Guillaume Estrade
email: estrade.guillaume@gmail.com

Stefano Salvi

Didier Béziat

Crystallization and destabilization of eudialyte-group minerals in peralkaline granite and pegmatite: a

Keywords: eudialyte-group minerals, peralkaline granites, agpaitic rocks, zirconosilicate, HFSE and REE, pegmatites

published or not. The documents may come

Introduction

Eudialyte-group minerals (EGM) are complex Na-Ca-Zr-cyclosilicates with the general formula Na15(Ca,REE)6(Fe,Mn)3Zr3Si(Si25O72)(O,OH,H2O)3(Cl,OH)2 [START_REF] Johnsen | The nomenclature of eudialyte-group minerals[END_REF] characteristic of evolved peralkaline [molar (Na2O+K2O)/Al2O3>1] SiO2-undersaturated syenites, also called agpaitic syenites. This mineral is generally considered as diagnostic of agpaicity, i.e., those rocks in which High Field Strength Elements (HFSE, such as Zr, Hf, Nb, Ta, U and Th) and Rare Earth Elements (REE) are incorporated into complex Na-K-Ca-Zrsilicates, rich in volatiles (Cl, F and H2O) [START_REF] Sørensen | Agpaitic nepheline syenites -a potential source of rare elements[END_REF][START_REF] Sørensen | The agpaitic rocks -an overview[END_REF][START_REF] Khomyakov | mineralogy of hyperagpaitic alkaline rocks[END_REF][START_REF] Le Maitre | Igneous rocks: a classification and glossary of terms[END_REF][START_REF] Marks | The mineralogical diversity of alkaline igneous rocks: critical factors for the transition from miaskitic to agpaitic phase assemblages[END_REF]. By contrast, when HFSE are incorporated in more common minerals (e.g. zircon, titanite), rocks are termed miaskitic. EGM can contain important amounts of REE and are considered as a potentially valuable ore of REE and Zr (e.g., the Kringlerne deposit in the Ilímaussaq complex, the Norra Kärr complex in Sweden and the Kipawa complex in Canada; [START_REF] Goodenough | Europe's rare earth element resource potential: An overview of REE metallogenetic provinces and their geodynamic setting[END_REF] and [START_REF] Saucier | report -Feasibility Study for Kipawa Project[END_REF]). Because EGM crystallize through a range of magmatic to hydrothermal conditions, their compositional variability can been used to monitor the conditions of the environment in which they crystallized [START_REF] Mitchell | Subsolidus deuteric/hydrothermal alteration of eudialyte in lujavrite from the Pilansberg alkaline complex, South Africa[END_REF][START_REF] Schilling | Reconstruction of magmatic to subsolidus processes in an agpaïtic system using eudialyte textures and composition: a case study from Tamazeght, Morocco[END_REF][START_REF] Marks | Eudialyte-Group Minerals as Monitors of Magmatic and Hydrothermal Processes in Peralkaline Rocks[END_REF][START_REF] Ratschbacher | Emplacement and geochemical evolution of highly evolved syenites investigated by a combined structural and geochemical field study: The lujavrites of the Ilímaussaq complex, SW Greenland[END_REF]. Very commonly, EGM are partly-to-completely replaced by secondary phases, at late magmatic-tohydrothermal stages [START_REF] Salvi | Hydrothermal mobilization of high field strength elements in alkaline igneous systems: Evidence from the Tamazeght complex (Morocco)[END_REF][START_REF] Mitchell | Subsolidus deuteric/hydrothermal alteration of eudialyte in lujavrite from the Pilansberg alkaline complex, South Africa[END_REF][START_REF] Karup-Møller | Eudialyte decomposition minerals with new hitherto undescribed phases from the Ilímaussaq complex, South Greenland[END_REF][START_REF] Sheard | Controls on the concentration of zirconium, niobium, and the rare earth-elements in the Thor Lake Rare Metal Deposit, Northwest Territories, Canada[END_REF][START_REF] Karup-Møller | New data on eudialyte decomposition minerals from kakortokites and associated pegmatites of the Ilímaussaq complex, South Greenland[END_REF].

Although EGM were initially considered to be characteristic of highly differentiated SiO2undersaturated rocks, these minerals have also been reported in a few SiO2-oversaturated peralkaline rocks. The only known examples, to our knowledge, are: quartz syenite from the Carlingford complex, Ireland [START_REF] Nockolds | On the occurrence of neptunite and eudialyte in quartz-bearing syenites from Barnavave, Carlingford, Ireland[END_REF]; the Pajarito mountain, Texas [START_REF] Mclemore | Rare Earth Elements (REE) Deposits in New Mexico: Update[END_REF]; granitic dykes from the Ascension Island in the South Atlantic [START_REF] Harris | An occurrence of rare-earth-rich eudialyte from Ascension Island, south-atlantic[END_REF]; the Straumsvola complex in Antarctica [START_REF] Harris | Rare-earth-rich eudialyte and dalyite from a peralkaline granite dyke at Straumsvola, Dronning Maud Land, Antarctica[END_REF]; the Windy Fork pluton in Alaska [START_REF] Gunter | Optical, X-ray, and Chemical Analysis of Four Eudialytes from Alaska[END_REF]; pegmatitic granitic dykes from the Ambohimirahavavy complex in Madagascar (Estrade et al., 2014a); the Dara-i-Pioz massif in Tajikistan [START_REF] Grew | Reedmergnerite and associated minerals from peralkaline pegmatite, Dara-i-Pioz, southern Tien Shan, Tajikistan[END_REF];

Rockall Island in the North Atlantic [START_REF] Sabine | The geology of Rockall, North Atlantic[END_REF]. However, in studies of most of these occurrences, EGM are only mentioned as an accessory mineral and are not completely described in terms of texture and composition, although in their recent compilation, [START_REF] Schilling | The compositional variability of eudialyte-group minerals[END_REF] characterized the EGM from the Ascension Island and Straumsvola.

In place of EGM, other magmatic complex Zr-silicates are usually described in peralkaline granites and pegmatites (Table 1). The most commonly reported Zr-minerals include dalyite (K2ZrSi6O15), wadeite (K2ZrSi3O9), elpidite (Na2ZrSi6O15.3H2O), catapleiite (Na2ZrSi3O9.2H2O) and, more rarely, gittinsite (CaZrSi2O7) and armstrongite (CaZrSi6O15.2H2O). It is noteworthy that, among these six minerals, none contain Cl or F while three contain H2O (elpidite, catapleiite and armstrongite). Several Zr-minerals are usually reported in the same peralkaline rocks and their complex textural relationships have often led to multiple interpretations (e.g.

Strange Lake, [START_REF] Birkett | Zirconium-bearing minerals of the Strange Lake intrusive complex, Quebec-Labrador[END_REF][START_REF] Roelofsen | Relationships among zirconosilicates: examination by cathodoluminescence and transmission electron microscopy[END_REF]. Moreover, in many cases, post-magmatic processes have destabilised the primary assemblages, greatly complicating identification of the original magmatic mineralogy.

The main factors controlling the stability of EGM in a melt are its peralkalinity and high HFSE (mainly Zr) and volatile contents (mainly Cl, F and H2O) [START_REF] Sørensen | The agpaitic rocks -an overview[END_REF]. These conditions are usually found in highly-evolved undersaturated melts derived from the differentiation of magmas under low oxygen fugacity [START_REF] Markl | On the controls of oxygen fugacity in the generation and crystallization of peralkaline melts[END_REF]. Conversely, the problem of scarcity of EGM in peralkaline granites has not been discussed so far in the literature.

This study focuses on the occurrence of EGM in peralkaline granitic pegmatites in the Ambohimirahavavy alkaline complex, northwest Madagascar. On the basis of textural and compositional data for EGM, other agpaitic minerals, clinopyroxene and amphibole, we assess the magmatic conditions required for the stability of EGM in peralkaline SiO2-oversaturated rocks and compare them to their undersaturated counterpart.

Geological setting and petrography

The Ambohimirahavavy alkaline complex (24.2 ± 0.6 Ma for nepheline syenite and 23.5 ± 6.8 for peralkaline granite; in situ U-Pb dating of zircon, Estrade et al., 2014b) is part of the Cenozoic alkaline province located in the north-western part of Madagascar, in the Ampasindava peninsula. The complex consists of silica-under-and -oversaturated syenites and granites as well as volcanic units of alkaline affinity, including basalt, phonolite, trachyte, and rhyolitic obsidian (Fig. 1). A network of granitic and pegmatitic dykes intruded the Isalo sedimentary units along the external flank of the south syenitic ring-dyke. The dykes are characterized by an alkaline mineralogy (i.e. contain sodic clinopyroxene and sodic amphibole)

and by the presence of minerals rich in HFSE and REE. Their local intrusion in limestone resulted in the formation of a REE-rich skarn [START_REF] Estrade | The Origin of Skarn-Hosted Rare-Metal Mineralization in the Ambohimirahavavy Alkaline Complex, Madagascar[END_REF].

This complex is currently under exploration by Tantalus Rare Earth AG, which focuses on the ion-adsorption REE mineralization in clays associated with laterites. The company has also evaluated the economic potential of the bedrock, as most of the HFSE and REE occur as primary mineralization in peralkaline granite and pegmatite dykes. In a previous study, we distinguished three types of dykes according to their textures and major mineralogy (Estrade et al., 2014a):

(1) A coarse-grained granitic type (GR-I), characterized by an allotriomorphic granular texture, composed of quartz, perthitic alkali feldspar, Na-amphibole and Na-clinopyroxene. The main HFSE-bearing minerals form a miaskitic assemblage consisting of zircon, pyrochlore-group minerals, monazite-(Ce) and chevkinite-(Ce).

(2) A pegmatitic granitic type (GR-II), consisting of quartz, perthitic alkali feldspar, Naclinopyroxene, Na-amphibole, and containing a agpaitic to miaskitic accessory assemblage consisting of EGM, mostly altered to a secondary miaskitic assemblage, dominated by zircon and quartz (Fig. 2a-b-c). This rock is termed transitional because of this feature and because EGM only occur as accessory minerals.

(3) A pegmatitic agpaitic granitic type (GR-III) which consists of K-feldspar, albite, Naclinopyroxene, Na-amphibole and quartz, plus EGM as rock-forming minerals (Fig. 2d-e).

Other agpaitic minerals include nacareniobsite-(Ce) (Na3Ca3(Ce,La)(Nb,Ti)(Si2O7)2OF3) and turkestanite (Th(Ca,Na)2 K1-x□x (Si8O20).nH2O).

In the following sections, we describe in detail the EGM and the complex mineralogy of both the pegmatitic transitional (GR-II) and the pegmatitic agpaitic (GR-III) dykes. These dykes form a more-or-less continuous belt around the ring-dyke of syenite. They vary in thickness from a few centimetres to a few meters. Although no relationships have been observed between GR-II and GR-III dykes, their similar mode of emplacement suggests a contemporaneous origin.

GR-II dykes are far more common in the complex than GR-III, which have been only found in boreholes. However, [START_REF] Lacroix | Sur un type nouveau de roche granitique alcaline, renfermant une eucolite[END_REF][START_REF] Lacroix | Minéralogie de Madagascar, Tome III, lithologie, appendice, index géographique[END_REF] and [START_REF] Ganzeev | A new genetic type of rare-metal alkali granites of Madagascar[END_REF] have described similar rocks to GR-III dykes containing more than 40% of EGM, suggesting that they outcrop somewhere in the flank of the complex.

Analytical Methods

The mineralogy and textural relationships were investigated using optical microscopy and back-scattered electron (BSE) imaging using a JEOL JSM 6360LV scanning electron microscope (SEM) equipped with a silicon drift detector analysis system. The instrument was also used to obtain energy dispersive X-ray phase maps.

Major and minor element concentrations in minerals were determined using a Cameca-SX-50 electron probe microanalyser (EPMA) with SAMx automation, at the Géosciences Environment Toulouse (GET) laboratory at the University of Toulouse. Operating conditions were an accelerating voltage of 15kV and a beam current of 20nA. Standardization was obtained using, periclase (Mg), wollastonite (Ca and Si), corundum (Al), pyrophanite (Mn and Ti), hematite (Fe), barite (Ba), albite (Na), sanidine (K), zircon (Hf and Zr), graftonite (P), UO2 (U), ThO2

(Th), Pb2 P2O7 (Pb), sphalerite (Zn), orthophosphate for REE and yttrium, Nb metal (Nb), Ta metal (Ta), topaz (F) and tugtupite (Cl).

In-situ trace element concentrations were determined by laser ablation inductively coupled plasma mass-spectrometry (LA-ICP-MS) at the University of Montpellier. The instrument used for analysis was a Geolas Q excimer CompEx 102 laser ablation system coupled to a ThermoFinnigan Element XR ICP-MS. We used a beam diameter of 60 µm for all analyses, which allowed a high detection threshold even for very low-level trace elements. For each analysis, the signal was recorded for 180 s, consisting of 60 s of background measurement followed by 120 s of ablation. To calibrate the instrument, we used NIST SRM 610 glass as external standard and NIST SRM 612 as a secondary standard. SiO2 was used as internal standard for the correction of different ablation rates between sample and standard. Silica concentration had been previously determined by EPMA in the ablation area. Data processing was carried out with the SILLS software [START_REF] Guillong | SILLS: A MATLAB-based program for the reduction of laser ablation ICP-MS data of homogeneous materials and inclusions[END_REF]. Typical concentration uncertainties are ±5 % for concentrations >10 µg/g and ±10 % for concentration <10 µg/g.

Mineral textures and alteration

Eudialyte-group minerals

In GR-II, EGM are accessory minerals (<1%) occurring as interstitial late-formed magmatic phases surrounded by Na-clinopyroxene, Na-amphibole, perthitic alkali feldspars and quartz (Fig. 3a-b). In most samples, EGM underwent partial-to-complete alteration and have been replaced by a complex assemblage of secondary minerals, among which zircon and quartz have been identified as the main replacing phases (Estrade et al., 2014a). Although most of the EGM grains are altered, rare, entirely unaffected grains may occur adjacent to altered ones. The latter crystals lack oscillatory growth or sector zoning usually observed in EGM from other alkaline complexes, although high-contrast BSE images show common small bright phases and dark grey patches, scattered along fractures.

In GR-III, EGM are rock-forming minerals (>10 vol.%) occurring as euhedral, early magmatic crystals together with Na-clinopyroxene, Na-amphibole, nacareniobsite-(Ce), turkestanite, grains of albite and K-feldspar and quartz (Fig. 3c-d). Except from quartz, all these minerals occur as individual grains and as inclusions in cores of the EGM, as well as along concentric layers that follow growth zones. Quartz mainly occurs as late anhedral crystals and as layers flanked by euhedral eudialyte. Unlike in GR-II, most of the EGM are pristine; locally-altered EGM grains occur in narrow bands, together with calcite, altered nacareniobsite-(Ce) and turkestanite. All other silicates were not altered.

Other agpaitic minerals

In addition to EGM, the agpaitic minerals nacareniobsite-(Ce) and turkestanite occur in significant modal amounts (1-2 vol.%) in GR-III, whereas EGM are the only agpaitic minerals in GR-II. Nacareniobsite-(Ce), is also a mineral typical of agpaitic SiO2-undersaturated rocks, but has been only rarely described in SiO2-saturated rocks [START_REF] Vilalva | Nacaraniobsite-(Ce) and britholite-(Ce) in peralkaline granites from the Morro Redondo complex, Graciosa province, southern brazil: occurence and compositional data[END_REF]. In GR-III, it occurs as early magmatic elongated euhedral crystals, which enclose small chadacrysts of albite, K-feldspar, Na-clinopyroxene and Na-amphibole (Fig. 4a-b). In altered portions of GR-III, nacareniobsite-(Ce) is replaced by a complex assemblage of secondary Ca-rich minerals including calcite and titanite. Turkestanite is an extremely rare mineral that has been reported in only four other alkaline complexes [START_REF] Pautov | Turkestanite Th(Ca,Na)2(K1-xx) Si8O20.nH2O -a new mineral with doubled fourfold silicon-oxygen rings[END_REF][START_REF] Kabalov | Crystal structure of a new mineral turkestanite: A calcium analogoue of steacyite[END_REF][START_REF] Vilalva | Major-and trace-element composition of REE-rich turkestanite from peralkaline granites of the Morro Redondo Complex, Graciosa Province, south Brazil[END_REF]. In GR-III, it is an early magmatic phase occurring as diamond-shaped euhedral crystals that enclose small chadacrysts of albite, K-feldspar, Na-clinopyroxene and Naamphibole (Fig. 4c). In BSE images, these crystals commonly show zoning and alteration textures consisting of a heterogeneous core containing a network of very thin U-rich veinlets, surrounded by a BSE-brighter homogeneous rim (Fig. 4d).

Na-Clinopyroxene and Na-amphibole

Sodic clinopyroxene is the main mafic constituent in GR-II and -III. In GR-II, it forms two main, texturally distinct generations: Na-Clinopyroxene-I (cpx-I) is relatively uncommon and forms large euhedral phenocrysts (up to 1 mm across), locally showing distinct cores and rims; Naclinopyroxene-II (cpx-II) is more abundant and occurs as homogeneous small grains or thin acicular crystals. In GR-III, Na-clinopyroxene occurs as small euhedral crystals and as chadacryst in EGM, nacareniobsite-(Ce) and turkestanite.

Sodic amphibole is the second main mafic constituent after Na-clinopyroxene. In GR-II, its habit varies considerably and, depending on its location in the dyke, can form large euhedral pegmatitic crystals of up to 20 cm or small anhedral grains. In GR-III, Na-amphibole occurs only as small euhedral crystals.

Mineral composition

Eudialyte-group minerals

Representative compositions of EGM are shown in Table 2. Structural formulae of EGM are based on Σ (Si +Al + Zr + Ti + Hf + Nb) = 29 a.p.f.u. and were calculated using the Excel spreadsheet of [START_REF] Pfaff | A fast and easy-to-use approach to cation site assignment for eudialyte-group minerals[END_REF]. EGM from GR-II and GR-III have different compositions, mainly in Mn, Ca and REE and minor variations in Si, Fe, Na, and Nb. Zirconium and chlorine contents of EGM are similar in both rock types. Binary plots of Fe versus Mn and (La+Ce+Nd+Y) versus Ca expressed as atoms per formula unit are shown in Figure 5, where they are compared with EGM from other peralkaline granites (Straumsvola and Ascension Island) and foid syenites (Ilímaussaq, Mont Saint-Hilaire, Tamazeght, Pilansberg, Kipawa, Khibiny, Lovozero, Saima, Pocos de Caldas, Langesundfjord and Norra Kärr) using the data of [START_REF] Schilling | The compositional variability of eudialyte-group minerals[END_REF]. The Mn content of early-magmatic EGM from GR-III is lower than that of late-magmatic EGM from GR-II and is consistent with data from the other complexes,

showing that, in a single intrusive complex, Mn/Fe ratio increases in later-formed EGM [START_REF] Schilling | The compositional variability of eudialyte-group minerals[END_REF]. Calcium correlates negatively with the sum of the major rare-earth elements La, Ce, Nd and Y; this trend is consistent with their preferential incorporation in the same structural site (M1; [START_REF] Johnsen | The crystal chemistry of the eudialyte group[END_REF]. In addition, most of the EGM from quartz- (Fig. 6a). Concentrations of the LREE in EGM from quartz bearing-rocks (>40 000ppm) are similar to the most LREE-rich EGM from foid-syenites in Ilímaussaq and Mont Saint-Hilaire, whereas concentrations of the HREE are significantly higher in EGM from GR-II and Ascension Island (Fig. 7). All patterns show a strong negative Eu anomaly which is also a characteristic of the whole-rock REE distribution patterns of the dykes; this is consistent with the model for the origin of the melt in the Ambohimirahavavy complex (Estrade et al., 2014b), i.e., differentiation of an alkali basaltic parental melt by fractionation of plagioclase. Trace-element distribution patterns have similar overall shapes except for U and Pb, which show a negative and positive anomaly, respectively, in GR-II while they show an opposite pattern in GR-III.

Such opposed trends are absent in the whole-rock patterns, which show similar concentrations for these two elements.

Alteration paragenesis of EGM

Most of the EGM in GR-II samples are entirely replaced by a secondary paragenesis, ultimately consisting of zircon and quartz. Locally, however, EGM are partly altered and replaced by an assemblage of Zr-Ca-bearing phases and REE-Ca-F-bearing phases with no zircon (Estrade et al., 2014a). In this work, we have identified EGM that show partial replacement by zircon, and we consider this texture as representative of the alteration pattern of EGM in GR-II. An Xray element map of partially-replaced EGM is shown in Figure 8 and the compositions of the phases present are reported in

Other agpaitic minerals

Representative compositions of nacareniobsite-(Ce) and turkestanite are given in Table 3. The composition of different grains of nacareniobsite-(Ce) is homogeneous and comparable to that of nacareniobsite-(Ce) published for other complexes [START_REF] Sokolova | From structure topology to chemical composition. V. Titanium silicates: the crystal chemistry of nacareniobsite-(Ce)[END_REF][START_REF] Vilalva | Nacaraniobsite-(Ce) and britholite-(Ce) in peralkaline granites from the Morro Redondo complex, Graciosa province, southern brazil: occurence and compositional data[END_REF][START_REF] Borst | Zirconosilicates in the kakortokites of the Ilímaussaq complex, South Greenland: Implications for fluid evolution and high-field-strength and rare-earth element mineralization in agpaitic systems[END_REF]. Fluorine content is higher than in the ideal formulae as the calculated cations at around 3.7 a.p.f.u. exceed the ideal value of 3 cations. REE distribution patterns show a steep negative slope from LREE to HREE, similarly to published patterns [START_REF] Vilalva | Nacaraniobsite-(Ce) and britholite-(Ce) in peralkaline granites from the Morro Redondo complex, Graciosa province, southern brazil: occurence and compositional data[END_REF] (Fig. 6b). Trace element distribution patterns reproduce the strong negative anomalies for Sr, Ti, and Li that characterize EGM. Alteration products consist mainly of calcite, titanite, and quartz (Fig. 9c-d).

Turkestanite is characterized by a low sum of oxides (88-95 wt. %) and compositional differences between crystals, and between core and rim of altered crystals (Fig. 9e-f). The low total oxide sum is consistent with most of the compositions reported in the literature, and is probably related to structural H2O not analysed with EPMA [START_REF] Pautov | Turkestanite Th(Ca,Na)2(K1-xx) Si8O20.nH2O -a new mineral with doubled fourfold silicon-oxygen rings[END_REF][START_REF] Vilalva | Major-and trace-element composition of REE-rich turkestanite from peralkaline granites of the Morro Redondo Complex, Graciosa Province, south Brazil[END_REF]. However, the very low sum of oxides of altered cores could result from porosity created by alteration processes and subsequent loss of volume. Altered cores are characterized by lower Si, Th, Na and K and higher Mn content compared to their rims and the unaltered crystals. Similarly to nacareniobsite-(Ce), REE distribution patterns show a steep negative slope from LREE to HREE, not unlike the patterns given by [START_REF] Vilalva | Major-and trace-element composition of REE-rich turkestanite from peralkaline granites of the Morro Redondo Complex, Graciosa Province, south Brazil[END_REF] (Fig. 6c).

Na-Clinopyroxene and Na-amphibole

Further insights into the crystallisation processes can be obtained by studying the detailed chemical changes of other rock-forming, non-agpaitic minerals, which are also liable to incorporate HFSE and REE. Representative compositions of Na-clinopyroxene and Naamphibole in GR-II and GR-III are reported in Table 4 and5. Structural formulae of clinopyroxene are based on four cations and six oxygens and those of amphibole have been calculated using the spreadsheet of [START_REF] Locock | An Excel spreadsheet to classify chemical analyses of amphiboles following the IMA 2012 recommendations[END_REF]. All Na-clinopyroxenes analysed in both dyke types are aegirine. In GR-II, the core of cpx-I is richer in Ca and Zr (1.0 wt. % for both CaO and ZrO2) than the rim (0.6 wt. % CaO and 0.2 wt. % ZrO2) whereas the Ti content increases slightly in the rim from 1.1 to 1.6 wt. %. The composition of cpx-II is similar to that of the cpx-I rim. REE distribution patterns have the same appearance in both dyke types although the REE concentrations are slightly higher in aegirine from GR-II than in GR-III (Fig. 6d). Trace elements distribution patterns are similar, except for Rb, Ba, Th, and U, which are all below detection limits in GR-II, and above them in GR-III.

BSE images and X-ray element mapping of a cpx-I phenocryst in GR-II illustrate the discontinuous zoning pattern between a homogeneous core and a zoned rim, as well as their compositional differences (Fig. 10). The qualitative X-ray Si map (Fig. 10b) shows the distribution of alkali feldspar (orange), clinopyroxene (green), quartz (red) and Zr-minerals Amphiboles in both dyke types are Na-rich, classified using the spreadsheet of [START_REF] Locock | An Excel spreadsheet to classify chemical analyses of amphiboles following the IMA 2012 recommendations[END_REF] as an arfvedsonite in GR-II and as a ferri-fluoro-leakeite in GR-III. Lithium and fluorine contents are twice as in amphibole from GR-III than in GR-II. The most significant difference is the very high Mg content (7.6 wt. %) in amphibole from GR-III, which is very low (< 0.1 wt. %) in amphibole from GR-II. Their REE distribution patterns have a similar appearance in the LREE portion, with a higher content of LREE in GR-III than in GR-II, and an opposed HREE portion with a steep slope in GR-III and a slightly curved shape in GR-II (Fig. 6e). Their trace element distribution patterns have minor variations except for U, which is three orders of magnitude more concentrated in GR-III than in GR-II, and the geochemical twins Zr-Hf, which are one order of magnitude more concentrated in GR-II than in GR-III (Fig. 6e).

Discussion

Unusual occurrence of EGM in SiO2-oversaturated rocks

Cl solubility in the melt as the main limiting factor for EGM crystallisation

The EGM described above are new examples occurring in SiO2-oversaturated rocks, and add to the list of other complex Na-K-Ca-Zr-silicates occurring in peralkaline granites (Table 1). It is now accepted that the term agpaitic, originally used to designate SiO2undersaturated rocks that contain complex Na-K-Ca-Zr-silicates [START_REF] Sørensen | The agpaitic rocks -an overview[END_REF][START_REF] Le Maitre | Igneous rocks: a classification and glossary of terms[END_REF], can be extended to SiO2-oversaturated rocks [START_REF] Marks | The mineralogical diversity of alkaline igneous rocks: critical factors for the transition from miaskitic to agpaitic phase assemblages[END_REF]. Marks et al.

(2011) also point out that most Zr-minerals occurring in peralkaline granite (e.g. elpidite and dalyite) have higher molar amount of SiO2 relative to alkalis and ZrO2 than Zr-minerals in nepheline syenite (e.g. catapleiite and wadeite), due to the higher SiO2 activity in this type of melt. In addition, Zr-minerals in peralkaline granite are either volatile free (e.g. dalyite and vlasovite) or H2O-rich (e.g. elpidite). The EGM, unlike other agpaitic minerals found in peralkaline granites and pegmatites, are rich in Cl. Therefore, in addition to strongly peralkaline conditions and high Zr melt contents, the Cl content of the melt appears to be a critical parameter for crystallisation of EGM in peralkaline granites [START_REF] Sørensen | The agpaitic rocks -an overview[END_REF][START_REF] Giehl | An experimental study on the influence of fluorine and chlorine on phase relations in peralkaline phonolitic melts[END_REF].

Chlorine is considered to be an incompatible element, thus enriched in most evolved melts, although small amounts can also be incorporated in amphibole, mica and apatite [START_REF] Aiuppa | Halogens in volcanic systems[END_REF]. It has been shown that the fundamental controls on the solubility of Cl in silicate melts include the composition and structure of the melt, pressure and temperature [START_REF] Signorelli | Experimental study of Cl solubility in hydrous alkaline melts: constraints on the theoretical maximum amount of Cl in trachytic and phonolitic melts[END_REF][START_REF] Oppenheimer | 4.4 -Volcanic Degassing: Process and Impact[END_REF]. Chlorine solubility in silicic melts increases with decreasing pressure and increasing temperature (Webster, 1992a). Chlorine is also known to have a high liquid/melt partition coefficient, leading to depletion of melts in Cl when a fluid phase is exsolved (Webster, 1992b). The high capacity of peralkaline melts, and more particularly of agpaitic melts, to retain volatiles and rare elements has been discussed by several authors (e.g. [START_REF] Kogarko | Role of volatiles[END_REF][START_REF] Metrich | Experimental study of chlorine behavior in hydrous silicic melts[END_REF]. Several experimental studies have shown that the solubility of Cl in peralkaline SiO2-oversaturated (pantellerititic)

and undersaturated (phonolitic) melts is similar, in agreement with the concentration of Cl measured in natural samples [START_REF] Metrich | Experimental study of chlorine behavior in hydrous silicic melts[END_REF]Signorelli andCarroll, 2000, 2002). However, in granites and nepheline syenites, their intrusive equivalents, the retention of Cl is controlled by the composition of the crystallizing phases and by the eventuality of fluid exsolution. In SiO2-undersaturated rocks such as nepheline syenite, Cl can be incorporated into the Cl-rich rock-forming mineral sodalite, but in peralkaline granite, there are no major Clrich minerals. Furthermore, exsolution of a NaCl-rich fluid phase is common in peralkaline granites and is usually evoked to explain the scarcity of Cl in these rocks [START_REF] Webster | Exsolution of magmatic volatile phases from Cl-enriched mineralizing granitic magmas and implications for ore metal transport[END_REF].

Thus, the window for EGM crystallization in SiO2-oversaturated rocks is rather restricted, requiring a highly evolved peralkaline melt composition and no, or very late, exsolution of a fluid phase. We thus suggest that the scarcity of EGM in peralkaline granites is related to the unavailability of Cl in the melt due to exsolution of a fluid phase at a late stage of crystallization.

In the Ambohimirahavavy complex, we have shown in a previous paper that an orthomagmatic fluid exsolved from the melt at a late stage of crystallization of the peralkaline dykes [START_REF] Estrade | The Origin of Skarn-Hosted Rare-Metal Mineralization in the Ambohimirahavavy Alkaline Complex, Madagascar[END_REF]. The interstitial texture of EGM indicates that favorable conditions for its crystallization, i.e. a sufficient amount of Cl and Zr in the melt, were only achieved at the very late magmatic stage. However, these conditions rapidly evolved towards exsolution of an orthomagmatic fluid that partly altered the EGM.

The very unusual association of early magmatic EGM and quartz in the GR-III peralkaline pegmatite.

The agpaitic GR-III granite represents the most differentiated lithology in the complex. This is shown by its agpaitic mineralogy and the coexistence of separate grains of albite and K-feldspar, indicating that the temperature of crystallization had decreased to below the feldspar solvus, and contrasts with crystallization of perthitic alkali feldspar in GR-II. These characteristics are attributed to the extremely evolved composition of the melt from which GR-III crystallised, and its extreme enrichment in HFSE, Na, and volatiles (Estrade et al., 2014a).

To our knowledge, the association of early magmatic EGM and quartz in GR-III is the only known example of EGM as an early liquidus phase in granite. However, unlike other main minerals, quartz is not present as inclusions in EGM, suggesting that quartz probably crystallized late, as also indicated by its interstitial texture. This raises the question of whether quartz could have crystallized at a post-magmatic stage, i.e., from a hydrothermal fluid.

However, the lack of reaction textures between these two minerals, or with any other agpaitic mineral, suggest a magmatic origin for quartz. Indeed, circulation of a hydrothermal fluid among these minerals would have severally affected the very unstable agpaitic minerals. The unusual composition of the GR-III melt compared to GR-II is further shown by the high Mg content of amphibole (Table 5, 8.0 wt. % MgO) and by the high Ca content of all the agpaitic minerals (Tables 2 and3, 7.7 wt. % in EGM, 19.5 wt. % in nacareniobsite-(Ce) and 9.0 wt. % in turkestanite). High Mg contents, similar to those measured in GR-III, have been reported in ferri-fluoro-leakeite in nepheline syenite pegmatite from the Larvik Plutonic complex in Norway [START_REF] Oberti | Ferri-fluoro-leakeite: a second occurrence at Bratthagen (Norway), with new data on Zn partitioning and the oxo component in Na amphiboles[END_REF] and in the Verkhnee Espe deposit in Kazakhstan [START_REF] Cámara | Fluoroleakeite, NaNa2(Mg2Li)Si8O22F2, a new mineral of the amphibole group from the Verkhnee Espe deposit, Akjailyautas Mountains, Eastern Kazakhstan District, Kazakhstan: description and crystal structure[END_REF].

However, in the former occurrence, the Mg enrichment is not discussed, whereas in the latter, it is unclear whether the amphibole is magmatic or crystallized at a hydrothermal stage. The high Mg and Ca contents of these minerals contrasts with the composition of agpaitic melts, which are typically highly depleted in Mg -a highly compatible and early fractionating element -and moderately depleted in Ca [START_REF] Sørensen | The agpaitic rocks -an overview[END_REF]. To this effect, [START_REF] Marks | The mineralogical diversity of alkaline igneous rocks: critical factors for the transition from miaskitic to agpaitic phase assemblages[END_REF] have

shown that the Ca content of evolved agpaitic melts varies depending on the nature of the parental melt and whether or not plagioclase had fractionated from the melt. The strongly negative Eu anomaly of the whole-rock REE patterns for both GR-II and GR-III dyke types (Fig. 6a) evidences the strong fractionation of plagioclase from their parental melt; thus, the melt from which both dykes crystallized has been depleted in Ca, following an evolution similar to the Ca-depleted trend of the Ilímaussaq complex [START_REF] Marks | The mineralogical diversity of alkaline igneous rocks: critical factors for the transition from miaskitic to agpaitic phase assemblages[END_REF]. And, as far as we know, Mg enrichment has never been documented in alkaline complexes.

A possible explanation for the high Mg and Ca contents in the GR-III melt is contamination of the dykes by the host sediments (marls, mudstone, and limestone) during emplacement. It is also possible that some of the Ca could have been introduced during fluid-rock interaction at a post-magmatic stage such as described at Strange Lake during Ca-metasomatism [START_REF] Salvi | The role of hydrothermal processes in concentrating high-field-strength elements in the Strange Lake peralkaline complex, northeastern Canada[END_REF][START_REF] Gysi | Lithogeochemical Vectors for Hydrothermal Processes in the Strange Lake Peralkaline Granitic REE-Zr-Nb Deposit[END_REF][START_REF] Vasyukova | Fluid evolution in the Strange Lake granitic pluton, Canada: Implications for HFSE mobilisation[END_REF]. However, textural evidence clearly rules out a hydrothermal overprint of the primary Ca-bearing agpaitic minerals and Mg-bearing amphibole at Ambohimirahavavy.

The addition of Ca to the GR-III melt by contamination would have had a strong effect on the solubility of Cl. Indeed, [START_REF] Chevychelov | Chlorine dissolution in fluid-rich granitic melts: The effect of calcium addition[END_REF] has shown that the solubility of Cl in a melt correlates positively with its CaO content and with the CaO/SiO2 molar ratio. Using whole-rock compositional data from our previous studies on pegmatitic dykes, the CaO/SiO2 ratios are one order of magnitude higher in GR-III (0.053, sample EU01; Estrade et al., 2014a) compared with GR-II (≤0.007, samples AM30, AM50 and AM113A; Estrade et al., 2014b). Therefore, we propose that the contamination of the highly evolved GR-III melt by Ca-rich material allowed for crystallisation of early-magmatic eudialyte by increasing the concentration level of Cl in the melt because fluid saturation was suppressed. In GR-II, the low Mg content of amphibole and other minerals and the relatively low Ca content in cpx-I and EGM (Tables 2,4, and 5) may indicate a lower contamination level than for GR-III.

REE and trace elements in EGM

High REE content of EGM Mont Saint Hilaire) complexes. In SiO2-oversaturated rocks, EGM generally have higher REE contents than in SiO2-undersaturated counterparts. In addition, most of the EGM from SiO2undersaturated rocks that have similarly high REE contents are reported to be post-magmatic EGM (hatched pattern in Fig. 7), so probably crystallized from a REE-rich fluid (Figs. 5b and7). The REE enrichment in EGM in GR-II can be explained by the fact that EGM are the only REE-bearing minerals in GR-II, and thus they scavenged most of the REE in the melt. By contrast, in GR-III, nacareniobsite-(Ce) is also a major REE-bearing mineral and competed with EGM for the uptake of REE. [START_REF] Harris | An occurrence of rare-earth-rich eudialyte from Ascension Island, south-atlantic[END_REF][START_REF] Harris | Rare-earth-rich eudialyte and dalyite from a peralkaline granite dyke at Straumsvola, Dronning Maud Land, Antarctica[END_REF] considered the Ca-poor composition of peralkaline granites from Ascension Island and Straumsvola to explain the REE enrichment in EGM. They suggested that, because REE are incorporated in the same structural site as Ca in EGM, high amounts of REE entered the Ca site to compensate for its paucity in the melt from which the mineral crystallized. The negative correlation between La+Ce+Nd+Y and Ca clearly indicates that these elements compete for the same structural site (Fig. 5b). However, although whole-rock Ca contents in GR-II, Ascension Island and Straumsvola are similarly low (0.2 to 0.5 wt. %), EGM from Straumsvola are depleted in HREE compared to those in the other two localities. Thus, another mechanism must be evoked to explain the difference in HREE content.

HREE enrichment in EGM: the role of melt composition

The HREE content of the melt can be qualitatively estimated by examining the REE distribution patterns of the major minerals present in the rocks (Fig. 6). In GR-II, the major minerals aegirine, amphibole, and EGM all show HREE enrichments, suggesting that the GR-II melt was enriched in HREE. In GR-III, however, all minerals have lower HREE concentrations, surely reflecting an overall lower concentration of HREE in the GR-III melt.

This difference is also evident from the whole-rock REE distribution patterns; in GR-II the HREE show a flat profile (Gd/Lu=0.97), whereas it decreases slightly in GR-III (Gd/Lu=1.73).

We have pointed out above that the GR-III dykes are the most evolved lithology in the complex, and that they represent a melt produced by extensive fractionation. We suggest that at a late stage of evolution the HREE became compatible due to the abundant crystallization of phases that could incorporate them, such as aegirine and arfvedsonite, and were thus fractionated.

The resulting melt, albeit very evolved, was thus relatively depleted in HREE.

U and Pb in EGM

Among all trace elements analysed in EGM from both dykes, U and Pb show the most markedly opposite behaviour (Fig. 6a). Uranium concentration in EGM, as for aegirine and amphibole, is higher in GR-III than in GR-II. As proposed for HREE above, the opposing behaviour of U in EGM might be attributed to its difference in concentration in the GR-II and GR-III melts. A much higher U concentration in the melt from which GR-III crystallized would be consistent with the presence of turkestanite in this granite, as U is a major constituent of this rare mineral, with up to 2 wt. % UO2. The higher U concentration in the GR-III melt thus reflects its highly incompatible behaviour, leading to an enrichment in the most evolved melts that were formed by intense fractional crystallisation. The opposite observation can be made for Pb, which shows a positive and negative anomaly compared to its neighbouring elements in EGM from GR-II and GR-III, respectively (Fig. 6a). This opposed behaviour contrasts with the bulk Pb content, which is similar in both dykes. In GR-II, EGM and K-feldspar are the only minerals that can accommodate significant amounts of Pb, as aegirine and amphibole have very low Pb contents (few ppm to below ppm, electronic supplement). In GR-III, in addition to EGM and K-feldspar, Pb is easily incorporated into turkestanite (~400 ppm, electronic supplement). As feldspars are present in similar modal amounts in GR-II and GR-III, we think that they had a similar effect on bulk Pb content of the two melts. Therefore, we attribute the relative low Pb content in EGM from GR-III to its concomitant uptakes by turkestanite.

Destabilisation of EGM and post-magmatic assemblage Alteration of GR-II

The destabilisation of EGM and concomitant sudden change in cpx-I composition in GR-II (Figs. 8 and 10), together with the local destabilisation of the three agpaitic minerals (EGM, nacareniobsite-(Ce) and turkestanite) in GR-III (Fig. 9), indicate that both granites experienced late-to post-magmatic alteration. The occurrence of alteration is a very common feature in peralkaline granites [START_REF] Salvi | Alteration, HFSE mineralization and hydrocarbon formation in peralkaline igneous systems: Insights from the Strange Lake Pluton, Canada[END_REF][START_REF] Kynicky | Distribution and evolution of zirconium mineralization in peralkaline granites and associated pegmatites of the Khan Bogd complex, southern Mongolia[END_REF][START_REF] Kempe | The genesis of Zr-Nb-REE mineralisation at Khalzan Buregte (Western Mongolia) reconsidered[END_REF][START_REF] Gysi | Lithogeochemical Vectors for Hydrothermal Processes in the Strange Lake Peralkaline Granitic REE-Zr-Nb Deposit[END_REF][START_REF] Vasyukova | Fluid evolution in the Strange Lake granitic pluton, Canada: Implications for HFSE mobilisation[END_REF] and in most cases the primary agpaitic minerals in these rocks undergo complete replacement, to the point that the precursor is not always easy to recognize. Examples include the Strange Lake complex in Canada, where most of the subsolvus granitic facies contain pseudomorphs of gittinsite after a euhedral precursor phase [START_REF] Birkett | Zirconium-bearing minerals of the Strange Lake intrusive complex, Quebec-Labrador[END_REF][START_REF] Mariano | Cathodoluminescence as a tool in exploration geology[END_REF]. Rare occurrences of partial replacement from drill core samples allowed identification of the primary mineral as elpidite, which was transformed to gittinsite via an intermediate step involving armstrongite [START_REF] Salvi | Zirconosilicate phase-relations in the Strange Lake (Lac-Brisson) pluton, Quebec-Labrador, Canada[END_REF]. Other instances of complete pseudomorphism include the Khan Bogd complex [START_REF] Kynicky | Distribution and evolution of zirconium mineralization in peralkaline granites and associated pegmatites of the Khan Bogd complex, southern Mongolia[END_REF] and Khaldzan Buregtey complex [START_REF] Kempe | The genesis of Zr-Nb-REE mineralisation at Khalzan Buregte (Western Mongolia) reconsidered[END_REF]. Detailed mineralogical studies in some of these localities have shown that destabilisation of these agpaitic minerals is a subsolidus process, related either to interaction with external fluids or to the exsolution of a fluid from the melt at a very late-stage of crystallization. In some cases, fluid inclusion study documented the input of external fluids which may cause formation of relatively rare minerals, as it was the case at Strange Lake where Ca to form gittinsite was derived from a meteoric fluid (Salvi andWilliams-Jones, 1990, 1996).

The above discussion indicates that interaction with a fluid, either of orthomagmatic or external origin, at late-to post-magmatic stages is a recurrent phenomenon in agpaitic peralkaline granite. This is seems also to be the case in the Ambohimirahavavy complex, as shown in GR-II where secondary assemblages are mainly characterized by the occurrence of pseudomorphs of zircon and quartz after EGM plus an unidentified Ca-zirconosilicate (Fig. 8).

Interaction with a fluid is also evidenced by the rims of cpx-I, which show a porous texture associated with zircon inclusions (Fig. 10). A similar texture has been previously described by the authors in zircon in a peralkaline granitic dyke of this complex (Estrade et al., 2014a). The association of Zr-rich patches, zircon inclusions and pores in the rim of the cpx-I can be interpreted in terms of coupled dissolution-reprecipitation which occurred at the fluid-cpx-I interface [START_REF] Putnis | Mineral replacement reactions[END_REF]. The presence of Al, Fe, and Ca in zircon inclusions, elements that are not compatible in its structure, is further evidence of their hydrothermal origin [START_REF] Geisler | Re-equilibration of zircon in aqueous fluids and melts[END_REF]. The fact that the alteration is restricted to the light grey bands in the zoned rims of these crystals is intriguing (Fig. 10d,f). We suggest that this may be due to their higher content in Zr, thus making them more prone to alteration. The outermost dark rims are poor in Zr and likely precipitated during fluid-rock interaction concomitantly with the small cpx-II grains and late hydrothermal zircon (rich in Ca, Fe, and Al) in the groundmass.

We propose that, during the interaction with a fluid, Cl and H2O were liberated to the fluid phase, causing the destabilisation of previously formed EGM and precipitation of zircon and quartz. The elements initially present in EGM were redistributed in the rocks according to their respective mobility in the fluid phase. The precipitation of zircon within the edges of precursor EGM indicates that Zr could not be transported over a long distance. Moreover, Ti could no longer be incorporated in EGM and was therefore incorporated in the crystallising rims of cpx-I and in the secondary cpx-II crystals (Fig. 10, Table 4). The similar Na2O content of cpx-I cores and rims indicate that Na activity did not change significantly between magmatic and late-to post-magmatic conditions. The amount of Ca incorporated in secondary phases (mainly in secondary Zr-minerals) could partly derive from the Ca released in the fluid during the replacement of EGM and cpx-I. However, it is likely that some Ca was added to the system by an external fluid.

Alteration in GR-III is local and Ca-rich

Unlike GR-II, where most of the EGM have been completely replaced, alteration of EGM in GR-III is only a local phenomenon, and most of the EGM are pristine. In the altered parts, the three main agpaitic minerals (EGM, nacareniobsite-(Ce) and turkestanite) are destabilised and replaced, but aegirine and amphibole are mostly preserved. The most significant effect of alteration is the systematic removing of alkalis from the three agpaitic minerals and the precipitation of Ca-rich phases such as calcite and titanite in secondary assemblages (Fig. 9 and Tables 2 and3). These observations suggest that, similarly to GR-II, a Ca-rich fluid interacted with GR-III at a late-to post-magmatic stage. The origin of the fluid could be both magmatic and external [START_REF] Estrade | The Origin of Skarn-Hosted Rare-Metal Mineralization in the Ambohimirahavavy Alkaline Complex, Madagascar[END_REF].

Conclusions

We document two new occurrences of EGM in two types of peralkaline granitic dykes from the Ambohimirahavavy complex in northwest Madagascar. We propose that Cl availability is the main limiting factor for the crystallisation of EGM in SiO2-oversaturated rocks. The transitional GR-II granite was produced from a melt that only achieved a sufficient Cl content to crystallize

Figure captions

Table captions

Table 1: List of the main Zr-silicates in agpaitic peralkaline granite and pegmatite.

Table 2: Average compositions of EGM and their replacing phases in pegmatitic transitional (GR-II) and pegmatitic agpaitic (GR-III) dykes.

Table 3: Average compositions of nacareniobsite-(Ce) and turkestanite in pegmatitic agpaitic (GR-III) dykes.

Table 4: Average compositions of aegirine in pegmatitic transitional (GR-II) and pegmatitic agpaitic (GR-III) dykes.

Table 5: Average compositions of amphibole in pegmatitic transitional (GR-II) and pegmatitic agpaitic (GR-III) dykes. Lithium determined by LA-ICP-MS.

Electronic supplement: five tables with trace element abundances of EGM, clinopyroxene, amphibole, nacareniobsite-(Ce) and turkestanite obtained by LA-ICP-MS.

  bearing rocks (GR-II, Straumsvola, and Ascension Island) have lower Ca and higher La+Ce+Nd+Y contents than EGM from foid-bearing rocks. Most EGM from foid-bearing rocks with high La+Ce+Nd+Y content (Mont Saint-Hilaire and Pilansberg) have a post-magmatic origin.Trace element analyses for EGM, agpaitic minerals, clinopyroxene and amphibole are presented in an electronic supplement. Rare-earth elements and trace element distribution patterns of EGM, nacareniobsite-(Ce), turkestanite, clinopyroxene and amphibole are shown in Figure6. Rare-earth elements and trace elements patterns of EGM are compared with patterns of EGM from other EGM-bearing granites (Straumsvola and Ascension Island) and foid-syenites using the data of[START_REF] Schilling | The compositional variability of eudialyte-group minerals[END_REF]. We only present the patterns from the most REE-rich EGM (from Ilímaussaq and Mont Saint-Hilaire) as EGM from other complexes plot far below the REE distribution patterns of GR-II and GR-III. We also compare the concentrations of the light REE (LREE; La to Sm) and the heavy REE (HREE; Gd to Lu) in EGM from different complexes in Figure7using the data of[START_REF] Schilling | The compositional variability of eudialyte-group minerals[END_REF]. Among all EGM, those from quartz bearing-rocks have the highest REE concentrations and are generally enriched by up to four orders of magnitude relative to chondrite[START_REF] Mcdonough | The composition of the earth[END_REF]

(

  blue). The cpx-I shows a homogeneous light grey core enriched in Zr and Ca and depleted in Ti with respect to the external dark rim. This rim is characterized by porous, light and dark grey overgrowths containing inclusions of zircon, alkali feldspar and light grey patches (Fig.10c-de-f). These features are restricted to the external rim and do not affect the light core. The light grey patches, porosity and zircon inclusions are mostly restricted to the light grey bands. The composition of zircon and light grey patches has been qualitatively analysed by EDS. Zircon contains significant concentrations of Ce, Ca, Fe, and Al, whereas the light grey patches mainly contain Si, Zr and Na.

Figure

  Figure 6a displays trace-element patterns of EGM for SiO2-oversaturated (Ambohimirahavavy, Ascension Island, and Straumsvola) and undersaturated (Ilímaussaq and

  EGM at very late stages, resulting in formation of interstitial EGM. The melt rapidly evolved towards fluid exsolution, losing its Cl and thus hampering EGM crystallization. The resulting orthomagmatic fluid altered the EGM, although only to a limited extent. The agpaitic GR-III granite contains early-formed, abundant EGM. Contamination of the highly evolved GR-III melt by Ca-rich material increased Cl solubility, inducing early EGM crystallization. EGM in these granites have higher REE contents than most occurrences in undersaturated complexes. This is explained by the low Ca content of peralkaline melts, which favours REE intake in EGM as substitution for Ca. The enrichment of the heavy REE in GR-II with respect to EGM in GR-III is a feature inherited from the respective melt compositions, related to fractionation of the more compatible HREE in late-forming minerals at late stages of GR-III melt differentiation. In GR-II, exsolution of a NaCl-rich fluid caused destabilisation of EGM and precipitation of zircon and quartz. In GR-III, the exsolving fluid was rich in Ca and produced a calcic alteration assemblage.

Figure 1 :

 1 Figure 1:

Figure 2 :

 2 Figure 2:

Figure 3 :

 3 Figure 3:

Figure 4 :

 4 Figure 4:

Figure 5 :

 5 Figure 5:

Figure 6 :

 6 Figure 6:

Figure 7 :

 7 Figure 7:

Figure 8 :

 8 Figure 8:

Figure 9 :

 9 Figure 9:

Figure 10 :

 10 Figure 10:

Table 2 .

 2 In this Figure, EGM is ultimately replaced by zircon and quartz through an intermediate step consisting of an unidentified Ca-zirconosilicate with higher Ca and Zr and lower Fe and Mn contents than the original EGM. All of Na, Cl, Nb, and most of the REE have been lost. REE-rich and Zr-rich phases co-crystallized with the Ca-

	zirconosilicate but were not analysed with EPMA due to their very small size. Secondary zircon
	is characterized by a low ZrO2 content (57.8 wt. %), a low sum of oxides (91.5 wt. %) and the
	presence of Fe and Ca. In GR-III, replacement of EGM involved an intermediate phase slightly

enriched in Si (Fig.

9a-b

). The replacing phase is an unidentified Ca-Na zirconosilicate lacking Cl, REE, Mn, and Fe.

Acknowledgements

Financial support for this research was provided by a CESSUR grant from the French Institut National des Sciences de l'Univers to Stefano Salvi, and by the company Tantalus Rare Earth A.G., who also kindly provided access to the Ambohimirahavavy complex and logistical support during fieldwork. We would like to thank Wolfgang Hampel for his invaluable help in the field, Olivier Bruguier for laboratory assistance with the LA-ICP-MS and Sophie Gouy, Philippe De Parseval and Thierry Aigouy for assistance with EPMA and SEM analyses. We are grateful to Roger H. Mitchell and Iain Samson for their constructive and thorough reviews, which helped improve the quality of this manuscript.


Koleen Mccrink
email: kmccrink@barnard.edu

Keywords: Space, Number, Quantity, Magnitude, Neonates, Lateralization

Forty-eight newborn infants were tested in one of three multimodal stimulus conditions, in which auditory quantities were presented alongside visual object arrays in two test trials. These tests varied with respect to which side (either left or right) numerically matched the auditory number. The infants looked longer to the test trials in which the left side of the visual display exhibited a quantity that matched the presented auditory quantity. This study provides the first evidence for an untrained, innate bias for humans to preferentially process quantity information presented in the left field of vision.

Introduction

The relation between mental concepts of space and number is evolutionarily and developmentally privileged; it has been crystallized into the popular conception of a 'mental number line' in Westernized adults wherein small numbers are associated with the left side of visual space, and large numbers the right [START_REF] Dehaene | The mental representation of parity and number magnitude[END_REF][START_REF] Moyer | Time required for judgments of numerical inequality[END_REF] . Work on populations with little-to-no interaction with the world has documented a similar tendency to spontaneously map quantity to a spatial continuum. Experimentally naïve young chicks [START_REF] Rugani | Is it only humans that count from left to right?[END_REF] and monkeys [START_REF] Drucker | Rhesus monkeys (Macaca mulatta) map number onto space[END_REF] possess a bias to start their search for food on the left side of a set of locations and progress towards the right, seemingly "counting" rightward [START_REF] Rugani | Is it only humans that count from left to right?[END_REF] . Newborn chicks also preferentially orient to small numbers on the left side, and large numbers on the right [START_REF] Rugani | Number-space mapping in the newborn chick resembles humans' mental number line[END_REF] . Work by de Hevia and colleagues [START_REF] Bulf | Small on the left, large on the right: numbers orient visual attention onto space in preverbal infants[END_REF][START_REF] De Hevia | Representations of space, time, and number in neonates[END_REF][START_REF] De Hevia | Number-space mapping in human infants[END_REF][START_REF] De Hevia | Cross-dimensional mapping of number, and brightness by preschool children[END_REF] has demonstrated this left-to-right mental number line in infants as well. Infants learn to order a set of arrays if they are presented from smallest on the left to largest on the right [START_REF] De Hevia | Human infants' preference for increasing left-to-right oriented numerical sequences[END_REF] , but not vice versa, and are quicker to attend to a left-side probe after central presentation of a small number vs. central presentation of a large number (but not a small object vs. large object 6). In a recent study, newborn infants preferentially viewed more-numerous arrays placed on the right side of space, and less-numerous on the left, suggesting that we selectively map few to left and more to right even during the first few days of life [START_REF] De Hevia | At birth, humans associate "few" with left and "many" with right[END_REF] (see also ref. 12). For these young populations, this lateralized relationship is present only when discrete quantity is introduced as a variable to be represented, suggesting that space and number have a uniquely close relationship [START_REF] De Hevia | Cross-dimensional mapping of number, and brightness by preschool children[END_REF][START_REF] Bonn | The association of brightness with number/duration in human newborns[END_REF][START_REF] Dehaene | Space, time and number in the brain: Searching for the foundations of mathematical thought[END_REF][START_REF] De Hevia | Not all continuous dimensions map equally: Numberbrightness mapping in human infants[END_REF][START_REF] Kaufmann L 1 Koppelstaetter | Neural correlates of distance and congruity effects in a numerical Stroop task: an event-related fMRI study[END_REF][START_REF] Pinel | Distributed and overlapping cerebral representations of number, size, and luminance during comparative judgments[END_REF][18] .

According to an evolutionary theory of the mental number line [START_REF] De Hevia | Minds without language represent number through space: origins of the mental number line[END_REF] , a bias to initially fixate on the left side of space is paired with a bias to prefer sequences that increase in magnitude [START_REF] De Hevia | Infants' detection of increasing numerical order comes before detection of decreasing number[END_REF][START_REF] Macchi Cassia | Increasing magnitude counts more: Asymmetrical processing of ordinality in 4-month-old infants[END_REF] , and thus it is in part a spatial bias that yields lateralized processing of number seen in infancy. Several theorists have posited the existence of an innate visual processing advantage for the left side of space [START_REF] Chatterjee | The neural organization of spatial thought and language[END_REF][START_REF] Rugani | Number-space associations without language: Evidence from preverbal human infants and non-human animal species[END_REF] , due to the left visual hemifield being preferentially processed by the right hemisphere of the brain (which is especially dominant for global spatial-attentional processes [START_REF] Vallortigara | Core knowledge of object, number, and geometry: A comparative and neural approach[END_REF] and quantity processing [START_REF] Edwards | Functional brain organization for number processing in pre-verbal infants[END_REF] ). This lateralized processing is especially pronounced when mentally organizing quantities, as seen by a leftward bias when bisecting number lines in near space [START_REF] Longo | Approaching stimuli bias attention in numerical space[END_REF][START_REF] Longo | Space perception and body morphology: extent of near space scales with arm length[END_REF] . The existence of a general bias towards the left hemifield of vision has been documented in the first year of life for faces [START_REF] De Schonen | Hemispheric asymmetry in a face discrimination task in infants[END_REF][START_REF] Deruelle | Do the right and left hemispheres attend to the same visuospatial information within a face in infancy[END_REF][START_REF] Xiao | Eye tracking reveals a crucial role for facial motion in recognition of faces by infants[END_REF] and patterns [START_REF] Deruelle | Pattern processing in infancy: Hemispheric differences in the processing of shape and location of visual components[END_REF] . It is heightened when the task requires holistic processing of stimuli [START_REF] Deruelle | Hemispheric asymmetries in visual pattern processing in infancy[END_REF] , and exacerbated when initially orienting to a stimulus [START_REF] Butler | Are the perceptual biases found in chimeric face processing reflected in eye-movement patterns?[END_REF] . In some studies, it is pervasive [START_REF] Deruelle | Pattern processing in infancy: Hemispheric differences in the processing of shape and location of visual components[END_REF][START_REF] Guo | Left gaze bias in humans, rhesus monkeys, and domestic dogs[END_REF] . For example, infants orient first, and gaze longer, to the left side of everyday objects, upright and inverted faces, and non-human animal faces [START_REF] Guo | Left gaze bias in humans, rhesus monkeys, and domestic dogs[END_REF] . Thus, there is evidence that we have evolved a left visual advantage, present in infancy. To date, however, there is no evidence that this phenomenon is innate, forming the basis for interactions with the world from birth and providing a key component for the early mental number line. Here, we probe for the existence of this left visual advantage in the very first days of life.

Method

We adapted previous methods that probed numerical processing in human newborns across sensory modalities; in particular, newborns fixate longer to visual numerical arrays that match in number an auditory sequence of tones [START_REF] Izard | Newborn infants perceive abstract numbers[END_REF] . We reasoned that if newborns present a left visual advantage, then they would fixate longer to a visual stimulus when its left side contained the same numerical magnitude as an auditory numerical sequence, as opposed to when the same stimulus was inversely oriented (i.e., presenting the critical numerical information on its right side). The auditory stimulus is the "cue" for the infant to use to intermodally match a visual magnitude, and is present in both a familiarization phase (auditory quantity only) and during a testing phase (auditory + visual quantity). Further, drawing from the literature on left visual advantage in older infants and children, we decided to primarily focus on methods that utilize a chimera stimulus [START_REF] Chiang | Development of Perceptual Asymmetry for Free Viewing of Chimeric Stimuli[END_REF][START_REF] Levine | Perceptual asymmetry for chimeric faces across the life span[END_REF][START_REF] Luh | Perceptual asymmetries for free viewing of several types of chimeric stimuli[END_REF] . In these types of displays, a visual stimulus is uneven around a vertical axis, and flipped along this axis for each test trial to ensure maximal similarity on all dimensions except laterality. Early work using chimera-type displays emphasized the use of a serial presentation, tachistoscopically [START_REF] Kimura | Dual functional asymmetry of the brain in visual perception[END_REF] , because this increases the distinctiveness of the two visual hemifields. However, free-viewing of chimeras is also implemented in the literature, and also yields left visual advantage effects [START_REF] Gilbert | Visual asymmetry in perception of faces[END_REF][START_REF] Levy | Asymmetry of perception in freeviewing of chimeric faces[END_REF] .

Because it was unclear how these newborn infants would be interpreting the scenes, with respect to placing their attention, three stimuli sets were created to test for the presence of this left visual advantage. In Experiment 1 (Chimera Fixation), the infants had a centralized fixation point (a 4 cm red star) present during the auditory familiarization period and testing trials, and the display off-and on-set every 10 seconds. The chimeric nature of the stimuli was implemented to encourage global processing, which in other populations increases right hemispheric engagement, and the subsequent left visual advantage [START_REF] Butler | Are the perceptual biases found in chimeric face processing reflected in eye-movement patterns?[END_REF][START_REF] Spagna | Hemispheric modulations of the attentional networks[END_REF] . The display offset and onset of Experiment 1 aimed to encourage initial orienting behavior, which is especially prone to a leftward bias [START_REF] Butler | Are the perceptual biases found in chimeric face processing reflected in eye-movement patterns?[END_REF] . In Experiment 2 (Chimera No Fixation), the same design was used, but the infants saw this fixation point only during familiarization, and the displays were not off-and onset periodically. We removed the fixation point to determine if it was influencing their tendency to perceive the whole scene (critical for the LVA phenomenon) or simply the salient red star. In Experiment 3 (One-Sided No Fixation), the infants saw the fixation point during familiarization, but not test, and the arrays were no longer in the form of a 2-sided chimera.

Here, the less-numerous and more-numerous sets were presented serially across the two test trials, on either the left or right side of the screen. In this way, we simplify the task for the infants, using stimuli that lessened the lateralized competition of the presented set. For all three experiments, it is hypothesized that infants will look longer to test trials in which the leftside visual quantity matches the auditory quantity. (See Fig. 1 for the displays and designs for each experiment and trial type.) Figure 1. Infants were familiarized with a target number of tones, without any visual arrays present. The visual arrays then appeared in the test trials, and moved stroboscopically every 1 second. The tones played throughout the testing trials. Three versions were created, as it is unclear whether at test infants need frequent onsets of the array while fixating (Exp 1), need a fixation point for focus on the center of an array (Exp 1 and 2), or will naturally fixate on the center of the whole screen (Exp 3). Test stimuli consistent with a left visual advantage are bordered in green for this figure.

Participants

A total of 48 healthy, full-term newborn infants successfully completed the study (16 for each experiment; 27 female; mean age = 42.2 hours/31.2 minutes; range = 9 hours 53 minutes to 82 hours 4 minutes). An a-priori power analysis in G*Power [START_REF] Faul | G* Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences[END_REF] was conducted to arise at this number of participants, with 2 measurements (left-side looking, right-side looking), 12 groups (boys and girls, in 6-or 18-familiarization conditions, in 3 experiments), power of 1-Beta = .80, effect size f=.4, and alpha error probability .05. Forty-nine other newborns were recruited and tested but excluded for sleepiness (9), lack of interest in the stimuli (3), crying (9), looking times exceeding the maximum trial length on both test trials (10), experimenter error (6), fussiness (5), postural bias (5) and parental interference (2). All infants had an Apgar score of 10 after 10 minutes. Infants were recruited directly inside the maternity ward, with the authorization of the director of the maternity department at L'Hôpital Bichat-Claude Bernard, Paris, France. All infants were tested in the presence of the mother or father; informed consent was obtained under IRB #00001072 from the institution of the last author.

Stimuli

Numerosities were presented auditorily in the form of sequences of syllables, repeated either 6 or 18 times (see de Hevia et al., 2014, 2017; Izard et al., 2009 for studies using the same syllable sequences). Eight different syllables pronounced by male and female speakers were used. The duration of individual syllables was similar in both auditory sequences such that the total duration of the sequences was shorter for the 6-syllable sequence (1.4 s) and three times longer for the 18-syllable sequence (4.2 s). Therefore, the auditory sequences contained information from both numerosity and temporal information. The silence between two sequences varied randomly between 2 and 3 s.

We conducted three different experiments that were identical for the familiarization phase but differed in the test phase (see Fig. 1). For Experiments 1 and 2, visual stimuli (chimeras) consisted of numerical arrays that contained overall 24 items, and individual elements were spatially arranged in such a way that the left and right sides of the array contained 6 and 18 elements. For Experiment 3, visual stimuli (one-sided arrays) consisted of only one part of the chimeras used in Experiments 1 and 2, therefore containing only either 6 or 18 elements. We used four different stimulus configurations in order to avoid perceptual preferences for specific visual patterns. Chimeras and one-sided chimeras were formed by colored circles measuring each 2.2 cm and moving as an array stroboscopically every 1 second.

Design and Procedure

The paradigm had a familiarization phase (60 s) immediately followed by a test phase (two trials). During familiarization, each newborn heard auditory sequences of syllables, either 6 or 18 syllables, paired with a centered, rotating visual star. Test trials contained the same auditory stimulus as familiarization, now paired with a visual numerical array, presenting the numerosity that matched the auditory stimulus on the left on one trial and on the right on the other trial (bilateral chimeras for Experiments 1 and 2, and unilateral arrays for Experiment 3). The order of the test trials was counterbalanced across participants and familiarization types. Each test trial continued until the baby looked away for two consecutive seconds, or until a maximum trial length of 60 s.

Infants were placed in an infant seat, 60 cm from a 22-inch monitor, and an experimenter stood behind the infant to monitor for potential signs of discomfort. Another experimenter, placed behind the stimuli screen, coded online looking times from the image of a camera directed to the infant's face. Another experimenter coded looking times offline, from the video recording played at slow speed. Because newborns' looks are not always easy to code (if the eyes are not wide open), and online coding was necessarily permissive (for example, if an infant sneezed, the experimenter did not stop the trial), a third experimenter coded looking times offline when the two first coders' judgments differed by more than 5 s (22% of all trials). All coders were blind to the visual, but not the auditory stimuli. Coding was not done for side of screen, but rather whether or not the infant was looking at the screen, or not (so, an 'on-off' coding scheme). The analyses reported are based on the average of the two closest measurements for each trial (the correlation between the two measurements was R 2 = 0.99 for all conditions). If the infant presented signs of distress or drowsiness, the experimenter who coded the looking times online terminated the study before it was completed. Offline coders, who were blind to the experimental conditions, decided when an infant who had completed the study was too drowsy/fussy to be included in the data analyses.

Results

The data were analyzed in a repeated-measures ANOVA over participants' looking times with a within-subject factor of Target Side (Left, Right) and between-subjects factors of Experiment (Chimera Fixation, Chimera No Fixation, One-Sided No Fixation), Familiarization Condition (6 sounds, 18 sounds), and Sex (Female, Male). There was a significant main effect of target side (F(1,42) = 4.77, p = .039, partial η 2 = .12). Overall, these newborns looked longer to the screen when the image presented had a visual magnitude on the left side of space (either of the chimera display, or of the screen in general) that matched the auditory magnitude that played in the background during familiarization and test (Left Side = 43.1 sec, SEM = 2.6; Right Side = 35.0, SEM = 2.9). Of the 48 infants, 30 looked longer when the target appeared on the left side relative to the right side (p = .055, one-side binomial sign-test). There was no interaction of this Target Side factor with Experiment, Familiarization Condition, or Sex. There is an interaction between the between-subjects factors of Experiment and Familiarization Condition (F(2,36) = 4.49, p = .02, partial η 2 .20). Pairwise comparisons, Bonferroni-corrected for multiple comparisons, reveal that infants familiarized to 6 sounds exhibited different looking times across experiments; specifically, infants in the One-Sided No Fixation experiment who heard 6 sounds looked longer to the screen than infants in the Chimera No Fixation experiment. In the Chimera Fixation experiment, infants looked for 43.

Discussion

In the present study, we adopted the use of chimeric stimuli to ask whether neonates guide their behavior by preferentially orienting towards the left side of a numerical array. Since newborns preferentially fixate a visual numerical array that matches a concomitant auditory numerical sequence [START_REF] Izard | Newborn infants perceive abstract numbers[END_REF] , we asked whether they would look longer to a stimulus whose left side contains the target number relative to the chimera version containing it on its right side. Across three experimental conditions, we found a general preference for fixating the visual stimulus whose left side numerically matched the auditory numerical sequence. This finding constitutes preliminary evidence for human newborns spontaneously privileging the left side of visual stimulation, and extends previous findings of this phenomenon in older infants for faces and patterns to numerical/quantity information.

Although we observed a general left-sided advantage across the three experiments, it is important to note that the present findings were not as strong as other phenomena recently described in human newborns using similar methods [START_REF] De Hevia | At birth, humans associate "few" with left and "many" with right[END_REF][START_REF] Izard | Newborn infants perceive abstract numbers[END_REF] . There are two main classes of thought as to why this may be the case. First, the newborn left visual advantage may genuinely be a weak effect, not just statistically but in the mind of the infants. This bias may be present, but only seen on a larger population (N= 48, and not N=16 within each experiment), because it is small or fragile, and additional power is needed to detect it reliably. Second, the attenuated nature of the effect may be due to the fact that in our design there were likely different conflicting processes at play in the infants' minds. First, the visual chimera that conform to the canonical left-to-right oriented mental number line (e.g., contain fewer objects on the left side and more on the right side) might have been treated differently than the paired chimera that was inversely oriented. In fact, a preference for small visual numbers to appear on the left side and large visual numbers on the right has been recently described in newborns [START_REF] Di | A mental number line in human newborns[END_REF] . Our methods were not designed or appropriately powered to control or test for this variable, however.

Another caveat to consider in our study is that it is conceivable that newborns formed a numerical representation of the array in Experiments 1 and 2 whose numerical value (24) was indistinguishable from the auditory number in the 18-syllable sequences, but easily distinguishable from the 6-syllable sequences. If infants were perceiving the test array as '24' (instead of a chimera of 18 and 6), then an increase from 6 auditory tones during familiarization to 24 objects at test would have prompted fixation to the right side of the screen [START_REF] De Hevia | At birth, humans associate "few" with left and "many" with right[END_REF] , dampening the finding of a left visual advantage. This is supported by an examination of how the infants behaved in each familiarization condition; the left visual advantage at test for the infants familiarized to 6 was a mean of 6.4 seconds, whereas the difference between left and right fixation for infants familiarized to 18 was 10.6 seconds. This interaction was not significant within the model, but the overall pattern does suggest that other factors within this design were 'working against' our predicted effect. The chimeric nature of the stimuli was implemented to encourage global processing (which increases right hemispheric engagement, and the subsequent left visual advantage [START_REF] Butler | Are the perceptual biases found in chimeric face processing reflected in eye-movement patterns?[END_REF][START_REF] Spagna | Hemispheric modulations of the attentional networks[END_REF] ), but may have ultimately led to some infants perceiving only the entire array as one single magnitude. Going forward, we are planning future experiments in which the stimuli are more segregated into left and right percepts by increasing the saliency of the two different parts, either by spatially separating them or using different colors for each side.

It is worth noting that our visual stimuli confounded continuous extent (the area taken up by the set) and number (the number of discrete units in the set). In the subfield of numerical cognition, this distinction becomes important, because many theorists have argued that infants either have [START_REF] De Hevia | Perceiving numerosity from birth[END_REF][START_REF] Libertus | Behavioral and neural basis of number sense in infancy[END_REF][START_REF] Opfer | How not to develop a sense of number[END_REF][START_REF] Starr | Evidence against continuous variables driving numerical discrimination in infancy[END_REF] or do not have [START_REF] Clearfield | Number versus contour length in infants' discrimination of small sets[END_REF][START_REF] Leibovich | Behavioral and Brain Sciences. From "sense of number" to "sense of magnitude[END_REF] truly numerical representations that are abstract, and not simply based on perceptual cues such as size, density, or contour length. In the current study, we were solely focused on providing as many cues to quantity as we could to the child, to prompt a strong left visual advantage, insofar as it existed. Future work would aim at disentangling whether both sources of magnitude information contributed to the effect, or only one source of information gave rise to it. Our hypothesis is that this is a non-specific phenomenon that applies to any visual information presented to the newborn infant. However, previous work has found that only the presence of numerical information gave rise to a lateralized spatial mapping of quantity [START_REF] De Hevia | At birth, humans associate "few" with left and "many" with right[END_REF] , which calls for a deeper investigation of this phenomenon to examine whether the left visual advantage is found here only because we included discrete magnitudes as part of the test stimuli.

In sum, we provide here the first evidence for a left visual field processing advantage in the first days of human life. Although we must interpret this new finding cautiously, given the overall strength of the effect, we believe it is in accord with a theory that helps to explain the presence of a mental number line in similar untrained populations. This finding suggests that the nature of visual processing in infancy has behavioral continuity with a prominent visual bias found later in development. It provides an example of how the neural systems devoted to different types of information in the environment are on-line from the first hours of life, and how these systems impact the nature of more-mature systems later in development.

  9 sec [SEM = 4.0] to the Left-Side target and 37.8 [SEM = 4.5] to the Right-Side target. In the Chimera No Fixation experiment, infants looked for 39.5 [SEM = 4.4] to the Left-Side target and 27.9 [SEM = 4.9] to the Right-Side target. In the One-Sided No Fixation experiment, infants looked for 46.0 [SEM = 5.2] to the Left-Side target and 39.4 [SEM = 5.8] to the Right-Side target. Looking at each experiment individually, paired ttests over the looking time to test trials with left-side targets vs. trials with right-side targets reveals no main effect in the Chimera With Fixation experiment (t(15)=.84, =.21), a marginally significant main effect in Chimera No Fixation experiment (t(15) = 1.75, p = .05) and a significant main effect in One-Sided No Fixation experiment (t(15) = 2.03, p = .03). (See Fig 2. for the data, for each Experiment.)

Figure 2 .

 2 Figure 2. Infants' looking times when targets (the visual quantities that matched the auditory quantities) were presented on the left or right side of the screen, as a function of experiment. Error bars represent +/-1 SEM. The † indicates a significant difference at p-value < .10, and the * indicates significance at p-value < .05.

Acknowledgments

We are indebted to the families that participated in these studies. We thank Loona Charbonneau, Schaines Flih, Hausberger, Lucile Jarielle, Yu-Na Lee, and Eloise West for their help in the recruiting of participants and coding of the data. This work was supported by 1R15HD096363-01 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development to KM, and by ANR-15-CE28-0003-01 NUMSPA from the Agence Nationale de la Recherche Scientifique to MDH. The author contributions are as follows: Idea for experiment -KM and MDH; Stimuli creation -KM, MDH, LV; Implementation of study -MDH and LV; Recruiting, testing, and coding of participants -LV; Data analyses --KM;

writing -KM, LV, and MDH.

Competing Interests

The authors have no competing interests to disclose.