# Strewn field, mineralogy, and petrology of Al Haggounia 001: A unique enstatite chondrite

M. Leili, H. Chennaoui Aoudjehane, B. Devouard, P. Rochette, J. Gattacceca, L. Folco, M. Gemelli, I. Baziotis

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M. Leili, H. Chennaoui Aoudjehane, B. Devouard, P. Rochette, J. Gattacceca, et al., Strewn field, mineralogy, and petrology of Al Haggounia 001: A unique enstatite chondrite. Meteoritics and Planetary Science, 2024, 59 (2), pp.301-320. 10.1111/maps.14119. hal-04427592

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# Strewn field, mineralogy, and petrology of Al Haggounia 001: A unique enstatite chondrite

M. H. LEILI ID<fnref n="1" />*, H. CHENNAOUI AAUDJEHANE ID<fnref n="1" />, B. DEVOUARD ID<fnref n="2" />, P. ROCHETTE ID<fnref n="2" />, J. GATTACCECA ID<fnref n="2" />, L. FOLCO ID<fnref n="3" />, M. GEMELLI ID<fnref n="3" />, and I. BAZIOTIS ID<fnref n="4" />

*(Received 08 November 2021; revision accepted 14 December 2023)*

**Abstract**–In this work, we investigate macroscopic characteristics, magnetic susceptibility, mineralogy, and mineral composition of Al Haggounia 001. The samples were collected during eight field missions in the period between 2015 and 2019. In the strewn field of about 65 km in length, the specimens are found either on the surface or shallowly buried in loose sediments, which rules out the previous suggestions that this meteorite is a fossil meteorite. Macroscopically, the samples exhibit three major lithologies with various colors, porosities, and distributions of oxidized veins. The data obtained using transmitted and reflected light microscopy, scanning electron microscopy, and electron microprobe analysis confirm the macroscopic observations and show a heterogenous distribution of silicates and metal sulfides. Al Haggounia 001 is composed of enstatite, plagioclase, kamacite, taenite, schreibersite, daubreelite, troilite, graphite, sinoite, and silica polymorphs. We identified a new type of chondrules that are flattened and composed of rods of albite and enstatite, as well as elongated nodules of metal and sulfides, in addition to compression fractures in the form of subparallel veinlets. These features presumably reflect the deformation caused by shock. The magnetic susceptibility of Al Haggounia 001 (4.39 ± 0.20) is much lower than that of usual EH (5.48 ± 0.16) and EL (5.46 ± 0.04) chondrites but is in the range of E finds (5.05 ± 0.43). The thermomagnetic and hysteresis measurements are controlled by type, size, distribution of metal-sulfide nodules, arrangement of oxyhydroxide veins, and weathering. Al Haggounia 001 is an anomalous meteorite with a polymict nature. It records multiple events revealing its unique origin which expands the groups of enstatite chondrites and provides insights into the complex formation and evolution history of their parent body.

## INTRODUCTION

Enstatite chondrites (ECs) are highly reduced meteorites divided into EH and EL groups based on their siderophile and rare earth element contents (Kallemeyn & Wasson, 1986; Weeks & Sears, 1985). The presence of

ECs that are distinctly different from “ordinary” EH and EL chondrites led to the suggestion of new subgroups (Weyrauch et al., 2018) and possible new groups of these meteorites (Goss et al., 2023; Weisberg & Kimura, 2012). ECs contain up to 60–80 vol% enstatite, which is the Mg-rich endmember of the orthopyroxene solid-solution

<footnote n="1">¹GAIA Laboratory, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Casablanca, Morocco</footnote>

<footnote n="2">²France Aix Marseille University, CNRS, Coll France, IRD, INRAE, CEREGE, Aix-en-Provence, France</footnote>

<footnote n="3">³Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy</footnote>

<footnote n="4">⁴Laboratory of Mineralogy and Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Athens, Greece</footnote>

<footnote>*Correspondence</footnote>

<footnote>M. H. Leili, GAIA Laboratory, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Km 8 Route d'El Jadida, Casablanca, Morocco.</footnote>

<footnote>Email: mohamedhassanleili@gmail.com</footnote>
series (Krot et al., 2009; Norton, 2002). They also contain much more metal (~10 vol%) than any other class of chondrites (Barrat et al., 2014; Weisberg et al., 2006). ECs have been considered possible analogs for Mercury (Wasson, 1988) and are believed to have formed in the inner solar system (Lin, 2022). Their silicates, sulfide, and metal compositions reflect strongly reducing conditions during their formation in the innermost region of the solar system (Keil, 1968; Larimer, 1968). ECs are also of particular interest to meteoriticists since they display compositions matching those of Earth building blocks (Goss et al., 2023).

Thousands of individual stones believed to represent Al Haggounia 001 finds were collected from a strewn field east of the city of Laayoune, in the southern Moroccan desert (Chennaoui-Aoudjehane et al., 2007; Rubin, 2016), in the Tarfaya Basin (TB), which is one of the largest structural basins extending from the African continent into the eastern Atlantic Ocean (Hafid et al., 2008; Michard et al., 2008). According to the Meteoritical Bulletin Database (MBD), Al Haggounia 001 has been paired with 17 NWA meteorites (002, 1067, 2736, 2828, 2965, 4232, 4295, 4450, 4561, 4844, 4919, 6153, 7401, 14248, 12962, 13210, and 14163) (Table S1), which have been classified as aubrites (Lowe et al., 2005), unequilibrated EL3 ECs (Kuehner et al., 2006), and EL6/7 and EL impact melts (Rubin, 2016).

Among these paired samples, two have known oxygen isotopic compositions that were measured in previous work, and they all plot along the terrestrial fractionation line (TFL). The analyses of two whole-rock fragments of NWA 2828 (Connolly, Zipfel, et al., 2007) by laser fluorination resulted in the following values: δ¹⁷O = 2.89, 2.90; δ¹⁸O = 5.50, 5.56, and Δ¹⁷O = +0.001, -0.026 (all ‰). For NWA 2736, the following values were obtained: δ¹⁷O = 2.017; δ¹⁸O = 3.732, and, Δ¹⁷O = 0.076 (all in ‰) (Connolly et al., 2006).

The principal aim of this study was to collect specimens of Al Haggounia 001 with their precise GPS coordinates to constrain their distribution in the strewn field. We also provide a detailed study of the geological, geomorphological, and climatic setting of the find area to determine whether Al Haggounia 001 is a fossil meteorite or not. Finally, we investigate the macroscopic, petrographic, mineralogical, and magnetic characteristics of various lithologies from this meteorite, and discuss their possible origins.

## FIELD WORK

We conducted eight field campaigns between 2015 and 2019 in the rural district of Al Haggounia, located 100 km east of the city of Laayoune in the south of Morocco in the TB (Figure 1). We initiated the field work from the

<figure><img src="image_2.png" /><figcaption>FIGURE 1. A map showing the major structures of the Tarfaya Basin, and the possible surrounding regions (adapted after Michard et al., 2008). The red dot indicates the position of the Al Haggounia area in Morocco. The red rectangle shows the area that was subjected to meteorite searching in this study. (Color figure can be viewed at wileyonlinelibrary.com)</figcaption></figure>

topographic depression of Saheb Negd to the Sebkha of Fadda (Figure 2), passing across the wadi of Al Haggounia. The search was carried out following the orientation of the strewn field proposed in the work of Chennaoui-Aoudjehane et al. (2007), with the assistance of two collectors of meteorites who already found samples of Al Haggounia 001; Addi Smara and Mohamed Ouaicha.

The geographic coordinates of the specimens were obtained using a Garmin 72H GPS. We conducted the search exclusively on foot, which is the appropriate method since there are few dark rocks in the area. This made it easier to identify meteorites on the surface, or in the subsurface after digging where some small black to brown oxidized fragments are visible, mixed with friable sediments.

In total, we collected hundreds of fragments from 52 locations (Table S2), ranging from a single 1.4 g stone to a group of stones (2–40 pieces) with a mass of 1500 g. They were found either on the surface or shallowly buried in depth (10–20 cm) within alluvial loose sediments (Figure 2).

## ANALYTICAL PROCEDURES

Fifty-two selected specimens (from 52 locations) were sliced and prepared at CEREGE, France, with a total area of ~400 cm² (represented by 54 polished thin sections and 15 thick sections). We have performed
<figure><img src="image_3.png" /><figcaption>FIGURE 2. (a) Photograph of a sample collected on the surface. The specimens were found in the reg areas (rocky and gravel areas in desert), they were covered with a black desert varnish. (b) Numerous fragments of Al Haggounia 001 meteorite were extracted from the soil after the digging. The white fragments are sedimentary rocks. (Color figure can be viewed at wileyonlinelibrary.com)</figcaption></figure>

petrographic observations using both optical microscopy and scanning electron microscopy (SEM). For mineral composition analyses, we used an electron probe microanalyzer (EPMA).

For optical observations, we used a Zeiss Axio Imager polarizing microscope coupled with an AxioCam-105-color digital camera, at the Dipartimento di Scienze della Terra, Università di Pisa in Italy. For SEM imaging, we used a Hitachi S3000-N equipped with X-Flash Bruker EDX and Spirit software (at CEREGE, Aix-en-Provence, France) and a FEI Quanta 450 ESEM FEG equipped with Energy Dispersive Spectrometer (EDS) Bruker QUANTAX XFlash Detector 6|10 (at Centro per l'integrazione della Strumentazione dell'Università di Pisa, CISUP, Italy). The mineral compositions were obtained using a JEOL JXA-8900 SuperProbe, equipped with four wavelength-dispersive spectrometers (WDS) and an EDS at the Agricultural University of Athens, Greece, at an accelerating voltage of 15 kV and a beam current of 15 nA. Natural minerals and synthetic standards were used to analyze the following elements: Si, Ti, Al, Cr, Fe, Mn, Mg, Ca, Na, K, F, P, Ni, Co, and S. Additional analyses have been carried out at UNITECH COSPECT, at the Dipartimento di Scienze della Terra, Università di Milano, Italy, using a JEOL Superprobe 8200 equipped with five WDS spectrometers, with an accelerating voltage of 15 kV and a beam current of 10 nA.

The magnetic susceptibility ($\chi$) measurements were performed (before proceeding on the petrographic investigations) using the KAPPABRIDGE KLY-2 apparatus and the SM 30—ZH instrument (Rochette et al., 2008), on the 52 selected specimens varying from 1.4 to 151.8 g in weight. The hysteresis parameters of specimens were measured using a Princeton Micromag VSM (Vibrating Specimen Magnetometer) with a noise level of approximately 10–9 Am$^2$ and a maximum applied field of 1T. The coercivity of remanence ($H_{CR}$) was evaluated by DC back-field demagnetization of the saturation remanence (Gattacceca et al., 2014). Thermomagnetic properties of nine measurements were performed (on powdered specimens) using the Kappabridge thermomagnetometer (AGICO, model MFK1 with CS-3 furnace). A detailed description of the methods can be found in the supplementary material of this paper.

## GEOLOGICAL AND PALEOCLIMATE CONTEXTS OF AL HAGGOUNIA 001

### Geological and Geomorphological Setting

The village of Al Haggounia is located in the northern part of the Tarfaya Basin (TB) (Figure 1), which is one of a series of elongated coastal or marginal basins formed seaward of the West African Craton during the Mesozoic and Cenozoic (Hafid et al., 2008). Cretaceous-Eocene marine deposits, including the marly limestones of the Tarfaya Basin (Michard et al., 2008), give way to a
Quaternary sequence deposited at the distal end of the basin, consisting of pelagic carbonate muds overlain by mixed carbonate volcanic sands and silts (Young & Hollister, 1974).

The Al Haggounia region shows a trend of large diversified sedimentary formations. The Wadi Al Haggounia spreads to its confluence with the Wadi Ouinegh, forming the Wadi El Meltgui toward the Atlantic Ocean to the east. The latter (El Meltgui wadi) is transformed into many small rivers called Lemsayel, which cross the dune belts from Asatef in the Moroccan desert to the Atlantic rim in the west.

The sand flow from the geological boundaries of the Tarfaya basin formed parallel small to large dunes in barchan structures, which are oriented NE-SW with ripples extending from Sidi Akhfénir to the south of the wadi of Sagia El Hamra (Laayoune). The estimated average annual migration rate for the barchan dunes derived from satellite imagery in this region is $21.4 \text{ m year}^{-1}$ (Bristow, 2019). Megadunes (corridors of sand dunes) mark a specific recent structure of Holocene sedimentation (Kabbachi et al., 2001), in addition to sediment-filled valleys and frequent depressions and sebkhas (e.g., Tah, Fadda, and Oum Dbaa).

The western and southwestern parts are marked by the Plio-Pleistocene platform (marine formation) that was named "Dalle Moghrebienne," which is composed of sandy limestone (Adnani et al., 2018). The biogeodynamic development began during the Pleistocene to Holocene (Brebion & Ortlieb, 1976).

## Climatic Conditions and Pleistocene Weathering

The African humid period (AHP) in North and West Africa is referred as the Green Sahara period.

According to Lézine et al. (2011) and Aboulahris et al. (2019), the paleoclimatic interpretations suggest that the wet period in the Sahara lasted for a period of 5–15 kyr due to the large amounts of rainfall, where the African paleohydrological range was very rich in water. This allowed the growth of diverse vegetation, permanent lakes, numerous rivers, and human populations (Tierney et al., 2017). At present, the climate, in terms of temperatures and humidity, in the basin is typical of the near semiarid oceanic Atlantic climate. In the analysis of the climate of the Tarfaya coastal basin during the period between 1984 and 2014 (three decades; Adnani et al., 2018), it was determined that the temperature varies between a minimum of 12°C and a maximum of 29°C, with an overall average of 20°C. Precipitation was described as a rare event with an average of 0.45 mm per day and 164 mm per year. Also, the high relative humidity (between 70% and 80%) with a sharp drop in air temperature on clear nights leads to the condensation

of atmospheric moisture. Since the atmospheric humidity normally enhances chemical weathering, these conditions promote the destruction of metal-rich meteorites such as ordinary chondrites (Aboulahris et al., 2019).

## RESULTS

### The Strewn Field of Al Haggounia 001

The collected samples were found following a SW-NE direction (Figure 3), consistent with the direction suggested by Chennaoui-Aoudjehane et al. (2007). The large pieces were found in the northwest of Wadi of Al Haggounia. Many small pieces were found in the southern-east area and between the dunes of Asatef (Mega-Barkhans). From Amat Rjim, we began to find some excavations with small meteorite debris. In the salt deposit of Sebkha Fadda, we found two old digging sites at a depth of $\le 0.7 \text{ m}$, following the same direction (Point 1: lat: 27.674456 and long: -12.363876; Point 2: lat: 27.628431 and long: -12.370939) (Figure 3).

### Petrography and Mineralogy

#### Macroscopic Aspect of the Specimens

Macroscopic examination of the rocks revealed a heterogeneous sampling, often within the same location. The specimens have a color ranging from bluish-gray, brownish, to dark brown. They all lack fusion crust and are weathered and rusted to varying degrees. Graphite (mm-sized) is frequently observed in most of the samples ($\le 1 \text{ vol%}$) after slicing. We also identified abundant millimetric radial pyroxene (RP) chondrules, and white clast-like material with rounded to elongated shapes they are defined hereafter as macrochondrules. The color, porosity, arrangement of the oxyhydroxide veins (no preserved veins of metal or sulfides were detected in the current study), and distribution of metal-sulfide nodules and chondrules all differ from one sample to another. Three main lithologies have been distinguished:

##### Lithology A (LA)

Characterized by porous bluish to gray material inside, and yellowish to light brownish outside, with no veins but a few oxidized cracks. Millimetric voids are observed. No metallic reflectance is detected. Round millimetric to subrounded abundant white shapes (wsh) are visible, in addition to multiple millimetric graphite grains with a gray reflectance (Figure 4a,b).

##### Lithology B (LB)

Composed of light to dark brown fragments, which are characterized by a subparallel arrangement of thin, unidirectional veinlets filled with oxyhydroxides. These
<figure><img src="image_4.png" /></figure>

FIGURE 3. A map of the Tarfaya basin between 13°20′W to 12°10′W and 27°N to 27°50N. The map degitized from the map of the Instituto geologico y minero de espana con colaboracion del departamento de investigacions petroliferas de auxine, s.a (Primera edicion—Madrid 1971) and the map from Editions du Service géologique du Maroc (Maquette achevée en 1977— révisée en 1982) Notes et Mémoires N° 260—Carte publiée en 1985. The blue stars indicate the distribution of Al Haggounia 001 finds. Two red stars show two digging locations of large fragments. The red ellipsoid represents the strewn field of Al Haggounia 001, which is 65 km in length. The geological map was georeferenced and digitized using ArcGIS software. (Color figure can be viewed at wileyonlinelibrary.com)

fragments show a fractured exterior, with cracks filled with white-colored terrestrial products, and sand silica grains (Figure 4c,d). Large, white chondrules with rounded to ellipsoidal shapes are observed (Figure S1).

## Lithology C (LC)

This lithology is found in dark-brown to black samples. It is distinguished by irregular and abundant shining metallic grains generally located in its outermost parts, as well as rare interconnected veins with a brownish color. Silica grains with whitish terrestrial material are found in the fractures (Figure 4e,f). The voids are not observed.

Both lithologies LA and LB were collected in the same location. The same goes for LB and LC. This implies that all collected samples are from the same fall of Al Haggounia 001.

## Optical Microscopy

The microscopic investigations confirm our macroscopic findings, in which we found that the samples are lithologically diverse. The samples contain rusty material and terrestrial products filling the fractures. The matrix contains recrystallized, mostly fractured orthopyroxene and rarely unfractured pyroxene crystals exhibiting an undulatory extinction. But we did not observe any undulose extinction in plagioclase. Reflected light observations indicate that the opaque phases (metal and sulfides) are mostly located in the matrix, and often occur as tiny grains in chondrules. Some enstatite grains appear darkened in transmitted light due to the presence of tiny blebs of metal and sulfides in the crystals.

Chondrules are present in various sizes, compositions, and textures. We identified RP, porphyritic
<figure><img src="image_5.png" /><figcaption>FIGURE 4. Photographs of various specimens of Al Haggounia 001. Panels (a), (c), and (e) show the macroscopic aspects of the fragments. The panels (b), (d), and (f) are their respective slices. Lithology A: (a) brown to whitish exterior, with oxyhydroxide products and abundant graphite grains. (b) Interior of (a), with a reddish, bluish, and dark-gray layers. Abundant graphite grains and white shapes are observed. The voids are rare. Lithology B: (c) a fragment with oxidized and subparallel veins. Note the presence of silica grains in the fractures. (d) Continuous subparallel oxidized veins within the sample. Large grains of metal are detected. Lithology C: (e) a specimen with a fractured exterior, filled with whitish terrestrial products. Silica grains are found in the fractures. (f) The interior contains 0.7–0.8 mm-sized grains of metal. Few thin interconnected veins are observed. Fr, fracture; Gr, graphite; M, metal; SG, silica grain; V, veins; Vo, void; Wsh, white shape. (Color figure can be viewed at wileyonlinelibrary.com)</figcaption></figure>

pyroxene (PP), barred rods of albite–enstatite (RAE), mixed porphyritic-cryptocrystalline (CC) chondrules, as well as dozens of abundant relict RP chondrules (Figure 5). In the studied area (400 cm²), we detected 82 chondrules (60 RP, 19 PP, 2 RAE, and 1 PP-CC) ranging from 0.1 to 6 mm in diameter. Note that the large white elongated grain (Figure S1), which is macrochondrule with coarse-grained rims, is composed of albite (70%–80%) and enstatite rods. In LA, there are no veins that crosscut the sample. However, we detected various thin to thick (up to ~100 µm) subparallel veinlets in LB, as

well as anastomosing veins in LC. These latter are filled with oxide/hydroxide products. Graphite grains with various shapes are present in all specimens. Some of them contain glassy (vitreous) minerals with high birefringence, defined as fragments of sinoite with a few grains of silica polymorphs (tridymite and cristobalite; Leili et al., 2019).

Mineralogy

SEM examination shows the overall petrographic characteristics of Al Haggounia 001 specimens (Figure 6),
<figure><img src="image_6.png" /></figure>

FIGURE 5. Microphotographs of different types of chondrules found in the Al Haggounia 001 meteorite. (a) Chondrule composed of rods of enstatite filled with plagioclase, note the thick rim. (b) Large elongated and broken macrochondrule composed of barred albite and pyroxene, note the thick rim. The white rectangle is shown in Figure 8. (c) Radial pyroxene (RP) chondrule. (d) Porphyritic (PP) chondrule. (e) Mixed porphyritic-cryptocrystalline pyroxene chondrule (PP-CC). (f) Relict of broken RP chondrule. (Color figure can be viewed at wileyonlinelibrary.com)

which exhibit various textures and complex oxyhydroxide networks of veins. The samples contain metallic and non-metallic phases with random distribution. Metal and sulfide grains were detected in all specimens. However, they are rimmed or completely replaced by iron oxyhydroxide minerals in the veins and between the silicate grains. The weathering grade varies between W2, W3, and W4 (Wlotzka, 1993).

Enstatite is the predominant mineral phase (~70 vol %) that occurs in the form of 100- to 200-µm-sized juxtaposed, sometimes fractured, and mosaic crystals. The grains are unaltered and sometimes are surrounded by kamacite (Figure 7a,c). In some areas, large and unfractured euhedral crystals of enstatite are found within voids (Figure 7e). Enstatite is also found often juxtaposed and enclosed in silica polymorph minerals

(Figure 7f). Plagioclase is the second most abundant mineral after enstatite (~20 vol%), and it appears unweathered and predominantly conforms to enstatite outlines. It can be recognized by its lower contrast (in comparison with enstatite) and its fine-grained texture. Enstatite and plagioclase minerals ranging from 50 to 150 µm in size are found inside (in the form of rods) and outside macrochondrules, such as the one shown in Figure 8. Another macrochondrule is shown in Figure S2, which is composed of Ca- and Na-rich plagioclase intergrown with pyroxene as indicated by x-ray elemental maps.

Metal and sulfides occur as irregular-shaped grains in the interstices of silicates and often contain protrusions of enstatite (Figure 7a,c). Kamacite-rich grains are present as irregular and elongated nodules ranging
<figure><img src="image_7.png" /></figure>

FIGURE 6. Backscattered electron images showing the petrographic and the textural features of Al Haggounia 001 (the lithologies LA, LB, and LC). (a, b) Two images of LA. Large enstatite and plagioclase grains are identified. The white-colored phases are metal and sulfides. Note the large crystallized veins filled with terrestrial materials, calcite, and iron sulfates. (c, d) Two images of LB. Subparallel altered veins are present (BSE-gray veins). Shocked graphite is observed. Note that most metal-sulfide grains (BSE-light-gray areas) are severely weathered. (e, f) Two images of LC. BSE images show the distribution of metal-sulfide grains. The large millimetric metal-sulfide grains are not completely altered (light-gray areas). Note the presence of multiple generations of anastomosing networks of iron oxyhydroxides (BSE-gray) and fractures (BSE-black), as well as the rarity of voids. A various distribution of metal and sulfides within the two figures is detected. En, enstatite; Gr, graphite; Plg, plagioclase; Tm, terrestrial material; V, veins; Vo, void.

from a few µm to 200 µm in size and are common in the matrix (Figure 7a-c). The same applies to the schreibersite. Metal and sulfides are also found as sub-micrometer inclusions within pyroxene (Figure 7d), and in chondrules, as exemplified in Figure 5a. In addition to metal, we identified magnetite, hydroxide, and possibly maghemite by thermomagnetic measurements (Figure 9).

Daubreelite (FeCr₂S₄) is fractured with parallel cracks (Figure 7b,e) and occurs as exsolution lamellae in troilite (FeS). Large troilite and daubreelite grains (10–100 µm) are abundant and they appear to have escaped terrestrial weathering. Troilite is found between

enstatite and kamacite in some cases (Figure 7a). Schreibersite [(Fe, Ni)₃P], up to 600 µm in size, is rare and is always associated with kamacite (Figure 7c). Neither oldhamite (CaS) nor alabandite (MnS) were detected in this study. Small laths and unusually deformed rounded graphite are also identified (Figure S3).

## Mineral Compositions

The endmember composition of pyroxene (enstatite) is Fs₀.₆₂Wo₁.₄₃ (Table 1). The composition of plagioclase is Ab₇₄.₈₄Or₃.₇, with a FeO content ranging from 0.03 to
<figure><img src="image_8.png" /></figure>

FIGURE 7. Backscattered electron images showing additional petrographic characteristics of Al Haggounia 001. (a) SEM image showing a large rusted metal (rusted vein crossing kamacite and schreibersite). An enstatite grain protruding kamacite is observed, as well as a small troilite grain between kamacite and enstatite. Note the occurrence of fractures and iron oxides. (b) SEM image showing large grains of kamacite and troilite with exsolved daubreelite. (c) Elongated, fractured and altered nodules of kamacite and schreibersite following the orientation of the veins. (d) Abundant inclusions of metal-sulfide grains within enstatite. Tiny grains of troilite and kamacite are observed. (e) Enstatite crystal is intergrown in a large rounded void filled with oxyhydroxides and sulfates. (f) Enstatite within silica polymorph, juxtaposed to plagioclase. Note that the veins are filled with oxyhydroxides. Db, daubreelite; En, enstatite; IO, iron oxide; Km, kamacite; Plg, plagioclase; Schr, schreibersite; Si, silica; Tr, troilite; V, veins; Vo, void.

1.2 wt% (Table 2). The compositions of kamacite, taenite, schreibersite, troilite, and daubreelite are given in Table 3. All metal grains in our sections have Ni content ranging from 5.7 to 22 wt%. The Si content of kamacite varies between 0.85 and 2.03 wt% (with an average of 1.15 wt%; n = 46). We identified taenite in one location, with a Ni content and a Si content of 21.4 and 1.7 wt% (n = 2), respectively (Table 3). Schreibersite has a Ni content that varies between 19 and 38.5 wt%, a Si content up to 0.17 wt% (mean value = 0.09; n = 26), and a Co content ranging from 0.14 to 0.24 wt% (Table 3).

Troilite is enriched in Cr, Ti, and Mn, and their averages are 0.89, 0.52, and 0.06 wt%, respectively (Table 3). The averages of Cr, Ti, and Mn contents in daubreelite are 35.4, 0.10, and 1.52 wt%, respectively (Table 3).

## Shock Features

Fractures in Al Haggounia 001 are irregular and crosscut the whole matrix. Rare large grains of enstatite exhibit planar fractures and sometimes display weak undulatory extinction. We also detected shock
<figure><img src="image_9.png" /><figcaption>FIGURE 8. Backscattered electron images and x-ray elemental maps of chondrules in Al Haggounia 001. (a) BSE image of a chondrule with barred albite and enstatite (also shown in Figure 5a), partially overlapped with an x-ray map of Na, Al, and Mg to show their distributions. (b) SEM image (white rectangle in Figure 5b) showing elongated structure (rods) of enstatite and plagioclase in the macrochondrule. En, enstatite; Plg, plagioclase. (Color figure can be viewed at wileyonlinelibrary.com)</figcaption></figure>

<figure><img src="image_10.png" /><figcaption>FIGURE 9. Thermal dependence of apparent magnetic susceptibility measured under argon atmosphere at different temperatures of selected samples of Al Haggounia 001 (Specimens 29, 31, 35, 37, 38, 42, 46, 47, and 48). The masses (mg) of these specimens are 39, 72, 45, 53, 30, 47, 51, 66, and 85 mg, respectively. Red line: heating variation; blue line: cooling variation. (Color figure can be viewed at wileyonlinelibrary.com)</figcaption></figure>
<table><caption>TABLE 1. Average EPMA data (wt%) of pyroxene in Al Haggounia 001 meteorite.</caption><thead><tr><th>n = 68</th><th>Average</th><th>SD</th><th>Min</th><th>Max</th></tr></thead><tbody><tr><td>SiO<sub>2</sub></td><td>60.14</td><td>0.67</td><td>58.12</td><td>63.79</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>0.21</td><td>0.02</td><td>0.15</td><td>0.26</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.01</td><td>0.01</td><td>0</td><td>0.04</td></tr><tr><td>FeO</td><td>0.43</td><td>0.22</td><td>0.1</td><td>1.14</td></tr><tr><td>Na<sub>2</sub>O</td><td>0.01</td><td>0.01</td><td>0</td><td>0.04</td></tr><tr><td>TiO<sub>2</sub></td><td>0.01</td><td>0.02</td><td>0</td><td>0.09</td></tr><tr><td>Cr<sub>2</sub>O<sub>3</sub></td><td>0.01</td><td>0.01</td><td>0</td><td>0.05</td></tr><tr><td>MgO</td><td>38.73</td><td>0.77</td><td>35.15</td><td>39.63</td></tr><tr><td>CaO</td><td>0.79</td><td>0.03</td><td>0.71</td><td>0.87</td></tr><tr><td>NiO</td><td>0.03</td><td>0.03</td><td>0</td><td>0.1</td></tr><tr><td>K<sub>2</sub>O</td><td>0.01</td><td>0.01</td><td>0</td><td>0.04</td></tr><tr><td>MnO</td><td>0.01</td><td>0.01</td><td>0</td><td>0.05</td></tr><tr><td>Total</td><td>100.39</td><td>0.71</td><td>99.01</td><td>101.3</td></tr><tr><td>Fs</td><td>0.62</td><td>0.32</td><td>0.14</td><td>1.62</td></tr><tr><td>En</td><td>97.95</td><td>0.35</td><td>96.93</td><td>98.47</td></tr><tr><td>Wo</td><td>1.43</td><td>0.07</td><td>1.28</td><td>1.57</td></tr><tr><td>Si</td><td>2.0082</td><td>0.02</td><td>1.97</td><td>2.10</td></tr><tr><td>Al</td><td>0.0083</td><td>0</td><td>0.01</td><td>0.01</td></tr><tr><td>Ti</td><td>0.0003</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Fe</td><td>0.0121</td><td>0.01</td><td>0</td><td>0.03</td></tr><tr><td>Mn</td><td>0.0004</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Mg</td><td>1.9281</td><td>0.04</td><td>1.73</td><td>2.00</td></tr><tr><td>Zn</td><td>0.0000</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Ca</td><td>0.0282</td><td>0</td><td>0.03</td><td>0.03</td></tr><tr><td>Na</td><td>0.0006</td><td>0</td><td>0</td><td>0</td></tr><tr><td>K</td><td>0.0003</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Ni</td><td>0.0009</td><td>0</td><td>0</td><td>0</td></tr><tr><td>P</td><td>0.0002</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Total</td><td>3.9875</td><td>0.02</td><td>3.89</td><td>4.03</td></tr></tbody></table>

Abbreviations: n, number of spot analysis; SD, standard deviation.

macrofeatures in the form of subparallel fractures filled with oxyhydroxides in Lithology B (Figure 4c,d). Overall, fractures are observed in all lithologies and are filled with oxyhydroxide products (Figure 6c,f). The pervasive shock affects silicates, graphite, sinoite, and silica polymorphs (Figures 6d and S3). It also affects some chondrules, resulting in ellipsoidal and flattened shapes (Figure 7c). In reflected light, we noted that some enstatite crystals are darkened due to the presence of tiny inclusions of metal and sulfides.

## Magnetic Properties

### Magnetic Susceptibility

Magnetic susceptibility measurements of 52 specimens yielded values of Log (χ) ranging from a minimum value of 3.48 in Specimen 2, to a maximum value of 4.9 in Specimen 26 (Table 4). The average magnetic susceptibility value is 4.39 ± 0.20, with most specimens having uniform values ranging from 4.17 to 4.57.

### Hysteresis Cycles

Hysteresis cycles of nine selected specimens were used to characterize the magnetic mineralogy, particularly the amount of metal and the nature of secondary magnetic minerals. Ms ranges from 2.42 to 7.27 Am² kg⁻¹, Mrs from 29.8 to 116.7 Am² kg⁻¹, Hc from 6.0 to 10.4 mT, Hcr from 10.9 to 29.4 mT, Hcr/Hc from 1.8 to 3.9, and Mrs/Ms from 0.05 to 0.20. Detailed results are presented in Table 5.

### Thermomagnetic Investigations

After examining the thermomagnetic curves (Figure 9), we noticed that all of them show changes in magnetic susceptibility at ~580°C after heating and cooling. This implies that the magnetization drops rapidly to a minimum value when the Curie temperature is 580°C for magnetite. Comparing heating and cooling curves allows the identification of the more-or-less abundant neoformation of magnetite during heating. We identified the significant presence of metal by a magnetization above 580°C, well above the signal of the empty furnace (−160 10⁻⁶ SI). We distinguish three types of specimens that are characterized by the following:

1. High abundance of metal and strong production of magnetite on heating in Specimens 31, 38, 42, and 46.

2. Lack of metal, with low production of magnetite, and the presence of a metastable magnetic phase at 350°C (hydroxide or maghemite) in Specimens 29 and 35.

3. Metal without magnetite formation in Specimens 48 and 37.

## DISCUSSION

### Strewn Field of Al Haggounia 001

The origin of Al Haggounia 001 was significantly discussed in the literature. It was reported to be found in Algeria (Kuehner et al., 2006) or in an unknown location. Chennaoui-Aoudjehane et al. (2007) confirmed its origin in the region of Al Haggounia in the southern desert of Morocco. Our results provide an accurate and updated location of the strewn field and show that its dimensions (65 km in length and 10 km in diameter) are larger than what was previously described by Chennaoui-Aoudjehane et al. (2007). We report that the higher abundance of large finds is in the northern area and within the saline deposit, which is consistent with the orientation of the fall, which has a SW to NE direction. The large moving dune belts in the central and northern areas may cover an important part of the strewn field. In addition, we suggest that the meteorite was transported and covered by sediments in the wadi of Al Haggounia which crosses the strewn field.
<table><caption>TABLE 2. EPMA chemical composition data of plagioclase in Al Haggounia 001 meteorite (22 points).</caption><thead><tr><th></th><th>1</th><th>2</th><th>3</th><th>4</th><th>5</th><th>6</th><th>7</th><th>8</th><th>9</th><th>10</th><th>11</th></tr></thead><tbody><tr><td>SiO<sub>2</sub></td><td>66.45</td><td>66.42</td><td>65.58</td><td>66.46</td><td>66.80</td><td>65.06</td><td>66.62</td><td>68.21</td><td>66.08</td><td>66.13</td><td>66.62</td></tr><tr><td>TiO<sub>2</sub></td><td>0.00</td><td>0.00</td><td>0.00</td><td>0.00</td><td>0.00</td><td>0.00</td><td>0.01</td><td>0.00</td><td>0.00</td><td>0.00</td><td>0.03</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>21.65</td><td>20.98</td><td>21.26</td><td>21.03</td><td>20.91</td><td>22.32</td><td>21.61</td><td>20.34</td><td>21.53</td><td>21.38</td><td>21.07</td></tr><tr><td>FeO</td><td>0.03</td><td>0.10</td><td>0.05</td><td>0.17</td><td>0.12</td><td>0.48</td><td>0.36</td><td>0.65</td><td>0.15</td><td>0.27</td><td>0.26</td></tr><tr><td>MnO</td><td>0.00</td><td>0.01</td><td>0.00</td><td>0.00</td><td>0.02</td><td>0.00</td><td>0.00</td><td>0.02</td><td>0.04</td><td>0.00</td><td>0.01</td></tr><tr><td>MgO</td><td>0.04</td><td>0.05</td><td>0.05</td><td>0.05</td><td>0.01</td><td>0.03</td><td>0.05</td><td>0.01</td><td>0.04</td><td>0.01</td><td>0.02</td></tr><tr><td>CaO</td><td>3.47</td><td>3.49</td><td>3.61</td><td>3.48</td><td>3.47</td><td>4.43</td><td>3.53</td><td>1.79</td><td>3.45</td><td>3.51</td><td>3.33</td></tr><tr><td>Na<sub>2</sub>O</td><td>8.81</td><td>8.50</td><td>8.72</td><td>8.75</td><td>8.81</td><td>8.31</td><td>8.60</td><td>9.40</td><td>9.15</td><td>8.88</td><td>8.59</td></tr><tr><td>K<sub>2</sub>O</td><td>0.77</td><td>0.70</td><td>0.68</td><td>0.51</td><td>0.60</td><td>0.57</td><td>0.72</td><td>1.21</td><td>0.57</td><td>0.58</td><td>0.87</td></tr><tr><td>Total</td><td>101.21</td><td>100.25</td><td>99.95</td><td>100.45</td><td>100.74</td><td>101.21</td><td>101.49</td><td>101.62</td><td>101.01</td><td>100.76</td><td>100.80</td></tr><tr><td>Si</td><td>2.889</td><td>2.912</td><td>2.889</td><td>2.910</td><td>2.916</td><td>2.847</td><td>2.895</td><td>2.962</td><td>2.885</td><td>2.893</td><td>2.912</td></tr><tr><td>Al</td><td>1.110</td><td>1.084</td><td>1.104</td><td>1.085</td><td>1.076</td><td>1.151</td><td>1.107</td><td>1.041</td><td>1.108</td><td>1.103</td><td>1.086</td></tr><tr><td>Ti</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0.001</td></tr><tr><td>Fe</td><td>0</td><td>0.002</td><td>0.002</td><td>0</td><td>0.002</td><td>0.001</td><td>0.001</td><td>0</td><td>0</td><td>0.001</td><td>0</td></tr><tr><td>Mn</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0.001</td><td>0</td><td>0</td><td>0.001</td><td>0.001</td><td>0</td><td>0</td></tr><tr><td>Mg</td><td>0.002</td><td>0.004</td><td>0.003</td><td>0.003</td><td>0.001</td><td>0.002</td><td>0.003</td><td>0</td><td>0.003</td><td>0.001</td><td>0.001</td></tr><tr><td>Ca</td><td>0.162</td><td>0.164</td><td>0.170</td><td>0.163</td><td>0.162</td><td>0.208</td><td>0.164</td><td>0.083</td><td>0.161</td><td>0.165</td><td>0.156</td></tr><tr><td>Na</td><td>0.743</td><td>0.723</td><td>0.745</td><td>0.743</td><td>0.746</td><td>0.705</td><td>0.725</td><td>0.792</td><td>0.775</td><td>0.753</td><td>0.728</td></tr><tr><td>K</td><td>0.042</td><td>0.039</td><td>0.038</td><td>0.029</td><td>0.033</td><td>0.032</td><td>0.040</td><td>0.067</td><td>0.032</td><td>0.032</td><td>0.048</td></tr><tr><td>Total</td><td>4.948</td><td>4.927</td><td>4.951</td><td>4.933</td><td>4.936</td><td>4.946</td><td>4.934</td><td>4.946</td><td>4.964</td><td>4.948</td><td>4.932</td></tr><tr><td>An</td><td>17.07</td><td>17.71</td><td>17.87</td><td>17.47</td><td>17.24</td><td>21.99</td><td>17.70</td><td>8.84</td><td>16.68</td><td>17.32</td><td>16.73</td></tr><tr><td>Ab</td><td>78.44</td><td>78.06</td><td>78.11</td><td>79.47</td><td>79.22</td><td>74.63</td><td>78.03</td><td>84.04</td><td>80.05</td><td>79.30</td><td>78.08</td></tr><tr><td>Or</td><td>4.48</td><td>4.23</td><td>4.02</td><td>3.06</td><td>3.53</td><td>3.38</td><td>4.27</td><td>7.12</td><td>3.28</td><td>3.38</td><td>5.19</td></tr><tr><td></td><td>12</td><td>13</td><td>14</td><td>15</td><td>16</td><td>17</td><td>18</td><td>19</td><td>20</td><td>21</td><td>22</td></tr><tr><td>SiO<sub>2</sub></td><td>65.99</td><td>66.39</td><td>64.67</td><td>64.91</td><td>65.25</td><td>66.37</td><td>66.42</td><td>66.62</td><td>66.63</td><td>66.67</td><td>69.47</td></tr><tr><td>TiO<sub>2</sub></td><td>0.01</td><td>0.01</td><td>0.01</td><td>0.00</td><td>0.00</td><td>0.00</td><td>0.01</td><td>0.01</td><td>0.00</td><td>0.00</td><td>0.00</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>21.09</td><td>21.49</td><td>21.27</td><td>20.71</td><td>21.23</td><td>20.99</td><td>20.76</td><td>21.25</td><td>20.88</td><td>21.01</td><td>19.26</td></tr><tr><td>FeO</td><td>1.19</td><td>0.49</td><td>0.65</td><td>0.58</td><td>0.65</td><td>0.70</td><td>0.56</td><td>0.36</td><td>0.26</td><td>0.34</td><td>0.35</td></tr><tr><td>MnO</td><td>0.02</td><td>0.00</td><td>0.00</td><td>0.01</td><td>0.00</td><td>0.00</td><td>0.01</td><td>0.00</td><td>0.02</td><td>0.03</td><td>0.00</td></tr><tr><td>MgO</td><td>0.14</td><td>0.03</td><td>0.01</td><td>0.03</td><td>0.02</td><td>0.00</td><td>0.02</td><td>0.03</td><td>0.04</td><td>0.02</td><td>0.03</td></tr><tr><td>CaO</td><td>3.53</td><td>3.51</td><td>3.31</td><td>3.35</td><td>3.30</td><td>3.35</td><td>3.28</td><td>3.31</td><td>3.13</td><td>3.21</td><td>2.36</td></tr><tr><td>Na<sub>2</sub>O</td><td>9.08</td><td>9.06</td><td>9.10</td><td>9.97</td><td>9.07</td><td>9.56</td><td>9.75</td><td>9.48</td><td>8.97</td><td>9.24</td><td>8.70</td></tr><tr><td>K<sub>2</sub>O</td><td>0.57</td><td>0.63</td><td>0.60</td><td>0.56</td><td>0.81</td><td>0.74</td><td>0.72</td><td>0.70</td><td>0.62</td><td>0.70</td><td>0.89</td></tr><tr><td>Total</td><td>101.62</td><td>101.61</td><td>99.62</td><td>100.12</td><td>100.34</td><td>101.71</td><td>101.52</td><td>101.75</td><td>100.54</td><td>101.24</td><td>101.06</td></tr><tr><td>Si</td><td>2.893</td><td>2.890</td><td>2.879</td><td>2.883</td><td>2.885</td><td>2.898</td><td>2.902</td><td>2.895</td><td>2.917</td><td>2.908</td><td>3.011</td></tr><tr><td>Al</td><td>1.090</td><td>1.103</td><td>1.116</td><td>1.084</td><td>1.106</td><td>1.080</td><td>1.069</td><td>1.088</td><td>1.077</td><td>1.080</td><td>0.984</td></tr><tr><td>Ti</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Fe</td><td>0</td><td>0.001</td><td>0</td><td>0.001</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Mn</td><td>0.001</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0.001</td><td>0.001</td><td>0</td></tr><tr><td>Mg</td><td>0.009</td><td>0.002</td><td>0.001</td><td>0.002</td><td>0.001</td><td>0</td><td>0.001</td><td>0.002</td><td>0.002</td><td>0.002</td><td>0.002</td></tr><tr><td>Ca</td><td>0.166</td><td>0.164</td><td>0.158</td><td>0.159</td><td>0.156</td><td>0.157</td><td>0.153</td><td>0.154</td><td>0.147</td><td>0.150</td><td>0.110</td></tr><tr><td>Na</td><td>0.772</td><td>0.765</td><td>0.785</td><td>0.859</td><td>0.778</td><td>0.809</td><td>0.826</td><td>0.798</td><td>0.761</td><td>0.782</td><td>0.731</td></tr><tr><td>K</td><td>0.032</td><td>0.035</td><td>0.034</td><td>0.032</td><td>0.046</td><td>0.041</td><td>0.040</td><td>0.039</td><td>0.034</td><td>0.039</td><td>0.049</td></tr><tr><td>Total</td><td>4.963</td><td>4.958</td><td>4.973</td><td>5.020</td><td>4.973</td><td>4.986</td><td>4.993</td><td>4.978</td><td>4.940</td><td>4.962</td><td>4.887</td></tr><tr><td>An</td><td>17.10</td><td>17.00</td><td>16.17</td><td>15.18</td><td>15.96</td><td>15.56</td><td>15.05</td><td>15.57</td><td>15.59</td><td>15.47</td><td>12.33</td></tr><tr><td>Ab</td><td>79.60</td><td>79.39</td><td>80.34</td><td>81.78</td><td>79.37</td><td>80.37</td><td>81.02</td><td>80.54</td><td>80.76</td><td>80.52</td><td>82.13</td></tr><tr><td>Or</td><td>3.30</td><td>3.62</td><td>3.49</td><td>3.04</td><td>4.67</td><td>4.06</td><td>3.93</td><td>3.89</td><td>3.65</td><td>4.01</td><td>5.55</td></tr></tbody></table>

Note: Elements are in wt% and the endmember compositions in mole%.

## Is Al Haggounia 001 a Fossil Meteorite?

As mentioned above, the initial reports regarding the discovery of Al Haggounia 001 were vague and

misleading. Kuehner et al. (2006) reported that NWA 2828, which is paired with Al Haggounia 001, was found in Algeria from a subsurface deposit and concluded that it was a fossil meteorite. Rubin (2016) used the work of
<table><caption>TABLE 3. EPMA analyses of metallic Fe-Ni, schreibersite, troilite, and daubreelite in Al Haggounia 001 meteorite.</caption><thead><tr><th rowspan="2">Mineral</th><th colspan="4">Kamacite (n = 46)</th><th colspan="4">Taenite (n = 2)</th><th colspan="4">Schreibersite (n = 26)</th></tr><tr><th>Average</th><th>SD</th><th>Min</th><th>Max</th><th>Average</th><th>SD</th><th>Min</th><th>Max</th><th>Average</th><th>SD</th><th>Min</th><th>Max</th></tr></thead><tbody><tr><td>Si</td><td>1.15</td><td>0.24</td><td>0.85</td><td>2.03</td><td>1.7</td><td>0.01</td><td>1.69</td><td>1.71</td><td>0.09</td><td>0.04</td><td>0.01</td><td>0.17</td></tr><tr><td>Fe</td><td>91.89</td><td>0.94</td><td>89.73</td><td>93.84</td><td>76.53</td><td>0.77</td><td>75.99</td><td>77.07</td><td>55.66</td><td>5.09</td><td>45.94</td><td>65.21</td></tr><tr><td>Cr</td><td>0.01</td><td>0.01</td><td>0</td><td>0.05</td><td>0.01</td><td>0.02</td><td>0</td><td>0.03</td><td>0.03</td><td>0.07</td><td>0</td><td>0.39</td></tr><tr><td>Ti</td><td>0.01</td><td>0.01</td><td>0</td><td>0.05</td><td>0.01</td><td>0.01</td><td>0</td><td>0.01</td><td>0.01</td><td>0.02</td><td>0</td><td>0.06</td></tr><tr><td>P</td><td>0.11</td><td>0.04</td><td>0.01</td><td>0.22</td><td>0.01</td><td>0.02</td><td>0</td><td>0.03</td><td>15.24</td><td>1.46</td><td>10.13</td><td>17.21</td></tr><tr><td>Ni</td><td>6.2</td><td>0.32</td><td>5.71</td><td>7.11</td><td>21.44</td><td>0.98</td><td>20.75</td><td>22.13</td><td>28.92</td><td>4.93</td><td>19.26</td><td>38.72</td></tr><tr><td>S</td><td>0.01</td><td>0.01</td><td>0</td><td>0.03</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0.05</td><td>0.03</td><td>0.01</td><td>0.11</td></tr><tr><td>Co</td><td>0.52</td><td>0.03</td><td>0.46</td><td>0.57</td><td>0.25</td><td>0.01</td><td>0.24</td><td>0.25</td><td>0.18</td><td>0.03</td><td>0.14</td><td>0.24</td></tr><tr><td>Mn</td><td>0</td><td>0</td><td>0</td><td>0.02</td><td>0.03</td><td>0.02</td><td>0.01</td><td>0.04</td><td>0.01</td><td>0.01</td><td>0</td><td>0.03</td></tr><tr><td>Total</td><td>99.86</td><td>0.8</td><td>97.98</td><td>101.93</td><td>99.98</td><td>0.19</td><td>99.84</td><td>100.11</td><td>100.19</td><td>0.89</td><td>97.94</td><td>101.45</td></tr></tbody></table><table><thead><tr><th rowspan="2"></th><th colspan="4">Troilite (n = 55)</th><th colspan="4">Daubreelite (n = 13)</th></tr><tr><th>Average</th><th>SD</th><th>Min</th><th>Max</th><th>Average</th><th>SD</th><th>Min</th><th>Max</th></tr></thead><tbody><tr><td>Si</td><td>0.03</td><td>0.09</td><td>0</td><td>0.63</td><td>0.02</td><td>0.02</td><td>0</td><td>0.06</td></tr><tr><td>Fe</td><td>60.71</td><td>0.88</td><td>57.69</td><td>63.13</td><td>18.12</td><td>1.26</td><td>16.71</td><td>21.34</td></tr><tr><td>Cr</td><td>0.89</td><td>0.48</td><td>0.58</td><td>3.54</td><td>35.39</td><td>0.93</td><td>32.39</td><td>35.91</td></tr><tr><td>Ti</td><td>0.52</td><td>0.06</td><td>0.42</td><td>0.81</td><td>0.1</td><td>0.06</td><td>0.04</td><td>0.26</td></tr><tr><td>P</td><td>0</td><td>0</td><td>0</td><td>0.02</td><td>0</td><td>0</td><td>0</td><td>0.01</td></tr><tr><td>Ni</td><td>0.08</td><td>0.27</td><td>0</td><td>2</td><td>0.06</td><td>0.03</td><td>0.02</td><td>0.13</td></tr><tr><td>S</td><td>37.06</td><td>0.39</td><td>36.16</td><td>37.89</td><td>43.87</td><td>0.69</td><td>42.64</td><td>44.96</td></tr><tr><td>Co</td><td>0.09</td><td>0.03</td><td>0.05</td><td>0.23</td><td>0.03</td><td>0.01</td><td>0.01</td><td>0.06</td></tr><tr><td>Mn</td><td>0.06</td><td>0.05</td><td>0</td><td>0.28</td><td>1.52</td><td>0.94</td><td>0.32</td><td>2.74</td></tr><tr><td>Total</td><td>99.44</td><td>0.64</td><td>98.53</td><td>101.81</td><td>99.12</td><td>0.5</td><td>98.08</td><td>100.04</td></tr></tbody></table>

Abbreviations: n, number of spot analysis; SD, standard deviation.

Kuehner et al. (2006) to conclude that Al Haggounia 001 is a fossil meteorite. Fossil meteorites are officially designated as relict meteorites in section 1.2c of the Meteoritical Society's guidelines on Meteorite Nomenclature. Such meteorites are “highly altered materials that may have a meteoritic origin” and are “dominantly (>95%) composed of secondary minerals formed on the body on which the object was found.” This is not the case for Al Haggounia 001, as the samples in this study were found on the soil surface, or shallowly buried in loose sediments, which is consistent with the work of Chennaoui-Aoudjehane et al. (2009). In addition, Al Haggounia 001 is not composed dominantly of secondary terrestrial minerals. We detected unoxidized large mm-sized metal and sulfide grains in almost all examined samples. Thus, although the fall of Al Haggounia 001 occurred during a humid period 23 ± 2 ka ago (Chennaoui-Aoudjehane et al., 2009), it could have facilitated the penetration of meteorite into the soil. So here we argue against it being a fossil meteorite.

## The Porosity in Al Haggounia 001

Al Haggounia 001 consists of a variety of lithologies (LA, LB, and LC). The porosity is a major characteristic in our samples, with LA being the most porous

resembling the bluish-gray specimens of NWA 2828 (paired with Al Haggounia 001) characterized by a high porosity and cavities (0.2–0.5 mm) filled with calcite and minor halite and gypsum (Kuehner et al., 2006). Irving et al. (2010) pointed out that pervasive and unusual oxidation, reduction, and pH conditions in a semiarid environment led to the selective dissolution of most of the primary metals in NWA 2828.

NWA 7401, which is another Al Haggounia 001 paired sample, has an interior that is not as weathered as the exterior and contains friable material and numerous voids (Ruzicka et al., 2015). According to Rubin (2016), the formation of voids in this meteorite is not due to the dissolution of metal and sulfides, since the volume of voids gives a modal abundance value of metal/sulfides of 7 vol% before dissolution, which is far lower than EL3 abundances of 19 vol%. Alternatively, these authors suggested a mechanism involving the evaporation of sulfide phases during impact melting to explain the formation of porous regions in NWA 7401, and therefore in paired samples Al Haggounia 001 and NWA 2828. During this process, metal/sulfide melts were drained away leaving void-rich regions, similar to those found in LA. The presence of metal-rich regions (more than 20 vol % is metal and sulfides), such as the one reported in
<table><caption>TABLE 4. Data of samples in this study (mass (g) is the mass used for the magnetic susceptibility measurements).</caption><thead><tr><th>Sample</th><th>Mass (g)</th><th>Lithology type</th><th>Log (χ)</th><th>m2 (mg)</th><th>HYTS.C</th><th>m3 (mg)</th><th>TMC</th></tr></thead><tbody><tr><td>1</td><td>142.82</td><td>LA</td><td>4.47</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>2</td><td>49.1</td><td>LA</td><td>3.48</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>3</td><td>24.14</td><td>LA</td><td>4.46</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>4</td><td>24.57</td><td>LA</td><td>4.32</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>5</td><td>36.7</td><td>LA</td><td>4.25</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>6</td><td>64.97</td><td>LB</td><td>4.48</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>7</td><td>53.25</td><td>LB</td><td>4.26</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>8</td><td>55.28</td><td>LB</td><td>4.23</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>9</td><td>21.38</td><td>LB</td><td>4.76</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>10</td><td>30.3</td><td>LC</td><td>4</td><td>124</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>11</td><td>90.29</td><td>LC</td><td>4.21</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>12</td><td>19.54</td><td>LB</td><td>4.2</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>13</td><td>26.9</td><td>LC</td><td>4.54</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>14</td><td>22.37</td><td>LB</td><td>4.23</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>15</td><td>47.18</td><td>LB</td><td>4.2</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>16</td><td>20.32</td><td>LA</td><td>4.66</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>17</td><td>10.6</td><td>LA</td><td>4.36</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>18</td><td>41.68</td><td>LB</td><td>4.43</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>19</td><td>50.7</td><td>LC</td><td>4.21</td><td>175</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>20</td><td>27.1</td><td>LC</td><td>4.39</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>21</td><td>34.82</td><td>LB</td><td>4.52</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>22</td><td>41.54</td><td>LC</td><td>4.33</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>23</td><td>22.07</td><td>LC</td><td>4.49</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>24</td><td>55.18</td><td>LC</td><td>4.41</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>25</td><td>17.6</td><td>LC</td><td>4.47</td><td>151</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>26</td><td>21.9</td><td>LC</td><td>4.9</td><td>147</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>27</td><td>17.8</td><td>LC</td><td>4.33</td><td>143</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>28</td><td>1.4</td><td>LC</td><td>4.48</td><td>138</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>29</td><td>21.3</td><td>LB</td><td>4.48</td><td>130</td><td>Mes.</td><td>39</td><td>Mes.</td></tr><tr><td>30</td><td>16.1</td><td>LC</td><td>4.34</td><td>137</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>31</td><td>12.2</td><td>LC</td><td>4.34</td><td>191</td><td>Mes.</td><td>72</td><td>Mes.</td></tr><tr><td>32</td><td>22.7</td><td>LB</td><td>4.31</td><td>126</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>33</td><td>27.7</td><td>LB</td><td>4.51</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>34</td><td>41.3</td><td>LB</td><td>4.3</td><td>183</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>35</td><td>9.0</td><td>LC</td><td>4.51</td><td>190</td><td>Mes.</td><td>45</td><td>Mes.</td></tr><tr><td>36</td><td>151.8</td><td>LC</td><td>4.11</td><td>162</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>37</td><td>59.7</td><td>LC</td><td>4.18</td><td>160</td><td>Mes.</td><td>53</td><td>Mes.</td></tr><tr><td>38</td><td>69.7</td><td>LC</td><td>4.39</td><td>140</td><td>Mes.</td><td>30</td><td>Mes.</td></tr><tr><td>39</td><td>37.2</td><td>LB</td><td>4.48</td><td>163</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>40</td><td>38.3</td><td>LC</td><td>4.48</td><td>170</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>41</td><td>83.3</td><td>LB</td><td>4.39</td><td>185</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>42</td><td>45.4</td><td>LC</td><td>4.46</td><td>131</td><td>Mes.</td><td>47</td><td>Mes.</td></tr><tr><td>43</td><td>30.3</td><td>LC</td><td>4.38</td><td>130</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>44</td><td>33.1</td><td>LC</td><td>4.34</td><td>162</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>45</td><td>44.3</td><td>LC</td><td>4.55</td><td>185</td><td>Mes.</td><td>—</td><td>—</td></tr><tr><td>46</td><td>29.9</td><td>LC</td><td>4.65</td><td>167</td><td>Mes.</td><td>51</td><td>Mes.</td></tr><tr><td>47</td><td>22.9</td><td>LC</td><td>4.31</td><td>172</td><td>Mes.</td><td>66</td><td>Mes.</td></tr><tr><td>48</td><td>19.2</td><td>LC</td><td>4.36</td><td>166</td><td>Mes.</td><td>85</td><td>Mes.</td></tr><tr><td>49</td><td>45.48</td><td>LC</td><td>4.43</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>50</td><td>45.51</td><td>LB</td><td>4.43</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>51</td><td>42.05</td><td>LC</td><td>4.17</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>52</td><td>46.54</td><td>LC</td><td>4.66</td><td>—</td><td>—</td><td>—</td><td>—</td></tr></tbody></table>

Note: Lithology type in this study (LA, LB, and LC).

Abbreviations: HYST.C, hysteresis cycle; Log (χ), magnetic susceptibility; m2, mass used for hysteresis cycles; m3, mass used for thermomagnetic curves; Mes., measured; TM.C, thermomagnetic curves.
<table><caption>TABLE 5. Magnetic properties of nine selected samples.</caption><thead><tr><th>Sample</th><th>Log (χ)</th><th>Ms (Am² kg⁻¹)</th><th>Hc (mT)</th><th>Hcr (mT)</th><th>Mrs/ Ms</th><th>Hcr/ Hc</th></tr></thead><tbody><tr><td>29</td><td>4.48</td><td>3.04</td><td>6.00</td><td>10.88</td><td>0.19</td><td>1.81</td></tr><tr><td>31</td><td>4.34</td><td>3.26</td><td>8.77</td><td>26.75</td><td>0.07</td><td>3.05</td></tr><tr><td>35</td><td>4.51</td><td>3.11</td><td>7.65</td><td>14.24</td><td>0.20</td><td>1.86</td></tr><tr><td>37</td><td>4.18</td><td>2.42</td><td>8.78</td><td>19.88</td><td>0.15</td><td>2.27</td></tr><tr><td>38</td><td>4.39</td><td>6.42</td><td>6.99</td><td>23.62</td><td>0.05</td><td>3.38</td></tr><tr><td>42</td><td>4.46</td><td>5.00</td><td>7.17</td><td>26.22</td><td>0.05</td><td>3.66</td></tr><tr><td>46</td><td>4.65</td><td>7.27</td><td>7.31</td><td>28.21</td><td>0.05</td><td>3.86</td></tr><tr><td>47</td><td>4.31</td><td>3.19</td><td>10.37</td><td>29.41</td><td>0.09</td><td>2.84</td></tr><tr><td>48</td><td>4.36</td><td>5.91</td><td>9.70</td><td>26.21</td><td>0.09</td><td>2.70</td></tr><tr><td>Average</td><td>4.41</td><td>4.40</td><td>8.08</td><td>22.82</td><td>0.10</td><td>2.83</td></tr><tr><td>SD</td><td>0.14</td><td>1.77</td><td>1.41</td><td>6.48</td><td>0.06</td><td>0.74</td></tr><tr><td>Minimum</td><td>4.18</td><td>2.42</td><td>6.00</td><td>10.88</td><td>0.05</td><td>1.81</td></tr><tr><td>Maximum</td><td>4.65</td><td>7.27</td><td>10.37</td><td>29.41</td><td>0.20</td><td>3.86</td></tr></tbody></table>

Abbreviations: Hc, coercivity; Hcr, coercivity of remanence; Mrs/Ms, (ratio of remanent saturation moment Mrs, to saturation moment Ms).

Figure 6e, is consistent with such transport mechanism caused by impact melting. Based on these lines of evidence, we suggest that the porous regions in Al Haggounia 001's LA are formed by the impact melting of sulfides. However, we do not rule out a mechanism involving the dissolution of metal phases by pervasive weathering, since our specimens are highly altered and recovered from semiarid regions with long humid periods that occurred during the past 23 ± 2 ka.

## Enstatite-Plagioclase-Bearing Macrochondrules: A New Type of Chondrules

Understanding the characteristics of chondrules helps trace the origins of chondrules and chondrite groups. The term macrochondrules was first used by Weisberg et al. (1988) to refer to chondrules that are larger than 5 mm in diameter. These macrochondrules exhibit the classic textures and mineral compositions of chondrules and they are different from impact-engendered clasts (Zanda, 2004).

In Al Haggounia 001, we found chondrules up to 6 mm in diameter with partially melted rims (Figures 5a, b, 8, and S1; Leili et al., 2018). The chondrule shown in Figure 5b is a fragment of a larger macrochondrule, which likely had a pre-fragmentation size exceeding 1 cm. Kuehner et al. (2006) reported, in the same meteorite, RP chondrules up to 3 mm across, as well as fine-grained aggregates up to 6 mm across rich in either enstatite or sodic plagioclase, but they didn't classify them as macrochondrules. In this study, similar aggregates exhibit typical barred textures and are composed of rods of enstatite (En98) and plagioclase (An22; Table 2) with sizes

exceeding 5 mm, hence their classification as a new type of chondrules (or macrochondrules based on their size). Roughly similar chondrules (ARCs) have been reported in the anomalous enstatite chondrite LEW 87223, which does not belong to the known subgroups of enstatite meteorites (EH and EL; Weisberg & Kimura, 2012). However, in this meteorite, these chondrules contain, in addition to plagioclase (An21-74) and enstatite, other phases such as forsterite, which are not observed in the chondrules of Al Haggounia 001.

## Sample Heterogeneity and Weathering Effects on Magnetic Properties

In addition to the evident lithologic heterogeneity of Al Haggounia 001, this meteorite was affected by weathering in the Sahara desert for the past 23 ± 2 ka, causing a significant variation in its magnetic properties. The magnetic susceptibility of NWA 2965, which is paired to Al Haggounia 001 and has a weathering grade ranging from W2 to W5, is $logχ = 4.47 ± 0.09$ (Macke et al., 2010). This value falls in the range of the values measured in our samples, which range from 3.48 to 4.9. The values we measured are also in the range of $logχ$ in slightly weathered ECs ($logχ = 2.8-4.8$; Devaux et al., 2011).

The lowest values of magnetic susceptibility ($logχ = 3.48$) were measured in LA (Table 4). This value is slightly comparable to the $logχ$ value of 3.2 measured in NWA 4282, which indicates a total dissolution of metal (Brandstätter & Kurat, 2006; Rochette et al., 2008). This is consistent with our observations from LA, which contains less metal and abundant voids that likely formed by its dissolution. The highest values of magnetic susceptibility are measured in LC ($logχ = 4.9$). These values are significantly lower than the $logχ$ of EH and EL falls of $5.48 ± 0.16$ and $5.46 ± 0.04$, respectively (Rochette et al., 2008).

The mean magnetic susceptibility of Al Haggounia 001 is $4.39 ± 0.20$. This value overlaps the lower end of E finds and the upper end of aubrites as shown in Figure 10. These results indicate that Al Haggounia 001 falls in the normal range of E finds ($logχ = 5.05 ± 0.43$; Rochette et al., 2008), which is also consistent with the measurement ranges of slightly weathered ECs reported in the work of Devaux et al. (2011).

On the other hand, the magnetic grain sizes may control the magnetic properties of natural specimens (Dunlop & Özdemir, 2018). Thus, the diversity of hysteresis properties is influenced by the variations in grain size of magnetic minerals. Also, this might be related to the different Ni and Si contents in the kamacite (Zhang et al., 1995), as well as the different metamorphic history (Rochette et al., 2008).
<figure><img src="image_11.png" /><figcaption>FIGURE 10. Comparison of the mean magnetic susceptibility Logχ (with χ 10−9 m³ kg⁻¹) of Al Haggounia 001, and its standard deviation, compared to E chondrites (based on Rochette et al., 2008) and Aubrites (Rochette et al., 2009). (Color figure can be viewed at wileyonlinelibrary.com)</figcaption></figure>

The comparison of the hysteresis results (Mrs/Ms vs. Hc) of chondrites groups, in fig. 3 of Kohout et al. (2010) following the work of Pesonen et al. (1993) and Sugiura (1977) with the results of Al Haggounia 001; Mrs/Ms = 0.10, SD = 0.06 and Hc = 8.08, SD = 1.41, shows a distinct range and reveals no agreement with E chondrites values.

According to the results of thermomagnetic curves (Figure 9), Tc = 550–770 could correspond to the transition temperature from stable kamacite to metastable kamacite and taenite mixture (kamacite → kamacite + taenite; Kohout et al., 2010; Rochette et al., 2008), confirming our investigations of kamacite and little taenite grains, same as for NWA 2828 (Connolly, Zipfel, et al., 2007) and NWA 7401 (Ruzicka et al., 2015).

The loss of metal in Al Haggounia 001 is possibly
caused by impact (Rubin, 2016). Metal and sulfides show a
random distribution throughout the different lithologies
(sometimes within the same sample), the weathering effect,
and the terrestrial contamination during the residence of the
meteorite on Earth (Pourkhorsandi et al., 2019; Rochette
et al., 2008), which increased the rusting and leaching of

metal and sulfides by water, all these facts lead to a variety
on the magnetism, in addition to the multidirectional
oxyhydroxides veins (network or parallel).

Pairings of Al Haggounia 001

Based on the MBD (Table S1), the following meteorites are all paired with Al Haggounia 001: NWA 002, NWA 1067, NWA 2736, NWA 2828, NWA 2965, NWA 4232, NWA 4295, NWA 4450, NWA 4561, NWA 4844, NWA 4919, NWA 6153, NWA 7401, NWA 14248, NWA 12962, NWA 13210, and NWA 14163. Here, we suggest that NWA 4282 is also paired with Al Haggounia 001 based on numerous similar characteristics such as logχ values, macroscopic features, and the presence of voids that formed by the dissolution of metal (Brandstätter & Kurat, 2006; Rochette et al., 2008).

Another plausible paired sample to Al Haggounia
001 could be Al Haggounia 010, which is classified as an
aubrite according to the MBD. This meteorite was
recovered from the same location as Al Haggounia 001
(27°30′N, 12°30′W), weighs 35 kg, and has no fusion
crust. The compositions of its major mineral phases
(enstatite En98.5; plagioclase Ab80.5) match those of Al
Haggounia 001 obtained in this study. In addition, the
two specimen photos, published along with
the classification in the bulletin, macroscopically resemble
the porous samples of Al Haggounia 001.

Also, the NWA 13996 (EL-melt rock, Gattacceca et al., 2022) could be paired with Al Haggounia 001. The classified sample is weathered and the related photos of NWA 13996 show a gray-to-bluish color and a high abundance of vesicles, identical to the LA lithology in the current work. Also, it contains a few relict chondrules (up to 3 mm) same as for Al Haggounia 001, in addition to enstatite (~94 vol%), and accessory albitic plagioclase, oldhamite, daubreelite, troilite, silica glass, and sparse grains of kamacite (<1 vol%, containing ~1.5 wt% Si, n = 3) (Gattacceca et al., 2022).

Shock Features and Subparallel Veinlets in Al
Haggounia 001

Al Haggounia 001 exhibits a shock stage S2 as
indicated by the presence of planar fractures and frequent
weak undulatory extinction in enstatite (Rubin, 2016;
Stöffler et al., 1991). Enstatite also exhibits another
feature interpreted as a result of shock in the form of
metal and sulfide inclusions in silicates, causing their
darkening (Rubin, 2016; Rubin et al., 1997). Goss
et al. (2023) suggested, based on their findings from the
enstatite chondrite LEW 87223, that this feature is not
the result of shock but could be due to the reduction of
Fe in silicates during a heating event. In the samples
analyzed in this study, we identified planar fractures in enstatite and found that it also displays weak undulatory extinction. Darkening of silicates is also observed, as indicated by the presence of tiny inclusions of kamacite and troilite in enstatite (Figure 7d), which could be evidence of shock (Rubin, 2016). The occurrence of ellipsoidal to flattened chondrules and elongated opaque nodules in Al Haggounia 001 (Figure 7c) indicates that this meteorite is heavily shocked (shock stage 5), which is comparable to what has been observed in PCA 91020; the most heavily shocked EL3 chondrite (Rubin et al., 1997, 2009), also showing evidence of deformation and foliation induced by impacts (Boleaga et al., 2021).

In our samples (Lithology B; Figure 4c,d), we detected subparallel fractures filled with oxyhydroxides. Similar fractures were identified in the EL3-melt rock NWA 4295 (W5), which is an Al Haggounia 001 paired sample that consists of aggregates of small whitish grains crosscut by distinctive thin compression fractures filled with terrestrial limonite (Gattacceca et al., 2021). NWA 4232 (EL3, S1, W4/5) is also paired with Al Haggounia 001 and contains multiple subparallel and anastomosing thin veinlets filled with iron oxyhydroxides and calcite (Connolly, Smith, et al., 2007). These subparallel cracks are also reported in NWA 1840, classified as an ungrouped EC, in the form of parallel compression fractures (0.1 to 0.8 mm apart), crosscutting the whole specimen, which acted as conduits for weathering agents (Russell et al., 2005). Furthermore, comparable fractures have been described in MET 01072 and SCO 06043, which are CM carbonaceous chondrites that contain 5–20 µm wide, well-developed fractures, following the same plane as the alignment of chondrules, as well as 10–60 µm wide fractures following the same orientation of chondrule petrofabric (see fig. 2 in Lindgren et al., 2015).

Subparallel compression fractures are rarely identified in meteorites. However, striated fractures in some chondrites have been interpreted as slickensides (fault dislocations), but Dietz (1966) showed that this is not the case, and these fractures are probably shock features related to shatter coning.

Nicolaysen and Reimold (1999) described numerous near-parallel, curviplanar to near-planar joints and microjoints in the Vredefort impact structure, they show examples of multiply striated joint sets (MSJS) occurring with shatter cones as results of impact. Albat and Mayer (1989) described fractures (s-surfaces) of Megascopic planar as shock features in the Vredefort structure, and said that such resulting rock failure (shatter cones and s-surfaces) is likely to have occurred practically instantaneously. The spacing joints can be as large as 1 cm but are macroscopically recognized at 1–5 mm (Baratoux & Reimold, 2016). The shatter cones, after Ferrière et al. (2013), are related to low pressure and

this is consistent with the presence of low silica polymorphs “cristobalite and tridymite” in the LB of Al Haggounia 001 (Leili et al., 2019).

The volume expansion caused by iron oxidation in the desert gives multiple cracks as irregular fractures but not subparallel features similar to what we observe in LB of Al Haggounia 001. We assume that the subparallel veinlets are thin fractures inherited from a shock compression (mechanical effects) in some regions of Al Haggounia 001's meteoroid.

## Unusual Features and Complexity of the Parent Body of Al Haggounia 001

Al Haggounia 001 is controversial and characterized by multiple features that make its parent body out of the known ECs. In addition to the macro-shock features described in the previous section, we identified deformed and broken graphites in Al Haggounia 001 as a fingerprint of an intense shock event. On the other hand, the preservation of low-pressure silica polymorphs, tridymite, and cristobalite in Al Haggounia 001 indicates that the last impact metamorphism was characterized by a rapid cooling (Kimura et al., 2005; Leili et al., 2019), but the evidence of daubreelite exsolution lamellae within troilite in Grein 002 (EL4-5) suggests slow cooling at subsolidus temperatures (Patzer et al., 2004), inconsistent with the formation of Al Haggounia 001 through impact melting process followed by rapid cooling (Bullock et al., 2013), but the EC parent bodies experienced varying degrees of thermal metamorphism and impact melting, which modified the original assemblages (Bullock et al., 2013).

For that, the characteristics of Al Haggounia 001 make it difficult to constrain the exact thermal history and the shock-induced different features, and it has evidence of a complex history of successive shock events before or during the accretion of its EC parent body, via successive impacts of compaction and deformation of the mixed regolith of Al Haggounia 001.

## CONCLUSION

Based on our observations during the field missions in the strewn field of Al Haggounia 001, as well as our results from the macroscopic, magnetic, microscopic, and mineralogical investigations, we conclude the following:

* The 52 collected samples with their locations indicate the same fall of Al Haggounia 001 meteorite, with the length of a strewn field of approximately 65 km.

* Al Haggounia 001 is not a fossil meteorite as previously suggested, because the specimens were collected on the surface, or shallowly buried in loose
sediments. As well as the samples also contain large unaltered metal and sulfide grains.

* Al Haggounia 001 is composed of different lithologies representing the same fall but referring to the heterogeneity of the parent body. This meteorite suffered various weathering effects on Earth, mainly controlled by climate changes, topography, and geology of the region.

* The magnetic measurements of Al Haggounia 001 indicate that it belongs in a distinct range and reveals no agreement with EH or EL groups. And, the magnetic parameters are mainly controlled by weathering grades, distribution and size of the metal-sulfide grains, and the arrangement of oxyhydroxide veins.

* Al Haggounia 001 experienced multiple shock events recorded with different features. They modified the original features inherited from the accretion of the parent body.

* The subparallel fractures are identified as macrofeatures related to shock on the parent body, not to a volume expansion.

* The unusual chondrules are composed of albite and enstatite rods, these features are specific to Al Haggounia 001.

* Al Haggounia 001 should be reclassified as anomalous EC due to its extremely heterogeneous nature with new features and the complicated thermal history which makes its classification difficult within the existing groups and subgroups of ECs.

*Acknowledgments*—The authors thank M. Meryem Magharbi for her efforts to promote collaboration between Moroccan and international universities. We thank the director of CEREGE for his kindness in admitting LEILI Mohamed Hassan twice for training in 2016 and 2017. The authors also thank the technician Julien Longerey for his art in preparing our thin sections. We would like to thank the help of the technical and support staff of the Groupe de Magnétisme des Roches et Paléomagnétisme of CEREGE. The first author would also like to express his deep appreciation to M. Rjimati who helped in completing the geological settings. We gratefully thank the reviewers for their great efforts to ameliorate this paper. We want to show gratitude to Stamatis Xydous and Angie Papoutsa from the Agricultural University of Athens—Laboratory of Mineralogy and Geology for helping with the analysis by EPMA, as well as Taha Shisseh for his help with the figures in this paper. This research was partly supported by an Erasmus program 2017-1-IT02-KA107-036224.

*Editorial Handling*—Dr. Michael Zolensky

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## SUPPORTING INFORMATION

Additional supporting information may be found in the online version of this article.

**FIGURE S1.** Photo of sample characterized by subparallel oxyhydroxide veins, sometimes filled by white terrestrial products. Aggregate of rounded to ellipsoidal chondrules in lithology (LB).

**FIGURE S2.** (a) Selected area from chondrule in figure (Figure 5a). The images b–g are EDX element distributions (maps) of Fe, Mg, Ca, Na, S, and Cr respectively. Db, daubreelite; En, enstatite; Plg, plagioclase.

**FIGURE S3.** Backscattered electron images showing graphite shapes in Al Haggounia 001. (a) Millimetric

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(1000 µm-sized) rounded bent graphite lathe-like with two grains of sinoite with pyramidal terminations and subparallel veins filled with iron oxides. (b) Veins of iron oxides are spreading around and inside the graphite broken laths of graphite characterized by thin subparallel veinlets. Note small grains of Kamacite juxtaposed to graphite. En, enstatite; Gr, graphite; IO, iron oxide; Km, kamacite; Sin, sinoite; Tr, troilite; V, veins.

**TABLE S1.** List of 18 meteorites possibly related to Al Haggounia 001 meteorite, in MBD (date: September 20, 2022). n.d., not described.

**TABLE S2.** List of 52 recovered samples of the Al Haggounia 001 meteorite, with their latitude and longitude.