><td>0.20</td><td>0.15</td><td>0.14</td><td>0.20</td><td>0.16</td><td>0.19</td><td>0.14</td><td>0.21</td><td>0.18</td><td>0.13</td><td>0.21</td><td>0.16</td></tr><tr><td>MgO</td><td>0.12</td><td>8.8</td><td>7.4</td><td>6.8</td><td>6.9</td><td>7.6</td><td>6.9</td><td>5.4</td><td>8.0</td><td>6.9</td><td>7.2</td><td>8.0</td><td>10.1</td><td>11.6</td><td>9.3</td><td>7.9</td></tr><tr><td>CaO</td><td>0.07</td><td>8.9</td><td>9.2</td><td>8.7</td><td>7.7</td><td>9.1</td><td>9.0</td><td>10.3</td><td>9.5</td><td>8.5</td><td>8.5</td><td>8.9</td><td>11.0</td><td>10.8</td><td>9.5</td><td>9.5</td></tr><tr><td>Na<sub>2</sub>O</td><td>0.05</td><td>3.6</td><td>3.9</td><td>3.7</td><td>3.8</td><td>3.7</td><td>4.1</td><td>3.8</td><td>3.6</td><td>4.8</td><td>4.2</td><td>3.8</td><td>2.6</td><td>2.9</td><td>3.7</td><td>3.4</td></tr><tr><td>K<sub>2</sub>O</td><td>0.04</td><td>1.1</td><td>1.4</td><td>1.6</td><td>1.6</td><td>1.4</td><td>1.7</td><td>1.4</td><td>1.1</td><td>0.3</td><td>0.4</td><td>0.9</td><td>0.9</td><td>0.9</td><td>1.3</td><td>1.2</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.02</td><td>0.23</td><td>-</td><td>0.12</td><td>0.35</td><td>0.25</td><td>0.31</td><td>0.15</td><td>0.24</td><td>0.08</td><td>0.09</td><td>0.11</td><td>0.20</td><td>0.17</td><td>0.25</td><td>0.25</td></tr><tr><td>S</td><td>0.01</td><td>0.14</td><td>0.01</td><td>0.05</td><td>0.17</td><td>0.13</td><td>0.14</td><td>0.10</td><td>0.16</td><td>0.03</td><td>0.03</td><td>0.07</td><td>0.13</td><td>0.11</td><td>0.14</td><td>0.16</td></tr><tr><td>Cl</td><td>0.01</td><td>0.05</td><td>0.44</td><td>-</td><td>0.08</td><td>0.06</td><td>0.07</td><td>0.05</td><td>0.06</td><td>-</td><td>-</td><td>-</td><td>0.05</td><td>0.04</td><td>0.06</td><td>0.06</td></tr><tr><td>F</td><td>0.03</td><td>0.09</td><td>-</td><td>0.04</td><td>0.10</td><td>0.07</td><td>0.13</td><td>0.08</td><td>0.13</td><td>0.09</td><td>0.11</td><td>0.11</td><td>0.04</td><td>0.07</td><td>0.15</td><td>0.12</td></tr><tr><td>H<sub>2</sub>O</td><td>-</td><td>1.25</td><td>1.36</td><td>1.37</td><td>1.12</td><td>0.96</td><td>1.23</td><td>0.86</td><td>0.60</td><td>1.41</td><td>0.96</td><td>1.01</td><td>0.58</td><td>0.31</td><td>0.90</td><td>0.95</td></tr><tr><td>Total</td><td>100.29</td><td>100.46</td><td>100.12</td><td>100.36</td><td>100.28</td><td>100.35</td><td>100.24</td><td>100.35</td><td>100.14</td><td>100.15</td><td>100.22</td><td>100.23</td><td>100.22</td><td>100.34</td><td>100.35</td></tr><tr><td>Li ppm</td><td>1.990</td><td>3.6</td><td>-</td><td>2.0</td><td>5.5</td><td>9.2</td><td>5.7</td><td>3.6</td><td>8.2</td><td>7.3</td><td>-</td><td>4.8</td><td>5.5</td><td>9.5</td><td>6.8</td></tr><tr><td>Sc</td><td>0.116</td><td>25</td><td>-</td><td>-</td><td>22</td><td>22</td><td>30</td><td>33</td><td>20</td><td>20</td><td>-</td><td>25</td><td>29</td><td>25</td><td>27</td></tr><tr><td>V</td><td>0.041</td><td>251</td><td>-</td><td>-</td><td>289</td><td>271</td><td>277</td><td>341</td><td>281</td><td>239</td><td>216</td><td>-</td><td>253</td><td>251</td><td>290</td><td>293</td></tr><tr><td>Cr</td><td>1.440</td><td>97</td><td>-</td><td>-</td><td>32</td><td>74</td><td>74</td><td>92</td><td>106</td><td>52</td><td>52</td><td>-</td><td>213</td><td>241</td><td>72</td><td>61</td></tr><tr><td>Co</td><td>0.020</td><td>36</td><td>-</td><td>-</td><td>48</td><td>41</td><td>43</td><td>50</td><td>46</td><td>41</td><td>38</td><td>-</td><td>41</td><td>36</td><td>42</td><td>39</td></tr><tr><td>Ni</td><td>0.538</td><td>50</td><td>-</td><td>-</td><td>52</td><td>57</td><td>64</td><td>73</td><td>52</td><td>57</td><td>58</td><td>-</td><td>67</td><td>72</td><td>42</td><td>45</td></tr><tr><td>Cu</td><td>0.175</td><td>29</td><td>-</td><td>-</td><td>41</td><td>26</td><td>29</td><td>19</td><td>19</td><td>26</td><td>13</td><td>-</td><td>48</td><td>58</td><td>25</td><td>31</td></tr><tr><td>Zn</td><td>0.224</td><td>106</td><td>-</td><td>-</td><td>136</td><td>124</td><td>121</td><td>104</td><td>151</td><td>123</td><td>115</td><td>-</td><td>117</td><td>82</td><td>135</td><td>110</td></tr><tr><td>Rb</td><td>0.014</td><td>27</td><td>-</td><td>-</td><td>37</td><td>32</td><td>40</td><td>34</td><td>26</td><td>4.1</td><td>4.4</td><td>-</td><td>22</td><td>23</td><td>29</td><td>30</td></tr><tr><td>Sr</td><td>0.009</td><td>534</td><td>-</td><td>-</td><td>586</td><td>581</td><td>469</td><td>607</td><td>713</td><td>1698</td><td>2245</td><td>-</td><td>469</td><td>493</td><td>553</td><td>481</td></tr><tr><td>Y</td><td>0.005</td><td>24</td><td>-</td><td>-</td><td>27</td><td>23</td><td>23</td><td>28</td><td>33</td><td>21</td><td>20</td><td>-</td><td>21</td><td>19</td><td>23</td><td>26</td></tr><tr><td>Zr</td><td>0.012</td><td>208</td><td>-</td><td>-</td><td>240</td><td>223</td><td>240</td><td>227</td><td>255</td><td>40</td><td>110</td><td>-</td><td>167</td><td>151</td><td>209</td><td>225</td></tr><tr><td>Nb</td><td>0.008</td><td>40</td><td>-</td><td>-</td><td>54</td><td>54</td><td>57</td><td>53</td><td>56</td><td>4.8</td><td>8.9</td><td>-</td><td>35</td><td>33</td><td>52</td><td>50</td></tr><tr><td>Cs</td><td>0.007</td><td>0.32</td><td>-</td><td>-</td><td>0.38</td><td>0.30</td><td>0.38</td><td>0.25</td><td>0.48</td><td>0.04</td><td>0.04</td><td>-</td><td>0.23</td><td>0.21</td><td>0.31</td><td>0.31</td></tr><tr><td>Ba</td><td>0.034</td><td>281</td><td>-</td><td>-</td><td>471</td><td>342</td><td>434</td><td>311</td><td>330</td><td>135</td><td>178</td><td>-</td><td>243</td><td>231</td><td>349</td><td>240</td></tr><tr><td>La</td><td>0.007</td><td>26</td><td>-</td><td>-</td><td>35</td><td>34</td><td>35</td><td>34</td><td>40</td><td>7.1</td><td>15</td><td>-</td><td>23</td><td>22</td><td>31</td><td>31</td></tr><tr><td>Ce</td><td>0.007</td><td>59</td><td>-</td><td>-</td><td>78</td><td>75</td><td>77</td><td>64</td><td>94</td><td>17</td><td>37</td><td>-</td><td>52</td><td>49</td><td>73</td><td>69</td></tr><tr><td>Pr</td><td>0.004</td><td>7.4</td><td>-</td><td>-</td><td>9.3</td><td>8.9</td><td>8.9</td><td>7.4</td><td>10.5</td><td>2.3</td><td>4.9</td><td>-</td><td>6.3</td><td>6.1</td><td>8.6</td><td>8.1</td></tr><tr><td>Nd</td><td>0.028</td><td>32</td><td>-</td><td>-</td><td>37</td><td>37</td><td>36</td><td>31</td><td>54</td><td>11</td><td>25</td><td>-</td><td>27</td><td>25</td><td>37</td><td>36</td></tr><tr><td>Sm</td><td>0.039</td><td>7.6</td><td>-</td><td>-</td><td>8.0</td><td>7.9</td><td>6.7</td><td>7.3</td><td>9.6</td><td>3.8</td><td>7.0</td><td>-</td><td>6.1</td><td>5.5</td><td>8.7</td><td>7.8</td></tr><tr><td>Eu</td><td>0.008</td><td>2.3</td><td>-</td><td>-</td><td>2.7</td><td>2.4</td><td>2.4</td><td>2.5</td><td>3.1</td><td>1.9</td><td>2.3</td><td>-</td><td>1.8</td><td>1.9</td><td>2.4</td><td>2.4</td></tr></tbody></table>

<figure><img src="image_6.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>GRA 1-1</th><th>GRA 1-2b</th><th>GRA 1-2c</th><th>GRA 1-3</th><th>GRA 1-4b</th><th>GRA 1-4c</th><th>GRA 1-5</th><th>GRA 1-6</th><th>GRA 1-7a</th><th>GRA 1-7b</th><th>GRA 1-9</th><th>GRA 1-10a</th><th>GRA 1-10b</th><th>GRA 1-11b</th><th>GRA 2-1a</th></tr></thead><tbody><tr><td>Gd</td><td>0.041</td><td>6.5</td><td>-</td><td>-</td><td>7.3</td><td>7.0</td><td>6.0</td><td>6.7</td><td>10.3</td><td>5.3</td><td>5.8</td><td>-</td><td>5.4</td><td>5.2</td><td>6.7</td><td>6.6</td></tr><tr><td>Tb</td><td>0.006</td><td>0.9</td><td>-</td><td>-</td><td>1.0</td><td>0.9</td><td>0.9</td><td>0.9</td><td>1.2</td><td>0.7</td><td>0.8</td><td>-</td><td>0.8</td><td>0.7</td><td>1.0</td><td>1.0</td></tr><tr><td>Dy</td><td>0.023</td><td>4.8</td><td>-</td><td>-</td><td>5.7</td><td>4.7</td><td>4.5</td><td>5.8</td><td>6.5</td><td>4.5</td><td>4.4</td><td>-</td><td>4.5</td><td>4.4</td><td>4.9</td><td>5.9</td></tr><tr><td>Ho</td><td>0.006</td><td>0.8</td><td>-</td><td>-</td><td>1.1</td><td>0.9</td><td>0.8</td><td>1.0</td><td>1.3</td><td>0.9</td><td>0.8</td><td>-</td><td>0.8</td><td>0.7</td><td>0.7</td><td>1.0</td></tr><tr><td>Er</td><td>0.016</td><td>2.4</td><td>-</td><td>-</td><td>2.8</td><td>2.2</td><td>2.3</td><td>2.5</td><td>2.8</td><td>2.0</td><td>2.0</td><td>-</td><td>2.0</td><td>2.0</td><td>2.5</td><td>2.5</td></tr><tr><td>Tm</td><td>0.005</td><td>0.32</td><td>-</td><td>-</td><td>0.34</td><td>0.35</td><td>0.32</td><td>0.42</td><td>0.43</td><td>0.25</td><td>0.31</td><td>-</td><td>0.29</td><td>0.27</td><td>0.33</td><td>0.34</td></tr><tr><td>Yb</td><td>0.032</td><td>2.0</td><td>-</td><td>-</td><td>2.2</td><td>1.9</td><td>1.8</td><td>2.1</td><td>2.8</td><td>1.7</td><td>1.7</td><td>-</td><td>1.7</td><td>1.6</td><td>2.3</td><td>2.8</td></tr><tr><td>Lu</td><td>0.010</td><td>0.28</td><td>-</td><td>-</td><td>0.32</td><td>0.22</td><td>0.25</td><td>0.40</td><td>0.29</td><td>0.23</td><td>0.20</td><td>-</td><td>0.25</td><td>0.21</td><td>0.24</td><td>0.32</td></tr><tr><td>Hf</td><td>0.026</td><td>5</td><td>-</td><td>-</td><td>5</td><td>5</td><td>5</td><td>5</td><td>6</td><td>0.7</td><td>2</td><td>-</td><td>4</td><td>4</td><td>5</td><td>5</td></tr><tr><td>Ta</td><td>0.009</td><td>2.4</td><td>-</td><td>-</td><td>3.3</td><td>3.4</td><td>3.3</td><td>2.9</td><td>3.3</td><td>0.3</td><td>0.4</td><td>-</td><td>2.1</td><td>2.1</td><td>3.0</td><td>3.1</td></tr><tr><td>Pb</td><td>0.034</td><td>2.8</td><td>-</td><td>-</td><td>2.8</td><td>2.4</td><td>2.2</td><td>2.5</td><td>2.6</td><td>0.9</td><td>1.3</td><td>-</td><td>1.7</td><td>1.7</td><td>2.1</td><td>1.9</td></tr><tr><td>Th</td><td>0.011</td><td>2.7</td><td>-</td><td>-</td><td>3.5</td><td>3.5</td><td>3.8</td><td>3.5</td><td>3.2</td><td>0.3</td><td>0.6</td><td>-</td><td>2.3</td><td>2.1</td><td>3.1</td><td>3.1</td></tr><tr><td>U</td><td>0.014</td><td>0.77</td><td>-</td><td>-</td><td>1.3</td><td>1.3</td><td>1.4</td><td>1.1</td><td>1.5</td><td>0.11</td><td>0.29</td><td>-</td><td>0.73</td><td>0.72</td><td>1.2</td><td>1.0</td></tr><tr><th>D.L. %</th><th></th><th>GRA 2-1b</th><th>GRA 2-1c</th><th>GRA 2-1d</th><th>GRA 2-2a</th><th>GRA 2-4a</th><th>GRA 2-4b</th><th>GRA 2-4c</th><th>GRA 2-5</th><th>GRA 5-1b</th><th>GRA 5-1c</th><th>GRA 5-2a</th><th>GRA 5-2a-2</th><th>GRA 5-3a</th><th>GRA 5-3b</th><th>GRA 5-3c</th></tr><tr><td>PEC</td><td>%</td><td>4.14</td><td>6.85</td><td>4.44</td><td>6.78</td><td>6.33</td><td>5.59</td><td>-1.35</td><td>2.58</td><td>0.56</td><td>-2.29</td><td>1.85</td><td>-0.67</td><td>15.85</td><td>3.88</td><td>7.13</td></tr><tr><td>Fo</td><td>%</td><td>80.4</td><td>80.9</td><td>80.6</td><td>80.4</td><td>79.5</td><td>79.6</td><td>79.3</td><td>80.8</td><td>78.7</td><td>76.4</td><td>78.7</td><td>78.6</td><td>84.0</td><td>83.5</td><td>82.6</td></tr><tr><td>SiO<sub>2</sub></td><td>%</td><td>0.13</td><td>46.1</td><td>46.8</td><td>47.1</td><td>46.4</td><td>46.2</td><td>49.1</td><td>48.7</td><td>48.8</td><td>47.3</td><td>49.0</td><td>49.0</td><td>45.4</td><td>47.8</td><td>46.2</td></tr><tr><td>TiO<sub>2</sub></td><td>%</td><td>0.10</td><td>3.38</td><td>3.34</td><td>3.36</td><td>3.60</td><td>3.70</td><td>3.64</td><td>2.96</td><td>3.35</td><td>3.52</td><td>3.38</td><td>3.37</td><td>3.52</td><td>3.02</td><td>3.41</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>%</td><td>0.06</td><td>16.6</td><td>15.8</td><td>16.8</td><td>15.7</td><td>15.8</td><td>16.1</td><td>16.0</td><td>16.9</td><td>16.1</td><td>18.0</td><td>15.5</td><td>17.0</td><td>14.3</td><td>16.6</td></tr><tr><td>FeO<sub>t</sub></td><td>%</td><td>0.11</td><td>10.9</td><td>11.6</td><td>10.7</td><td>11.9</td><td>11.8</td><td>11.8</td><td>10.1</td><td>9.6</td><td>10.6</td><td>10.5</td><td>10.6</td><td>9.5</td><td>11.6</td><td>8.9</td></tr><tr><td>MnO</td><td>%</td><td>0.11</td><td>0.20</td><td>0.21</td><td>0.21</td><td>0.19</td><td>0.18</td><td>0.20</td><td>0.20</td><td>0.21</td><td>0.16</td><td>0.22</td><td>0.18</td><td>0.20</td><td>0.17</td><td>0.16</td></tr><tr><td>MgO</td><td>%</td><td>0.12</td><td>7.4</td><td>8.4</td><td>7.4</td><td>8.4</td><td>7.7</td><td>7.7</td><td>6.1</td><td>6.4</td><td>6.2</td><td>5.0</td><td>6.2</td><td>5.2</td><td>11.1</td><td>8.5</td></tr><tr><td>CaO</td><td>%</td><td>0.07</td><td>9.6</td><td>9.6</td><td>10.0</td><td>9.7</td><td>8.6</td><td>8.4</td><td>9.0</td><td>9.4</td><td>7.9</td><td>7.5</td><td>7.8</td><td>8.4</td><td>9.3</td><td>10.9</td></tr><tr><td>Na<sub>2</sub>O</td><td>%</td><td>0.05</td><td>3.3</td><td>3.2</td><td>3.3</td><td>2.9</td><td>3.3</td><td>3.8</td><td>4.0</td><td>4.1</td><td>4.4</td><td>4.8</td><td>4.0</td><td>4.1</td><td>2.8</td><td>3.2</td></tr><tr><td>K<sub>2</sub>O</td><td>%</td><td>0.04</td><td>1.3</td><td>1.1</td><td>1.0</td><td>1.4</td><td>1.5</td><td>1.9</td><td>1.6</td><td>1.4</td><td>1.5</td><td>1.7</td><td>1.5</td><td>1.5</td><td>1.4</td><td>1.3</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>%</td><td>0.02</td><td>0.27</td><td>-</td><td>-</td><td>0.25</td><td>0.27</td><td>0.26</td><td>0.28</td><td>0.29</td><td>0.20</td><td>0.17</td><td>0.27</td><td>0.33</td><td>0.22</td><td>0.21</td></tr><tr><td>S</td><td>%</td><td>0.01</td><td>0.15</td><td>-</td><td>-</td><td>0.11</td><td>0.17</td><td>0.47</td><td>0.55</td><td>0.51</td><td>0.09</td><td>0.08</td><td>0.18</td><td>0.19</td><td>0.03</td><td>0.07</td></tr><tr><td>Cl</td><td>%</td><td>0.01</td><td>0.06</td><td>-</td><td>-</td><td>0.06</td><td>0.06</td><td>0.06</td><td>0.08</td><td>0.08</td><td>0.07</td><td>0.05</td><td>0.07</td><td>0.08</td><td>0.07</td><td>0.08</td></tr><tr><td>F</td><td>%</td><td>0.03</td><td>0.10</td><td>-</td><td>-</td><td>0.08</td><td>0.09</td><td>0.10</td><td>0.14</td><td>0.09</td><td>0.06</td><td>0.09</td><td>0.11</td><td>0.14</td><td>0.10</td><td>0.10</td></tr><tr><td>H<sub>2</sub>O</td><td>%</td><td>-</td><td>0.95</td><td>-</td><td>-</td><td>0.44</td><td>0.78</td><td>-</td><td>-</td><td>-</td><td>0.71</td><td>1.15</td><td>1.56</td><td>1.45</td><td>0.21</td><td>0.38</td></tr><tr><td>Total</td><td>%</td><td>1.990</td><td>6.9</td><td>100.00</td><td>99.99</td><td>100.25</td><td>100.34</td><td>100.63</td><td>100.76</td><td>100.68</td><td>100.21</td><td>100.22</td><td>100.36</td><td>100.41</td><td>100.19</td><td>100.26</td></tr><tr><td>Li ppm</td><td>%</td><td>0.116</td><td>26</td><td>-</td><td>-</td><td>-</td><td>7.4</td><td>9.1</td><td>9.9</td><td>7.9</td><td>-</td><td>11.4</td><td>10.2</td><td>-</td><td>1.5</td><td>4.9</td></tr><tr><td>Sc</td><td>%</td><td></td><td></td><td>-</td><td>-</td><td>-</td><td>24</td><td>23</td><td>26</td><td>27</td><td>-</td><td>25</td><td>21</td><td>-</td><td>31</td><td>33</td></tr></tbody></table>

<figure><img src="image_7.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>GRA 5-4</th><th>GRA 5-5a</th><th>GRA 5-6</th><th>GRA 5-7a</th><th>GRA 5-7b</th><th>GRA 5-8a</th><th>GRA 5-8b</th><th>GRA 5-9</th><th>GRA 5-10</th><th>GRA 5-10e</th><th>GRA 5-11</th><th>SJ 250713a-6</th><th>SJ 250713a-9</th><th>SJ 240713b-1a</th><th>SJ 240713b-1b</th></tr></thead><tbody><tr><td>PEC %</td><td>4.33</td><td>0.49</td><td>8.73</td><td>-0.23</td><td>7.78</td><td>0.89</td><td>-0.02</td><td>-1.03</td><td>2.73</td><td>-</td><td>-</td><td>7.13</td><td>10.83</td><td>2.53</td><td>1.67</td><td></td></tr><tr><td>Fo %</td><td>80.2</td><td>77.6</td><td>83.6</td><td>78.7</td><td>81.8</td><td>79.9</td><td>79.2</td><td>78.2</td><td>80.7</td><td>84.0</td><td>78.3</td><td>82.8</td><td>84.8</td><td>78.2</td><td>78.1</td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>0.13</td><td>46.3</td><td>47.4</td><td>46.9</td><td>49.2</td><td>47.2</td><td>47.7</td><td>47.8</td><td>47.8</td><td>48.7</td><td>49.8</td><td>49.3</td><td>45.0</td><td>45.7</td><td>46.6</td><td>47.0</td></tr><tr><td>TiO<sub>2</sub></td><td>0.10</td><td>3.35</td><td>3.18</td><td>3.10</td><td>3.53</td><td>3.00</td><td>3.75</td><td>3.65</td><td>3.37</td><td>3.33</td><td>3.21</td><td>3.36</td><td>4.13</td><td>4.11</td><td>3.66</td><td>3.64</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>0.06</td><td>16.6</td><td>17.4</td><td>16.0</td><td>15.6</td><td>15.7</td><td>18.0</td><td>18.1</td><td>18.5</td><td>17.2</td><td>14.1</td><td>17.7</td><td>15.7</td><td>13.9</td><td>17.9</td><td>18.3</td></tr><tr><td>FeO<sub>t</sub></td><td>0.11</td><td>10.9</td><td>11.4</td><td>10.1</td><td>10.1</td><td>10.8</td><td>9.6</td><td>9.6</td><td>9.6</td><td>9.6</td><td>9.6</td><td>9.6</td><td>10.9</td><td>10.5</td><td>9.6</td><td>9.8</td></tr><tr><td>MnO</td><td>0.11</td><td>0.23</td><td>0.14</td><td>0.17</td><td>0.23</td><td>0.16</td><td>0.18</td><td>0.16</td><td>0.20</td><td>0.13</td><td>0.13</td><td>0.17</td><td>0.16</td><td>0.11</td><td>0.17</td><td>0.15</td></tr><tr><td>MgO</td><td>0.12</td><td>7.4</td><td>6.4</td><td>8.9</td><td>5.8</td><td>8.3</td><td>5.9</td><td>5.5</td><td>5.0</td><td>6.4</td><td>8.6</td><td>5.1</td><td>9.1</td><td>10.5</td><td>5.0</td><td>5.1</td></tr><tr><td>CaO</td><td>0.07</td><td>7.7</td><td>7.5</td><td>10.0</td><td>7.6</td><td>10.1</td><td>8.0</td><td>7.7</td><td>7.8</td><td>7.4</td><td>9.5</td><td>7.2</td><td>10.7</td><td>10.7</td><td>9.9</td><td>9.7</td></tr><tr><td>Na<sub>2</sub>O</td><td>0.05</td><td>4.2</td><td>4.8</td><td>3.2</td><td>4.3</td><td>2.9</td><td>4.3</td><td>4.3</td><td>4.4</td><td>4.1</td><td>3.4</td><td>4.7</td><td>2.9</td><td>2.7</td><td>3.9</td><td>4.2</td></tr><tr><td>K<sub>2</sub>O</td><td>0.04</td><td>1.5</td><td>0.50</td><td>1.2</td><td>1.6</td><td>1.2</td><td>1.7</td><td>1.7</td><td>1.7</td><td>1.5</td><td>2.0</td><td>0.85</td><td>0.86</td><td>1.5</td><td>1.8</td><td>0.37</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.02</td><td>0.28</td><td>0.21</td><td>0.20</td><td>0.37</td><td>0.21</td><td>0.22</td><td>0.31</td><td>0.38</td><td>0.29</td><td>0.06</td><td>0.29</td><td>0.16</td><td>0.20</td><td>0.35</td><td>0.69</td></tr><tr><td>S</td><td>0.01</td><td>0.15</td><td>0.14</td><td>0.03</td><td>0.18</td><td>0.05</td><td>0.15</td><td>0.15</td><td>0.17</td><td>0.13</td><td>0.44</td><td>0.14</td><td>0.17</td><td>0.17</td><td>0.19</td><td>0.07</td></tr><tr><td>Cl</td><td>0.01</td><td>0.06</td><td>-</td><td>0.06</td><td>0.08</td><td>0.07</td><td>0.18</td><td>0.11</td><td>0.08</td><td>0.09</td><td>-</td><td>0.07</td><td>0.04</td><td>0.05</td><td>0.06</td><td>0.15</td></tr><tr><td>F</td><td>0.03</td><td>0.11</td><td>0.13</td><td>0.08</td><td>0.14</td><td>0.08</td><td>-</td><td>0.13</td><td>0.13</td><td>0.08</td><td>-</td><td>0.10</td><td>0.06</td><td>0.05</td><td>0.14</td><td>0.15</td></tr><tr><td>H<sub>2</sub>O</td><td>-</td><td>1.68</td><td>1.11</td><td>0.30</td><td>1.55</td><td>0.59</td><td>0.64</td><td>1.19</td><td>1.27</td><td>1.13</td><td>-</td><td>0.54</td><td>0.30</td><td>0.83</td><td>1.46</td><td>-</td></tr><tr><td>Total</td><td></td><td>100.31</td><td>100.28</td><td>100.20</td><td>100.41</td><td>100.22</td><td>100.35</td><td>100.39</td><td>100.40</td><td>100.29</td><td>100.47</td><td>100.32</td><td>100.26</td><td>100.28</td><td>100.41</td><td>100.92</td></tr><tr><td>Li ppm</td><td>1.990</td><td>8.2</td><td>-</td><td>2.5</td><td>10.8</td><td>2.5</td><td>7.7</td><td>-</td><td>10.0</td><td>-</td><td>-</td><td>-</td><td>-</td><td>3.8</td><td>7.8</td><td>-</td></tr><tr><td>Sc</td><td>0.116</td><td>23</td><td>-</td><td>28</td><td>21</td><td>25</td><td>26</td><td>-</td><td>22</td><td>-</td><td>-</td><td>-</td><td>-</td><td>26</td><td>16</td><td>-</td></tr><tr><td>V</td><td>0.041</td><td>294</td><td>-</td><td>283</td><td>309</td><td>264</td><td>327</td><td>-</td><td>315</td><td>-</td><td>-</td><td>-</td><td>-</td><td>337</td><td>261</td><td>-</td></tr><tr><td>Cr</td><td>1.440</td><td>52</td><td>-</td><td>129</td><td>63</td><td>128</td><td>84</td><td>-</td><td>44</td><td>-</td><td>-</td><td>-</td><td>-</td><td>219</td><td>11</td><td>-</td></tr><tr><td>Co</td><td>0.020</td><td>34</td><td>-</td><td>32</td><td>44</td><td>37</td><td>44</td><td>-</td><td>40</td><td>-</td><td>-</td><td>-</td><td>-</td><td>36</td><td>32</td><td>-</td></tr><tr><td>Ni</td><td>0.538</td><td>51</td><td>-</td><td>49</td><td>62</td><td>72</td><td>102</td><td>-</td><td>45</td><td>-</td><td>-</td><td>-</td><td>-</td><td>50</td><td>32</td><td>-</td></tr><tr><td>Cu</td><td>0.175</td><td>22</td><td>-</td><td>39</td><td>43</td><td>52</td><td>32</td><td>-</td><td>50</td><td>-</td><td>-</td><td>-</td><td>-</td><td>31</td><td>17</td><td>-</td></tr><tr><td>Zn</td><td>0.224</td><td>103</td><td>-</td><td>94</td><td>149</td><td>96</td><td>121</td><td>-</td><td>140</td><td>-</td><td>-</td><td>-</td><td>-</td><td>93</td><td>107</td><td>-</td></tr><tr><td>Rb</td><td>0.014</td><td>33</td><td>-</td><td>33</td><td>40</td><td>32</td><td>52</td><td>-</td><td>43</td><td>-</td><td>-</td><td>-</td><td>-</td><td>17</td><td>30</td><td>-</td></tr><tr><td>Sr</td><td>0.009</td><td>640</td><td>-</td><td>434</td><td>734</td><td>460</td><td>589</td><td>-</td><td>948</td><td>-</td><td>-</td><td>-</td><td>-</td><td>433</td><td>664</td><td>-</td></tr><tr><td>Y</td><td>0.005</td><td>25</td><td>-</td><td>21</td><td>32</td><td>20</td><td>30</td><td>-</td><td>33</td><td>-</td><td>-</td><td>-</td><td>-</td><td>15</td><td>23</td><td>-</td></tr><tr><td>Zr</td><td>0.012</td><td>223</td><td>-</td><td>159</td><td>272</td><td>144</td><td>238</td><td>-</td><td>352</td><td>-</td><td>-</td><td>-</td><td>-</td><td>109</td><td>218</td><td>-</td></tr><tr><td>Nb</td><td>0.008</td><td>49</td><td>-</td><td>46</td><td>66</td><td>42</td><td>71</td><td>-</td><td>76</td><td>-</td><td>-</td><td>-</td><td>-</td><td>29</td><td>54</td><td>-</td></tr><tr><td>Cs</td><td>0.007</td><td>0.31</td><td>-</td><td>0.36</td><td>0.38</td><td>0.36</td><td>0.54</td><td>-</td><td>0.40</td><td>-</td><td>-</td><td>-</td><td>-</td><td>0.15</td><td>0.30</td><td>-</td></tr><tr><td>Ba</td><td>0.034</td><td>350</td><td>-</td><td>328</td><td>378</td><td>305</td><td>537</td><td>-</td><td>459</td><td>-</td><td>-</td><td>-</td><td>-</td><td>183</td><td>313</td><td>-</td></tr><tr><td>La</td><td>0.007</td><td>33</td><td>-</td><td>27</td><td>40</td><td>25</td><td>41</td><td>-</td><td>52</td><td>-</td><td>-</td><td>-</td><td>-</td><td>18</td><td>34</td><td>-</td></tr><tr><td>Ce</td><td>0.007</td><td>75</td><td>-</td><td>60</td><td>91</td><td>56</td><td>84</td><td>-</td><td>114</td><td>-</td><td>-</td><td>-</td><td>-</td><td>45</td><td>79</td><td>-</td></tr></tbody></table>

<figure><img src="image_8.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th colspan="12">D.L. %</th></tr><tr><th></th><th>GRA 5-4</th><th>GRA 5-5a</th><th>GRA 5-6</th><th>GRA 5-7a</th><th>GRA 5-7b</th><th>GRA 5-8a</th><th>GRA 5-8b</th><th>GRA 5-9</th><th>GRA 5-10</th><th>GRA 5-10e</th><th>GRA 5-11</th><th>SJ 250713a-6</th><th>SJ 250713a-9</th><th>SJ 240713b-1a</th><th>SJ 240713b-1b</th></tr></thead><tbody><tr><td>Pr</td><td>0.004</td><td>9.0</td><td>-</td><td>6.9</td><td>10.7</td><td>6.6</td><td>9.7</td><td>-</td><td>14.0</td><td>-</td><td>-</td><td>-</td><td>5.4</td><td>9.8</td><td>-</td></tr><tr><td>Nd</td><td>0.028</td><td>38</td><td>-</td><td>29</td><td>48</td><td>26</td><td>41</td><td>-</td><td>55</td><td>-</td><td>-</td><td>-</td><td>22</td><td>41</td><td>-</td></tr><tr><td>Sm</td><td>0.039</td><td>7.4</td><td>-</td><td>6.4</td><td>9.1</td><td>5.4</td><td>8.3</td><td>-</td><td>10.8</td><td>-</td><td>-</td><td>-</td><td>4.9</td><td>7.6</td><td>-</td></tr><tr><td>Eu</td><td>0.008</td><td>2.5</td><td>-</td><td>2.2</td><td>3.1</td><td>1.9</td><td>3.0</td><td>-</td><td>3.2</td><td>-</td><td>-</td><td>-</td><td>1.8</td><td>2.7</td><td>-</td></tr><tr><td>Gd</td><td>0.041</td><td>6.6</td><td>-</td><td>5.6</td><td>9.6</td><td>4.8</td><td>6.9</td><td>-</td><td>10.1</td><td>-</td><td>-</td><td>-</td><td>4.1</td><td>6.5</td><td>-</td></tr><tr><td>Tb</td><td>0.006</td><td>0.9</td><td>-</td><td>0.7</td><td>1.2</td><td>0.6</td><td>1.0</td><td>-</td><td>1.2</td><td>-</td><td>-</td><td>-</td><td>0.5</td><td>0.9</td><td>-</td></tr><tr><td>Dy</td><td>0.023</td><td>5.4</td><td>-</td><td>4.7</td><td>7.4</td><td>4.5</td><td>7.4</td><td>-</td><td>7.2</td><td>-</td><td>-</td><td>-</td><td>3.4</td><td>4.8</td><td>-</td></tr><tr><td>Ho</td><td>0.006</td><td>1.0</td><td>-</td><td>0.8</td><td>1.3</td><td>0.7</td><td>1.1</td><td>-</td><td>1.2</td><td>-</td><td>-</td><td>-</td><td>0.6</td><td>0.9</td><td>-</td></tr><tr><td>Er</td><td>0.016</td><td>2.6</td><td>-</td><td>2.3</td><td>3.2</td><td>2.1</td><td>3.2</td><td>-</td><td>3.1</td><td>-</td><td>-</td><td>-</td><td>1.4</td><td>2.2</td><td>-</td></tr><tr><td>Tm</td><td>0.005</td><td>0.34</td><td>-</td><td>0.29</td><td>0.49</td><td>0.30</td><td>0.32</td><td>-</td><td>0.51</td><td>-</td><td>-</td><td>-</td><td>0.19</td><td>0.29</td><td>-</td></tr><tr><td>Yb</td><td>0.032</td><td>2.4</td><td>-</td><td>2.2</td><td>2.5</td><td>2.0</td><td>3.0</td><td>-</td><td>3.0</td><td>-</td><td>-</td><td>-</td><td>1.5</td><td>2.0</td><td>-</td></tr><tr><td>Lu</td><td>0.010</td><td>0.34</td><td>-</td><td>0.30</td><td>0.44</td><td>0.24</td><td>0.42</td><td>-</td><td>0.40</td><td>-</td><td>-</td><td>-</td><td>0.15</td><td>0.25</td><td>-</td></tr><tr><td>Hf</td><td>0.026</td><td>5</td><td>-</td><td>3</td><td>6</td><td>3</td><td>5</td><td>-</td><td>8</td><td>-</td><td>-</td><td>-</td><td>3</td><td>5</td><td>-</td></tr><tr><td>Ta</td><td>0.009</td><td>3.2</td><td>-</td><td>2.7</td><td>3.9</td><td>2.4</td><td>3.9</td><td>-</td><td>5.2</td><td>-</td><td>-</td><td>-</td><td>1.6</td><td>3.1</td><td>-</td></tr><tr><td>Pb</td><td>0.034</td><td>2.6</td><td>-</td><td>2.3</td><td>2.3</td><td>1.7</td><td>3.6</td><td>-</td><td>3.7</td><td>-</td><td>-</td><td>-</td><td>1.4</td><td>2.1</td><td>-</td></tr><tr><td>Th</td><td>0.011</td><td>3.1</td><td>-</td><td>3.1</td><td>4.0</td><td>2.9</td><td>4.6</td><td>-</td><td>4.9</td><td>-</td><td>-</td><td>-</td><td>1.5</td><td>2.9</td><td>-</td></tr><tr><td>U</td><td>0.014</td><td>1.18</td><td>-</td><td>0.99</td><td>1.47</td><td>1.01</td><td>1.41</td><td>-</td><td>1.78</td><td>-</td><td>-</td><td>-</td><td>0.77</td><td>1.23</td><td>-</td></tr><tr><th></th><th colspan="12">D.L. %</th></tr><tr><th></th><th>SJ 240713b-2</th><th>SJ 240713b-3</th><th>SJ 240713b-4a</th><th>SJ 240713b-5</th><th>SJ 240713b-6</th><th>SJ 240713b-7</th><th>SJ 240713b-8</th><th>SJ 240713b-9</th><th>SJ 240713b-10</th><th>SJ 240713b-11</th><th>SJ 240713b-12</th><th>SJ 240713b-13</th><th>SJ 240713b-14</th><th>SJ 240713b-15</th></tr><tr><td>PEC</td><td>-1.14</td><td>-0.33</td><td>0.51</td><td>1.58</td><td>0.28</td><td>0.47</td><td>1.98</td><td>0.53</td><td>-2.27</td><td>1.53</td><td>1.1</td><td>1.03</td><td>3.08</td><td>2.4</td><td>3.82</td></tr><tr><td>Fo</td><td>77.2</td><td>77.7</td><td>78.2</td><td>78.0</td><td>77.5</td><td>77.5</td><td>77.5</td><td>77.7</td><td>78.1</td><td>78.2</td><td>81.8</td><td>79.4</td><td>81.3</td><td>81.1</td><td>80.9</td></tr><tr><td>%</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>0.13</td><td>47.3</td><td>45.7</td><td>47.6</td><td>46.4</td><td>45.7</td><td>46.2</td><td>44.4</td><td>46.0</td><td>45.6</td><td>45.2</td><td>48.0</td><td>47.2</td><td>46.8</td><td>46.7</td><td>47.9</td></tr><tr><td>TiO<sub>2</sub></td><td>0.10</td><td>3.90</td><td>3.81</td><td>3.50</td><td>4.02</td><td>3.83</td><td>3.40</td><td>3.71</td><td>4.07</td><td>3.52</td><td>3.63</td><td>3.23</td><td>2.85</td><td>3.41</td><td>3.42</td><td>3.43</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>0.06</td><td>18.0</td><td>18.4</td><td>18.4</td><td>18.4</td><td>18.2</td><td>18.3</td><td>18.3</td><td>18.2</td><td>17.6</td><td>17.6</td><td>16.3</td><td>17.3</td><td>17.1</td><td>17.1</td><td>17.7</td></tr><tr><td>FeO<sub>t</sub></td><td>0.11</td><td>10.2</td><td>9.8</td><td>9.6</td><td>9.3</td><td>9.7</td><td>9.4</td><td>10.0</td><td>9.9</td><td>10.5</td><td>9.6</td><td>8.7</td><td>9.6</td><td>9.4</td><td>9.4</td><td>8.9</td></tr><tr><td>MnO</td><td>0.11</td><td>0.12</td><td>0.16</td><td>0.13</td><td>0.15</td><td>0.18</td><td>0.14</td><td>0.14</td><td>0.14</td><td>0.18</td><td>0.15</td><td>0.20</td><td>0.17</td><td>0.17</td><td>0.14</td><td>0.20</td></tr><tr><td>MgO</td><td>0.12</td><td>5.1</td><td>5.0</td><td>5.0</td><td>4.6</td><td>4.8</td><td>4.5</td><td>5.1</td><td>5.1</td><td>5.8</td><td>5.1</td><td>6.0</td><td>5.7</td><td>6.5</td><td>6.4</td><td>5.8</td></tr><tr><td>CaO</td><td>0.07</td><td>9.0</td><td>9.7</td><td>9.4</td><td>10.8</td><td>10.2</td><td>10.3</td><td>10.2</td><td>11.1</td><td>10.7</td><td>10.1</td><td>10.3</td><td>9.5</td><td>9.2</td><td>9.5</td><td>10.0</td></tr><tr><td>Na<sub>2</sub>O</td><td>0.05</td><td>4.2</td><td>4.2</td><td>4.2</td><td>4.0</td><td>4.4</td><td>4.9</td><td>4.5</td><td>4.0</td><td>3.7</td><td>4.1</td><td>3.9</td><td>3.9</td><td>3.9</td><td>4.0</td><td>4.1</td></tr><tr><td>K<sub>2</sub>O</td><td>0.04</td><td>1.7</td><td>1.5</td><td>1.5</td><td>1.4</td><td>1.5</td><td>1.5</td><td>1.4</td><td>1.3</td><td>1.1</td><td>1.3</td><td>1.7</td><td>1.6</td><td>1.6</td><td>1.6</td><td>1.7</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.02</td><td>0.31</td><td>0.33</td><td>0.33</td><td>0.37</td><td>0.29</td><td>0.30</td><td>0.28</td><td>0.28</td><td>0.32</td><td>0.31</td><td>0.26</td><td>0.26</td><td>0.26</td><td>0.25</td><td>0.26</td></tr><tr><td>S</td><td>0.01</td><td>0.35</td><td>0.17</td><td>0.14</td><td>0.18</td><td>0.19</td><td>0.13</td><td>0.12</td><td>0.50</td><td>0.20</td><td>0.18</td><td>0.18</td><td>0.19</td><td>0.19</td><td>0.19</td><td>0.35</td></tr></tbody></table>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>FYS<br>369 s-4</th><th>FYS<br>369 s-5a</th><th>FYS<br>369 s-5b</th><th>FYS<br>369 s-6a</th><th>FYS<br>369 s-6b</th><th>FYS<br>369 s-6c</th><th>FYS<br>369 s-7a</th><th>FYS<br>369 s-8</th><th>FYS<br>369 s-9a</th><th>FYS<br>369 s-9b</th><th>FYS<br>369 s-9c1</th><th>FYS<br>369 s-9c2</th><th>FYS<br>369 s-9d1</th><th>FYS<br>369 s-9d2</th></tr></thead><tbody><tr><td>Sr</td><td>0.009</td><td>697</td><td>-</td><td>-</td><td>575</td><td>567</td><td>-</td><td>737</td><td>553</td><td>743</td><td>706</td><td>-</td><td>729</td><td>669</td><td>774</td><td>725</td></tr><tr><td>Y</td><td>0.005</td><td>24</td><td>-</td><td>-</td><td>27</td><td>27</td><td>-</td><td>27</td><td>24</td><td>28</td><td>28</td><td>-</td><td>28</td><td>24</td><td>29</td><td>27</td></tr><tr><td>Zr</td><td>0.012</td><td>228</td><td>-</td><td>-</td><td>258</td><td>251</td><td>-</td><td>213</td><td>179</td><td>244</td><td>226</td><td>-</td><td>235</td><td>297</td><td>230</td><td>218</td></tr><tr><td>Nb</td><td>0.008</td><td>44</td><td>-</td><td>-</td><td>51</td><td>50</td><td>-</td><td>45</td><td>35</td><td>51</td><td>49</td><td>-</td><td>47</td><td>43</td><td>47</td><td>44</td></tr><tr><td>Cs</td><td>0.007</td><td>0.45</td><td>-</td><td>-</td><td>0.55</td><td>0.42</td><td>-</td><td>0.32</td><td>0.29</td><td>0.37</td><td>0.38</td><td>-</td><td>0.38</td><td>0.36</td><td>0.39</td><td>0.41</td></tr><tr><td>Ba</td><td>0.034</td><td>363</td><td>-</td><td>-</td><td>472</td><td>466</td><td>-</td><td>380</td><td>307</td><td>405</td><td>402</td><td>-</td><td>464</td><td>588</td><td>403</td><td>369</td></tr><tr><td>La</td><td>0.007</td><td>33</td><td>-</td><td>-</td><td>43</td><td>42</td><td>-</td><td>34</td><td>28</td><td>41</td><td>38</td><td>-</td><td>40</td><td>41</td><td>36</td><td>34</td></tr><tr><td>Ce</td><td>0.007</td><td>75</td><td>-</td><td>-</td><td>90</td><td>89</td><td>-</td><td>75</td><td>60</td><td>89</td><td>81</td><td>-</td><td>86</td><td>86</td><td>80</td><td>76</td></tr><tr><td>Pr</td><td>0.004</td><td>9.1</td><td>-</td><td>-</td><td>10.2</td><td>9.9</td><td>-</td><td>9.1</td><td>7.7</td><td>9.6</td><td>9.7</td><td>-</td><td>9.9</td><td>10.1</td><td>9.4</td><td>9.3</td></tr><tr><td>Nd</td><td>0.028</td><td>38</td><td>-</td><td>-</td><td>42</td><td>42</td><td>-</td><td>40</td><td>33</td><td>42</td><td>41</td><td>-</td><td>42</td><td>42</td><td>41</td><td>40</td></tr><tr><td>Sm</td><td>0.039</td><td>7.9</td><td>-</td><td>-</td><td>8.0</td><td>8.2</td><td>-</td><td>8.3</td><td>7.1</td><td>7.7</td><td>8.4</td><td>-</td><td>7.9</td><td>7.9</td><td>8.4</td><td>7.0</td></tr><tr><td>Eu</td><td>0.008</td><td>2.2</td><td>-</td><td>-</td><td>2.5</td><td>2.5</td><td>-</td><td>2.5</td><td>2.3</td><td>2.6</td><td>2.8</td><td>-</td><td>2.5</td><td>2.3</td><td>2.6</td><td>2.3</td></tr><tr><td>Gd</td><td>0.041</td><td>6.2</td><td>-</td><td>-</td><td>7.3</td><td>7.2</td><td>-</td><td>7.2</td><td>7.7</td><td>7.9</td><td>7.5</td><td>-</td><td>7.5</td><td>6.4</td><td>7.4</td><td>6.6</td></tr><tr><td>Tb</td><td>0.006</td><td>0.88</td><td>-</td><td>-</td><td>0.98</td><td>1.00</td><td>-</td><td>0.97</td><td>0.82</td><td>0.95</td><td>1.09</td><td>-</td><td>1.01</td><td>0.86</td><td>1.01</td><td>0.97</td></tr><tr><td>Dy</td><td>0.023</td><td>4.9</td><td>-</td><td>-</td><td>5.9</td><td>6.0</td><td>-</td><td>5.9</td><td>5.5</td><td>5.4</td><td>6.0</td><td>-</td><td>5.9</td><td>5.1</td><td>5.9</td><td>6.0</td></tr><tr><td>Ho</td><td>0.006</td><td>0.86</td><td>-</td><td>-</td><td>1.03</td><td>1.08</td><td>-</td><td>1.03</td><td>0.93</td><td>1.14</td><td>1.10</td><td>-</td><td>1.09</td><td>0.92</td><td>1.06</td><td>1.10</td></tr><tr><td>Er</td><td>0.016</td><td>2.2</td><td>-</td><td>-</td><td>2.8</td><td>2.6</td><td>-</td><td>2.6</td><td>2.5</td><td>2.9</td><td>2.9</td><td>-</td><td>2.8</td><td>2.5</td><td>3.0</td><td>2.6</td></tr><tr><td>Tm</td><td>0.005</td><td>0.30</td><td>-</td><td>-</td><td>0.38</td><td>0.37</td><td>-</td><td>0.34</td><td>0.33</td><td>0.48</td><td>0.44</td><td>-</td><td>0.36</td><td>0.33</td><td>0.39</td><td>0.42</td></tr><tr><td>Yb</td><td>0.032</td><td>2.0</td><td>-</td><td>-</td><td>2.5</td><td>2.3</td><td>-</td><td>2.3</td><td>2.3</td><td>2.2</td><td>1.7</td><td>-</td><td>2.4</td><td>2.0</td><td>2.4</td><td>2.0</td></tr><tr><td>Lu</td><td>0.010</td><td>0.29</td><td>-</td><td>-</td><td>0.34</td><td>0.28</td><td>-</td><td>0.35</td><td>0.29</td><td>0.38</td><td>0.43</td><td>-</td><td>0.33</td><td>0.29</td><td>0.32</td><td>0.31</td></tr><tr><td>Hf</td><td>0.026</td><td>5</td><td>-</td><td>-</td><td>6</td><td>6</td><td>-</td><td>5</td><td>5</td><td>6</td><td>5</td><td>-</td><td>6</td><td>7</td><td>5</td><td>6</td></tr><tr><td>Ta</td><td>0.009</td><td>2.8</td><td>-</td><td>-</td><td>3.4</td><td>3.3</td><td>-</td><td>2.9</td><td>2.4</td><td>3.1</td><td>2.9</td><td>-</td><td>2.9</td><td>2.8</td><td>2.8</td><td>2.8</td></tr><tr><td>Pb</td><td>0.034</td><td>2.7</td><td>-</td><td>-</td><td>4.4</td><td>3.9</td><td>-</td><td>3.1</td><td>2.5</td><td>3.7</td><td>3.1</td><td>-</td><td>4.4</td><td>4.3</td><td>3.3</td><td>2.9</td></tr><tr><td>Th</td><td>0.011</td><td>3.4</td><td>-</td><td>-</td><td>4.4</td><td>4.3</td><td>-</td><td>3.2</td><td>3.1</td><td>4.2</td><td>3.6</td><td>-</td><td>3.9</td><td>3.6</td><td>3.7</td><td>3.4</td></tr><tr><td>U</td><td>0.014</td><td>1.23</td><td>-</td><td>-</td><td>1.47</td><td>1.28</td><td>-</td><td>1.06</td><td>0.98</td><td>1.33</td><td>1.22</td><td>-</td><td>1.20</td><td>1.08</td><td>1.19</td><td>1.24</td></tr></tbody><thead><tr><th></th><th>D.L. %</th><th>FYS<br>369 s-9d3</th><th>FYS<br>369 s-10a</th><th>FYS<br>369 s-10b</th><th>FYS<br>369 s-11</th><th>FYS<br>369 s-12</th><th>FYS<br>371 s-1</th><th>FYS<br>371 s-2</th><th>FYS<br>371 s-3a</th><th>FYS<br>371 s-3b</th><th>FYS<br>371 s-5</th><th>FYS<br>371 s-7a</th><th>FYS<br>371 s-7b</th><th>FYS<br>371 s-7c</th><th>FYS<br>371 s-8</th></tr></thead><tbody><tr><td>PEC</td><td>%</td><td>1.31</td><td>1.31</td><td>3.11</td><td>3.97</td><td>2.45</td><td>1.91</td><td>1.95</td><td>0.16</td><td>12.11</td><td>0.59</td><td>1.58</td><td>3.54</td><td>3.87</td><td>2.55</td><td>1.87</td></tr><tr><td>Fo</td><td>%</td><td>80.5</td><td>79.4</td><td>79.4</td><td>79.7</td><td>80.6</td><td>80.2</td><td>83.0</td><td>80.4</td><td>82.5</td><td>79.5</td><td>81.6</td><td>82.4</td><td>83.1</td><td>83.3</td><td>82.0</td></tr><tr><td>SiO<sub>2</sub></td><td>%</td><td>0.13</td><td>49.0</td><td>47.9</td><td>48.6</td><td>47.7</td><td>47.1</td><td>47.8</td><td>47.7</td><td>48.2</td><td>47.9</td><td>48.6</td><td>47.5</td><td>47.6</td><td>46.8</td><td>46.9</td><td>48.1</td></tr><tr><td>TiO<sub>2</sub></td><td>%</td><td>0.10</td><td>2.74</td><td>3.11</td><td>3.38</td><td>3.08</td><td>3.37</td><td>3.72</td><td>2.67</td><td>3.32</td><td>2.97</td><td>2.82</td><td>3.25</td><td>3.49</td><td>3.71</td><td>3.97</td><td>3.56</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>%</td><td>0.06</td><td>17.5</td><td>16.6</td><td>15.6</td><td>16.9</td><td>16.9</td><td>17.0</td><td>17.7</td><td>19.5</td><td>15.8</td><td>18.9</td><td>18.6</td><td>17.2</td><td>17.9</td><td>18.2</td><td>18.1</td></tr><tr><td>FeO<sub>t</sub></td><td>%</td><td>0.11</td><td>9.3</td><td>9.4</td><td>10.0</td><td>10.3</td><td>9.5</td><td>9.8</td><td>8.3</td><td>8.0</td><td>10.5</td><td>8.8</td><td>8.6</td><td>8.9</td><td>8.5</td><td>8.4</td></tr></tbody></table>

<figure><img src="image_9.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>FYS<br>369-9d3</th><th>FYS<br>369-10a</th><th>FYS<br>369-10b</th><th>FYS<br>369-10c</th><th>FYS<br>369-11</th><th>FYS<br>369-12</th><th>FYS<br>371 s-1</th><th>FYS<br>371 s-2</th><th>FYS<br>371 s-3a</th><th>FYS<br>371 s-3b</th><th>FYS<br>371 s-5</th><th>FYS<br>371 s-7a</th><th>FYS<br>371 s-7b</th><th>FYS<br>371 s-7c</th><th>FYS<br>371 s-8</th></tr></thead><tbody><tr><td>MnO</td><td>0.11</td><td>0.17</td><td>0.13</td><td>0.15</td><td>0.18</td><td>0.19</td><td>0.18</td><td>0.12</td><td>0.11</td><td>0.18</td><td>0.15</td><td>0.11</td><td>0.12</td><td>0.16</td><td>0.16</td><td>0.12</td></tr><tr><td>MgO</td><td>0.12</td><td>5.9</td><td>5.5</td><td>6.0</td><td>6.4</td><td>6.2</td><td>6.3</td><td>6.3</td><td>4.3</td><td>8.5</td><td>4.8</td><td>5.8</td><td>6.6</td><td>7.1</td><td>6.7</td><td>5.8</td></tr><tr><td>CaO</td><td>0.07</td><td>9.4</td><td>10.1</td><td>9.2</td><td>9.2</td><td>9.1</td><td>9.4</td><td>9.7</td><td>8.8</td><td>9.2</td><td>8.1</td><td>8.7</td><td>8.8</td><td>9.4</td><td>9.6</td><td>8.4</td></tr><tr><td>Na<sub>2</sub>O</td><td>0.05</td><td>4.1</td><td>4.2</td><td>4.1</td><td>3.8</td><td>4.0</td><td>4.1</td><td>4.1</td><td>5.3</td><td>2.6</td><td>5.0</td><td>5.0</td><td>4.2</td><td>4.5</td><td>4.5</td><td>4.4</td></tr><tr><td>K<sub>2</sub>O</td><td>0.04</td><td>1.5</td><td>2.0</td><td>2.0</td><td>1.5</td><td>1.6</td><td>1.4</td><td>1.5</td><td>2.0</td><td>1.7</td><td>2.6</td><td>1.9</td><td>1.5</td><td>1.5</td><td>1.6</td><td>2.1</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.02</td><td>0.29</td><td>0.28</td><td>0.29</td><td>0.22</td><td>0.26</td><td>0.27</td><td>0.13</td><td>0.16</td><td>0.20</td><td>0.25</td><td>0.29</td><td>0.26</td><td>—</td><td>—</td><td>0.30</td></tr><tr><td>S</td><td>0.01</td><td>0.43</td><td>0.07</td><td>0.09</td><td>0.09</td><td>0.19</td><td>0.34</td><td>0.07</td><td>0.08</td><td>0.11</td><td>0.91</td><td>0.18</td><td>0.15</td><td>—</td><td>—</td><td>0.13</td></tr><tr><td>Cl</td><td>0.01</td><td>0.08</td><td>0.08</td><td>0.08</td><td>0.06</td><td>0.08</td><td>0.06</td><td>—</td><td>0.04</td><td>0.07</td><td>0.07</td><td>0.08</td><td>0.07</td><td>—</td><td>—</td><td>0.09</td></tr><tr><td>F</td><td>0.03</td><td>0.11</td><td>0.11</td><td>0.12</td><td>0.09</td><td>0.11</td><td>0.12</td><td>0.10</td><td>0.13</td><td>0.13</td><td>0.06</td><td>0.13</td><td>0.11</td><td>—</td><td>—</td><td>0.10</td></tr><tr><td>H<sub>2</sub>O</td><td>—</td><td>—</td><td>0.84</td><td>0.74</td><td>0.55</td><td>1.63</td><td>—</td><td>1.63</td><td>0.13</td><td>0.35</td><td>—</td><td>0.26</td><td>1.43</td><td>—</td><td>—</td><td>0.79</td></tr><tr><td>Total</td><td></td><td>100.61</td><td>100.26</td><td>100.29</td><td>100.25</td><td>100.37</td><td>100.53</td><td>100.20</td><td>100.25</td><td>100.32</td><td>101.05</td><td>100.39</td><td>100.35</td><td>100.00</td><td>100.00</td><td>100.32</td></tr><tr><td>Li ppm</td><td>1.990</td><td>—</td><td>8</td><td>6</td><td>—</td><td>8</td><td>6</td><td>6</td><td>—</td><td>—</td><td>—</td><td>6</td><td>6</td><td>7</td><td>—</td><td>—</td></tr><tr><td>Sc</td><td>0.116</td><td>—</td><td>29</td><td>25</td><td>—</td><td>22</td><td>21</td><td>22</td><td>—</td><td>—</td><td>—</td><td>—</td><td>20</td><td>24</td><td>26</td><td>—</td></tr><tr><td>V</td><td>0.041</td><td>—</td><td>331</td><td>306</td><td>—</td><td>306</td><td>299</td><td>253</td><td>—</td><td>—</td><td>—</td><td>—</td><td>236</td><td>318</td><td>321</td><td>—</td></tr><tr><td>Cr</td><td>1.440</td><td>—</td><td>72</td><td>56</td><td>—</td><td>42</td><td>21</td><td>56</td><td>—</td><td>—</td><td>—</td><td>—</td><td>60</td><td>52</td><td>41</td><td>—</td></tr><tr><td>Co</td><td>0.020</td><td>—</td><td>41</td><td>36</td><td>—</td><td>36</td><td>42</td><td>30</td><td>—</td><td>—</td><td>—</td><td>—</td><td>29</td><td>35</td><td>33</td><td>—</td></tr><tr><td>Ni</td><td>0.538</td><td>—</td><td>48</td><td>44</td><td>—</td><td>48</td><td>44</td><td>45</td><td>—</td><td>—</td><td>—</td><td>—</td><td>46</td><td>59</td><td>57</td><td>—</td></tr><tr><td>Cu</td><td>0.175</td><td>—</td><td>49</td><td>76</td><td>—</td><td>32</td><td>41</td><td>31</td><td>—</td><td>—</td><td>—</td><td>—</td><td>25</td><td>53</td><td>41</td><td>—</td></tr><tr><td>Zn</td><td>0.224</td><td>—</td><td>131</td><td>105</td><td>—</td><td>104</td><td>120</td><td>86</td><td>—</td><td>—</td><td>—</td><td>—</td><td>85</td><td>104</td><td>86</td><td>—</td></tr><tr><td>Rb</td><td>0.014</td><td>—</td><td>53</td><td>49</td><td>—</td><td>39</td><td>35</td><td>32</td><td>—</td><td>—</td><td>—</td><td>—</td><td>31</td><td>37</td><td>35</td><td>—</td></tr><tr><td>Sr</td><td>0.009</td><td>—</td><td>631</td><td>548</td><td>—</td><td>723</td><td>731</td><td>1078</td><td>—</td><td>—</td><td>—</td><td>—</td><td>593</td><td>718</td><td>650</td><td>—</td></tr><tr><td>Y</td><td>0.005</td><td>—</td><td>30</td><td>28</td><td>—</td><td>26</td><td>26</td><td>22</td><td>—</td><td>—</td><td>—</td><td>—</td><td>24</td><td>27</td><td>25</td><td>—</td></tr><tr><td>Zr</td><td>0.012</td><td>—</td><td>271</td><td>247</td><td>—</td><td>217</td><td>207</td><td>214</td><td>—</td><td>—</td><td>—</td><td>—</td><td>188</td><td>222</td><td>216</td><td>—</td></tr><tr><td>Nb</td><td>0.008</td><td>—</td><td>56</td><td>52</td><td>—</td><td>52</td><td>45</td><td>43</td><td>—</td><td>—</td><td>—</td><td>—</td><td>39</td><td>48</td><td>46</td><td>—</td></tr><tr><td>Cs</td><td>0.007</td><td>—</td><td>0.49</td><td>0.51</td><td>—</td><td>0.40</td><td>0.40</td><td>0.30</td><td>—</td><td>—</td><td>—</td><td>—</td><td>0.31</td><td>0.38</td><td>0.35</td><td>—</td></tr><tr><td>Ba</td><td>0.034</td><td>—</td><td>495</td><td>450</td><td>—</td><td>435</td><td>377</td><td>368</td><td>—</td><td>—</td><td>—</td><td>—</td><td>333</td><td>393</td><td>375</td><td>—</td></tr><tr><td>La</td><td>0.007</td><td>—</td><td>46</td><td>42</td><td>—</td><td>40</td><td>34</td><td>33</td><td>—</td><td>—</td><td>—</td><td>—</td><td>29</td><td>35</td><td>34</td><td>—</td></tr><tr><td>Ce</td><td>0.007</td><td>—</td><td>97</td><td>88</td><td>—</td><td>82</td><td>75</td><td>68</td><td>—</td><td>—</td><td>—</td><td>—</td><td>62</td><td>75</td><td>73</td><td>—</td></tr><tr><td>Pr</td><td>0.004</td><td>—</td><td>10.9</td><td>10.4</td><td>—</td><td>9.3</td><td>9.0</td><td>7.8</td><td>—</td><td>—</td><td>—</td><td>—</td><td>7.6</td><td>8.9</td><td>8.7</td><td>—</td></tr><tr><td>Nd</td><td>0.028</td><td>—</td><td>46</td><td>42</td><td>—</td><td>40</td><td>39</td><td>30</td><td>—</td><td>—</td><td>—</td><td>—</td><td>32</td><td>38</td><td>38</td><td>—</td></tr><tr><td>Sm</td><td>0.039</td><td>—</td><td>8.7</td><td>8.3</td><td>—</td><td>7.7</td><td>8.1</td><td>5.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>6.6</td><td>7.6</td><td>6.9</td><td>—</td></tr><tr><td>Eu</td><td>0.008</td><td>—</td><td>2.7</td><td>2.3</td><td>—</td><td>2.4</td><td>2.5</td><td>2.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>2.2</td><td>2.7</td><td>2.4</td><td>—</td></tr><tr><td>Gd</td><td>0.041</td><td>—</td><td>7.5</td><td>7.1</td><td>—</td><td>6.8</td><td>7.5</td><td>5.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>6.1</td><td>7.0</td><td>6.1</td><td>—</td></tr><tr><td>Tb</td><td>0.006</td><td>—</td><td>1.07</td><td>0.99</td><td>—</td><td>0.98</td><td>0.94</td><td>0.75</td><td>—</td><td>—</td><td>—</td><td>—</td><td>0.85</td><td>1.03</td><td>0.90</td><td>—</td></tr><tr><td>Dy</td><td>0.023</td><td>—</td><td>6.3</td><td>5.5</td><td>—</td><td>5.6</td><td>5.5</td><td>4.5</td><td>—</td><td>—</td><td>—</td><td>—</td><td>5.0</td><td>5.7</td><td>5.5</td><td>—</td></tr></tbody></table>

<figure><img src="image_10.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>FYS<br>369-9d3</th><th>FYS<br>369-10a</th><th>FYS<br>369-10b</th><th>FYS<br>369-10c</th><th>FYS<br>369-11</th><th>FYS<br>369-12</th><th>FYS<br>371 s-1</th><th>FYS<br>371 s-2</th><th>FYS<br>371 s-3a</th><th>FYS<br>371 s-3b</th><th>FYS<br>371 s-5</th><th>FYS<br>371 s-7a</th><th>FYS<br>371 s-7b</th><th>FYS<br>371 s-7c</th><th>FYS<br>371 s-8</th></tr></thead><tbody><tr><td>Ho</td><td>0.006</td><td>-</td><td>1.20</td><td>1.08</td><td>-</td><td>1.03</td><td>0.97</td><td>0.80</td><td>-</td><td>-</td><td>-</td><td>-</td><td>0.88</td><td>1.02</td><td>0.95</td><td>-</td></tr><tr><td>Er</td><td>0.016</td><td>-</td><td>3.1</td><td>2.7</td><td>-</td><td>2.7</td><td>2.6</td><td>2.1</td><td>-</td><td>-</td><td>-</td><td>-</td><td>2.4</td><td>2.6</td><td>2.5</td><td>-</td></tr><tr><td>Tm</td><td>0.005</td><td>-</td><td>0.41</td><td>0.35</td><td>-</td><td>0.35</td><td>0.35</td><td>0.25</td><td>-</td><td>-</td><td>-</td><td>-</td><td>0.31</td><td>0.36</td><td>0.32</td><td>-</td></tr><tr><td>Yb</td><td>0.032</td><td>-</td><td>2.4</td><td>2.4</td><td>-</td><td>2.0</td><td>2.1</td><td>1.9</td><td>-</td><td>-</td><td>-</td><td>-</td><td>2.1</td><td>2.2</td><td>1.6</td><td>-</td></tr><tr><td>Lu</td><td>0.010</td><td>-</td><td>0.34</td><td>0.32</td><td>-</td><td>0.29</td><td>0.30</td><td>0.25</td><td>-</td><td>-</td><td>-</td><td>-</td><td>0.29</td><td>0.31</td><td>0.26</td><td>-</td></tr><tr><td>Hf</td><td>0.026</td><td>-</td><td>6</td><td>6</td><td>-</td><td>5</td><td>5</td><td>4</td><td>-</td><td>-</td><td>-</td><td>-</td><td>4</td><td>5</td><td>5</td><td>-</td></tr><tr><td>Ta</td><td>0.009</td><td>-</td><td>3.6</td><td>3.3</td><td>-</td><td>3.4</td><td>2.7</td><td>2.8</td><td>-</td><td>-</td><td>-</td><td>-</td><td>2.5</td><td>3.1</td><td>3.0</td><td>-</td></tr><tr><td>Pb</td><td>0.034</td><td>-</td><td>4.7</td><td>4.6</td><td>-</td><td>3.2</td><td>2.9</td><td>3.0</td><td>-</td><td>-</td><td>-</td><td>-</td><td>2.5</td><td>3.5</td><td>2.9</td><td>-</td></tr><tr><td>Th</td><td>0.011</td><td>-</td><td>4.8</td><td>4.1</td><td>-</td><td>3.8</td><td>3.1</td><td>3.3</td><td>-</td><td>-</td><td>-</td><td>-</td><td>2.9</td><td>3.5</td><td>2.9</td><td>-</td></tr><tr><td>U</td><td>0.014</td><td>-</td><td>1.59</td><td>1.38</td><td>-</td><td>1.32</td><td>1.10</td><td>1.12</td><td>-</td><td>-</td><td>-</td><td>-</td><td>0.95</td><td>1.06</td><td>1.23</td><td>-</td></tr><tr><th colspan="2">D.L. %</th><th>FYS<br>371 s-10</th><th>FYS<br>371 s-11a</th><th>FYS<br>371 s-11b</th><th>FYS<br>371 s-13a</th><th>FYS<br>371 s-13b</th><th>FYS<br>371 s-14</th><th>FYS<br>371 s-14b</th><th>FYS<br>371 s-1</th><th>PIC<br>67 s-2</th><th>PIC<br>67 s-3</th><th>PIC<br>67 s-4</th><th>PIC<br>67 s-5a</th><th>PIC<br>67 s-5b</th><th>PIC<br>68 s-1</th><th>PIC<br>68 s-3</th></tr><tr><td>PEC</td><td>%</td><td>2.85</td><td>4.5</td><td>3.44</td><td>2.92</td><td>1.09</td><td>5.69</td><td>4.3</td><td>3.73</td><td>3.32</td><td>3.19</td><td>5.56</td><td>3.41</td><td>4.29</td><td>1.09</td><td>2.15</td></tr><tr><td>Fo</td><td>%</td><td>78.3</td><td>76.9</td><td>75.8</td><td>81.7</td><td>78.2</td><td>80.8</td><td>80.4</td><td>84.2</td><td>83.9</td><td>82.1</td><td>83.9</td><td>82.4</td><td>82.5</td><td>80.8</td><td>78.5</td></tr><tr><td>SiO<sub>2</sub></td><td></td><td>0.13</td><td>46.3</td><td>46.8</td><td>47.1</td><td>47.3</td><td>46.0</td><td>47.0</td><td>47.9</td><td>49.9</td><td>48.7</td><td>48.4</td><td>48.3</td><td>48.0</td><td>50.1</td><td>49.3</td></tr><tr><td>TiO<sub>2</sub></td><td></td><td>0.10</td><td>3.31</td><td>3.03</td><td>3.16</td><td>2.98</td><td>4.20</td><td>3.35</td><td>3.35</td><td>2.69</td><td>2.66</td><td>2.94</td><td>2.50</td><td>2.82</td><td>2.39</td><td>2.45</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td></td><td>0.06</td><td>17.0</td><td>16.1</td><td>17.1</td><td>17.6</td><td>18.7</td><td>16.1</td><td>15.9</td><td>15.7</td><td>17.1</td><td>14.7</td><td>15.5</td><td>15.3</td><td>16.8</td><td>16.9</td></tr><tr><td>FeO<sub>t</sub></td><td></td><td>0.11</td><td>11.4</td><td>11.9</td><td>11.3</td><td>8.8</td><td>9.3</td><td>11.4</td><td>11.5</td><td>8.2</td><td>8.1</td><td>8.8</td><td>9.0</td><td>9.5</td><td>9.8</td><td>9.1</td></tr><tr><td>MnO</td><td></td><td>0.11</td><td>0.15</td><td>0.23</td><td>0.20</td><td>0.15</td><td>0.19</td><td>0.20</td><td>0.19</td><td>0.15</td><td>0.14</td><td>0.16</td><td>0.17</td><td>0.17</td><td>0.16</td><td>0.17</td></tr><tr><td>MgO</td><td></td><td>0.12</td><td>6.7</td><td>6.4</td><td>5.4</td><td>6.0</td><td>4.7</td><td>8.2</td><td>8.0</td><td>7.1</td><td>6.8</td><td>6.4</td><td>7.9</td><td>7.2</td><td>7.7</td><td>5.9</td></tr><tr><td>CaO</td><td></td><td>0.07</td><td>7.7</td><td>7.8</td><td>8.4</td><td>11.3</td><td>7.5</td><td>8.6</td><td>8.6</td><td>11.0</td><td>10.3</td><td>9.1</td><td>11.1</td><td>10.7</td><td>10.5</td><td>9.5</td></tr><tr><td>Na<sub>2</sub>O</td><td></td><td>0.05</td><td>4.1</td><td>4.1</td><td>4.6</td><td>3.9</td><td>5.1</td><td>3.5</td><td>3.7</td><td>3.4</td><td>3.6</td><td>3.6</td><td>3.4</td><td>3.8</td><td>3.4</td><td>4.0</td></tr><tr><td>K<sub>2</sub>O</td><td></td><td>0.04</td><td>2.1</td><td>1.7</td><td>1.6</td><td>1.3</td><td>2.5</td><td>1.2</td><td>1.4</td><td>1.7</td><td>1.5</td><td>2.1</td><td>1.3</td><td>1.2</td><td>1.3</td><td>0.6</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td></td><td>0.02</td><td>0.29</td><td>0.28</td><td>0.25</td><td>0.20</td><td>0.14</td><td>0.27</td><td>-</td><td>0.29</td><td>0.24</td><td>0.16</td><td>0.26</td><td>0.20</td><td>0.21</td><td>0.15</td></tr><tr><td>S</td><td></td><td>0.01</td><td>0.14</td><td>0.16</td><td>0.17</td><td>0.11</td><td>0.06</td><td>0.15</td><td>-</td><td>0.08</td><td>0.05</td><td>0.03</td><td>0.17</td><td>0.14</td><td>0.13</td><td>-</td></tr><tr><td>Cl</td><td></td><td>0.01</td><td>0.07</td><td>0.07</td><td>0.07</td><td>0.06</td><td>0.07</td><td>0.06</td><td>-</td><td>0.06</td><td>0.04</td><td>0.03</td><td>0.06</td><td>0.05</td><td>0.05</td><td>0.08</td></tr><tr><td>F</td><td></td><td>0.03</td><td>0.14</td><td>0.11</td><td>0.10</td><td>0.10</td><td>0.13</td><td>0.09</td><td>-</td><td>0.09</td><td>-</td><td>-</td><td>0.09</td><td>-</td><td>0.12</td><td>0.14</td></tr><tr><td>H<sub>2</sub>O</td><td></td><td>-</td><td>0.86</td><td>1.63</td><td>0.77</td><td>0.38</td><td>0.36</td><td>1.14</td><td>-</td><td>1.03</td><td>1.07</td><td>1.38</td><td>0.84</td><td>0.88</td><td>0.69</td><td>1.33</td></tr><tr><td>Total</td><td></td><td>100.37</td><td>100.34</td><td>100.35</td><td>100.26</td><td>100.26</td><td>100.32</td><td>100.01</td><td>100.23</td><td>100.10</td><td>100.08</td><td>100.32</td><td>100.20</td><td>100.18</td><td>100.12</td><td>100.35</td></tr><tr><td>Li ppm</td><td></td><td>1.990</td><td>9</td><td>10</td><td>9</td><td>-</td><td>11</td><td>6</td><td>6</td><td>7</td><td>5</td><td>8</td><td>5</td><td>6</td><td>8</td><td>7</td></tr><tr><td>Sc</td><td></td><td>0.116</td><td>18</td><td>15</td><td>17</td><td>-</td><td>20</td><td>23</td><td>24</td><td>29</td><td>26</td><td>22</td><td>29</td><td>28</td><td>25</td><td>19</td></tr><tr><td>V</td><td></td><td>0.041</td><td>295</td><td>220</td><td>263</td><td>-</td><td>312</td><td>273</td><td>271</td><td>286</td><td>235</td><td>266</td><td>275</td><td>264</td><td>252</td><td>213</td></tr><tr><td>Cr</td><td></td><td>1.440</td><td>20</td><td>15</td><td>22</td><td>-</td><td>27</td><td>70</td><td>66</td><td>198</td><td>123</td><td>87</td><td>185</td><td>116</td><td>123</td><td>82</td></tr></tbody></table>

<figure><img src="image_11.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>FYS<br>371 s-10</th><th>FYS<br>371 s-11a</th><th>FYS<br>371 s-11b</th><th>FYS<br>371 s-13a</th><th>FYS<br>371 s-13b</th><th>FYS<br>371 s-14</th><th>FYS<br>371 s-14b</th><th>PIC<br>67 s-1</th><th>PIC<br>67 s-2</th><th>PIC<br>67 s-3</th><th>PIC<br>67 s-4</th><th>PIC<br>67 s-5a</th><th>PIC<br>67 s-5b</th><th>PIC<br>68 s-1</th><th>PIC<br>68 s-3</th></tr></thead><tbody><tr><td>Co</td><td>0.020</td><td>39</td><td>35</td><td>37</td><td>-</td><td>32</td><td>45</td><td>44</td><td>30</td><td>31</td><td>32</td><td>36</td><td>40</td><td>40</td><td>34</td><td>38</td></tr><tr><td>Ni</td><td>0.538</td><td>50</td><td>32</td><td>35</td><td>-</td><td>35</td><td>51</td><td>46</td><td>56</td><td>55</td><td>48</td><td>61</td><td>71</td><td>72</td><td>60</td><td>43</td></tr><tr><td>Cu</td><td>0.175</td><td>71</td><td>23</td><td>24</td><td>-</td><td>11</td><td>30</td><td>26</td><td>54</td><td>31</td><td>41</td><td>56</td><td>27</td><td>33</td><td>28</td><td>41</td></tr><tr><td>Zn</td><td>0.224</td><td>141</td><td>155</td><td>168</td><td>-</td><td>125</td><td>134</td><td>133</td><td>79</td><td>80</td><td>89</td><td>94</td><td>103</td><td>97</td><td>122</td><td>119</td></tr><tr><td>Rb</td><td>0.014</td><td>53</td><td>34</td><td>45</td><td>-</td><td>56</td><td>32</td><td>35</td><td>38</td><td>38</td><td>55</td><td>35</td><td>34</td><td>34</td><td>9</td><td>46.2</td></tr><tr><td>Sr</td><td>0.009</td><td>692</td><td>611</td><td>620</td><td>-</td><td>789</td><td>541</td><td>570</td><td>622</td><td>561</td><td>495</td><td>582</td><td>517</td><td>551</td><td>1877</td><td>681</td></tr><tr><td>Y</td><td>0.005</td><td>26</td><td>26</td><td>28</td><td>-</td><td>32</td><td>24</td><td>23</td><td>24</td><td>23</td><td>19</td><td>23</td><td>24</td><td>24</td><td>26</td><td>29</td></tr><tr><td>Zr</td><td>0.012</td><td>274</td><td>172</td><td>248</td><td>-</td><td>288</td><td>221</td><td>234</td><td>224</td><td>207</td><td>160</td><td>193</td><td>186</td><td>191</td><td>92</td><td>263</td></tr><tr><td>Nb</td><td>0.008</td><td>65</td><td>35</td><td>54</td><td>-</td><td>82</td><td>48</td><td>60</td><td>43</td><td>38</td><td>29</td><td>41</td><td>35</td><td>38</td><td>9</td><td>57</td></tr><tr><td>Cs</td><td>0.007</td><td>0.46</td><td>0.33</td><td>0.40</td><td>-</td><td>0.85</td><td>0.32</td><td>0.35</td><td>0.33</td><td>0.34</td><td>0.65</td><td>0.29</td><td>0.27</td><td>0.30</td><td>0.07</td><td>0.48</td></tr><tr><td>Ba</td><td>0.034</td><td>574</td><td>344</td><td>458</td><td>-</td><td>612</td><td>308</td><td>366</td><td>424</td><td>396</td><td>271</td><td>338</td><td>340</td><td>355</td><td>267</td><td>478</td></tr><tr><td>La</td><td>0.007</td><td>48</td><td>26</td><td>41</td><td>-</td><td>49</td><td>31</td><td>36</td><td>36</td><td>31</td><td>27</td><td>32</td><td>30</td><td>31</td><td>13</td><td>42</td></tr><tr><td>Ce</td><td>0.007</td><td>102</td><td>56</td><td>83</td><td>-</td><td>113</td><td>69</td><td>80</td><td>74</td><td>68</td><td>59</td><td>68</td><td>64</td><td>65</td><td>30</td><td>87</td></tr><tr><td>Pr</td><td>0.004</td><td>12.0</td><td>6.6</td><td>9.8</td><td>-</td><td>12.6</td><td>8.3</td><td>9.0</td><td>8.9</td><td>8.0</td><td>7.3</td><td>8.0</td><td>7.7</td><td>7.6</td><td>4.3</td><td>9.9</td></tr><tr><td>Nd</td><td>0.028</td><td>48</td><td>28</td><td>41</td><td>-</td><td>53</td><td>34</td><td>36</td><td>35</td><td>31</td><td>30</td><td>33</td><td>33</td><td>34</td><td>23</td><td>37</td></tr><tr><td>Sm</td><td>0.039</td><td>8.7</td><td>6.0</td><td>8.1</td><td>-</td><td>11.9</td><td>6.8</td><td>7.9</td><td>6.0</td><td>6.2</td><td>6.1</td><td>6.6</td><td>7.2</td><td>6.6</td><td>6.8</td><td>8.7</td></tr><tr><td>Eu</td><td>0.008</td><td>2.6</td><td>2.0</td><td>2.5</td><td>-</td><td>3.1</td><td>2.4</td><td>2.5</td><td>2.0</td><td>2.0</td><td>1.8</td><td>2.1</td><td>2.2</td><td>2.0</td><td>2.2</td><td>2.2</td></tr><tr><td>Gd</td><td>0.041</td><td>7.3</td><td>5.9</td><td>7.0</td><td>-</td><td>8.6</td><td>6.4</td><td>6.3</td><td>6.4</td><td>6.6</td><td>5.2</td><td>6.3</td><td>6.6</td><td>6.1</td><td>6.9</td><td>7.3</td></tr><tr><td>Tb</td><td>0.006</td><td>0.95</td><td>0.82</td><td>0.97</td><td>-</td><td>1.57</td><td>0.87</td><td>0.88</td><td>0.87</td><td>0.75</td><td>0.72</td><td>0.84</td><td>0.84</td><td>0.92</td><td>0.83</td><td>0.92</td></tr><tr><td>Dy</td><td>0.023</td><td>5.6</td><td>5.2</td><td>5.8</td><td>-</td><td>6.3</td><td>5.1</td><td>4.6</td><td>5.1</td><td>4.9</td><td>4.4</td><td>5.0</td><td>5.1</td><td>4.8</td><td>5.4</td><td>6.0</td></tr><tr><td>Ho</td><td>0.006</td><td>1.10</td><td>0.97</td><td>1.00</td><td>-</td><td>1.14</td><td>0.96</td><td>0.91</td><td>0.98</td><td>0.96</td><td>0.75</td><td>0.89</td><td>0.96</td><td>0.90</td><td>1.01</td><td>1.26</td></tr><tr><td>Er</td><td>0.016</td><td>2.6</td><td>2.7</td><td>2.7</td><td>-</td><td>3.1</td><td>2.5</td><td>2.3</td><td>2.3</td><td>2.2</td><td>2.0</td><td>2.4</td><td>2.3</td><td>2.5</td><td>2.5</td><td>2.6</td></tr><tr><td>Tm</td><td>0.005</td><td>0.29</td><td>0.37</td><td>0.38</td><td>-</td><td>0.45</td><td>0.31</td><td>0.31</td><td>0.35</td><td>0.33</td><td>0.24</td><td>0.32</td><td>0.31</td><td>0.37</td><td>0.35</td><td>0.41</td></tr><tr><td>Yb</td><td>0.032</td><td>2.4</td><td>2.4</td><td>2.5</td><td>-</td><td>2.5</td><td>2.0</td><td>2.1</td><td>2.0</td><td>1.9</td><td>1.7</td><td>2.0</td><td>2.1</td><td>2.1</td><td>2.1</td><td>2.5</td></tr><tr><td>Lu</td><td>0.010</td><td>0.32</td><td>0.34</td><td>0.36</td><td>-</td><td>0.40</td><td>0.29</td><td>0.29</td><td>0.30</td><td>0.22</td><td>0.26</td><td>0.29</td><td>0.30</td><td>0.29</td><td>0.33</td><td>0.32</td></tr><tr><td>Hf</td><td>0.026</td><td>6</td><td>4</td><td>6</td><td>-</td><td>5</td><td>5</td><td>5</td><td>6</td><td>5</td><td>4</td><td>5</td><td>5</td><td>2</td><td>6</td><td>6</td></tr><tr><td>Ta</td><td>0.009</td><td>4.0</td><td>2.1</td><td>3.6</td><td>-</td><td>5.1</td><td>3.1</td><td>3.6</td><td>3.0</td><td>2.5</td><td>1.8</td><td>2.6</td><td>2.4</td><td>2.4</td><td>0.7</td><td>3.5</td></tr><tr><td>Pb</td><td>0.034</td><td>4.7</td><td>3.0</td><td>4.0</td><td>-</td><td>3.0</td><td>2.1</td><td>2.3</td><td>3.0</td><td>2.6</td><td>5.3</td><td>2.9</td><td>2.8</td><td>2.8</td><td>1.4</td><td>4.5</td></tr><tr><td>Th</td><td>0.011</td><td>4.5</td><td>2.7</td><td>4.3</td><td>-</td><td>5.5</td><td>3.2</td><td>3.7</td><td>3.6</td><td>3.1</td><td>2.3</td><td>3.1</td><td>2.8</td><td>2.9</td><td>0.8</td><td>5.1</td></tr><tr><td>U</td><td>0.014</td><td>1.61</td><td>0.86</td><td>1.40</td><td>-</td><td>1.98</td><td>1.11</td><td>1.44</td><td>1.11</td><td>0.94</td><td>1.01</td><td>0.86</td><td>1.01</td><td>0.27</td><td>2.79</td><td></td></tr></tbody></table>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>PIC<br>68 s-4</th><th>Pic<br>69 s-1</th><th>Pic<br>69 s-8a</th><th>Pic<br>69 s-8b</th><th>PIC<br>66 s-2a</th><th>PIC<br>66 s-4</th><th>PIC<br>66 s-9a</th><th>PIC<br>66 s-16</th><th>ZKP<br>6-1</th><th>ZKP<br>6-2</th><th>ZKP<br>6-3</th><th>ZKP<br>6-4</th><th>ZKP<br>6-5</th><th>ZKP<br>6-6</th><th>ZKP<br>6-7a</th></tr></thead><tbody><tr><td>PEC<br>%</td><td></td><td>3.72</td><td>6.15</td><td>5.21</td><td>4.16</td><td>9.3</td><td>8.68</td><td>8.24</td><td>9.45</td><td>4.42</td><td>1.76</td><td>4.25</td><td>4.91</td><td>1.88</td><td>3.52</td><td>4.76</td></tr><tr><td>Fo<br>%</td><td></td><td>85.0</td><td>82.0</td><td>82.1</td><td>82.6</td><td>84.5</td><td>83.7</td><td>84.7</td><td>84.1</td><td>83.6</td><td>83.0</td><td>83.9</td><td>84.4</td><td>82.9</td><td>83.8</td><td>83.8</td></tr><tr><td>SiO<sub>2</sub><br>%</td><td>0.13</td><td>48.7</td><td>48.7</td><td>49.2</td><td>50.9</td><td>45.9</td><td>46.7</td><td>47.2</td><td>46.4</td><td>47.3</td><td>49.7</td><td>48.8</td><td>46.8</td><td>49.6</td><td>49.2</td><td>47.2</td></tr><tr><td>TiO<sub>2</sub><br>%</td><td>0.10</td><td>2.83</td><td>2.75</td><td>2.76</td><td>2.13</td><td>2.35</td><td>2.43</td><td>2.63</td><td>2.23</td><td>3.86</td><td>2.92</td><td>3.23</td><td>3.51</td><td>2.63</td><td>3.28</td><td>3.83</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub><br>%</td><td>0.06</td><td>15.4</td><td>13.8</td><td>15.3</td><td>15.8</td><td>13.9</td><td>14.3</td><td>13.7</td><td>13.8</td><td>16.1</td><td>16.6</td><td>16.3</td><td>15.7</td><td>16.4</td><td>16.2</td><td>16.2</td></tr><tr><td>FeO<sub>t</sub><br>%</td><td>0.11</td><td>8.1</td><td>10.4</td><td>9.7</td><td>8.8</td><td>10.5</td><td>10.5</td><td>9.4</td><td>10.7</td><td>9.3</td><td>8.4</td><td>8.5</td><td>9.0</td><td>8.8</td><td>8.1</td><td>9.1</td></tr><tr><td>MnO<br>%</td><td>0.11</td><td>0.16</td><td>0.21</td><td>0.21</td><td>0.20</td><td>0.18</td><td>0.13</td><td>0.17</td><td>0.20</td><td>0.16</td><td>0.18</td><td>0.13</td><td>0.11</td><td>0.15</td><td>–</td><td>0.14</td></tr><tr><td>MgO<br>%</td><td>0.12</td><td>7.6</td><td>8.1</td><td>7.3</td><td>6.7</td><td>10.1</td><td>9.4</td><td>9.0</td><td>10.0</td><td>7.9</td><td>6.6</td><td>7.2</td><td>8.3</td><td>6.9</td><td>6.7</td><td>7.9</td></tr><tr><td>CaO<br>%</td><td>0.07</td><td>11.4</td><td>9.8</td><td>9.8</td><td>10.2</td><td>11.9</td><td>11.1</td><td>11.7</td><td>11.4</td><td>10.4</td><td>10.6</td><td>11.1</td><td>11.2</td><td>10.8</td><td>11.0</td><td>10.5</td></tr><tr><td>Na<sub>2</sub>O<br>%</td><td>0.05</td><td>3.6</td><td>3.5</td><td>4.0</td><td>4.0</td><td>3.5</td><td>3.7</td><td>3.9</td><td>3.6</td><td>2.8</td><td>3.4</td><td>2.9</td><td>2.9</td><td>3.0</td><td>3.1</td><td>2.8</td></tr><tr><td>K<sub>2</sub>O<br>%</td><td>0.04</td><td>1.2</td><td>1.4</td><td>1.4</td><td>0.8</td><td>1.1</td><td>1.2</td><td>1.5</td><td>1.1</td><td>0.9</td><td>0.6</td><td>0.7</td><td>0.7</td><td>0.5</td><td>1.2</td><td>0.9</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub><br>%</td><td>0.02</td><td>0.19</td><td>0.24</td><td>0.23</td><td>0.31</td><td>0.17</td><td>0.19</td><td>0.25</td><td>0.19</td><td>0.37</td><td>0.17</td><td>0.35</td><td>0.17</td><td>0.07</td><td>0.12</td><td>0.24</td></tr><tr><td>S<br>%</td><td>0.01</td><td>0.16</td><td>0.12</td><td>0.40</td><td>0.29</td><td>0.10</td><td>0.08</td><td>0.04</td><td>0.08</td><td>0.13</td><td>0.12</td><td>0.26</td><td>0.07</td><td>0.04</td><td>–</td><td>0.13</td></tr><tr><td>Cl<br>%</td><td>0.01</td><td>0.06</td><td>0.06</td><td>0.06</td><td>–</td><td>0.06</td><td>0.06</td><td>0.04</td><td>0.06</td><td>0.06</td><td>–</td><td>0.09</td><td>0.04</td><td>–</td><td>0.22</td><td>0.06</td></tr><tr><td>F<br>%</td><td>0.03</td><td>0.07</td><td>0.08</td><td>0.07</td><td>0.10</td><td>0.07</td><td>0.10</td><td>0.07</td><td>0.06</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td></tr><tr><td>H<sub>2</sub>O<br>%</td><td>–</td><td>0.83</td><td>1.15</td><td>–</td><td>–</td><td>0.36</td><td>0.38</td><td>0.61</td><td>0.33</td><td>1.01</td><td>0.78</td><td>0.80</td><td>1.52</td><td>1.13</td><td>1.03</td><td>1.12</td></tr><tr><td>Total<br>Li ppm</td><td>1.990</td><td>7</td><td>8</td><td>–</td><td>–</td><td>7</td><td>100.24</td><td>100.40</td><td>100.23</td><td>100.16</td><td>100.19</td><td>100.16</td><td>100.34</td><td>100.11</td><td>100.17</td><td>100.30</td><td>100.19</td></tr><tr><td>Sc<br>%</td><td>0.116</td><td>27</td><td>28</td><td>–</td><td>–</td><td>28</td><td>27</td><td>29</td><td>24</td><td>–</td><td>4</td><td>9</td><td>3</td><td>6</td><td>10</td><td>–</td><td>4</td></tr><tr><td>V<br>%</td><td>0.041</td><td>277</td><td>258</td><td>–</td><td>–</td><td>288</td><td>302</td><td>276</td><td>296</td><td>284</td><td>247</td><td>27</td><td>29</td><td>25</td><td>25</td><td>25</td><td>289</td></tr><tr><td>Cr<br>%</td><td>1.440</td><td>180</td><td>134</td><td>–</td><td>–</td><td>186</td><td>112</td><td>91</td><td>78</td><td>141</td><td>100</td><td>123</td><td>166</td><td>149</td><td>159</td><td>142</td><td>142</td></tr><tr><td>Co<br>%</td><td>0.020</td><td>33</td><td>41</td><td>–</td><td>–</td><td>37</td><td>42</td><td>33</td><td>37</td><td>37</td><td>32</td><td>40</td><td>37</td><td>30</td><td>34</td><td>34</td><td>34</td></tr><tr><td>Ni<br>%</td><td>0.538</td><td>77</td><td>74</td><td>–</td><td>–</td><td>52</td><td>58</td><td>46</td><td>49</td><td>53</td><td>57</td><td>46</td><td>76</td><td>65</td><td>45</td><td>43</td><td>43</td></tr><tr><td>Cu<br>%</td><td>0.175</td><td>19</td><td>61</td><td>–</td><td>–</td><td>74</td><td>87</td><td>58</td><td>70</td><td>22</td><td>25</td><td>20</td><td>36</td><td>19</td><td>39</td><td>23</td><td>23</td></tr><tr><td>Zn<br>%</td><td>0.224</td><td>79</td><td>105</td><td>–</td><td>–</td><td>93</td><td>95</td><td>72</td><td>93</td><td>94</td><td>108</td><td>94</td><td>88</td><td>105</td><td>91</td><td>89</td><td>89</td></tr><tr><td>Rb<br>%</td><td>0.014</td><td>26</td><td>36</td><td>–</td><td>–</td><td>21</td><td>26</td><td>30</td><td>23</td><td>25</td><td>19</td><td>16</td><td>12</td><td>47</td><td>25</td><td>331</td><td>427</td></tr><tr><td>Sr<br>%</td><td>0.009</td><td>515</td><td>554</td><td>–</td><td>–</td><td>436</td><td>471</td><td>440</td><td>484</td><td>381</td><td>407</td><td>509</td><td>427</td><td>439</td><td>331</td><td>427</td><td>427</td></tr><tr><td>Y<br>%</td><td>0.005</td><td>23</td><td>25</td><td>–</td><td>–</td><td>19</td><td>21</td><td>18</td><td>18</td><td>26</td><td>27</td><td>27</td><td>26</td><td>28</td><td>25</td><td>26</td><td>26</td></tr><tr><td>Zr<br>%</td><td>0.012</td><td>177</td><td>185</td><td>–</td><td>–</td><td>118</td><td>130</td><td>137</td><td>108</td><td>189</td><td>178</td><td>160</td><td>131</td><td>152</td><td>149</td><td>194</td><td>194</td></tr><tr><td>Nb<br>%</td><td>0.008</td><td>31</td><td>38</td><td>–</td><td>–</td><td>26</td><td>27</td><td>35</td><td>27</td><td>38</td><td>29</td><td>28</td><td>26</td><td>20</td><td>10</td><td>39</td><td>39</td></tr><tr><td>Cs<br>%</td><td>0.007</td><td>0.23</td><td>0.73</td><td>–</td><td>–</td><td>0.17</td><td>0.26</td><td>0.28</td><td>0.21</td><td>0.31</td><td>0.24</td><td>0.18</td><td>0.14</td><td>0.15</td><td>0.38</td><td>0.26</td><td>0.26</td></tr><tr><td>Ba<br>%</td><td>0.034</td><td>288</td><td>335</td><td>–</td><td>–</td><td>240</td><td>242</td><td>301</td><td>256</td><td>226</td><td>177</td><td>188</td><td>169</td><td>137</td><td>154</td><td>237</td><td>237</td></tr><tr><td>La<br>%</td><td>0.007</td><td>26</td><td>29</td><td>–</td><td>–</td><td>20</td><td>20</td><td>26</td><td>20</td><td>26</td><td>18</td><td>20</td><td>20</td><td>16</td><td>12</td><td>27</td><td>27</td></tr></tbody></table>

<figure><img src="image_12.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>PIC<br>68 s-4</th><th>Pic<br>69 s-1</th><th>Pic<br>69 s-8a</th><th>Pic<br>69 s-8b</th><th>PIC<br>66 s-2a</th><th>PIC<br>66 s-4</th><th>PIC<br>66 s-9a</th><th>PIC<br>66 s-16</th><th>ZKP<br>6-1</th><th>ZKP<br>6-2</th><th>ZKP<br>6-3</th><th>ZKP<br>6-4</th><th>ZKP<br>6-5</th><th>ZKP<br>6-6</th><th>ZKP<br>6-7a</th></tr></thead><tbody><tr><td>Ce</td><td>0.007</td><td>57</td><td>62</td><td>-</td><td>-</td><td>43</td><td>42</td><td>56</td><td>46</td><td>56</td><td>45</td><td>45</td><td>42</td><td>38</td><td>33</td><td>59</td></tr><tr><td>Pr</td><td>0.004</td><td>7.1</td><td>7.5</td><td>-</td><td>-</td><td>5.2</td><td>5.5</td><td>6.5</td><td>5.6</td><td>6.7</td><td>5.9</td><td>5.8</td><td>5.2</td><td>4.7</td><td>4.7</td><td>6.9</td></tr><tr><td>Nd</td><td>0.028</td><td>30</td><td>30</td><td>-</td><td>-</td><td>22</td><td>24</td><td>28</td><td>21</td><td>28</td><td>28</td><td>27</td><td>23</td><td>23</td><td>22</td><td>29</td></tr><tr><td>Sm</td><td>0.039</td><td>6.2</td><td>6.2</td><td>-</td><td>-</td><td>4.7</td><td>4.6</td><td>5.6</td><td>4.6</td><td>6.4</td><td>7.0</td><td>6.1</td><td>5.3</td><td>5.6</td><td>6.1</td><td>6.4</td></tr><tr><td>Eu</td><td>0.008</td><td>2.1</td><td>2.2</td><td>-</td><td>-</td><td>1.7</td><td>1.6</td><td>1.8</td><td>1.6</td><td>2.2</td><td>2.3</td><td>2.2</td><td>1.9</td><td>2.0</td><td>2.0</td><td>2.1</td></tr><tr><td>Gd</td><td>0.041</td><td>6.1</td><td>6.3</td><td>-</td><td>-</td><td>4.6</td><td>5.4</td><td>4.8</td><td>4.8</td><td>6.3</td><td>6.6</td><td>6.2</td><td>5.7</td><td>5.7</td><td>6.1</td><td>6.2</td></tr><tr><td>Tb</td><td>0.006</td><td>0.80</td><td>0.87</td><td>-</td><td>-</td><td>0.64</td><td>0.71</td><td>0.67</td><td>0.67</td><td>0.98</td><td>0.97</td><td>0.89</td><td>0.83</td><td>0.99</td><td>0.86</td><td>0.89</td></tr><tr><td>Dy</td><td>0.023</td><td>5.0</td><td>5.2</td><td>-</td><td>-</td><td>4.0</td><td>4.7</td><td>4.1</td><td>3.6</td><td>5.8</td><td>6.6</td><td>5.3</td><td>5.6</td><td>5.8</td><td>5.0</td><td>5.6</td></tr><tr><td>Ho</td><td>0.006</td><td>0.87</td><td>0.94</td><td>-</td><td>-</td><td>0.77</td><td>0.80</td><td>0.73</td><td>0.64</td><td>1.09</td><td>1.18</td><td>0.94</td><td>1.02</td><td>1.11</td><td>0.89</td><td>1.01</td></tr><tr><td>Er</td><td>0.016</td><td>2.4</td><td>2.7</td><td>-</td><td>-</td><td>1.7</td><td>2.2</td><td>1.9</td><td>1.7</td><td>2.8</td><td>2.8</td><td>2.6</td><td>2.4</td><td>3.0</td><td>2.5</td><td>2.3</td></tr><tr><td>Tm</td><td>0.005</td><td>0.32</td><td>0.36</td><td>-</td><td>-</td><td>0.23</td><td>0.29</td><td>0.27</td><td>0.26</td><td>0.39</td><td>0.31</td><td>0.32</td><td>0.35</td><td>0.33</td><td>0.42</td><td>0.31</td></tr><tr><td>Yb</td><td>0.032</td><td>1.9</td><td>2.2</td><td>-</td><td>-</td><td>1.9</td><td>1.7</td><td>1.9</td><td>1.9</td><td>1.9</td><td>2.1</td><td>2.2</td><td>2.0</td><td>2.7</td><td>1.9</td><td>2.3</td></tr><tr><td>Lu</td><td>0.010</td><td>0.27</td><td>0.36</td><td>-</td><td>-</td><td>0.26</td><td>0.29</td><td>0.22</td><td>0.23</td><td>0.29</td><td>0.30</td><td>0.28</td><td>0.28</td><td>0.31</td><td>0.24</td><td>0.32</td></tr><tr><td>Hf</td><td>0.026</td><td>5</td><td>5</td><td>-</td><td>-</td><td>3</td><td>3</td><td>4</td><td>3</td><td>4</td><td>5</td><td>4</td><td>3</td><td>4</td><td>3</td><td>5</td></tr><tr><td>Ta</td><td>0.009</td><td>2.0</td><td>2.4</td><td>-</td><td>-</td><td>1.7</td><td>1.8</td><td>2.4</td><td>1.6</td><td>2.4</td><td>2.4</td><td>1.7</td><td>1.7</td><td>1.3</td><td>0.6</td><td>2.4</td></tr><tr><td>Pb</td><td>0.034</td><td>2.5</td><td>3.6</td><td>-</td><td>-</td><td>2.4</td><td>2.5</td><td>2.5</td><td>2.5</td><td>1.8</td><td>1.1</td><td>1.2</td><td>1.1</td><td>0.8</td><td>3.5</td><td>1.8</td></tr><tr><td>Th</td><td>0.011</td><td>2.4</td><td>3.0</td><td>-</td><td>-</td><td>1.6</td><td>1.8</td><td>2.5</td><td>1.7</td><td>2.8</td><td>1.9</td><td>2.0</td><td>1.7</td><td>1.4</td><td>2.1</td><td>2.6</td></tr><tr><td>U</td><td>0.014</td><td>0.85</td><td>1.65</td><td>-</td><td>-</td><td>-</td><td>0.70</td><td>0.74</td><td>0.94</td><td>0.75</td><td>1.04</td><td>0.72</td><td>0.71</td><td>0.62</td><td>0.57</td><td>0.71</td><td>1.04</td></tr><tr><td></td><td>D.L. %</td><td>ZKP<br>6-7b</td><td>TRS<br>24b-2</td><td>TRS<br>24b-3</td><td>TRS<br>24b-4</td><td>TRS<br>24a-1a</td><td>TRS<br>24a-1b</td><td>TRS<br>24a-2</td><td>TRS<br>24a-3a</td><td>TRS<br>24a-3b</td><td>TRS<br>24a-4</td><td>TRS<br>24a-5</td><td>TRS<br>24a-6</td><td>SM<br>0810 s-1</td><td>SM<br>0810 s-2</td><td>SM<br>0810 s-3</td></tr><tr><td>PEC</td><td>%</td><td>5.02</td><td>4.25</td><td>8.47</td><td>5.23</td><td>2.24</td><td>4.73</td><td>4.04</td><td>5.07</td><td>5.93</td><td>4.46</td><td>3.93</td><td>5.8</td><td>12.22</td><td>12.45</td><td>10.66</td></tr><tr><td>Fe</td><td>%</td><td>83.9</td><td>85.0</td><td>85.6</td><td>84.0</td><td>83.2</td><td>83.2</td><td>83.2</td><td>84.9</td><td>84.4</td><td>83.3</td><td>84.4</td><td>84.1</td><td>82.5</td><td>82.5</td><td>82.2</td></tr><tr><td>SiO<sub>2</sub></td><td>%</td><td>0.13</td><td>47.2</td><td>48.8</td><td>48.5</td><td>48.9</td><td>49.0</td><td>49.5</td><td>50.0</td><td>48.0</td><td>48.4</td><td>47.6</td><td>47.6</td><td>48.6</td><td>44.1</td><td>44.7</td><td>44.7</td></tr><tr><td>TiO<sub>2</sub></td><td>%</td><td>0.10</td><td>3.85</td><td>2.55</td><td>2.56</td><td>2.63</td><td>2.33</td><td>2.47</td><td>2.47</td><td>2.52</td><td>2.45</td><td>2.97</td><td>3.00</td><td>2.53</td><td>4.19</td><td>4.35</td><td>4.40</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>%</td><td>0.06</td><td>16.1</td><td>18.3</td><td>17.0</td><td>18.1</td><td>18.2</td><td>18.0</td><td>16.9</td><td>17.6</td><td>18.3</td><td>17.1</td><td>18.3</td><td>17.5</td><td>12.5</td><td>12.8</td><td>12.6</td></tr><tr><td>FeO<sub>t</sub></td><td>%</td><td>0.11</td><td>9.1</td><td>6.8</td><td>6.9</td><td>6.8</td><td>7.5</td><td>7.2</td><td>7.5</td><td>7.4</td><td>6.9</td><td>8.3</td><td>6.6</td><td>7.1</td><td>12.0</td><td>11.4</td><td>11.6</td></tr><tr><td>MnO</td><td>%</td><td>0.11</td><td>0.17</td><td>0.13</td><td>0.18</td><td>0.17</td><td>0.14</td><td>0.14</td><td>0.14</td><td>0.15</td><td>0.16</td><td>0.14</td><td>0.11</td><td>0.15</td><td>0.13</td><td>0.19</td><td>0.17</td></tr><tr><td>MgO</td><td>%</td><td>0.12</td><td>8.0</td><td>4.5</td><td>6.4</td><td>5.0</td><td>5.5</td><td>5.1</td><td>5.5</td><td>6.5</td><td>5.5</td><td>6.5</td><td>5.1</td><td>5.6</td><td>10.1</td><td>9.5</td><td>9.4</td></tr><tr><td>CaO</td><td>%</td><td>0.07</td><td>10.3</td><td>12.9</td><td>12.4</td><td>12.4</td><td>11.3</td><td>11.5</td><td>11.3</td><td>12.1</td><td>12.1</td><td>11.2</td><td>13.3</td><td>12.2</td><td>11.5</td><td>10.8</td><td>11.6</td></tr><tr><td>Na<sub>2</sub>O</td><td>%</td><td>0.05</td><td>2.9</td><td>3.7</td><td>3.5</td><td>2.4</td><td>3.8</td><td>3.8</td><td>3.8</td><td>3.5</td><td>3.6</td><td>3.7</td><td>3.6</td><td>3.9</td><td>2.6</td><td>2.6</td><td>2.7</td></tr><tr><td>K<sub>2</sub>O</td><td>%</td><td>0.04</td><td>0.9</td><td>1.2</td><td>1.1</td><td>1.3</td><td>1.2</td><td>1.1</td><td>0.48</td><td>1.1</td><td>1.2</td><td>1.2</td><td>1.3</td><td>0.94</td><td>1.4</td><td>2.1</td><td>1.4</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>%</td><td>0.02</td><td>0.24</td><td>0.15</td><td>0.08</td><td>0.06</td><td>0.09</td><td>0.05</td><td>0.06</td><td>0.23</td><td>0.11</td><td>0.26</td><td>0.12</td><td>0.17</td><td>0.24</td><td>0.33</td><td>0.30</td></tr><tr><td>S</td><td>%</td><td>0.01</td><td>0.13</td><td>0.06</td><td>0.15</td><td>0.11</td><td>0.11</td><td>0.08</td><td>0.04</td><td>0.17</td><td>0.05</td><td>0.16</td><td>-</td><td>0.15</td><td>0.26</td><td>0.26</td><td>0.31</td></tr><tr><td>Cl</td><td>%</td><td>0.01</td><td>0.06</td><td>-</td><td>0.03</td><td>-</td><td>0.06</td><td>0.25</td><td>-</td><td>0.07</td><td>-</td><td>0.07</td><td>-</td><td>0.08</td><td>0.05</td><td>0.09</td><td>0.06</td></tr><tr><td>F</td><td>%</td><td>0.03</td><td>0.05</td><td>-</td><td>0.04</td><td>0.04</td><td>0.03</td><td>0.04</td><td>0.05</td><td>0.10</td><td>0.07</td><td>0.07</td><td>-</td><td>0.07</td><td>0.11</td><td>0.11</td><td>0.12</td></tr></tbody></table>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>ZKP<br>6-7b</th><th>TRS<br>24b-2</th><th>TRS<br>24b-3</th><th>TRS<br>24b-4</th><th>TRS<br>24a-1a</th><th>TRS<br>24a-1b</th><th>TRS<br>24a-2</th><th>TRS<br>24a-3a</th><th>TRS<br>24a-3b</th><th>TRS<br>24a-4</th><th>TRS<br>24a-5</th><th>TRS<br>24a-6</th><th>SM<br>0810 s-1</th><th>SM<br>0810 s-2</th><th>SM<br>0810 s-3</th></tr></thead><tbody><tr><td>H₂O</td><td></td><td>1.27</td><td>1.02</td><td>1.42</td><td>2.14</td><td>0.92</td><td>1.05</td><td>1.83</td><td>0.81</td><td>1.28</td><td>1.07</td><td>0.90</td><td>1.29</td><td>1.14</td><td>1.42</td><td>1.10</td></tr><tr><td>Total</td><td></td><td>100.23</td><td>100.09</td><td>100.22</td><td>100.18</td><td>100.22</td><td>100.37</td><td>100.11</td><td>100.35</td><td>100.16</td><td>100.30</td><td>100.00</td><td>100.30</td><td>100.44</td><td>100.45</td><td>100.50</td></tr><tr><td>Li ppm</td><td>1.990</td><td>4</td><td>4</td><td>23</td><td>—</td><td>—</td><td>—</td><td>4</td><td>—</td><td>—</td><td>3</td><td>5</td><td>—</td><td>5</td><td>6</td><td>—</td></tr><tr><td>Sc</td><td>0.116</td><td>25</td><td>22</td><td>23</td><td>—</td><td>—</td><td>—</td><td>19</td><td>—</td><td>—</td><td>22</td><td>26</td><td>—</td><td>35</td><td>34</td><td>—</td></tr><tr><td>V</td><td>0.041</td><td>290</td><td>247</td><td>220</td><td>—</td><td>—</td><td>—</td><td>179</td><td>—</td><td>—</td><td>224</td><td>263</td><td>—</td><td>392</td><td>381</td><td>—</td></tr><tr><td>Cr</td><td>1.440</td><td>139</td><td>32</td><td>58</td><td>—</td><td>—</td><td>—</td><td>41</td><td>—</td><td>—</td><td>32</td><td>61</td><td>—</td><td>94</td><td>71</td><td>—</td></tr><tr><td>Co</td><td>0.020</td><td>39</td><td>12</td><td>17</td><td>—</td><td>—</td><td>—</td><td>20</td><td>—</td><td>—</td><td>24</td><td>30</td><td>—</td><td>44</td><td>36</td><td>—</td></tr><tr><td>Ni</td><td>0.538</td><td>55</td><td>3</td><td>7</td><td>—</td><td>—</td><td>—</td><td>14</td><td>—</td><td>—</td><td>18</td><td>114</td><td>—</td><td>52</td><td>33</td><td>—</td></tr><tr><td>Cu</td><td>0.175</td><td>19</td><td>4</td><td>34</td><td>—</td><td>—</td><td>—</td><td>30</td><td>—</td><td>—</td><td>17</td><td>10</td><td>—</td><td>65</td><td>65</td><td>—</td></tr><tr><td>Zn</td><td>0.224</td><td>92</td><td>59</td><td>57</td><td>—</td><td>—</td><td>—</td><td>65</td><td>—</td><td>—</td><td>68</td><td>74</td><td>—</td><td>116</td><td>115</td><td>—</td></tr><tr><td>Rb</td><td>0.014</td><td>27</td><td>22</td><td>22</td><td>—</td><td>—</td><td>—</td><td>5.4</td><td>—</td><td>—</td><td>28</td><td>22</td><td>—</td><td>47</td><td>77</td><td>—</td></tr><tr><td>Sr</td><td>0.009</td><td>442</td><td>408</td><td>353</td><td>—</td><td>—</td><td>—</td><td>1856</td><td>—</td><td>—</td><td>422</td><td>406</td><td>—</td><td>734</td><td>756</td><td>—</td></tr><tr><td>Y</td><td>0.005</td><td>25</td><td>16</td><td>13</td><td>—</td><td>—</td><td>—</td><td>15</td><td>—</td><td>—</td><td>16</td><td>19</td><td>—</td><td>29</td><td>29</td><td>—</td></tr><tr><td>Zr</td><td>0.012</td><td>188</td><td>106</td><td>94</td><td>—</td><td>—</td><td>—</td><td>59</td><td>—</td><td>—</td><td>109</td><td>120</td><td>—</td><td>227</td><td>343</td><td>—</td></tr><tr><td>Nb</td><td>0.008</td><td>40</td><td>29</td><td>22</td><td>—</td><td>—</td><td>—</td><td>4.7</td><td>—</td><td>—</td><td>33</td><td>25</td><td>—</td><td>45</td><td>72</td><td>—</td></tr><tr><td>Cs</td><td>0.007</td><td>0.30</td><td>0.21</td><td>0.19</td><td>—</td><td>—</td><td>—</td><td>0.06</td><td>—</td><td>—</td><td>0.25</td><td>0.23</td><td>—</td><td>0.35</td><td>0.67</td><td>—</td></tr><tr><td>Ba</td><td>0.034</td><td>245</td><td>281</td><td>218</td><td>—</td><td>—</td><td>—</td><td>187</td><td>—</td><td>—</td><td>301</td><td>284</td><td>—</td><td>362</td><td>611</td><td>—</td></tr><tr><td>La</td><td>0.007</td><td>27</td><td>18</td><td>15</td><td>—</td><td>—</td><td>—</td><td>7.8</td><td>—</td><td>—</td><td>20</td><td>20</td><td>—</td><td>37</td><td>62</td><td>—</td></tr><tr><td>Ce</td><td>0.007</td><td>58</td><td>40</td><td>33</td><td>—</td><td>—</td><td>—</td><td>19</td><td>—</td><td>—</td><td>40</td><td>45</td><td>—</td><td>80</td><td>123</td><td>—</td></tr><tr><td>Pr</td><td>0.004</td><td>6.9</td><td>4.7</td><td>4.1</td><td>—</td><td>—</td><td>—</td><td>2.8</td><td>—</td><td>—</td><td>4.7</td><td>5.4</td><td>—</td><td>9.8</td><td>14.2</td><td>—</td></tr><tr><td>Nd</td><td>0.028</td><td>30</td><td>20</td><td>17</td><td>—</td><td>—</td><td>—</td><td>15</td><td>—</td><td>—</td><td>20</td><td>20</td><td>—</td><td>43</td><td>56</td><td>—</td></tr><tr><td>Sm</td><td>0.039</td><td>6.0</td><td>4.3</td><td>3.7</td><td>—</td><td>—</td><td>—</td><td>4.1</td><td>—</td><td>—</td><td>4.4</td><td>4.9</td><td>—</td><td>8.6</td><td>10.8</td><td>—</td></tr><tr><td>Eu</td><td>0.008</td><td>2.2</td><td>1.4</td><td>1.2</td><td>—</td><td>—</td><td>—</td><td>1.4</td><td>—</td><td>—</td><td>1.5</td><td>1.7</td><td>—</td><td>3.1</td><td>3.4</td><td>—</td></tr><tr><td>Gd</td><td>0.041</td><td>6.2</td><td>3.8</td><td>3.2</td><td>—</td><td>—</td><td>—</td><td>3.7</td><td>—</td><td>—</td><td>4.2</td><td>4.9</td><td>—</td><td>8.7</td><td>9.3</td><td>—</td></tr><tr><td>Tb</td><td>0.006</td><td>0.90</td><td>0.50</td><td>0.38</td><td>—</td><td>—</td><td>—</td><td>0.52</td><td>—</td><td>—</td><td>0.52</td><td>0.89</td><td>—</td><td>1.10</td><td>1.18</td><td>—</td></tr><tr><td>Dy</td><td>0.023</td><td>5.2</td><td>3.2</td><td>2.9</td><td>—</td><td>—</td><td>—</td><td>3.2</td><td>—</td><td>—</td><td>3.4</td><td>4.5</td><td>—</td><td>6.4</td><td>6.8</td><td>—</td></tr><tr><td>Ho</td><td>0.006</td><td>1.05</td><td>0.66</td><td>0.43</td><td>—</td><td>—</td><td>—</td><td>0.59</td><td>—</td><td>—</td><td>0.65</td><td>0.75</td><td>—</td><td>1.17</td><td>1.15</td><td>—</td></tr><tr><td>Er</td><td>0.016</td><td>2.4</td><td>1.9</td><td>1.4</td><td>—</td><td>—</td><td>—</td><td>1.6</td><td>—</td><td>—</td><td>1.7</td><td>2.4</td><td>—</td><td>2.7</td><td>3.0</td><td>—</td></tr><tr><td>Tm</td><td>0.005</td><td>0.30</td><td>0.25</td><td>0.14</td><td>—</td><td>—</td><td>—</td><td>0.21</td><td>—</td><td>—</td><td>0.24</td><td>0.26</td><td>—</td><td>0.41</td><td>0.37</td><td>—</td></tr><tr><td>Yb</td><td>0.032</td><td>1.9</td><td>1.8</td><td>1.1</td><td>—</td><td>—</td><td>—</td><td>1.4</td><td>—</td><td>—</td><td>1.4</td><td>1.9</td><td>—</td><td>2.1</td><td>2.3</td><td>—</td></tr><tr><td>Lu</td><td>0.010</td><td>0.27</td><td>0.18</td><td>0.19</td><td>—</td><td>—</td><td>—</td><td>0.21</td><td>—</td><td>—</td><td>0.23</td><td>0.27</td><td>—</td><td>0.30</td><td>0.34</td><td>—</td></tr><tr><td>Hf</td><td>0.026</td><td>5</td><td>3</td><td>2</td><td>—</td><td>—</td><td>—</td><td>1</td><td>—</td><td>—</td><td>3</td><td>4</td><td>—</td><td>6</td><td>8</td><td>—</td></tr><tr><td>Ta</td><td>0.009</td><td>2.5</td><td>1.8</td><td>1.3</td><td>—</td><td>—</td><td>—</td><td>0.2</td><td>—</td><td>—</td><td>2.1</td><td>2.1</td><td>—</td><td>3.0</td><td>4.7</td><td>—</td></tr><tr><td>Pb</td><td>0.034</td><td>1.9</td><td>2.1</td><td>1.4</td><td>—</td><td>—</td><td>—</td><td>0.8</td><td>—</td><td>—</td><td>1.9</td><td>2.3</td><td>—</td><td>2.7</td><td>4.4</td><td>—</td></tr><tr><td>Th</td><td>0.011</td><td>2.7</td><td>1.8</td><td>1.4</td><td>—</td><td>—</td><td>—</td><td>0.3</td><td>—</td><td>—</td><td>2.1</td><td>2.0</td><td>—</td><td>4.3</td><td>7.6</td><td>—</td></tr><tr><td>U</td><td>0.014</td><td>1.0</td><td>0.6</td><td>0.6</td><td>—</td><td>—</td><td>—</td><td>0.1</td><td>—</td><td>—</td><td>0.7</td><td>0.7</td><td>—</td><td>1.2</td><td>1.8</td><td>—</td></tr></tbody></table>

<figure><img src="image_13.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>SM<br>0810 s-5</th><th>SM<br>0810 s-6a</th><th>SM<br>0810 s-6b</th><th>SM<br>0810 s-7</th><th>MFs-3</th><th>SMG<br>9 s-1</th><th>SMG<br>9 s-3</th></tr></thead><tbody><tr><td>PEC</td><td></td><td>13.83</td><td>14.28</td><td>11.49</td><td>11.97</td><td>3.31</td><td>6.35</td><td>4.72</td></tr><tr><td>%</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Fo</td><td></td><td>83.8</td><td>82.9</td><td>84.6</td><td>82.4</td><td>84.0</td><td>82.0</td><td>81.8</td></tr><tr><td>%</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>0.13</td><td>44.2</td><td>45.9</td><td>46.4</td><td>44.4</td><td>48.9</td><td>45.5</td><td>45.2</td></tr><tr><td>TiO<sub>2</sub></td><td>0.10</td><td>4.28</td><td>4.08</td><td>4.20</td><td>4.55</td><td>2.78</td><td>4.19</td><td>4.15</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>0.06</td><td>12.0</td><td>11.8</td><td>12.3</td><td>11.9</td><td>14.5</td><td>14.5</td><td>14.6</td></tr><tr><td>FeO<sub>t</sub></td><td>0.11</td><td>11.7</td><td>12.5</td><td>10.2</td><td>11.9</td><td>8.6</td><td>10.6</td><td>10.5</td></tr><tr><td>MnO</td><td>0.11</td><td>0.2</td><td>0.2</td><td>0.2</td><td>0.2</td><td>0.1</td><td>0.1</td><td>0.1</td></tr><tr><td>MgO</td><td>0.12</td><td>10.93</td><td>10.99</td><td>9.9</td><td>9.95</td><td>7.52</td><td>8.26</td><td>8.04</td></tr><tr><td>CaO</td><td>0.07</td><td>11.0</td><td>11.1</td><td>11.0</td><td>11.8</td><td>11.6</td><td>11.4</td><td>11.7</td></tr><tr><td>Na<sub>2</sub>O</td><td>0.05</td><td>2.5</td><td>2.7</td><td>2.2</td><td>2.7</td><td>3.2</td><td>2.5</td><td>2.7</td></tr><tr><td>K<sub>2</sub>O</td><td>0.04</td><td>1.5</td><td>1.1</td><td>2.2</td><td>1.6</td><td>1.4</td><td>1.2</td><td>1.3</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.02</td><td>0.46</td><td>0.33</td><td>0.28</td><td>0.33</td><td>0.24</td><td>0.31</td><td>0.33</td></tr><tr><td>S</td><td>0.01</td><td>0.22</td><td>0.26</td><td>0.19</td><td>0.34</td><td>0.05</td><td>0.23</td><td>0.24</td></tr><tr><td>Cl</td><td>0.01</td><td>0.08</td><td>0.07</td><td>0.06</td><td>0.07</td><td>0.04</td><td>0.07</td><td>0.08</td></tr><tr><td>F</td><td>0.03</td><td>0.10</td><td>0.10</td><td>0.11</td><td>0.11</td><td>-</td><td>0.09</td><td>0.10</td></tr><tr><td>H<sub>2</sub>O</td><td>-</td><td>1.12</td><td>1.42</td><td>1.20</td><td>0.61</td><td>1.19</td><td>1.20</td><td>1.43</td></tr><tr><td>Total</td><td></td><td>100.41</td><td>100.43</td><td>100.36</td><td>100.54</td><td>100.10</td><td>100.40</td><td>100.41</td></tr><tr><td>Li ppm</td><td>1.990</td><td>7</td><td>7</td><td>5</td><td>7</td><td>8</td><td>6</td><td>3</td></tr><tr><td>Sc</td><td>0.116</td><td>37</td><td>39</td><td>33</td><td>42</td><td>29</td><td>27</td><td>26</td></tr><tr><td>V</td><td>0.041</td><td>379</td><td>401</td><td>327</td><td>414</td><td>273</td><td>340</td><td>345</td></tr><tr><td>Cr</td><td>1.440</td><td>100</td><td>212</td><td>180</td><td>28</td><td>227</td><td>94</td><td>89</td></tr><tr><td>Co</td><td>0.020</td><td>38</td><td>46</td><td>38</td><td>36</td><td>39</td><td>41</td><td>43</td></tr><tr><td>Ni</td><td>0.538</td><td>48</td><td>49</td><td>57</td><td>47</td><td>75</td><td>54</td><td>52</td></tr><tr><td>Cu</td><td>0.175</td><td>84</td><td>87</td><td>52</td><td>107</td><td>47</td><td>64</td><td>55</td></tr><tr><td>Zn</td><td>0.224</td><td>111</td><td>107</td><td>99</td><td>113</td><td>107</td><td>98</td><td>97</td></tr><tr><td>Rb</td><td>0.014</td><td>46</td><td>35</td><td>64</td><td>48</td><td>38</td><td>30</td><td>32</td></tr><tr><td>Sr</td><td>0.009</td><td>625</td><td>925</td><td>695</td><td>821</td><td>554</td><td>695</td><td>697</td></tr><tr><td>Y</td><td>0.005</td><td>29</td><td>32</td><td>26</td><td>31</td><td>20</td><td>21</td><td>21</td></tr><tr><td>Zr</td><td>0.012</td><td>201</td><td>202</td><td>346</td><td>264</td><td>171</td><td>181</td><td>170</td></tr><tr><td>Nb</td><td>0.008</td><td>50</td><td>42</td><td>51</td><td>52</td><td>41</td><td>47</td><td>43</td></tr><tr><td>Cs</td><td>0.007</td><td>0.34</td><td>0.38</td><td>0.58</td><td>0.44</td><td>0.27</td><td>0.25</td><td>0.28</td></tr><tr><td>Ba</td><td>0.034</td><td>416</td><td>431</td><td>453</td><td>398</td><td>352</td><td>391</td><td>353</td></tr><tr><td>La</td><td>0.007</td><td>36</td><td>34</td><td>52</td><td>45</td><td>27</td><td>35</td><td>32</td></tr><tr><td>Ce</td><td>0.007</td><td>73</td><td>79</td><td>112</td><td>95</td><td>58</td><td>74</td><td>71</td></tr><tr><td>Pr</td><td>0.004</td><td>8.9</td><td>10.3</td><td>13.0</td><td>11.5</td><td>6.9</td><td>8.9</td><td>8.9</td></tr><tr><td>Nd</td><td>0.028</td><td>41</td><td>44</td><td>51</td><td>47</td><td>29</td><td>37</td><td>37</td></tr><tr><td>Sm</td><td>0.039</td><td>9.9</td><td>9.6</td><td>9.7</td><td>10.8</td><td>5.7</td><td>7.7</td><td>7.4</td></tr></tbody></table>

<figure><img src="image_14.png" /></figure>
<table><caption>Table 2 (continued)</caption><thead><tr><th></th><th>D.L. %</th><th>SM<br>0810 s-5</th><th>SM<br>0810 s-6a</th><th>SM<br>0810 s-6b</th><th>SM<br>0810 s-7</th><th>MFs-3</th><th>SMG<br>9 s-1</th><th>SMG<br>9 s-3</th></tr></thead><tbody><tr><td>Eu</td><td>0.008</td><td>3.1</td><td>3.0</td><td>2.9</td><td>3.4</td><td>2.0</td><td>2.4</td><td>2.2</td></tr><tr><td>Gd</td><td>0.041</td><td>8.5</td><td>9.5</td><td>8.2</td><td>9.6</td><td>5.9</td><td>6.8</td><td>6.9</td></tr><tr><td>Tb</td><td>0.006</td><td>1.06</td><td>1.31</td><td>1.06</td><td>1.07</td><td>0.80</td><td>0.79</td><td>0.83</td></tr><tr><td>Dy</td><td>0.023</td><td>6.3</td><td>7.2</td><td>5.8</td><td>6.9</td><td>4.4</td><td>4.6</td><td>4.6</td></tr><tr><td>Ho</td><td>0.006</td><td>1.09</td><td>1.21</td><td>1.00</td><td>1.26</td><td>0.76</td><td>0.84</td><td>0.82</td></tr><tr><td>Er</td><td>0.016</td><td>3.1</td><td>2.7</td><td>2.4</td><td>2.9</td><td>2.2</td><td>2.3</td><td>2.3</td></tr><tr><td>Tm</td><td>0.005</td><td>0.31</td><td>0.34</td><td>0.31</td><td>0.37</td><td>0.24</td><td>0.27</td><td>0.29</td></tr><tr><td>Yb</td><td>0.032</td><td>2.5</td><td>2.4</td><td>2.1</td><td>2.5</td><td>1.6</td><td>2.0</td><td>1.8</td></tr><tr><td>Lu</td><td>0.010</td><td>0.25</td><td>0.35</td><td>0.25</td><td>0.36</td><td>0.21</td><td>0.27</td><td>0.23</td></tr><tr><td>Hf</td><td>0.026</td><td>5</td><td>5</td><td>9</td><td>7</td><td>4</td><td>4</td><td>4</td></tr><tr><td>Ta</td><td>0.009</td><td>3.1</td><td>2.6</td><td>3.4</td><td>3.3</td><td>2.4</td><td>2.6</td><td>3.1</td></tr><tr><td>Pb</td><td>0.034</td><td>2.2</td><td>3.1</td><td>4.5</td><td>3.4</td><td>3.7</td><td>2.8</td><td>2.4</td></tr><tr><td>Th</td><td>0.011</td><td>3.9</td><td>3.0</td><td>5.3</td><td>4.7</td><td>2.6</td><td>2.8</td><td>3.0</td></tr><tr><td>U</td><td>0.014</td><td>1.08</td><td>0.83</td><td>1.54</td><td>1.18</td><td>0.97</td><td>0.83</td><td>0.91</td></tr></tbody></table>

SMIs geochemical database recalculated after PEC. D.L. stands for detection limit

from São Miguel (Fig. 3). These trace element patterns are akin to the Enriched MORB end-member (Hémond et al. 2006—Fig. 4a), although they show different degrees of enrichment in most elements, except for the Heavy REE, due to their evolutionary degree. Four SMIs from Graciosa, Terceira and Pico show distinct patterns of trace elements. These SMIs show variable degrees of depletion in HFSE and most LILE as compared to the Enriched MORB. However, exceptions are observed for Ba, Sr and Light REE (Fig. 4b).

The volatile element concentrations are variable. H₂O ranges from 0.2 to 2.8 wt.%, Cl from 330 to 1826 ppm, F from 405 to 1778 ppm, and S from 290 to 2568 ppm (Table 2). These values fall within the same range as those measured on SMIs at Pico and São Miguel (Métrich et al. 2014; Rose-Koga et al. 2017; Turner et al. 2017; van Gerve et al. 2024). Furthermore, H₂O does not reveal any correlation with Ce (Fig. 5a), La, or any other incompatible element. This absence of correlation was previously noted in the literature as a sign of water loss (Hartley et al. 2015).

The poorly evolved SMIs from Pico, Faial, and Graciosa exhibit a H₂O/Ce ratio reaching ~248 that is comparable to the value of 259 ± 11 determined for the SMIs originating from the Pico fissure zone, which remains largely unaffected (or minimally affected) by H⁺ gain/loss (Métrich et al. 2014). Using this value as a reference, we infer initial water contents ranging from 1.1 to 1.9 wt.% for the least evolved SMIs compositions and up to an 85% H₂O loss for the SMIs studied.

There is no correlation between water, halogens, and sulfur with the Fo content of the host (Supplementary Fig. 4). This indicates diverse volatile contents throughout the crystallisation path of olivine, similarly to the findings of van Gerve et al. (2023). Moreover, these trends show no correlation with differentiation indexes, like FeOt/MgO, on the island scale. Therefore, any connection between degassing and possible magma evolution during ascent can be excluded. This is also supported by the lack of intracrystal magma ponding stages where ascending magmas had time to rest and significantly degas (Zanon and Frezzotti 2013; Zanon 2015b; Zanon and Pimentel 2015). A few inclusions from Pico, Graciosa, and Terceira show a chlorine decrease related to the evolutionary degree (Fig. 5b).

Sulfur content differs in each volcano and at a regional scale and shows no correlation with FeOt, as illustrated in Fig. 5c. At Pico-Faial and Terceira, a decrease in sulfur follows that of MgO, indicating the presence of immiscible sulfide globules in numerous inclusions. The high sulfur values found in a few inclusions from all the islands and unrelated to differentiation, suggest the occasional entrapment of a melt enriched in sulfur, probably derived from a sulfide-enriched mantle source below the archipelago, as discussed in Waters et al. (2020).

<figure><img src="image_15.png" /></figure>
**Fig. 3** Chemical variability of PEC-corrected compositions of SMIs ► and olivines from the Azores. **a** The TAS classification diagram shows the compositions of SMIs compared to bulk rock compositions from the GEOROC database (http://georoc.mpch-mainz.gwdg.de/georoc/). Volcanic systems are distinguished into central volcanoes (c.v.) and fissure zones (f.z.), with the alkaline versus subalkaline field distinction following Middlemost (1975). **b** Evolution of SMIs revealed by FeO/MgO and CaO/Al₂O₃ differentiation indices. Geochemical data of SMIs from the Pico fissure zone (Métrich et al. 2014) are shown for comparison. **c** Comparison between CaO/Al₂O₃ and the forsterite content in the host olivines. **d** Variability of the Ca partition coefficient between olivine and melt, calculated from SMIs, allowing the identification of antecrysts between the hosts

# Discussion

## Entrapment conditions of silicate melt inclusions

Without CO₂ data, it is unattainable to determine the entrapment pressure of inclusions; nonetheless, certain observations can still be inferred. Published data on CO₂-rich fluid inclusion study, carried out on the same samples (Zanon et al. 2023), reveal an area of magma accumulation located in the deep crust, between ~18 and 20 km below the islands of Faial, Pico, Graciosa and Terceira and ~26 km below São Jorge and ~29 for São Miguel. These depths mark the boundary between the lithospheric mantle and the deep crust (Zanon et al. 2023). Furthermore, the complete re-equilibration of densities of fluid inclusions is indicative of prolonged magma ponding. This conclusion is also supported by the absence of zoning in olivine crystals, which is consistent with their chemical equilibrium with the hosting melt(s). This leads us to infer that these crystals are most likely antecrysts—leftover crystals from prior magma differentiation (Charlier et al. 2005; Davidson et al. 2007; Jerram and Martin 2008). Their origin has been already discussed at Pico and Faial (Zanon and Frezzotti 2013) and Corvo (Larrea et al. 2013).

Fluid inclusions evidenced rapid ascent without significant ponding at a shallow crustal level (Zanon and Frezzotti 2013; Métrich et al. 2014; Zanon 2015b; Zanon and Pimentel 2015; Zanon et al. 2020). Therefore, we conclude that the olivine-hosted SMIs were trapped at such depths. Other important consequences of this rapid ascent are that the effects of late degassing, magma mixing and slow cooling would be minimal. As a consequence, minimal post-entrapment modification of SMIs (Danyushevsky et al. 2002; Portnyagin et al. 2008; Gaetani et al. 2012; Bucholz et al. 2013; Lloyd et al. 2013) is expected.

## Constraints on CO₂ saturation condition

The amount of CO₂ required to saturate magma batches at the crust-mantle transition, as recorded by olivine-hosted SMIs, was calculated using the saturation model

<figure><img src="image_16.png" /></figure>
<figure><img src="image_17.png" /><figcaption>**Fig. 4** Primordial mantle normalised trace element patterns of SMIs. **a** Most patterns of SMIs recall that of E-MORB (Hémond et al. 2006). **b** A few SMIs from Graciosa, Terceira and Pico volcanoes show intermediate patterns between E-MORB and N-MORB, with specifically Ba, Sr, Ti enrichments and Zr and Hf depletions, evidencing possible episodes of melting of deep-seated syenites occurring at local scale</figcaption></figure>

of Shiskina et al. (2014), together with the published fluid pressures deduced from CO₂-rich fluid inclusions defined in Zanon et al. (2023), resumed in Supplementary Table 4. This results in a range of CO₂ values from 0.47 wt.% in the Terceira volcanic systems, to 0.78 wt.% in the oldest São Jorge volcanic system, and 0.99 wt.% in the São Miguel volcanic systems. In all the other volcanic centres, the maximum CO₂ content ranges from 0.54 to 0.58 wt.%. These values are in agreement with the recent results from van Gerve et al. (2023) for Pico Island.

Using the ratios CO₂/Ba = 81.3, CO₂/Rb = 991 and CO₂/Nb = 515, obtained from un-degassed Atlantic MORBs and melt inclusions (e.g. Cartigny et al. 2008; Le Voyer et al. 2019), the resulting original CO₂ values range from 2.0 wt.% for the Terceira volcanic systems, to 3.2–3.6 wt.% for the other islands near the MAR, up to 3.9 wt.% for the São Miguel volcanoes. These values are unrealistic for magmas that should have undergone significant degassing during prolonged ponding in deep reservoirs, and cast doubt on the validity of these ratios for calculating the dissolved CO₂ in melt inclusions.

<figure><img src="image_18.png" /><figcaption>**Fig. 5** Behaviour of the volatile component in PEC-corrected SMIs compositions. **a** Effect of proton loss/gain shown by the variability of the H₂O/Ce ratio. The blue asterisk refers to the averaged value calculated for the submarine basalts (and associated standard deviation is represented by blue bars) dredged at the MAR crossing the Azores region (Dixon et al. 2002). The black line shows the value of H₂O/Ce = 259 (±11, dashed lines) measured at the Pico fissure zone (Métrich et al. 2014). Chlorine (b) and sulfur (c) contents are not related to the melt differentiation (FeOₐMgO), except for a few SMIs</figcaption></figure>

## Crystal fractionation versus mantle processes

In this study, we focus on SMIs hosted in olivine crystals with a composition of Fo < 86. These show inverse relationship between CaO/Al₂O₃ and FeO/MgO ratios and positive

<figure><img src="image_19.png" /></figure>
correlations observed between incompatible elements which
can be attributed to a process of fractional crystallisation of
both olivine and clinopyroxene (Fig. 3b, c). Samples col-
lected at Faial, Graciosa, and Terceira show the presence of
plagioclase as a stable phase. However, the absence of any
Eu anomaly in the REE patterns, and the positive correlation
between Sr and other incompatible elements in our data set,
suggest that the crystallisation of plagioclase occurred at a
later stage in the history of these magmas and did not influ-
ence the geochemistry of the studied SMIs.

On the opposite, binary diagrams between highly incom-
patible elements such as Zr, Nb, Hf, Ta, U, Th, Rb reveal a
variability which cannot be explained by fractional crystal-
lization or melting conditions (supplementary Fig. 3) and
suggest the presence of geochemical heterogeneities. Man-
tle melting conditions could be revealed by comparing the
variability of ratios between REE (e.g. La/Yb vs Tb/Yb),
but Light REE are not perfectly incompatible and therefore
their concentrations are slightly affected by the process of
crystal fractionation. In plots where incompatible elements
are compared with the ratio of the same element to another
incompatible element, the effect of mantle melting is evi-
denced by a positive correlation. In Fig. 6, the lack of a posi-
tive correlation of Rb and Ba with Rb/La and Ba/Sr ratios,
respectively, is consistent with crystal fractionation of mafic
phases. This process was modelled for the samples from
Graciosa and Faial SMIs, which have the highest concen-
trations of both Rb (up to 53–56 ppm; Fig. 6a) and Ba (up
to 555–612 ppm; Fig. 6b). Fractional crystallisation trends
were modelled by using the partition coefficients of clino-
pyroxene for the elements considered, i.e., DLα=0.14–0.47;
DRb=0.011 (Vannucci et al. 1998); DSr=0.2–0.46 (Ching-
Oh et al. 1974); DBa=0.0058 (Hauri et al. 1994). Olivine-
liquid partition coefficients are, in fact, two to three orders
of magnitude lower and do not alter these elemental ratios.
The compositional variations of the chemical elements con-
sidered for these two islands are justified by 40–50% crystal
fractionation.

However, as suggested by the narrow compositional range
of the host olivines, and their antecrystic nature, the SMIs
could represent small volumes of intracumulus melts, whose
chemical evolution could also be successfully modelled by
considering the *in-situ* crystallisation model (Langmuir
1989). In both cases of fractional crystallisation and *in-situ*
crystallisation, the degree of fractionation is up to 50 vol.%,
close to the upper boundary of the “loose mush” defini-
tion, where crystals are jammed at the maximum packing
(Bretagne et al. 2023). This element would therefore justify
the formation of voluminous crystal mush layers.

A subset of the most primitive SMIs hosted in olivine
Fo₈₂-₈₅ have variable contents of both Nb (and in other
incompatible elements) and transition elements (such as
Sc ≥ 27 ppm; Supplementary Fig. 3). Such trace element

<figure><img src="image_20.png" /><figcaption>**Fig. 6** Discrimination between primary and secondary processes (i.e., partial melting versus fractional crystallisation). In these plots, using elements with different degrees of incompatibility, mantle melting produces trends that intercept the y-axis near zero (black dashed lines); fractional crystallisation of olivine produces a horizontal trend; and the addition of clinopyroxene to the fractionating assemblage produces gently sloping trends. The simulated models relate only to the most evolved composition, which are found on the islands of Graciosa and Faial. The models were generated by using a range of partition coefficients from the literature. **a** Model of the variation in Rb/La and **b** Ba/Sr ratios</figcaption></figure>

variations cannot be explained by simple fractional crystal-
lisation alone, but they require processes, such as the partial
melting of a heterogeneous mantle (e.g., Beier et al. 2008,
2012), or the variation in the degree of melting of a homo-
geneous source, or both.

As crystal fractionation may be superimposed to mantle
melting processes, we used ratios between highly incompat-
ible elements, which are not, or are only weakly, affected by
olivine fractionation, to explore mantle processes (Fig. 7).
Apart from a few outliers, the Nb/Zr ratio range from 0.19 to
0.29 (Fig. 7a), and the Nb/Ba and Rb/Nb ratios range from
0.10 to 0.17, and from 0.59 to 0.99 respectively (Fig. 7b,
c). These geochemical characteristics are comparable
with the data of SMIs published for São Miguel and Pico
islands (Métrich et al. 2014; Rose-Koga et al. 2017, van
Gerve et al. 2024). No correlations are observed with La/
<figure><img src="image_21.png" /><figcaption>**Fig. 7** Source heterogeneity from incompatible element variations in poorly evolved SMIs compositions, corrected after PEC. The whole geochemical dataset falls within a narrow range of incompatible element ratios. a Zr/Nb, b Nb/Ba and c Rb/Nb indicate the presence of geochemical heterogeneities at the source, with the mixing between different end members</figcaption></figure>

Yb (Supplementary Fig. 5), which is a monitor of the degree of melting besides the non-perfect incompatibility of La. It strongly suggests that these values depict a chemical variability of the mantle source that supplied magmas studied here and thus corroborate the heterogeneous character of the mantle beneath the Azores archipelago, according to previous studies (Madureira et al. 2011). Thus, the SMIs preserved the geochemical signature of the Azores mantle as reported for whole-rock analyses of samples from lava flows at the scale of the archipelago (e.g., Beier et al. 2007, 2008, 2012; Elliott et al. 2007; Millet et al. 2009; Hildenbrand

et al. 2014; Madureira et al. 2014; Béguelin et al. 2017, among others). However, from the present dataset, we show that mantle heterogeneity can be preserved at the scale of a single island (Fig. 7), a feature that suggests a vertical (continuous or patchy) zoned mantle. This could imply that the spatial distribution of mantle heterogeneity is non-continuous and/or vertically extended.

Appropriate modelling requires the analysis of the primitive melt composition (i.e. SMIs trapped in olivine Fo~88), which will be published elsewhere.

### Magma mixing and source enrichment: inference from halogens composition

Chlorine behaves like K during the fractional crystallisation process as illustrated in Fig. 8a. A large part of SMIs from all volcanic systems show a constant Cl/K ratio at 0.064 ± 0.006, that fall in the domain of E-MORB (0.05–0.08; Michael and Cornell 1998). It also includes the data from the Pico fissure zone (Métrich et al. 2014). Only a few SMIs have Cl/K ratios very close to the average unaltered N-MORB on a global scale (Cl/K = ~0.01; Michael and Cornell 1998). On the other hand, Cl is also positively correlated with other highly incompatible elements with Cl/Rb from 25.5 to 11.0) (Fig. 8b). The absence of a single correlation with K, and with all the incompatible elements, supports the mixing between melts generated from sources characterised by different degrees of enrichment in Cl and other incompatible elements.

Very few SMIs show extreme Cl enrichments (up to 0.39 wt.%; Table 2). Similar Cl enrichments have already been observed in the Loihi Seamount (Hawaii), some MORB glasses (Michael and Cornell 1998; Kent et al. 1999) and SMIs from Raivavae and Rapa, Austral Islands (Lassiter et al. 2002). At these sites, the Cl-enrichment was related to the assimilation of Cl-rich brines and/or brine-saturated melts (Stroncik and Haase 2004) released by subducted sediments and hydrothermally weathered oceanic crust. However, we discard this possibility for the Azores, because Cl-enrichment is limited to a few and MgO-poor SMIs of Terceira and Graciosa. Not all the coeval SMIs from these two islands show the same feature, and no Cl-rich FIs have been yet found, among the thousands analysed. This Cl-enrichment could be due to the occasional interaction with fluids released at the base of the hydrothermally weathered oceanic crust, where magmas possibly ponded, as also suggested by the values of δ⁷Li and δ¹¹B in olivines from the Azores (Genske et al. 2014). It should be noted that the few SMIs with this extreme Cl enrichment are from volcanoes on the islands of Graciosa and Terceira, which are close to each other, located on the same spreading system and with similar crust thicknesses. Therefore, this brine-magma interaction

<figure><img src="image_22.png" /></figure>
**Fig. 8** Halogen behaviour in SMIs compositions corrected after PEC. ► **a** In binary plots against K the Cl/K=0.064 characterises some SMIs from the Terceira, Graciosa and Pico (both the central volcano and the fissure zone) volcanic systems. The grey area represents the range of ratios found for E-MORBs, while the red dashed line indicates the averaged value for N-MORB. **b** In plot versus LILE, chlorine is dispersed and included between Cl/Rb~25.5 and Cl/Rb=11.0. **c** Plot of Cl versus K. **d** The values of Cl and F show different behaviour due to the different variability of these two chemical species. (d) The variability of F/Nd and K of poorly evolved SMIs from the Azores (MgO>6 wt.%) is limited compared to that of other volcanic archipelagos (Canary, Hawaii and Galapagos) and Iceland. However, the F/Nd ratios of these SMIs are systematically higher than the average of the MORB basalts erupted by the segments of the MAR crossing the Azores archipelago

should be limited to peculiar conditions existing only under
these two islands.

The more primitive SMIs (MgO>6 wt.%) show a range
of fluorine content from 0.04 to 0.15 wt.%, which is not cor-
related with the variations in compatible elements monitoring
fractional crystallisation of mafic phases, and with parameters
monitoring melting conditions (i.e., La/Yb and Tb/Yb). The
two halogens are not correlated with each other, suggesting
that the process responsible for the Cl variability did not affect
F (Fig. 8c).

The ranges of the F/Nd ratio and the K content discrimi-
nate well between volcanic systems from different geographi-
cal areas (Fig. 8d). The elements in this ratio behave similarly
during the melting process due to similar melt-solid partition
coefficients (Workman et al. 2006). Therefore, the overall high
F content of the Azores SMIs is not due to late-stage enrich-
ment, but is a characteristic derived from the mantle source.
The Azores magmas are characterised by high K contents and
F/Nd ratios ranging from 15.1 to 45.4. The lowermost val-
ues which are from São Jorge and a few SMIs from Terceira,
Graciosa and Pico, straddle F/Nd=18.84, characteristic of the
lavas erupted by the MAR segments at the intersection with
the Azores archipelago and resulting from the averaged F of
389±131 (Schilling et al. 1980) and Nd=20.6±2.5 (Gale
et al. 2013). Therefore, the fluorine variability at the Azores
seems to be related to the mixing of two mantle endmem-
bers: a MORB component and a F-enriched mantle source. A
comparison with the composition of lavas from the Hawaiian
and Galapagos archipelagos and Iceland (GEOROC database)
shows that the very variable K contents of the Azores SMIs
are higher anyway and the F/Nd range is similar. On the other
hand, in a comparison with the nearby Canarian lavas, the two
Atlantic archipelagos show the same F/Nd range, while the K
content of the Canarian lavas is overall comparable to the high-
est content of the Azores SMIs, but the variability is reduced.

<figure><img src="image_23.png" /></figure>

<figure><img src="image_24.png" /></figure>

<figure><img src="image_25.png" /></figure>

<figure><img src="image_26.png" /></figure>
## Concluding remarks

Magmas erupted in the Azores during the last 40 ka contain olivine crystals hosting fluid inclusions or melt inclusions (SMIs), or both. The geochemical dataset of olivine-hosted SMIs reported here from six islands east of the MAR shows that SMIs suffered minimal post-entrapment modifications, and allows us to discuss magmatic processes beneath the Azores archipelago.

The cross-check with published data on coexisting CO₂-rich fluid inclusions, and on textures of the host minerals led us to propose that SMIs were trapped in crystal from mush layers in the lower crust (~18 to 29 km beneath different islands), at or nearby the crust-mantle boundary. At these depths CO₂ values required to saturate magma batches range from 0.47 to 0.99 wt.%, varying across different volcanic systems. These values are significantly lower than those (4.5–4.7 wt.%) recently found in basanites erupted at Fogo volcano at Cape Verde and La Palma at Canary Islands (Burton et al. 2023; Lo Forte et al. 2024), but also in French continental basanites (4.3 wt.%; Buso et al. 2022). Pre-eruptive degassing significantly reduced the CO₂ content in melts, prior to SMIs trapping and intracrustal ascent, as suggested by the CO₂ values retrieved from ratios with Ba, Rb and Nb incompatible elements. This extensive degassing could be the responsible for the formation of carbonic fluid inclusions commonly found in olivine and clinopyroxene antecrysts (Zanon et al. 2023).

Fractional crystallisation process of olivine and further olivine + clinopyroxene well explain the chemical evolution recorded by SMIs, while ratios between highly incompatible trace elements reveal mantle compositional heterogeneity. Such a heterogeneity has been demonstrated by high resolution studies of bulk rocks (e.g. Beier et al. 2007, 2012; Beguelin et al. 2017). Here we found mantle heterogeneity at the scale of one single magmatic system.

The process of fractional crystallisation of up to 50% of mafic phases should be the responsible for the formation of voluminous ultramafic cumulates (dunites, wehrlites, and clinopyroxenites) and crystal mushes at the base of the crust.

Both trace elements and halogens demonstrate the interaction between melts produced by melting of a MORB-like source and a more enriched source, probably of a deeper origin.

**Supplementary Information** The online version contains supplementary material available at https://doi.org/10.1007/s00410-024-02142-z.

**Acknowledgements** This study was partially funded by the Fundação para a Ciência e Tecnologia, Portugal (MAGAT project, ref. CIRCNA/OCT/0016/2019) and the EU 7th FP MED-SUV project (contract 308665). The Institut de Physique du Globe de Paris (IPGP) has financially supported VZ as a visiting researcher (IPGP contribution 3812). Suggestions and comments by T. Hansteen, J. Snow and three anonymous reviewers improved the quality of this work.

**Funding** Open access funding provided by FCTIFCCN (b-on).

**Data availability** The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

**Open Access** This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

## References

* Béguelin P, Bizimis M, Beier C, Turner S (2017) Rift–plume interaction reveals multiple generations of recycled oceanic crust in Azores lavas. *Geochim Cosmochim Acta* 218:132–152

* Beier C, Stracke A, Haase KM (2007) The peculiar geochemical signatures of São Miguel (Azores) lavas: Metasomatised or recycled mantle sources? *Earth. Planet Sci Lett* 259:186–199

* Beier C, Haase KM, Abouchami W, Krienitz M-S, Hauff F (2008) Magma genesis by rifting of oceanic lithosphere above anomalous mantle: Terceira Rift, Azores. *Geochem Geophys Geosyst* 9:Q12013

* Beier C, Haase KM, Turner SP (2012) Conditions of melting beneath the Azores. *Lithos* 144–145:1–11

* Beattie P (1994) Systematics and energetics of trace-element partitioning between olivine and silicate melts: implications for the nature of mineral/melt partitioning. *Chem Geol* 117(1–4):57–71

* Borges JF, Bezzeghoud M, Buforn E, Pro C, Fitas A (2007) The 1980, 1997 and 1998 Azores earthquakes and some seismo-tectonic implications. *Tectonophysics* 435(1–4):37–54

* Bretagne E, Wadsworth FB, Vasseur J, Dobson KJ (2023) A scaling for the permeability of loose magma mush validated using X-ray computed tomography of packed confectionary in 3D and estimation methods from 2D crystal shapes. *Journal of Geophysical Research Solid Earth* 128(10):e2023JB026795

* Bucholz CE, Gaetani GA, Behn MD, Shimizu N (2013) Post-entrapment modification of volatiles and oxygen fugacity in olivine-hosted melt inclusions. *Earth Planet Sci Lett* 374:145–155

* Burton M, Aiuppa A, Allard P, Asensio-Ramos M, Cofrades AP, La Spina A, Nicholson EJ, Zanon V, Barrancos J, Bitetto M, Hartley M, Romero JE, Waters E, Stewart A, Hernández PA, Lages JP, Padrón E, Wood K, Esse B, Hayer C, Cyrzan K, Rose-Koga EF, Schiavi F, D'Auria L, Pérez NM (2023) Exceptional eruptive CO₂ emissions from intra-plate alkaline magmatism in the Canary volcanic archipelago. *Commun Earth Environ* 4(1):467

* Buso R, Laporte D, Schiavi F, Cluzel N, Fonquernie C (2022) High-pressure homogenization of olivine-hosted CO₂-rich melt inclusions in a piston cylinder: insight into the volatile content of primary mantle melts. *Eur J Mineral* 34:325–349. https://doi.org/10.5194/ejm-34-325-2022

* Calvert AT, Moore RB, McGeehin JP, Rodrigues da Silva AM (2006) Volcanic history and 40Ar/39Ar and 14C geochronology of Terceira Island, Azores, Portugal. *J Volcanol Geotherm Res* 156:103–115
Cannat M, Briais A, Deplus C, Escartín J, Georgen J, Lin J, Mercou-
riev S, Meyzen C, Muller M, Pouliquen G, Rabain A, da Silva P
(1999) Mid-Atlantic Ridge-Azores hotspot interactions: along-
axis migration of a hotspot-derived event of enhanced magmatism
10 to 4 Ma ago. Earth Planet Sci Lett 173(3):257–269

Cartigny P, Pineau F, Aubaud C, Javoy M (2008) Towards a consistent mantle carbon flux estimate: Insights from volatile systematics (H₂O/Ce, δD, CO₂/Nb) in the North Atlantic mantle (14°N and 34°N). Earth Planet Sci Lett 265(3-4):672–685. https://doi.org/10.1016/j.epsl.2007.11.011

Charlier BLA, Wilson CJN, Lowenstern JB, Blake S, Van Calsteren PW, Davidson JP (2005) Magma generation at a large, hyperactive silicic volcano (Taupo, New Zealand) revealed by U-Th and U-Pb systematics in zircons. J Petrol 46:3–32

Ching-Oh S, Williams RJ, Shine-Soon S (1974) Distribution coefficients of Eu and Sr for plagioclase-liquid and clinopyroxene-liquid equilibria in oceanic ridge basalt: an experimental study. Geochem Cosmochim Acta 38(9):1415–1433

Danyushevsky LV, Plechov P (2011) Petrolog 3: Integrated software for modeling crystallization processes. Geochem Geophys Geosyst 12:Q07021

Danyushevsky LV, Sobolev AV (1996) Ferric-ferrous ratio and oxygen fugacity calculations for primitive mantle-derived melts: calibration of an empirical technique. Miner Petrol 57:229–241

Danyushevsky LV, McNeill AW, Sobolev AV (2002) Experimental and petrological studies of melt inclusions in phenocrysts from mantle-derived magmas: an overview of techniques, advantages and complications. Chem Geol 183(1):5–24

Davidson JP, Morgan DJ, Charlier BLA, Harlou R, Hora JM (2007) Microsampling and isotopic analysis of igneous rocks: implications for the study of magmatic systems. Annu Rev Earth Planet Sci 35:273–311

Dixon JE, Leist L, Langmuir C, Schilling JG (2002) Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt. Nature 420(6914):385–389

Elliott T, Blichert-Toft J, Heumann A, Koetsier G, Forjaz VH (2007) The origin of enriched mantle beneath São Miguel, Azores. Geo-chim Cosmochim Acta 71:219–240

Falloon TJ, Danyushevsky LV (2000) Melting of refractory mantle at 1.5, 2 and 2.5 GPa under anhydrous and H₂O-undersaturated conditions: Implications for the petrogenesis of high-Ca boninites and the influence of subduction components on mantle melting. J Petrol 41(2):257–283

Fernandes RM, Catalão J, Trota AN (2018) The contribution of Space-Geodetic techniques to the understanding of the present-day geodynamics of the Azores Triple Junction. Volcanoes of the Azores. Springer, Berlin, pp 57–69

Gaetani GA, O'Leary JA, Shimizu N, Bulholz CE, Newville M (2012) Rapid re-equilibration of H₂O and oxygen fugacity in olivine hosted melt inclusions. Geology 40:915–918

Gale A, Dalton CA, Langmuir CH, Su Y, Schilling JG (2013) The mean composition of ocean ridge basalts. Geochem Geophys Geosyst 14:489–518

Gavrilenko M, Herzberg C, Vidito C, Carr MJ, Tenner T, Ozerov A (2016) A calcium-in-olivine geohygrometer and its application to subduction zone magmatism. J Pet 57(9):1811–1832

Genske FS, Turner SP, Beier C, Chu MF, Tonarini S, Pearson NJ, Haase KM (2014) Lithium and boron isotope systematics in lavas from the Azores islands reveal crustal assimilation. Chem Geol 373:27–36

Gente P, Dyment J, Maia M, Goslin J (2003) Interaction between the Mid-Atlantic Ridge and the Azores hot spot during the last 85 Myr: Emplacement and rifting of the hot spot-derived plateaus. Geochem Geophys Geosyst 4(10):8514–8537

Hartley ME, Neave DA, Maclennan J, Edmonds M, Thordarson T (2015) Diffusive over-hydration of olivine-hosted melt inclusions. Earth Planet Sci Lett 425:168–178

Hauri EH, Wagner TP, Grove TL (1994) Experimental and natural partitioning of Th, U, Pb and other trace elements between garnet, clinopyroxene and basaltic melts. Chem Geol 117:149–166

Hémond C, Hofmann AW, Vlastélic I, Nauret F (2006) Origin of MORB enrichment and relative trace element compatibilities along the Mid-Atlantic Ridge between 10° and 24°N. Geochem Geophys Geosyst 7:Q12010. https://doi.org/10.1029/2006GC001317

Herzberg C, O'hara MJ (2002) Plume-associated ultramafic magmas of Phanerozoic age. J Petrol 43(10):1857–1883

Hildenbrand A, Weis D, Madureira P, Marques FO (2014) Recent plate re-organization at the Azores Triple Junction: evidence from combined geochemical and geochronological data on Faial, S. Jorge and Terceira Volcanic Islands. Lithos 210–211:27–39

Jenner FE, O'Neill HSC (2012) Major and trace analysis of basaltic glasses by laser-ablation ICP-MS. Geochem Geophys Geosyst 13(3):Q03003

Jerram DA, Martin VM (2008) Understanding crystal populations and their significance through the magma plumbing system. In: Annen C, Zellmer GF (Eds). Dynamics of Crustal Magma Transfer, Storage and Differentiation. Geological Society, London, Special Publications, vol. 304:133–148

Kent AJR, Norman MD, Hutcheon ID, Stolper EM (1999) Assimilation of seawater-derived components in an oceanic volcano: evidence from matrix glasses and glass inclusions from Loihi. Chem Geol 156:299–319

Lange R, Carmichael ISE (1990) Thermodynamics properties of silicate liquids with emphasis on density, thermal expansion and compressibility. In: Nicholls J, Russell JK (eds) Modern methods of igneous petrology: understanding magmatic processes, vol 24. Mineralogical Society of America, Reviews in Mineralogy, pp 25–64

Langmuir CH (1989) Geochemical consequences of in situ crystallization. Nature 340:199–205

Larrea P, França Z, Lago M, Widom E, Galé C, Ubide T (2013) Magmatic processes and the role of antecrysts in the genesis of Corvo Island (Azores Archipelago, Portugal). J Petrol 54(4):769–793. https://doi.org/10.1093/petrology/egs084

Larrea P, Wijbrans PR, Galé C, Ubide T, Lago M, França Z, Widom E (2014) $^{40}$Ar/$^{39}$Ar constraints on the temporal evolution of Graciosa Island, Azores (Portugal). Bull Volcanol 76:796. https://doi.org/10.1007/s00445-014-0796-8

Lassiter JC, Hauri EH, Nikogosian IK, Barsczus HG (2002) Chlorine-potassium variations in melt inclusions from Raivavae and Rapa, Austral Islands: constraints on chlorine recycling in the mantle and evidence for brine-induced melting of oceanic crust. Earth Planet Sci Lett 202(3-4):525–540

Leeman WP, Scheidegger KF (1977) Olivine/liquid distribution coefficients and a test for crystal-liquid equilibrium. Earth Planet Sci Lett 35(2):247–257

Le Voyer M, Hauri EH, Cottrell E, Kelley KA, Salters VJ, Langmuir CH, Hilton DR, Barry PH, Füri E (2019) Carbon fluxes and primary magma CO₂ contents along the global mid-ocean ridge system. Geochem Geophys Geosys 20(3):1387–1424

Lloyd AS, Plank T, Ruprecht P, Hauri EH, Rose W (2013) Volatile loss from melt inclusions in pyroclasts of differing sizes. Contrib Miner Petrol 165(1):129–153

Lo Forte FM, Schiavi F, Rose-Koga EF, Rotolo SG, Verdier-Paoletti M, Aiuppa A, Zanon V (2024) High CO₂ in the mantle source of ocean island basanites. Geochem Cosmochim Acta 368:93–111. https://doi.org/10.1016/j.gca.2024.01.016

Luis JF, Miranda JM, Galdeano A, Patriat P (1998) Constraints on the structure of the Azores spreading center from gravity data. Mar Geophys Res 20:157–170

Maclennan J (2008) Concurrent mixing and cooling of melts under Iceland. J Petrol 49(11):1931–1953
Madeira J (1998) Estudos de neotectónica nas ilhas do Faial, Pico e S. Jorge: uma contribuição para o conhecimento geodinâmico da junção tripla dos Açores, Ph.D. Thesis, Lisbon University, pp. 481

Madureira P, Mata J, Mattielli N, Queiroz G, Silva P (2011) Mantle source heterogeneity, magma generation and magmatic evolution at Terceira Island (Azores archipelago): Constraints from elemental and isotopic (Sr, Nd, Hf, and Pb) data. Lithos 126(3-4):402-418

Madureira P, Moreira M, Mata J, Nunes JC, Gautheron C, Lourenço N, Carvalho R, de Abreu MP (2014) Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chem Geol 372:62-71

Marques FO, Catalão JC, DeMets C, Costa ACG, Hildenbrand A (2013) GPS and tectonic evidence for a diffuse plate boundary at the Azores Triple Junction. Earth Planet Sci Lett 381:177-187

Marques FO, Hildenbrand A, Hübscher C (2018) Evolution of a volcanic island on the shoulder of an oceanic rift and geodynamic implications: S. Jorge Island on the Terceira Rift Azores Triple Junction. Tectonophysics 738-739:41-50

McDonough WF, Sun S-S (1995) The composition of the Earth. Chem Geol 120(3-4):223-253

Mercier M, Di Muro A, Métrich N, Giordano D, Belhadj O, Mandeville CW (2010) Spectroscopic analysis (FTIR, RAMAN) of water in mafic and intermediate glasses and glass inclusions. Geochim Cosmochim Acta 74:5641-5656

Métrich N, Zanon V, Créon L, Hildenbrand A, Moreira M, Marques FO (2014) Is the “Azores hotspot” a wet spot? Insights from geochemistry of fluid and melt inclusions in olivines of Pico basalts. J Petrol 55:377-393

Michael PJ, Cornell WC (1998) Influence of spreading rate and magma supply on crystallization and assimilation beneath mid-ocean ridges: evidence from chlorine and major element chemistry of mid-ocean ridge basalts. J Geophys Res (solid Earth) 103:18325-18356

Middlemost EA (1975) The basalt clan. Earth-Sci Rev 11(4):337-364

Millet MA, Doucelance R, Baker JA, Schiano P (2009) Reconsidering the origins of isotopic variations in Ocean Island Basalts: Insights from fine-scale study of São Jorge Island, Azores archipelago. Chem Geol 265:289-302

Miranda JM, Luis JF, Lourenço N, Goslin J (2014) Distributed deformation close to the Azores Triple “Point.” Mar Geol 355:27-35

Moore RB (1990) Volcanic geology and eruption frequency, São Miguel, Azores. Bull Volcanol 52:602-614

Nunes JC (1999) A actividade vulcânica na ilha de Pico do Plistocénico Superior ao Holocénico: mecanismo eruptivo e hazard vulcânico. Departamento de Geociências/Universidade dos Açores, Ponta Delgada, p 357

Portnyagin MV, Almeev R, Matveev S, Holtz F (2008) Experimental evidence for rapid water exchange between melt inclusions in olivine and host magma. Earth Planet Sci Lett 272(3):541-552

Rose-Koga EF, Koga KT, Moreira M, Vlastelic I, Jackson MG, Whitehouse MJ, Shimizu N, Habib N (2017) Geochemical systematics of Pb isotopes, fluorine, and sulfur in melt inclusions from São Miguel, Azores. Chem Geol 458:22-37

Rose-Koga EF, Bouvier AS, Gaetani GA, Wallace PJ, Allison CM, Andrys JA, Angeles de la Torre CA, Barth A, Bodnar RJ, Bracco Gartner AJJ, Butters D, Castillejo A, Chilson-Parks B, Choudhary BR, Cluzel N, Cole M, Cottrell E, Daly A, Danyushevsky LV, Devitre CL, Drignon MJ, France L, Gaborieau M, Garcia MO, Gatti E, Genske FS, Hartley ME, Hughest EC, Iveson AA, Johnson ER, Jones M, Kagoshima T, Katzir Y, Kawaguchi M, Kawamoto T, Kelley KA, Koornneef JM, Kurz MD, Laubier M, Layne GD, Lerner A, Lin K-Y, Liu P-P, Lorenzo-Merino A, Luciani N, Magalhães N, Marschall HR, Michael PJ, Monteleone BD, Moore LR, Moussallam Y, Muth M, Myers ML, Narváez DF, Navon O, Newcombe ME, Nichols ARL, Nielsen RL, Pamukcu A, Plank

T, Rasmussen DJ, Roberge J, Schiavi F, Schwartz D, Shimizu K, Shimizu K, Shimizu N, Thomas JB, Thompson GT, Tucker JM, Ustunisik G, Waelkens C, Zhang Y, Zhou T (2021) Silicate melt inclusions in the new millennium: a review of recommended practices for preparation, analysis, and data presentation. Chem Geol 570:120145

Schilling JG, Bergeron MB, Evans R (1980) Halogens in the mantle beneath the North Atlantic. Philos Trans R Soc Lond Ser A Math Phys Sci 297(1431):147-178

Shishkina TA, Botcharnikov RE, Holtz F, Almeev RR, Jazwa AM, Jakubiak AA (2014) Compositional and pressure effects on the solubility of H₂O and CO₂ in mafic melts. Chem Geol 388:112-129

Silveira G, Vinnik L, Stutzmann E, Farra V, Kiselev S, Morais I (2010) Stratification of the Earth beneath the Azores from P and S receiver functions. Earth Planet Sci Lett 299:91-103

Stroncik NA, Haase KM (2004) Chlorine in oceanic intraplate basalts: constraints on mantle sources and recycling processes. Geology 32(11):945-948

Turner M, Turner S, Mironov N, Portnyagin MV, Hoernle K (2017) Can magmatic water contents be estimated from clinopyroxene phenocrysts in some lavas? A case study with implications for the origin of the Azores Islands. Chem Geol 466:436-445

Van Achterbergh E, Ryan CG, Jackson SE, Griffin WL (2001) Data reduction software for LA-ICP-MS. Laser-Ablation-ICPMS in the earth sciences—principles and applications. Miner Assoc Can (short Course Series) 29:239-243

van Gerve TD, Neave DA, Wieser P, Lamadrid H, Hulsbosch N, Namur O (2023) The origin and differentiation of CO₂-rich primary melts in Ocean Island volcanoes: Integrating 3D X-ray tomography with chemical microanalysis of olivine-hosted melt inclusions from Pico (Azores). J Petrol 65:1-24

Vannucci R, Bottazzi P, Wulffpedersen E, Neumann E (1998) Partitioning of REE, Y, Sr, Zr and Ti between clinopyroxene and silicate melts in the mantle under La Palma (Canary Islands): implications for the nature of the metasomatic agents. Earth Planet Sci Lett 158:39-51

Vogt PR, Jung WY (2004) The Terceira Rift as hyper-slow, hotspot-dominated oblique spreading axis: a comparison with other slow-spreading plate boundaries. Earth Planet Sci Lett 218:77-90

Wan Z, Coogan LA, Canil D (2008) Experimental calibration of aluminum partitioning between olivine and spinel as a geothermometer. Am Mineral 93:1142-1147

Waters CL, Day JM, Watanabe S, Sayit K, Zanon V, Olson KM, Hanan BB, Widom E (2020) Sulfide mantle source heterogeneity recorded in basaltic lavas from the Azores. Geochim Cosmochim Acta 268:422-445

Workman RK, Hauri EH, Hart SR, Wang J, Blusztajn J (2006) Volatile and trace elements in basaltic glasses from Samoa: Implications for water distribution in the mantle. Earth Planet Sci Lett 241(3-4):932-951

Zanon V, Frezzotti ML (2013) Magma storage and ascent conditions beneath Pico and Faial islands (Azores Islands). A study on fluid inclusions. Geochem Geophys Geosyst 14(9):3494-3514

Zanon V, Pimentel A (2015) Spatio-temporal variations of magma storage and ascent conditions in an extensional tectonic setting. The case of the Terceira Island, Azores (Portugal). Am Mineral 100:795-805

Zanon V (2015a) The magmatism of the Azores Islands. In: Gaspar JL, Guest JE, Duncan AM, Barriga FJAS, Chester DK (eds) Volcanic geology of São Miguel Island (Azores Archipelago). The Geological Society of London, Memoirs, pp 51-64

Zanon V (2015b) Conditions for mafic magma storage beneath fissure zones at oceanic islands. The case of São Miguel Island (Azores archipelago). In: Caricchi L, Blundy JD (eds) Chemical, physical and temporal evolution of magmatic systems, vol 422. The Geological Society of London
Zanon V, Pimentel A, Auxerre M, Marchini G, Stuart FM (2020) Unravelling the magma feeding system of a young basaltic oce-anic volcano. Lithos, pp 352–353

Zanon V, Silva R, Goulart C (2023) The crust-mantle transition beneath the Azores region (central-north Atlantic Ocean). Contrib Miner Petrol 178(8):50

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