J.-C Viennet

C Le Guillou

L Remusat

F Baron

L Delbes

A M Blanchenet

B Laurent

I Criouet

S Bernard

Experimental investigation of Fe-clay/organic interactions under asteroidal conditions

Keywords: Clay minerals, Organic-mineral interaction; Hydrothermal alteration, Asteroids, Carbonaceous chondrites

Carbonaceous chondrites contain both soluble and insoluble organic materials (SOM and IOM) which may have been produced in different environments via different processes or share possible genetic relationships. The SOM may have been produced from IOM during hydrothermal episodes on asteroids, and vice versa. The potential role played by the mineral matrix during these episodes (clay minerals of variable crystallinity) remains to be constrained. Here, we exposed a mixture of formaldehyde and glycolaldehyde with ammonia-bearing liquid water together with Fe-rich smectitic minerals to hydrothermal conditions mimicking asteroidal conditions. We used both amorphous gel of smectite or crystalline smectites in order to understand the influence of the crystallinity on the evolution of OM. The organo-mineral experimental residues were characterized at a multiple length scales using X-ray diffraction and microscopy/spectroscopic tools. Results evidence that some IOM polymerizes/condenses in the absence of Fe-rich smectites. Yet, the presence of Fe-rich smectites inhibits this production of IOM. Indeed, the interactions between the SOM and clay surfaces (interlayers or edges) reduce the concentration of SOM available for polymerization/condensation reactions, a necessary step for the production of IOM. In addition, the presence of OM disorganizes the crystallization of the Fe-rich amorphous silicates, leading to smaller crystal sized particles exhibiting a lower permanent charge. This might suggests that the smectite permanent charge distribution may help better constraining the origin and evolution of chondritic clay minerals. Altogether, the present study sheds new light on the organo-mineral interactions having occurred during hydrothermal episodes onto/within chondritic asteroids. Indeed, IOM formation from OM-rich aqueous fluids does not occur during the alteration of amorphous silicates. This would mean that IOM is either produced within pockets free of clay minerals or initially accreted as IOM-rich grain. Last, about ~50 wt.% of the initial C could not be removed from the clay minerals at the end of the experiments using classical solvent extraction protocols, demonstrating that a high fraction of the SOM in carbonaceous chondrites may have been overlooked.

Introduction

Carbonaceous chondrites (CC) contain up to 5 wt. % of organic matter (OM) dominated by an insoluble fraction (IOM -75 to 90 wt. %) associated with a minor soluble fraction (SOM -10 to 25 wt%) [START_REF] Robert | The concentration and isotopic composition of hydrogen, carbon and nitrogen in carbonaceous meteorites[END_REF][START_REF] Pearson | Carbon and nitrogen in carbonaceous chondrites: Elemental abundances and stable isotopic compositions[END_REF][START_REF] Alexander | The origin and evolution of chondrites recorded in the elemental and isotopic compositions of their macromolecular organic matter[END_REF][START_REF] Alexander | The nature, origin and modification of insoluble organic matter in chondrites, the major source of Earth's C and N[END_REF][START_REF] Sephton | Organic Geochemistry of Meteorites[END_REF][START_REF] Remusat | Organics in primitive meteorites[END_REF]. While the SOM is composed of a diversity of small organic molecules (such as carboxylic acids, amino acids, nucleobases, polycyclic aromatic hydrocarbons, sugars…) [START_REF] Pizzarello | The nature and distribution of the organic material in carbonaceous chondrites and interplanetary dust particles[END_REF], the IOM consists in high molecular weight molecules made of aromatic units and short aliphatic chains rich in hetero-elements [START_REF] Cody | NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups[END_REF]Remusat et al., 2005a;[START_REF] Remusat | Molecular and isotopic behavior of insoluble organic matter of the Orgueil meteorite upon heating[END_REF][START_REF] Alexander | The origin and evolution of chondrites recorded in the elemental and isotopic compositions of their macromolecular organic matter[END_REF][START_REF] Derenne | Model of molecular structure of the insoluble organic matter isolated from Murchison meteorite: Model of molecular structure of Murchison IOM[END_REF][START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF].

The possible genetic relationships between the SOM and the IOM remains a subject of investigations, notably because these compounds, potentially produced in different environments via different processes [START_REF] Kerridge | Origins of organic matter in meteorites[END_REF][START_REF] Remusat | Proto-planetary disk chemistry recorded by D-rich organic radicals in carbonaceous chondrites[END_REF][START_REF] Aléon | Multiple origins of nitrogen isotopic anomalies in meteorites and comets[END_REF], have undergone multiple processes since their accretion onto/by parent bodies [START_REF] Mcsween | Alteration in CM carbonaceous chondrites inferred from modal and chemical variations in matrix[END_REF][START_REF] Brearley | The action of water[END_REF][START_REF] Danger | Exploring the link between molecular cloud ices and chondritic organic matter in laboratory[END_REF]. In fact, the presence of mineral products of hydrothermal alteration (e.g., smectite and/or serpentine phyllosilicates, carbonates and/or sulfides) have been reported in all CCs [START_REF] Brearley | The action of water[END_REF]Le Guillou and Brearley, 2014;Le Guillou et al., 2014;[START_REF] King | Modal mineralogy of CI and CI-like chondrites by X-ray diffraction[END_REF][START_REF] Yesiltas | Associations of organic matter with minerals in Tagish Lake meteorite via high spatial resolution synchrotron-based FTIR microspectroscopy[END_REF][START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF][START_REF] Changela | Hydrothermal evolution of the morphology, molecular composition, and distribution of organic matter in CR (Renazzo-type) chondrites[END_REF][START_REF] Dionnet | Organic and mineralogic heterogeneity of the Paris meteorite followed by FTIR hyperspectral imaging[END_REF][START_REF] Nittler | A cometary building block in a primitive asteroidal meteorite[END_REF][START_REF] Vollmer | Isotopic compositions, nitrogen functional chemistry, and low-loss electron spectroscopy of complex organic aggregates at the nanometer scale in the carbonaceous chondrite Renazzo[END_REF].

Recent laboratory experiments demonstrated that IOM may form from SOM under asteroidal hydrothermal conditions. In fact, when exposed to 150°C, a mixture of formaldehyde and glycolaldehyde within liquid water containing ammonia will evolve into a diversity of soluble compounds together with macromolecular organic solids sharing similarities with the chondritic IOM through formose and condensation reactions [START_REF] Cody | Establishing a molecular relationship between chondritic and cometary organic solids[END_REF][START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity[END_REF][START_REF] Kebukawa | Molecular evolution during hydrothermal reactions from formaldehyde and ammonia simulating aqueous alteration in meteorite parent bodies[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF]. Similar results were obtained using HMT (Hexamethylenetetramine -Vinogradoff et al., (2018)), i.e. the main product component of interstellar ice analogs [START_REF] Bernstein | Organic Compounds Produced by Photolysis of Realistic Interstellar and Cometary Ice Analogs Containing Methanol[END_REF][START_REF] Cottin | Production of Hexamethylenetetramine in Photolyzed and Irradiated Interstellar Cometary Ice Analogs[END_REF][START_REF] Vinogradoff | New insight into the formation of hexamethylenetetramine (HMT) in interstellar and cometary ice analogs[END_REF]. This molecule decomposes into formaldehyde and ammonia in water at temperature > 70 °C [START_REF] Meissner | Continuous Production of Hexamethylenetetramine[END_REF][START_REF] Blazzevjic | Hexamethylenetetramine, A Versatile Reagent in Organic Synthesis[END_REF] producing solid macromolecular carbon insoluble in organic solvents within a few days at 150°C [START_REF] Vinogradoff | Evolution of interstellar organic compounds under asteroidal hydrothermal conditions[END_REF].

Yet, the possible role played by smectites in the production of IOM from SOM under asteroidal hydrothermal conditions (i.e. ~50 to ~200°C [START_REF] Brearley | The action of water[END_REF]) requires further investigations. In fact, smectites closely associated to OM have been reported in chondrite matrices [START_REF] Pearson | Carbon and nitrogen in carbonaceous chondrites: Elemental abundances and stable isotopic compositions[END_REF][START_REF] Garvie | Prebiotic carbon in clays from Orgueil and Ivuna (CI), and Tagish Lake (C2 ungrouped) meteorites[END_REF]Le Guillou and Brearley, 2014;[START_REF] Guillou | Widespread oxidized and hydrated amorphous silicates in CR chondrites matrices: Implications for alteration conditions and H2 degassing of asteroids[END_REF][START_REF] Yesiltas | Associations of organic matter with minerals in Tagish Lake meteorite via high spatial resolution synchrotron-based FTIR microspectroscopy[END_REF][START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF][START_REF] Changela | Hydrothermal evolution of the morphology, molecular composition, and distribution of organic matter in CR (Renazzo-type) chondrites[END_REF] and recent experimental studies have revealed that smectitic clay minerals may have a strong influence on organic reactions under hydrothermal conditions [START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF]Vinogradoff et al., 2020a, b). While OM may influence smectite crystallization [START_REF] Jacquemot | The degradation of organic compounds impacts the crystallization of clay minerals and vice versa[END_REF], clay minerals may promote/catalyze various organic reactions (including cyclization, dehydration, Michael-addition…) even at temperatures below 100°C [START_REF] Nagendrappa | Organic synthesis using clay and clay-supported catalysts[END_REF][START_REF] Nagendrappa | Organic Reactions Using Clay and Clay-Supported Catalysts: A Survey of Recent Literature[END_REF]. This is particularly the case of Fe-rich clay minerals, because the reactivity of some organic reactions in liquid water are enhanced in appropriate redox conditions [START_REF] Lewan | Experiments on the role of water in petroleum formation[END_REF][START_REF] Seewald | Aqueous geochemistry of low molecular weight hydrocarbons at elevated temperatures and pressures: constraints from mineral buffered laboratory experiments[END_REF][START_REF] Mccollom | Carbon isotope composition of organic compounds produced by abiotic synthesis under hydrothermal conditions[END_REF][START_REF] Pan | Kerogen pyrolysis in the presence and absence of water and minerals: Amounts and compositions of bitumen and liquid hydrocarbons[END_REF][START_REF] Mccollom | The influence of carbon source on abiotic organic synthesis and carbon isotope fractionation under hydrothermal conditions[END_REF][START_REF] Lewan | Role of water in hydrocarbon generation from Type-I kerogen in Mahogany oil shale of the Green River Formation[END_REF][START_REF] Foustoukos | Oxidation pathways for formic acid under low temperature hydrothermal conditions: Implications for the chemical and isotopic evolution of organics on Mars[END_REF][START_REF] Mccollom | The influence of minerals on decomposition of the n-alkyl-α-amino acid norvaline under hydrothermal conditions[END_REF].

Here, we document the hydrothermal evolution of a mixture of formaldehyde and glycolaldehyde within liquid water containing ammonia in the presence of Fe-rich smectitic phase, either amorphous or crystalline. The organo-mineral experimental residues were characterized at a multiple length scale using X-ray diffraction and advanced microscopy and spectroscopy tools, including infrared spectroscopic, scanning electron microscopy, scanning transmission X-ray microscopy coupled with X-ray absorption near edge spectroscopy and scanning transmission electron microscopy coupled with energy dispersive X-ray spectroscopy.

Materials and methods

Starting Materials

The organic starting material used for the present experiments is similar to that of previous studies [START_REF] Cody | Establishing a molecular relationship between chondritic and cometary organic solids[END_REF][START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity[END_REF][START_REF] Kebukawa | Molecular evolution during hydrothermal reactions from formaldehyde and ammonia simulating aqueous alteration in meteorite parent bodies[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF]. As done by [START_REF]Borate Minerals Stabilize Ribose[END_REF], paraformaldehyde (1.5 mmol -45 mg -Sigma Aldrich) and glycolaldehyde (1.5 mmol -45 mg -Sigma Aldrich) were mixed within 2mL of pure water in which was added 12 mg of Ca(OH)2 (Sigma Aldrich). Nitrogen was added as NH4OH (20 µl -14.8N -Sigma Aldrich) establishing the initial atomic N/C value at 0.1 (33 wt.% of C and 3.8 wt.% of N).

Pure nontronite (Na0.4(Fe(III)2)(Si3.6Fe(III)0.4)O10(OH)2) was used as the Fe-rich smectitic mineral phase. An amorphous gel of nontronite was obtained by mixing SiNa2O3.5H2O (Sigma Aldrich) and Fe(III)Cl3.6H2O (Sigma Aldrich) following the procedure detailed in [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF] and [START_REF] Petit | Synthesis of nontronite and other Fe-rich smectites: a critical review[END_REF]. Salts and cations in excess were removed via filtration. The crystalline nontronite was synthesized by submitting the amorphous gel of nontronite to hydrothermal conditions (3 days at 150°C -Water/Gel of 3/50) in PTFE Parr© reactors. Washing with dichloromethane was performed to remove potential organic contamination. These mineral starting materials were then dried at room temperature (~ 25°C) over a day.

Laboratory Experiments

A first experiment was conducted in the absence of mineral. Confirming previous studies [START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF], this experiment led to the production of IOM. For the experiments with minerals, 100 mg of either the crystalline nontronite or the nontronite gel were added to the 2 mL solution containing the organic mixture. These organo-mineral mixtures were introduced within titanium Parr© reactors loaded with 1 bar of Ar before closure and placed at 150 °C for 3 days (making them reach an authigenic water pressure of 5 bars). Note that, the NH4OH solution was introduced the latest, just before closing the reactors to avoid degassing of NH3(g). In agreement with previous studies [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF], after 3 days at 150 °C, the amorphous gel crystallizes in the absence of the organic mixture [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF] and the IOM yield is maximal in the absence of mineral [START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF].

The experimental residues were filtered and washed with ultrapure water and dichloromethane (DCM) to remove the free soluble organic compounds (i.e. the soluble organic compounds not retained by the solid phases) and dried under vacuum (3.10 -4 mBar) before characterization. Ten milligrams of each solid residue were subjected to HF/HCl dissolution protocols (Remusat et al., 2005b) to isolate the IOM possibly produced during the experiments. A 2:1 volume ratio HF/HCl (16/2 N) treatment was conducted for 24 hours, at room temperature. Note that, no IOM was recovered from the experiments with minerals. Control experiments without the organic mixture were also conducted to ensure the absence of contamination (Table S1 -Figure S1).

Characterization techniques

Elemental analyses

Total carbon and nitrogen contents were determined using a Flash2000, Thermo Fisher, elemental analyzer operating at the Service de Spectrometry de Masse Isotopique du Museum (SSMIM) at MNHN in Paris (France). A mass of 1 mg of each residue was combusted under oxygen/helium flux at 1020°C. The N2 and CO2 released by combustion were separated by a chromatography column and quantified using a thermal conductivity detector. Alanine was used as standard giving uncertainties at 0.1 wt. % for N and 0.2 wt. % for C.

XRD

The X-ray diffraction (XRD) patterns were obtained on a Panalytical X'pert Pro MPD 2 circles operating at IMPMC (Paris, France) The divergence slit, the anti-scatter slit and the two Soller slits were set at 0.5°, 1°, 0.04° and 0.04 radian, respectively. The bulk XRD measurements were performed on powder preparations throughout the 3-65 °2θ CoKα1,2 angular range (step size of 0.033 °2θ, counting time per step of 250 ms). The experiments dedicated to OM location were performed on oriented preparations at both atmospheric pressure and under vacuum (3.10 -4 atmosphere) at 20 °C using an Anton Parr HTK 1200 oven coupled to an EDWARDS RV3 pump throughout the 3-12 °2θ CoKα1,2 angular range (step size of 0.033 °2θ, counting time per step of 250 ms).

MIR

Mid-infrared (MIR) spectra were recorded in the 400-4000 cm -1 range with a 4 cm -1 resolution using a Nicolet 6700 FTIR spectrometer (IMPMC, Paris) equipped with a KBr beamsplitter and a DTGS-KBr detector, under ambient conditions by averaging 200 scans obtained in attenuated total reflectance (ATR) geometry using a Specac Quest ATR device fitted with a diamond internal reflection element. Transmission MIR spectra were obtained in the 400-4000 cm -1 range with a 4 cm -1 resolution using a Nicolet™ iS™ 50 FTIR spectrometer (IMPMC, Paris) equipped with a KBr beamsplitter, an Ever-Glo source and a DTGS-KBr detector, by averaging 200 scans from KBr pellets dried at 110°C obtained by mixing 1 mg of samples with 150 mg of KBr (Sigma Aldrich).

SEM

Scanning electron microscopy (SEM) investigations were performed on powders deposited on carbon tape using the SEM-FEG ZEISS ULTRA 55 (IMPMC, Paris) equipped with a Bruker EDS QUANTAX detector (Bruker Corporation, Houston, TX, USA). Images shown here (secondary electrons) were collected using an acceleration voltage below 2 kV, thereby preventing irradiation damages.

Cryo-ultramicrotomy

Cryo-ultramicrotome sections (100 nm thick) were prepared for X-ray absorption near edge structure (XANES) and transmission electron microscopy (STEM) investigations using a Leica cryo-ultramicrotome at UMET (Lille, France) following a recently developed protocol [START_REF] Jacquemot | The degradation of organic compounds impacts the crystallization of clay minerals and vice versa[END_REF][START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF]. Powders of experimental residues were mixed with 0.1 ml of deionized water, then a drop of the mixture was frozen in liquid nitrogen at -120 °C and cut. The ultrathin slices of residues were then deposited on holey carbon film TEM grids (coated with a ~3 nm chromium layer).

XANES

XANES data were collected using the HERMES STXM beamline at the synchrotron SOLEIL [START_REF] Belkhou | HERMES: a soft X-ray beamline dedicated to X-ray microscopy[END_REF][START_REF] Swaraj | Performance of the HERMES beamline at the carbon K-edge[END_REF]. Beamline optical elements were exposed to a continuous flow of pure O2 to remove carbon contamination. Energy calibration was done before measurements using the well-resolved 3p Rydberg peak of gaseous CO2 at 294.96 eV. XANES data were extracted from image stacks collected at energy increments of 0.1 eV over the carbon (270-350 eV) absorption range with a dwell time of ≤ 1 ms per pixel to prevent irradiation damage [START_REF] Wang | Radiation damage in soft X-ray microscopy[END_REF]. Alignment of stack images and extraction of XANES spectra were done using the aXis2000 software. The C-XANES spectra shown here correspond to homogenous carbon-rich areas of several hundreds of square nanometers. Following the method described in Le Guillou et al. (2018), background was subtracted using a power law before spectra were normalized to the carbon quantity by integrating the spectra from the pre-edge region up to the mean ionization energy (e.g. 282.0-291.5 eV at the C K edge).

TEM

Scanning transmission electron microscopy (STEM) and electron dispersive spectroscopy (EDS) mapping were performed using a Thermofisher Titan Themis 300 microscope operated at 300 keV, at the "centre commun de microscopie -CCM" at the University of Lille. High resolution images were obtained in STEM mode using the high angle annular dark field detector (HAADF), a convergence angle of 20 mrad, a camera length of ~ 150 mm, a beam current below 200 pA and a dwell time between 5 and 10 µs. Hyperspectral EDS data were obtained using the super-X detector system equipped with four windowless silicon drift detectors. The probe current was set at 600 pA with a dwell time of 2 µs per pixel. A key aspect is the post-acquisition processing of the hyperspectral data, performed using the Hyperspy python-based package (de la [START_REF] De La Pena | Electron Microscopy (Big and Small) Data Analysis With the Open Source Software Package HyperSpy[END_REF].

The EDS spectrum at each pixel was fitted by a combination of Gaussian functions for the X-ray lines and a 6 th order polynomial function for the background. Quantification was achieved using the integrated intensities of the Gaussian through the Cliff-Lorimer method [START_REF] Cliff | The quantitative analysis of thin specimens[END_REF], using experimentally determined k-factors. The thickness x density product strongly affects the X-ray reabsorption of the light elements (O, Fe_L). It was determined using the two-lines method [START_REF] Morris | The correction of thin foil microanalysis data for X-ray absorption effects[END_REF], which compares the quantification obtained from the Iron L-lines and Iron K-lines and accurate absorption correction was performed.

Results

MIR spectra of the SOM

In the following, we focus on the characterization of the DCM-washed solid residues. Of note, only the residue produced in the absence of minerals contained IOM, although the free soluble organic compounds extracted using DCM exhibit very similar MIR spectra (Figure 1). The spectra exhibit stretching of O-H or N-H bonds at 3370 and 3200 cm -1 , of aliphatic C-H at 2959 cm -1 and 2920 cm -1 , of C-H of -O-CHx bonds at 2851 cm -1 [START_REF] Kebukawa | Molecular evolution during hydrothermal reactions from formaldehyde and ammonia simulating aqueous alteration in meteorite parent bodies[END_REF], N-H bonds in amide at 1567-1580 cm -1 , of C-H, C-N, O-H bonds at 1412, 1382, 1315 cm -1 , of C-O in alkoxy at 1043, 1076, 1120 cm -1 , and C-H bending in alkene at 928 and 770 cm -1 . Note that the MIR spectra of the initial OM exhibit important differences than for the free soluble organic compounds demonstrating the OM evolution due to the experimental hydrothermalism.

TOC and N/C

Here, we focus on the characterization of the DCM-washed solid residues of experiments. The experiments conducted in the absence of minerals lead to the production of a solid organic residue insoluble in organic solvents, i.e. to the production of IOM. This IOM contains 65 wt.% of carbon (24 % of the initial mass of carbon) and 7.3 wt.% of nitrogen (22.8 % of the initial mass of nitrogen).

In contrast, no IOM was recovered after the dissolution of the silicates using acid demineralization.

The solid residues produced in the presence of the crystalline nontronite or in the presence of the gel of nontronite contain 14.3 and 14.1 wt.% of carbon (54.3 and 50.1 % of the initial carbon, respectively) and 2 and 1.9 wt% of nitrogen (64.4 and 56.2 % of the initial nitrogen, respectively). This OM exhibits slightly higher N/C values (0.12) than those of the starting organic material and of the IOM produced in the absence of minerals (0.10).

Starting Materials

Organic-150°C

XRD

XRD provide information on the nature and crystallinity of the solid fraction of the residues (Figure 2). Nontronite is a smectite made of 2:1 layers composed of an octahedral sheet sandwiched between two tetrahedral sheets. Isomorphic substitution by a lower charge cation in the tetrahedral sheets (Si 4+ substitution by Fe 3+ ) induces a negative charge, called "permanent charge". The latter is compensated by exchangeable cations present either within the interlayer space (originally Na + here) or on the basal planes. In addition, other charges due to crystal defects, such as silanol bonds are present on the edges of the clay minerals sheets.

In the absence of the organic mixture, the gel of nontronite (initially amorphous, as indicated by its XRD pattern -Figure 2) crystallizes into a low charge nontronite, as attested by the XRD peaks at 4.55, 3.15, 2.59, 1.73 and 1.525 Å corresponding to the 0.2.11, 004, 13.20, 15.24.31 and 06.33 reflections of the crystalline nontronite [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. In contrast, in the presence of the organic mixture, the nontronite gel does not crystallize that well. The XRD pattern of the solid residue do not show the 001 reflection. The wide peaks at 4.37, 2.57 and 1.537 Å correspond to the 0.2.11, 13.20 and 06.33 reflections of a poorly crystalline nontronite [START_REF] Baron | Experimental evidence of the metastability of ferric smectite[END_REF]. The crystallinity of the crystalline nontronite also decreases during the experiments conducted in the presence of the organic mixture as evidenced by the broadening of the hkl reflections. In addition, the 001 reflection of the solid residue is shifted to 18.00 Å, likely due to mixed-layer stacking and/or trapping of OM into its interlayer space [START_REF] Laird | Evaluation of the Structural Formula and Alkylammonium Methods of Determining Layer Charge[END_REF][START_REF] Lagaly | Chapter 10.3 -Clay Mineral-Organic Interactions[END_REF][START_REF] Viennet | Investigation of clay mineralogy in a temperate acidic soil of a forest using X-ray diffraction profile modeling: Beyond the HIS and HIV description[END_REF][START_REF] Viennet | Effect of particle size on the experimental dissolution and auto-aluminization processes of Kvermiculite[END_REF][START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF][START_REF] Gautier | Interactions of ammonium-smectite with volatile organic compounds from leachates[END_REF]. Such trapping of organic carbon within the interlayer spaces of the nontronites seems to be confirmed by XRD measurements performed under vacuum (Figure 3). In fact, under vacuum, the distance corresponding to the 001 reflection of the residues produced in the presence of the organic mixture do not collapse, in contrast to that of the crystalline nontronite that were never exposed to the organic mixture. Indeed, only small shifts of their 001 reflections attest that the interlayer spaces of these smectites are locked by organic compounds [START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF].

MIR

Transmission-MIR investigations in the 400-1300 cm -1 range confirm that, the crystalline nontronite is a low charge smectite (Figure 4). In fact, spectra show sharp bands attributed to stretching of Si-O (1008 cm -1 ), bending of Fe 3+ 2-OH (816 cm -1 ), symmetrical stretching of Si-O-Si (780 cm -1 ), [4] Fe(III)-O vibrations (707 cm -1 ), [6] Fe(III)-Oapical vibrations (677cm -1 ) and Si-Oapical- [6] Fe(III) vibrations (around 600 cm -1 ) (Farmer, 1974;[START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. Of note, below 600 cm - 1 and at 840 cm -1 , the attribution of the vibration bands remains complex [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. The band at 3630 cm -1 corresponds to the OH stretching vibrations of water molecules weakly bonded to the oxygen of the silicate lattice (Figure 4, [START_REF] Farmer | Interlayer complexes in layer silicates. The structure of water in lamellar ionic solutions[END_REF]). In addition, the bands at 1632, 3232 and 3353 cm -1 , correspond to the vibrations of OH bonds in H2O. The MIR spectra of the solid residues produced in the presence of the organic mixture exhibit the main absorption bands of nontronite, but these bands are rather wide compared to the sharp bands of crystalline nontronite, also indicating a lower degree of crystallinity [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. Plus, the bands attributed to the stretching of Si-O bonds are shifted at 1028 and 1015 cm -1 for the residues produced with the crystalline nontronite and with the gel of nontronite, respectively, which can be explained by a slightly lower charge compared to that of the starting nontronite [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF].

A lower charge may also explain the lower intensity of the band at 677 cm -1 and the higher intensity of the band at 707 cm -1 , attributed to [4] Fe(III)-O vibrations and [6] Fe(III)-Oapical vibrations, respectively [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF], while interactions with OM may explain the lower intensity of the band at 815 cm -1 , attributed to the bending of Fe 3+ 2-OH bonds. Compared to those of crystalline nontronite, the spectra of the residues produced in the presence of the organic mixture exhibit a broader and less intense band at 3562 cm -1 , corresponding to the stretching of Fe2 3+ -OH in octahedral position [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. This evolution indicates either a lower degree of crystallinity and/or interactions of OM with the structural OH, which is consistent with transmission-MIR data. In addition, the band at 3630 cm -1 , corresponding to the stretching of OH vibrations of water molecules weakly bonded to the oxygen of the silicate lattice [START_REF] Farmer | Interlayer complexes in layer silicates. The structure of water in lamellar ionic solutions[END_REF], is weaker in presence of organics, indicating either a lower degree of crystallinity and/or interactions of OM with the edges of smectites. ATR-MIR spectra also provide information on the chemical nature of the organic fraction of the residues (Figure 4). In addition to a large band centered at 3227 cm -1 attributed to O-H bonds, the spectrum of the IOM produced in the absence of minerals shows bands at 1376 and 1450 cm -1 and at 2872, 2925 and 2964 cm -1 attributed to the bending and stretching of aliphatic C-H, bands at 785 and 877 cm -1 attributed to the bending of aromatic C-H, bands at 1038, 1212 and 1301 cm -1 attributed to the stretching of alcohol C-O, a band at 1692 cm -1 attributed to the stretching of amide/ester C=O and a band at 1556 cm -1 attributed to the bending of amide N-H [START_REF] Bernard | Evolution of the macromolecular structure of sporopollenin during thermal degradation[END_REF]. In contrast, the spectra of the organic compounds trapped within the residues produced from the organic mixture in the presence of the crystalline nontronite or the gel of nontronite show bands at 1383 and 1447 cm -1 and at 2874, 2929 and 2974 cm -1 attributed to the bending and stretching of aliphatic C-H (although the band at 1447 cm -1 may also be attributed to R-NH3 + ), a band at 1314 cm -1 attributed to the bending vibration of phenol C-O, and a band at 1550 cm -1 attributed to the bending of amide N-H [START_REF] Yariv | Organo-clay complexes and interactions[END_REF][START_REF] Gautier | Interactions of ammonium-smectite with volatile organic compounds from leachates[END_REF][START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF].

XANES

The XANES spectra collected at the carbon edge on ultramicrotome sections also provide information on the chemical nature of the organic fraction of the residues (Figure 5). The XANES spectrum of the IOM produced in the absence of minerals shows peaks attributed to aromatic and olefinic carbons (285.0 eV), conjugated aromatic cycles (285.5 eV), heterocycles (286.0 eV), amine/imine/cyano groups and/or ketone and phenol groups (286.5 eV), aliphatic carbons (287.9 eV), amide groups (288.2 eV) and carboxylic groups (288.5 eV) [START_REF] Alleon | Organic molecular heterogeneities can withstand diagenesis[END_REF][START_REF] Guillou | XANES-Based Quantification of Carbon Functional Group Concentrations[END_REF]. No IOM was produced in the presence of the crystalline nontronite, the organic carbon trapped within the solid residue exhibits different spectrum, with peaks at the same energies indicating a roughly similar chemistry, although this carbon appears to contain a bit more aromatic and/or olefinic carbons (285.1 eV), more phenol carbons (287.2 eV) and a bit more aliphatic carbons (287.9-288.5 eV). The organic carbon trapped within the solid residue produced in the presence of the gel of nontronite also contains more aromatic and/or olefinic carbons (285.0 eV) and much more aliphatic carbons (287.9-288.5 eV) and amide groups (288.2), but less heterocycles ( 285.9 eV) and less amine/imine/cyano groups and/or ketone and phenol groups (286.5 eV).

SEM and TEM

SEM and TEM allowed comparing the textures and microstructures of the solid residues (Figure 6). At the micrometer scale, the solid residue produced in the presence of the crystalline nontronite displays the typical layered, flower-like texture of smectites while the solid residue produced in the presence of the gel of nontronite presents a rough and granular surface. These differences in texture correspond to differences in structure/crystallinity as revealed by TEM observations. At the TEM scale, while stacks of ~5 to ~10 layers (~ 10 nm thick along the 100 direction) extending laterally up to 100 nm can be observed within the solid residue produced in the presence of the crystalline nontronite, much smaller particles (< 10 nm) exhibiting less than 3-5 layers are observed within the solid residue produced in the presence of the gel of nontronite, in good agreement with XRD patterns and MIR data. Besides a few grains of Ca(OH)2, both residues appear homogenous.

No individual organic carbon grain can be observed within the solid residues, but in addition to Fe, Si, O and Ca, STEM-EDS data show that carbon and nitrogen are intimately associated with minerals and homogeneously distributed within the solid residues. Although the starting crystalline nontronite contains Na compensating its permanent charge (Na/Si = 0.11), the solid residues do not contain any Na, the permanent charge of the smectites being likely compensated by nitrogen (originating from NH4OH) and calcium (originating from Ca(OH)2). The Fe/Si of the solid residues (0.58 and 0.62) are lower than that of the starting crystalline nontronite (0.66). Of note, considering the theoretical formula of nontronite (M + x(Fe2)(Si4-xFex)O10(OH)2), the mean [4] Fe/Si values correspond to permanent charges of 0.2 and 0.28 in the residue produced in the presence of the gel of nontronite and the crystalline nontronite, respectively. The charge of the starting crystalline nontronite was initially 0.4, confirming the interpretation of XRD and MIR results. Based on the study of [START_REF] Dzene | Influence of Tetrahedral Layer Charge on the Fixation of Cesium in Synthetic Smectite[END_REF], even for synthetic samples with well-controlled chemistry, permanent tetrahedral charge can be modeled by a distribution heterogeneity as highlighted in figure 6.f. The distribution of the permanent charge values appears a lot broader for the solid residue produced from crystalline nontronite compared to the thinner distribution for the solid residue produced from the nontronite gel.

Discussion

Effect of organo-mineral interactions

In the absence of minerals, the organic mixture produces IOM when exposed to hydrothermal conditions at 150 °C for 3 days. This IOM accounts for ~ 10 % of the initial mass of the organic mixture (see Table 1). According to MIR and XANES data (Figures 4 & 5), this IOM contains aromatic cycles, heterocycles, amine/imine/cyano groups and/or ketone and phenol groups, aliphatic carbons, amide groups and carboxylic groups. The chemical structure of this IOM is thus similar to the organic solids produced in previous studies from the same starting material [START_REF] Cody | Establishing a molecular relationship between chondritic and cometary organic solids[END_REF][START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF]. Similarly to what occurred for HMT [START_REF] Vinogradoff | Evolution of interstellar organic compounds under asteroidal hydrothermal conditions[END_REF], the production of IOM from the organic mixture used here occurred via multiple reaction steps, including condensation, dehydration and cyclization reactions involving sugars produced from formaldehyde via the Formose reaction [START_REF] Kort | Reactions of Free Sugars with Aqueous Ammonia[END_REF][START_REF] Weber | The Sugar Model: Catalysis by Amines and Amino Acid Products[END_REF][START_REF] Cody | Establishing a molecular relationship between chondritic and cometary organic solids[END_REF][START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF].

However, the present results show that the same mixture does not produce IOM when exposed to similar conditions in the presence of an amorphous gel of nontronite or in the presence of a crystalline nontronite. In fact, no organic solid is retrieved after the acid dissolution of the solid residues investigated here. This is in agreement with results of a previous study, which indicated that the soluble compounds produced from HMT exposed to hydrothermal conditions in the presence of smectites have a lower molecular weight than those produced from HMT in the absence of minerals (Vinogradoff et al., 2020). The DCM-washed solid residues investigated here contain an important amount of C and N (Table 1), likely under the form of soluble compounds trapped within the interlayer spaces of smectites (Figure 3) and/or adsorbed at the surface of smectites (Figure 4). The organic compounds trapped within the residues are not drastically different from the IOM produced in the absence of minerals from a chemical point of view. Nevertheless, the organics trapped within the residues produced in the presence of the gel of nontronite are more aliphatic and contain less phenol carbons (Figure 4 & 5).

The presence of organic compounds within the interlayer spaces of the smectites is attested by the behavior of their 001 d-spacing under vacuum (Figure 3), while the presence of organic compounds on the edges is attested by the lower absorption of the OH stretching vibrations of water molecules weakly bonded to the oxygen of the silicate lattice (Figure 4). The quantity of organic compounds trapped within the solid residues (about 50% of the initial C and more than 60% of the initial N) is significant considering that only 10 % of the organic mixture is converted into IOM in the absence of minerals (note that this is not a kinetic limitation - [START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF]. Such entrapment of nitrogen may have prevented formation of IOM as [START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF] having noticed that high levels of nitrogen yield more IOM. In fact, because OM present in the liquid phase and the organic compounds trapped within/onto clays minerals share similar moieties (as revealed by MIR (Figures 1 and4) and XANES data (Figure 5)), a threshold effect could be proposed: if the concentration of the reactive species necessary to produce IOM through polymerization/condensations reactions [START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF] is not high enough, the reaction may not proceed. Altogether, the present results demonstrate that the presence of smectitic materials, independently of their degree of crystallinity, inhibits the production of IOM. This likely occurs by trapping organic compounds, hence limiting polymerization/condensation reactions. The presence of clay minerals has thus a strong influence on reactions between organic species.

The reciprocal is also true. When exposed to hydrothermal conditions at 150 °C for 3 days in the absence of the organic mixture, the crystalline nontronite remains crystalline while the gel of nontronite crystallizes (Figures 3 &4). However, the presence of the organic mixture modifies these behaviors: the crystallinity of crystalline nontronite decreases during the experiments, while the gel of nontronite does not produce crystalline nontronite but rather small particles of low degree of crystallinity (Figures 3,4 & 6). Similar behaviors were observed in experiments conducted with gels of (Al,Mg)-rich smectites in the presence of RNA [START_REF] Jacquemot | The degradation of organic compounds impacts the crystallization of clay minerals and vice versa[END_REF][START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF]. As is the case in these studies, the poorly crystalline smectites of the residues investigated here have retained organic compounds, both within their interlayer spaces (Figure 3 - Viennet et al., 2019Viennet et al., , 2020) ) and at their surface (Figure 4 - [START_REF] Viennet | Experimental clues for detecting biosignatures on Mars[END_REF][START_REF] Viennet | Influence of the nature of the gas phase on the degradation of RNA during fossilization processes[END_REF]. The smectites of the experimental residues exhibit lower Fe/Si values according to TEM data (Figure 6), indicating that their permanent charges (corresponding to the number of Si substitutions by [4] Fe in the tetrahedral sheets) is lower than those of the starting crystalline nontronite. Such low permanent charge is also attested by the MIR results showing a shift of the band position of the Si-O bonds and the relative intensity decrease of the bands corresponding to the [4] Fe-O bonds (Figure 4). The distinct distribution of the permanent charge values is also of interest. In contrast to the restricted distribution of the permanent charge values of the solid residue produced in the presence of the gel of nontronite, the solid residue produced in the presence of the crystalline nontronite exhibits a rather wide distribution of [4] Fe/Si values, i.e. a highly variable permanent charge. By analogy with the production of lower charge clay minerals via the alteration of micas by organic acids [START_REF] Jackson | Interlayering of Expansible Layer Silicates in Soils by Chemical Weathering[END_REF][START_REF] Robert | Role du facteur biochimique dans l'alteration des mineraux silicates[END_REF][START_REF] Wilson | The origin and formation of clay minerals in soils: past, present and future perspectives[END_REF], it can be assumed that this wide distribution reflects the alteration by acid-complexation of Fe of the crystalline nontronite during the experiments. While, the sharper distribution of the solid residue produced in the presence of the gel of nontronite would reflect crystallization process from the gel as for smectites produced in inorganic media [START_REF] Dzene | Influence of Tetrahedral Layer Charge on the Fixation of Cesium in Synthetic Smectite[END_REF]. Of note, in contrast to crystallinity, the permanent charge of nontronites is pH dependent [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. The nontronite was synthesized at pH comprise between 12-11.5 [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF]. The presence of CaOH2 in the starting materials of our experiments serves as a buffer for a pH at 11.5-11.7 [START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF]. Yet, such slight decrease of pH would not changes the permanent charge of the nontronites [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF][START_REF] Petit | Synthesis of nontronite and other Fe-rich smectites: a critical review[END_REF]. This decrease is likely related to the presence of organic matter. In any case, the present results demonstrate that the presence of organic materials disturbs the crystallization of Fe-rich smectites possibly as observed with (Al,Mg)-rich smectites in the presence of RNA [START_REF] Jacquemot | The degradation of organic compounds impacts the crystallization of clay minerals and vice versa[END_REF] and/or via complexation as with iron oxides in soils [START_REF] Schwertmann | Inhibitory Effect of Soil Organic Matter on the Crystallization of Amorphous Ferric Hydroxide[END_REF] and affects their permanent charge via the production of organic acids preventing/impacting tetrahedral substitutions [START_REF] Baron | Influence of Aqueous Si and Fe Speciation on Tetrahedral Fe(III) Substitutions in Nontronites: a Clay Synthesis Approach[END_REF].

Implications for carbonaceous chondrites

Asteroid parent bodies accreted organic molecules whose nature and diversity are not yet elucidated, notably because these bodies experienced a multitude of hydrothermal processes, having modified the initial nature of the accreted OM [START_REF] Cody | Establishing a molecular relationship between chondritic and cometary organic solids[END_REF][START_REF] Vollmer | Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites[END_REF]Le Guillou and Brearley, 2014;Le Guillou et al., 2014;[START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF]. The possible genetic relationships between the SOM and the IOM thus remain a subject of speculations: it has been suggested for instance that soluble compounds have formed via the oxidation of solid (insoluble) organic compounds [START_REF] Yabuta | The insoluble carbonaceous material of CM chondrites: A possible source of discrete organic compounds under hydrothermal conditions[END_REF], that IOM have formed through the polymerization of soluble compounds [START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF][START_REF] Kebukawa | Molecular evolution during hydrothermal reactions from formaldehyde and ammonia simulating aqueous alteration in meteorite parent bodies[END_REF], and that phyllosilicates have played a key role in the chemical evolution of both soluble and insoluble compounds (Le Guillou and Brearley, 2014;Le Guillou et al., 2014;[START_REF] Yesiltas | Associations of organic matter with minerals in Tagish Lake meteorite via high spatial resolution synchrotron-based FTIR microspectroscopy[END_REF][START_REF] Changela | Hydrothermal evolution of the morphology, molecular composition, and distribution of organic matter in CR (Renazzo-type) chondrites[END_REF]Vinogradoff et al., 2020a).

The present experimental results provide new clues for understanding the organo-mineral interactions at work under hydrothermal conditions. In agreement with previous studies [START_REF] Kebukawa | Exploring the Potential Formation of Organic Solids in Chondrites and Comets through Polymerization of Interstellar Formaldehyde[END_REF][START_REF] Kebukawa | One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity[END_REF][START_REF] Kebukawa | Molecular evolution during hydrothermal reactions from formaldehyde and ammonia simulating aqueous alteration in meteorite parent bodies[END_REF][START_REF] Kebukawa | A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects[END_REF], the production of IOM occurred during experiments conducted with the organic mixture in the absence of minerals. Yet we show here that the presence of clay minerals, either amorphous or crystalline, inhibits this production of IOM and that the organic compounds trapped within the residues are more aliphatic than the IOM. This is also the case of the diffuse OM intimately associated with clay minerals in chondrites, which has been documented as more aliphatic than the IOM (Le Guillou and Brearley, 2014;Le Guillou et al., 2014;[START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF][START_REF] Changela | Hydrothermal evolution of the morphology, molecular composition, and distribution of organic matter in CR (Renazzo-type) chondrites[END_REF][START_REF] Kebukawa | Nanoscale infrared imaging analysis of carbonaceous chondrites to understand organic-mineral interactions during aqueous alteration[END_REF][START_REF] Dionnet | Combining IR and X-ray microtomography data sets: Application to Itokawa particles and to Paris meteorite[END_REF]. The present results thus suggest that the chondritic IOM may have only form within pockets from which clay minerals or amorphous precursors of clay minerals were absent and/or that IOM grains may have pre-accretionary origins [START_REF] Remusat | Accretion and preservation of D-rich organic particles in carbonaceous chondrites: evidence for important transport in the early Solar System nebula[END_REF].

The quantity of organic compounds trapped within the residues investigated here is significantly higher than that of residues of experiments conducted by Vinogradoff et al. (2020) that the initial crystallinity of the mineral phase also plays a role in the final chemistry and quantities of the organic compounds eventually trapped within. The different trapping capacities of different smectites may explain the highly heterogeneous nature of the matrices of carbonaceous chondrites, both regarding the crystallochemistry of hydrated silicates and the quantity and chemistry of diffuse OM trapped within these mineral phases (Le Guillou et al., 2014;[START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF][START_REF] Changela | Hydrothermal evolution of the morphology, molecular composition, and distribution of organic matter in CR (Renazzo-type) chondrites[END_REF].

The presence of organics partially inhibits the growth of Fe-rich clay minerals such as nontronite (both the particle sizes and the degree of crystallinity of the smectitic clays are lower in residues produced in the presence of the organic mixture). Of note, the least altered carbonaceous chondrites are almost devoid of phyllosilicates and rather contain abundant amorphous silicates [START_REF] Brearley | Matrix and fine-grained rims in the unequilibrated CO3 chondrite, ALHA77307: Origins and evidence for diverse, primitive nebular dust components[END_REF][START_REF] Greshake | The primitive matrix components of the unique carbonaceous chondrite Acfer 094: A TEM study[END_REF][START_REF] Chizmadia | Mineralogy, aqueous alteration, and primitive textural characteristics of fine-grained rims in the Y-791198 CM2 carbonaceous chondrite: TEM observations and comparison to ALHA81002[END_REF][START_REF] Abreu | Deciphering the nebular and asteroidal record of silicates and organic material in the matrix of the reduced CV3 chondrite Vigarano: Matrix in the CV3 chondrite Vigarano[END_REF]Le Guillou and Brearley, 2014;Le Guillou et al., 2014[START_REF] Remusat | Organics in primitive meteorites[END_REF][START_REF] Dobrică | Aqueous alteration of porous microchondrules in Semarkona: Implications for hydration, oxidation and elemental exchange processes[END_REF][START_REF] Dobrică | Amorphous silicates in the matrix of Semarkona: The first evidence for the localized preservation of pristine matrix materials in the most unequilibrated ordinary chondrites[END_REF][START_REF] Vollmer | Isotopic compositions, nitrogen functional chemistry, and low-loss electron spectroscopy of complex organic aggregates at the nanometer scale in the carbonaceous chondrite Renazzo[END_REF]. Still, these amorphous silicates are intimately associated with diffuse OM, which is generally interpreted as having been transported by fluids during hydrothermal alteration episodes (Le Guillou et al., 2014;[START_REF] Vinogradoff | Paris vs. Murchison: Impact of hydrothermal alteration on organic matter in CM chondrites[END_REF][START_REF] Changela | Hydrothermal evolution of the morphology, molecular composition, and distribution of organic matter in CR (Renazzo-type) chondrites[END_REF]. By analogy with the present results, it may be suggested that the crystallization of amorphous silicates during hydrothermal alteration was limited by the presence of organic compounds, while amorphous silicates occurring in organic-poor regions would have crystallized faster/easier, producing relatively big particles relatively poor in OM. In addition, the present study suggests that determining the permanent charge of crystalline phyllosilicates associated to elevated contents of diffuse OM may bring additional constraints on their origin and history. In fact, according to the present results, the alteration of pre-existing crystalline phyllosilicates in the presence of organic compounds should produce smectites exhibiting a highly variable permanent charge while the crystallization of initially amorphous materials should produce phyllosilicates exhibiting a less variable permanent charge.

Last, it has been suggested that the SOM fraction recovered by solvent extraction does not represent the entire SOM pool of carbonaceous chondrites [START_REF] Pearson | Carbon and nitrogen in carbonaceous chondrites: Elemental abundances and stable isotopic compositions[END_REF][START_REF] Alexander | The nature, origin and modification of insoluble organic matter in chondrites, the major source of Earth's C and N[END_REF]

Figure 1 :

 1 Figure 1: ATR-MIR spectra of initial OM and of the free soluble organic compounds extracted

Figure 2 :

 2 Figure 2: XRD patterns of the starting gel of nontronite, the starting nontronite and the solid

Figure 3 :

 3 Figure 3: XRD patterns under ambient pressure and under vacuum of the starting gel of nontronite,

Figure 4 :

 4 Figure 4: Infrared spectra in ATR mode from 4000 to 1300 cm -1 and in transmission mode from

Figure 6 :

 6 Figure 6: (a-b) SEM and (c-d) STEM images of the organo-mineral residues. (e) Chemical maps

  which produced residues containing only 3-4 wt % of C. Although these experiments were conducted under similar conditions, Vinogradoff et al. (2020) used HMT and Al or Fe-rich smectites. Altogether, those results demonstrate the mutual effect of the crystallochemistry of smectites and the composition of OM on the composition of the final organo-mineral assemblages. Plus, the present study evidences

Table 1 :

 1 Carbon and nitrogen contents in solid experimental residues and N/C values.

	Nontronite	Gel-nontronite
	Organics	Organics
	150°C	150°C

Acknowledgements

This work was made possible thanks to financial support from the Agence Nationale de la Recherche (RAHIIA_SSOM, ANR-16-CE29-0015) ANR (project RAHIIA_SSOM -Local PI: LR) and by the European Research Council for funding via the ERC project HYDROMA (consolidator grant agreement No. 819587, HYDROMA). This work was supported by the Paris Île-de-France Region.. We thank Elisabeth Malassis for administrative support, Denis Fiorillo for his expert support with EA-IRMS, Imène Esteve for her expert support with the SEM. The authors wish to acknowledge the workforce of the spectroscopic and X-ray diffraction facilities at IMPMC. Special thanks go to Stefan Stanescu and Sufal Swaraj for their expert support with the HERMES STXM beamline at SOLEIL. The SEM facility at IMPMC is supported by Region Ile de France grant SESAME Number I-07-593/R, INSU-CNRS, INP-CNRS and UPMC-Paris 6, and by the Agence Nationale de la Recherche (ANR) grant number ANR-07-BLAN-0124-01. The TEM facility at the CCM (Lille University) is supported by the Chevreul Institute, the European FEDER and Région Nord-Pas-de-Calais. The HERMES beamline (SOLEIL) is supported by the CNRS, the CEA, the Region Ile de France, the Departmental Council of Essonne and the Region Centre.

Finally, this manuscript has benefited from constructive comments by Dionysis Foustoukos and one anonymous reviewer , as well as from associate editor Eric Quirico

 Vinogradoff et al., 2020a). Here, 50 wt. % of the initial amount of carbon has not been extracted from the residues using classical solvent extraction. Hence, a significant portion of the chondritic SOM could have been retained in chondritic clays and disregarded, especially since the abundance of smectites in carbonaceous chondrites increases with increasing alteration. The present study thus reinforces the need for in situ investigations of OM and/or for the development of new extraction protocols to better document these -so far-unknown chondritic soluble organic compounds.


"Man Made and Remade: the Avatars of Masculinity in Robocop (1987) and its Remake (2014)" Cyril Besson, MCF, Université Grenoble-Alpes, CEMRA, F-38000, Grenoble, France It is tempting to begin with a truism: nothing comes from nothing. This is a belief articulated by many in the twentieth century, among whom George Steiner in After Babel, 1 where he presents culture as a long chain of translations and transformations of verbal, thematic or formal constants. The problem raised by the notion of a syntax of culture, however, is the same as with language, as exemplified by de Saussure's distinction between langue and parole: if all one ever does is move around "building blocks" following the constraints imposed by a system, what of individual creativity? If the question is, generally speaking, of little import to most speakers of a given language, things are different when it comes to art and culture: finding one's voice, embodying a sort of progress for one's chosen form of expression and leaving one's mark on the latter, is what being an artist is about. The question of whether there is such a thing as true artistic singularity might be insoluble (no artist exists, who has not been influenced in some way, no matter how unpleasant the idea might be to him) 2 , but one could say that in the field of popular culture, the twenty-first century inverts the proposition, especially in the collaborative form of art that is the cinema. If there is of course a form of crass commercialism at work behind the bevvy of sequels, spin-offs, and remakes we are subjected to on an almost daily basis, it is also possible to envisage this familiarity the receiver is supposed to recognize in the cultural products he or she is exposed to as built in the works themselves. The spectators' sense of agnition would then only be the flip side of the creators' self-consciousness, recognition and admittance of an overbearing and multifaceted heritage.

In any case, on both ends of the creative spectrum, there is now in popular culture a sense of the inescapability of the reiteration of the same. It is a form of culture that knows itself to be always-already-made, ready-made, easily remade, all too aware that it constantly cannibalizes itself for parts; but if creative novelty is no longer of the essence, might the risk not be a certain disenchantment with art and the potentialities of culture? The sentiment of an exhaustion of the narrative models is certainly greater in genre production than elsewhere; no film today is perceived outside a vast, explicit normative system of reference, quotation and borrowing, and it is the explicitness of this self-reflexivity that characterizes genre fiction today, as the commercial and critical success of so openly referential a director as Quentin Tarantino demonstrates. The creator is no longer homo faber ("man the maker"), but homo fictus ("man modelled"), one is tempted to say.

Not so long ago, however, it was still possible to consider oneself original. In the documentary Flesh + Steel: the Making of Robocop on the Robocop DVD 3 , Paul Verhoeven explains, ingenuously one suspects, that he was not under the impression at the time of the 1 George Steiner, After Babel -Aspects of Language and Translation. London: O.U.P. 1977.

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See for example the many ways in which poets distance themselves from their forefathers and negotiate their debt as inheritors, in Harold Bloom, The Anxiety of Influence, 1973. making of the film that he was stealing from such classics as The Day the Earth Stood Still or Metropolis; even such an obvious connection as J. Whale's Frankenstein and its "mechanical" rendering of Mary Shelley's somewhat more organic creature 4 is discarded as of no or little consequence on the finished product. At best, he was an unwilling inheritor and he wouldn't let the heritage inherit the heir, to transplant Marx's phrase in a new context. The legacy, grudgingly acknowledged though it may have been in 2001, sounds to have been far from stifling for him, at least consciously.

An analogy could be made here with Robocop himself, man-made and yet who eventually turns into the creature no man made. He, too, escapes determinism, after old, dead tissue is almost mystically reanimated with new life. Robocop escaped his programming, on film and as a real-life project, Verhoeven seems to say. However, as a figure, or perhaps a pop culture icon, he created a new model, spawning a prolific if inconsistent franchise composed of sequels, TV movies and series, cartoons, comic-books, and the by-now mandatory remake. Of course, if ever there was a character worthy of being reworked and recycled in the context of mass production, it is this metal man, forged in a system (1980's Hollywood) that was then just beginning to understand the advantages of establishing a template for the purpose of churning out stories; it was about that time, a decade after the success of Star Wars, that the practice of film sequels became truly generalized, as the further adventures of Indiana Jones, John McClane, John Rambo, Axel Foley and their likes testify.

Obviously, the scope of this paper cannot be the whole of the Robocop franchise, or even just the film legacy, although a study of at least Robocop 2 (Irvin Kirschner, 1990) would be interesting, in conjunction perhaps with the more recent publication in comic-book form5 of an adaptation of the original screenplay written for the sequel by Frank Miller, whose Dark Knight Returns (DC Comics, 1986) had been at least tonally a major inspiration for the first film; arguably, this comic constitutes a re-making of Verhoeven's Robocop in its own right, but the elusiveness of this complex object, "Robocop 2," its transmedial nature and problematic shared authorship would make it a daunting task. One thing can be noted, however: the way in which both Irvin Kershner's 1990 film and Frank Miller's comic find it necessary to reduplicate the key episode in the original material by re-staging an erasure through violence of the hero's self: reprogrammed at the hands of "pro-social" forces, Robocop imposes self-willed electrocution upon himself to overcome the determinism of his status as machine. Even once established as a very identifiable figure after the first film, he has to be almost destroyed in order to be "rebuilt" anew. Obviously, this may be seen as symptomatic of the "anxiety of influence" seizing artists acting as continuators, and not creators in the literal sense, an almost meta-artistic comment on their own effort and relation to the original material. However, one has to consider how central the reconstruction of Robocop is to not just those two, but to all the iterations of the figure. The main character's sacrifice is the heart of the matter, as it were, and the most important common denominator 4

The two bolts at the base of the creature's neck were imagined by make-up artist Jack Pierce, and its mechanical, clumsy gestures, robot-like, elude the creature's mastery of bodily motion after a while in the original novel. between all the pieces of the franchise seems to be precisely the re-making of the hero: of Alex Murphy into Robocop, later of Robocop into himself as he should be. The main character's sacrifice, through his martyrdom, expresses the "making holy" (if we follow the etymology of the word "sacrifice") of an ordinary creature, its access to transcendence.

Arguably, then, re-making (and the related question of identity in both senses of the word), as a process is part of Robocop's DNA. The difference between sacrifice as a figure and the more mundane process of film remakes (both re-enactments of sorts) lies in the fact that the former entails repetition with a transcendence, an added value that comes without saying, while what a remake adds to the original is a question that is always subjected to close scrutiny, and open for discussion. Through its evocation of a man being re-made by technological means, and its insistence on sacrifice, Robocop, one could claim, already calls for a remake. Now remaking and sacrificing bear at least this much in common, that in a sense they always rest on an ambivalent celebration of the initial drive. As Jean Ungaro writes,

The celebration of sacrifice in general pertains to (…) ritualized repetition: the sacrificer's gesture performs again the original gesture of the first one to have accomplished the founding act, as repetition refers to what was, what has already happened at another point in time. Sacrificing is a murderous gesture, but at the same time, it is supposed to be a loving gesture, even one of adoration, to be equated with an offering to the mightier powers ruling over both the world and men.

6 [my translation]

In the documentary, Verhoeven acknowledges this dimension for Murphy/Robocop, whom he calls "an American Jesus," and it is striking that he should acknowledge the biblical intertext nothing loath, while refusing to trace his creation's lineage back to a more cinematographic inheritance, by explicitly rejecting, for example, the influence of the design of Fritz Lang's Maria in Metropolis as an inspiration for Robocop's armour. It is worth noting, then, that before his film asks the question, "What does man transcended look like?" it asks, rather, "What does he look at?" Indeed, after Murphy's death, the film fades to black, and when light returns, Robocop is first presented not externally, in terms of his new appearance, but as a point of view, the essence of film one could say -an I reduced to an eye. He first comes into existence through a long sequence filmed in fragmented point of view shots, in a low definition video format, clips that narrate, through his being switched on and off repeatedly, the various stages of the process of his "activation" (a birth more than a rebirth) at the hands of a team of scientists, under the supervision of an ambitious executive. Narratively, the choice of a change in film grammar at this point (subjective camera was not the principal mode of storytelling in the film so far) corresponds to a change in the focus of the story, and even the genre of the film: the fairly conventional, if futuristic, blue collar buddy movie gives way to an examination of the status of the individual when faced to extreme dehumanization from the corporate, capitalistic forces. Resorting to subjective camera here means that the film is no less being reset than the main character, and the fact that the focus should be on Murphy's vision, and not the machinery that produces the "robot-cop," is far from incidental.

Although ensuring continuity through identification with the main character for the spectator (or perhaps forcing it upon the latter), this disconnection of the narrative regime also puts into effect an erasure of the default parameters for the film, and this intradiegetic rebooting paves the way for an ontological sleight of hand. By any right, the creature that survives in the second part of the film is not the man Alex Murphy, or even a man for that matter: the offhand remark from an executive that the scientists can "ditch the hand" that could be saved as they reconstruct the body leaves no doubt as to the preservation of his literal manhood. Even the secondary sex characteristics, we can assume, are gone (what's physically left of Murphy, his head, is completely hairless when he takes off the helmet towards the end). Sexless (as the erasure of his masculinity obviously did not give way to feminization or androgyny), what is left of Murphy 7 is in a sense a tabula rasa, certainly a conundrum in light of gender, an aberration that only a teratology of the sexes could account for. His dis-memberment, however, is only one of the ways through which he might be established as no longer being a member of the class human beings; his lack of a social anchorage, the loss of his status as family man (as his wife and son left the city), is, the film insists, what might truly dehumanize, and as we shall see, devirilize, him. This is the point of the flashbacks regularly interspersed throughout the second part of the film, those ethereal domestic scenes establishing very explicitly a connection through the memory process between who Murphy was before and what Robocop is now. Therefore, the film posits not just a professional continuity between the human cop and the robot-cop, but also one of the mind, and chooses the endurance view of identity over that of identity as perdurance. 8 In other words, the film claims rather counter-intuitively, it is not some minor characteristics from Murphy that endure into Robocop, but some basic, ontological, inalienable principle and, if anything, the imposed metamorphosis was instrumental in confirming his true nature. This is not necessarily true for Robocop himself, as the armour, with its pectoral muscles aggressively on display, corresponds to an athletic physique that leaves little doubt as to what gender the completed creature is to be classified in.

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« … le perdurantisme se représente chaque objet existant au-delà d'un instant comme une somme de parties temporelles connectées. Le temps n'est donc pas un milieu que traverseraient les objets spatiaux comme c'est le cas dans la conception classique de la substance : c'est l'une des dimensions même de leur existence au même titre que les trois dimensions de l'espace euclidien, ce qui vaut au perdurantisme son qualificatif de 'quadridimensionnalisme'. A l'inverse, en considérant que les objets persistent en étant 'entièrement' présnets à chaque instant de leur carrière temporelle, l'endurantisme rejette l'idée même de parties temporelles et refuse de pousser plus loin l'analogie entre le temps et l'espace : les objets existent dans l'espace et au travers du temps ». Filipe Drapeau Contim, in Qu'est-ce que l'identité ? Paris: Vrin, 2010. P. 62. »Ce qui est nouveau et controversé dans le perdurantisme, c'est d'affirmer que les objets ordinaires ont des parties temporelles au même titre que les processus » ; p. 63.

quasi-reflex, but also as a symbol, when he twirls his gun around his finger after every shootout. While the criminals in the film indulge in a rather puzzling phallic arms race culminating with the use of a bazooka, their use of weaponry is purely destructive; Robocop's, by being signed and almost dedicated, celebrates his fatherhood. Tellingly, it is this trick that will lead Lewis to reconcile the figure of Robocop and Alex Murphy, and this recognition validates explicitly what the film posits implicitly. The film's biting social satire doesn't apply to gender roles, and it endorses a strict adherence to the conventional coding of masculinity, exalting strength and fatherhood.

One might think it fares better as far as women are concerned: Lewis, with her urchin cut and gait, is not coded as feminine, and the fact that there is no sexual segregation in the locker room at the police station could be taken as a sign of radical egalitarianism in the workplace, reinforced perhaps by the fact that Murphy is willing to let her use the patrol car they share-if she beats him to it, that is. However, the depiction of the police in the film systematically smacks of testosterone, a notion the film never sets into question or even examines, and one has the feeling that Lewis, who is threatened with rape during an arrest, had to adopt masculine characteristics to survive in this male-dominated environment. Although Murphy/Robocop is surrounded by women (his wife, Lewis, the leader of the team of scientists in the POV sequences, in a sense acting as a surrogate mother at the time of his recreation), Verhoeven never challenges gender roles, in fact. The unfeminine Lewis (a supporting character with no backstory) is not an object of desire for Murphy, while his wife, as she appears in the flashbacks, is "all woman," connoted erotically as a willing and enticing sexual partner. However, the film confines her to the role of Eurydice, evacuated as she is as an active participant in the events of the story: when Robocop visits his now-deserted home; her absence from the premises signifies the limbo of the American dream emptied out, but Robocop will never try and bring her back from this Hades. Unsurprisingly, women are sexually inaccessible for him, and as it cannot cast them in this role, the film uses them as instruments in the validation of the main character's identity: Robocop's first "feat" is to save a woman from rape, Lewis ensures the spectator never questions the equation of Robocop with Alex Murphy through her acknowledgement of the "twirling" as fatherly signature, and the wife (an ethereal Eurydice) is reduced through her absence to a potentially dehumanizing and devirilizing threat that will paradoxically goad the main character towards his revenge, and therefore, a restored sense of completion after it is accomplished.

In José Padilha's remake (2014), Mrs Murphy is not so easily discarded. She is an insistent figure, very much present in the film, so much so that she literally blocks Robocop's way to revenge at one point by placing herself physically on the path of his motorcycle. It is just one of the ways in which she feels (for the spectator) "displaced" in this world, as she seems, to begin with, to come from a genre very different from the action/science-fiction film she actually is in; in attitude and dress, she looks closer to a character one might expect in the context of sentimental melodrama. Be that as it may, she will not be silenced or let herself be "etherized", and even comes to embody the most powerful female figure in any iteration of Robocop 9 , exerting the right of life or death over her dying husband. Contrary to what happens in Verhoeven's film, she is given the choice here between euthanasia or extraordinary treatment when he is killed. The role she plays in his preservation is not just indirect, by not vetoing his reanimation: she also makes a man of him again, her man one could say, by maintaining contact with him during the final stages of his "convalescence," but also by replacing him in his role as family man after his return as a "finished product" on US soil. This is no small feat, and indeed takes an act of faith, as earlier, the film went further than the original by clearly showing what little is left of Murphy, in a scene expressing a sort of sanitized horror: at his own request, "Robocop," while attached to a life-preserving device in a laboratory that might as well be a germ-free room in a cancer ward, is gradually stripped of his limbs and torso, the dispossession culminating in the revelation that at this point, "Alex Murphy" is just a set of lungs, a hand and a head. The sense of his identity does not rest in Padilha's film on the survival of his gaze; there is no fade to black here, no point of view shots that refocus the perspective after a radical break, but "third-person" shots that locate our perception of his identity, and his own 10 , externally. In the original, subjective camera gestured at a "short circuiting" of the structural distance between film and viewer, placing the latter in the character's seat (of consciousness). Since we were experiencing his rebirth through his eyes, our entry point into this fictional world, seeing was believing, and we were in no position to question his nature or identity. By not replicating this narrative device, Padilha refuses to centre the film, and the spectator's point of view, on the character as principle, unchanging or "posthumously" revealed for what he has truly been since the beginning. Instead, he chooses to examine the social mechanisms through which the identity of Alex Murphy is maintained, all evidence to the contrary.

In this respect, it is particularly striking that the film should make so little use of an intriguing premise: in order to improve his fighting skills, the scientist in charge of the rebuild decides to replace Murphy's free will in combat mode with a programme that takes over when necessary. Murphy is unaware of this, but this a serious challenge to the notion that he is, as it were, "his own man." 11 The remake never examines this unacknowledged cybernetic 9

The flip side of the coin, however, is that all the other noteworthy female characters of the original become men: Lewis, the scientist in charge of the programme… 10 He looks at himself in the mirror in this scene, and therefore sees himself "from the outside," in the third person, as others see him.

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Further complicating the issue is Robocop's relation to the images "in his head". In the original, memory images were POV shots, these artifacts from his previous existence being presumably indicative of the presence of his former self in the new shell, interspersed as his former life appeared as fleeting flashes. In the remake, the images from his memory (his death right in front of his house, for example) are not inviolable indications of his preserved identity, but are subjected to a reworking that extends the point of view beyond what Murphy could have seen; when he remembers his death, the scene is presented as it was when we saw it, but a "scanning" of the environment is generated, recomposed, and through extremely fluid camera moves, seamlessly branches with a more omniscient point of view whereby details that Murphy could not have had access to directly are revealed. It is not just that Padilha's Robocop has no specific way of envisioning the world, contrary to the video format denoting his POV in the original; this also means that at the level of the narrative, there is no formal compartmentalization between Murphy's point of view, Robocop's and the spectator's in the film. The reason for this might be tonal and generic, more than the result of advances in special effects. In the original, the satire levelled at American society and politics in the 1980's depended on the recognition by the spectator of boundaries between discourses, exemplified by literal ways of envisioning the world: we came to accept Robocop's video-camera vision as flat, unconstructed, unmediated, paradoxically schizophrenia, but rather posits and enacts a direct continuity between Alex Murphy and Robocop, the catalyst for which is Mrs Murphy. The equivalence between Robocop and Murphy is not of his own accord or volition, contrary to what happened at the very end of Verhoeven's film, where Robocop ultimately claimed for himself the name of the dead policeman. The connection between human and cyborg is validated in the 2014 film through the recognition by his wife that they are one and the same, leading for example to a domestic scene where it takes an act of faith to envision Robocop, clad in full armour, as the father he used to be. However, by having him assume the role, she makes him so, in a process reminiscent of Searle's vision of institutions as creative of the reality around us through their imposition of status-functions on individuals. Here too, only through an operation of sheer willpower does "X count as Y in context C" 12 (Robocop counts as Murphy-the-father in the nuclear family) although his wife, not an institution, is the one to decide on the matter; but isn't her sole function in the film to embody the institution of marriage? Indeed, she is not presented in another context than matrimony, and "her" plot is hardly connected to what one might assume is the main plot, "Robocop's" revenge. This housewife feels like a character transplanted in a genre she's not native to, almost an experiment in genre grafting. However, if she does not challenge the clichés of gender from, say, sentimental films, she does embody a fairly surprising counterpart to the 'rewriting" of gender in the context of action/science-fiction films: from the 1980's onwards, many a female character in the genre 13 has been modelled after Ripley from the Alien franchise (Lewis certainly was), "natural", while the more colourful aesthetics of infotainment in the Newsbreak segments or the gaudiness of the inserted commercials had something outré about them that felt untrue, at best disingenuous. It was clear who the good guys and bad guys were just by looking at their very identifiable "worldviews" as embodied in their respective format. By contrast, Verhoeven's stance was not made literally visible, but had to be inferred by the audience as an overarching perspective, integrating all those on display in the film to presumably transcend them. Although it indulges in satire at times (the attitude of the journalists in US-occupied Tehran at the beginning for example), the remake endeavours (for better or for worse) to place the human element, not the social charge, at its core, and strives to convey a heartfelt quality far removed from Verhoeven's irony. Comparatively, the remake does not distance itself from what it shows, refusing to impose a transcendent point of view judging the society it depicts, that of the 2010's; the blending of Robocop's, Murphy's and the viewer's points of view is symbolical of an attempt at a more immersive quality than in the original.

Another aspect of this tonal change is that where the blame lay on community in the original, it rests on individuals in the remake. The processes (potentially) leading to Murphy's reification were exposed as communal: the up and coming executive may have opposed specific members of the OCP board of directors, but he was a figurehead for a shared ideology, corporatism running amok, presented as an offshoot of "the Old Man's" patriarchal capitalism, incidentally. In the remake, the satirical charge is defused somewhat by displacing this blame from a community to individuals: the allegorical dimension of the CEO is much lessened compared with his model in the first film -but not annihilated altogether. If the two journalists of the Newsbreak segments are replaced by a single host, the latter is far more striking a figure than they ever were; an agitator spouting outrageous discourse in favour of the military-industrial complex, the way he imposes silence on the reluctant representative who wants to pass a bill banning the use of military robots on US soil is reminiscent of the heated exchange between Bill O'Reilly and the French ambassador when France refused to commit to the Gulf War. The film's obvious satire is confined to him, however, while it was generalized in Verhoeven's Robocop.

12 See John R. Searle, The Construction of Social Reality. New York: The Free Press, 1995. P 114 13 One can think of the influence of the fiction of James Cameron here, where women are rarely "feminine" in a conventional sense: Sarah Connor in the second Terminator film, Lindsey Brigman in The Abyss, Max Guevara in the TV series Dark Angel… This is also true in the films of his then-partner, Kathryn Bigelow (Blue Steel, Near Dark…). The female captive in Predator by John McTiernan is another example. that is, "masculinized" or rendered man-like in her aptitude for combat, resolution and resilience. Action/science-fiction films have tended to accept women as active participants in the story (unlike for example Holly Genarro-McClane in Die Hard) only in so far as they tone down femininity to come to share traditionally masculine characteristics, starting with a gift for violence, supposedly a masculine attribute. This is one of the reasons why in Verhoeven's film, Mrs Murphy is removed while Lewis is very much present, although not exactly well delineated. In any case, these films posit a counter model for female characters that, by dint of repetition, turns into no less a cliché than the original attitude (that which consists in depicting necessarily feminine women). These "strong women" figures are fashioned after the traditional male hero, complete with aggressive muscles on display (see Sarah Connor in Terminator 2), and arguably, in the end, the only mode of existence for women in these films is their alignment with this model. The sexist structure is not really challenged; instead, the masculine cliché is just transferred onto some women, those who matter in those films because they share some of the hero's characteristics. Mrs Murphy, as for her, is connoted as very feminine, all the more so as she is little else than an embodiment of Marriage in the film. However, this makes her unconventional in this context, although the film could perhaps have found a different way to justify her existence than to implicitly pit one generic convention (the strong woman with quasi-male attributes) against another (the feminine woman).

However, such a disposition articulates the validation of Robocop/Murphy's masculine identity on her, making sure that she is the cornerstone of their respective positioning along the gender divide; the price to pay is certainly a form of conservatism, as this arrangement does not challenge, but rather re-establishes, conventional gender roles positioning. The only advantage is that Mr and Mrs Murphy's respective roles are not presented as truly interdependent: her defining characteristics (femininity, motherhood…) are never questioned, and they guarantee his position as man, husband, father…, which is entirely predicated upon her being a "true woman." It is in fact her transformative agency on Robocop that will ensure his remaining a man, while other forces (the CEO or even the chief scientist, Robocop's quest for revenge) could very well make him become pure cyborg. What might be of interest here, is that this attitude to gender, or rather the exposition 14 of masculinity not as an intrinsic given but as a product of culture, is part of the remake's larger project: the presentation of the "constructedness" of everything. In its very first seconds, the spectator hears Novack, the journalist implicitly in collusion with the military industrial complex, clearing his throat and indulging in the sort of vocal exercises people who are going to speak in public do. This replaces the lion's roar traditionally accompanying the MGM logo; the implication is that this voice warming up will be no less a lion's roar than what it covers, and it is true that the journalist's aggressiveness makes him a predator more than a balanced "chronicler" of facts. Here again, Padilha's strategy differs from Verhoeven's, even when he does use satire: in 1986, the Newsbreak segments interrupted the course of the narrative and were given as preconstructed blocks, "origin-less" as it were. Here, they are exposed as not pre-constituted but as "in the making," constructs created before our very eyes, and by gaining access backstage, once more, we see things from within not without, although the caricatural aspect of this outrageous discourse will speak for itself. Everything is presented as constructed in the remake, and Robocop himself no less than the rest.

As we have already seen, Verhoeven gave us access to the "remaking" of Alex Murphy only through his eyes, and whatever operations had been performed on him to keep him alive escaped the grasp of the viewer. He might have undergone Christ-like agony, sacrifice, and transfiguration, but in essence, he was made of one block, and external perspectives mattered but little. In the remake, we are exposed to what the original film did not show: the controversy about whether or not he should be let live, the system of production (and a trace of the globalized economy) that makes his survival a possibility, when he tries to escape the facility in China, but also in a sense his own production of himself. While in the original, Murphy saw what he looked like only when (significantly) Lewis held a mirror to him before the last shootout, and noted that it was far too late to do anything about it, in the 2014 film, this moment of self-appreciation comes far earlier: the sanitized horror scene already mentioned, but also, interestingly, during a scene where, before communicating with his wife via a Skype-like programme, he self-consciously examines his own image on the screen to adjust the camera and choose, cosmetically almost, what he is going to reveal of himself, selecting what makes an acceptable picture; this, incidentally, makes him a director of sorts, but in place of the spectator, we find his wife. Whether this was a way of targeting the female demographic is virtually impossible to determine, but in any case, what the film does tell us is that in order to remain a man, he must first be so in the eyes of his wife. His concern for his exotopic image is a sign that the unshakable sense of the masculine ego that prevailed through the use of vision in the first film is not an acceptable focus for Padilha.

While by no means revolutionizing gender as it is appropriated by action/science-fiction films, the Robocop remake at least acknowledges the constructedness of this aspect when the original did not, by positing that everything is produced, including what one might imagine is its core, the masculinity of the hero. It might be seen as a sign of the times, and perhaps of maturity for the genre, that in the 2014 film, Man (artificial or otherwise) is not a given but made and remade, the outcome of a long chain of production, the result of a negotiation between his inner self and his environment.

Masculinity, for Pierre Bourdieu in La domination masculine,15 is first and foremost a rather exacting programme for men; cybernetics is originally the science studying the mechanisms of communication and control, in machines but also men. The cyborg Robocop, "part-man, part-machine, all cop," as the slogan claimed on the film's poster in 1987, was the ideal vantage point from which to begin an examination of how the supposedly deterministic aspect of masculinity is only relative, a matter of social construction. The film's status as remake, implying its confrontation with an original and the necessity for it to exist relatedly to it but also independently from it, may have helped it come to this realization.

Frank Miller, Steven Grant and Juan Jose Ryp, Frank Miller's Robocop issues1-9. Avatar Press, 2003- 2006.

Jean Ungaro, « Le corps sacrificiel du héros » in Frédéric Gimello-Mesplomb (ed.), Le cinéma des années Reagan : un modèle hollywoodien ? P 170 : « La célébration du sacrifice relève en général… de la répétition ritualisée : le geste du sacrificateur refait le geste du premier qui a accompli l'acte originaire, la répétition faisant référence à ce qui a été, à ce qui s'est déjà produit dans un autre temps. Le geste du sacrifice est un geste meurtrier mais il est censé, en même temps, être geste d'amour ou d'adoration, synonyme d'offrande aux puissances supérieures qui commandent à l'existence du monde et des hommes ».

Not "criticism," as the film's goal is not to denounce: see footnote 11 on the "toning-down" of the satirical intent of the remake in relation to the original.

Pierre Bourdieu, La domination masculine. Paris : Editions duSeuil, 2002. Pp. 74-77.