New Minerals from Inclusions in Corundum Xenocrysts from Mt. Carmel, Israel: Magnéliite, Ziroite, Sassite, Mizraite-(Ce) and Yeite.

Our nanomineralogical investigation of melt inclusions in corundum xenocrysts from the Mt. Carmel area, Israel has revealed seven IMA-approved new minerals since 2021. We report here four new oxide minerals and one new alloy mineral. Magnéliite (Ti3+2Ti4+2O7; IMA 2021-111) occurs as subhedral crystals, ~4 µm in size, with alabandite, zirconolite, Ti,Al,Zr-oxide, and hibonite in corundum Grain 767-1. Magnéliite has an empirical formula (Ti3+1.66Al0.13Ti4+0.15Mg0.10Ca0.01Sc0.01)Σ2.06 (Ti4+1.93Zr0.08)Σ2.01O7 and the triclinic P1¯ Ti4O7-type structure with the cell parameters: a = 5.60(1) Å, b = 7.13(1) Å, c = 12.47(1) Å, α = 95.1(1)°, ß = 95.2(1)°, γ = 108.7(1)°, V = 466(2) Å3, Z = 4. Ziroite (ZrO2; IMA 2022-013) occurs as irregular crystals, ~1-4 µm in size, with baddeleyite, hibonite, and Ti,Al,Zr-oxide in corundum Grain 479-1a. Ziroite has an empirical formula (Zr0.72Ti4+0.26Mg0.02Al0.02Hf0.01)Σ1.03O2 and the tetragonal P42/nmc zirconia(HT)-type structure with the cell parameters: a = 3.60(1) Å, c = 5.18(1) Å, V = 67.1(3) Å3, Z = 2. Sassite (Ti3+2Ti4+O5; IMA 2022-014) occurs as subhedral-euhedral crystals, ~4-16 µm in size, with Ti,Al,Zr-oxide, mullite, osbornite, baddeleyite, alabandite, and glass in corundum Grain 1125C1. Sassite has an empirical formula (Ti3+1.35Al0.49Ti4+0.08Mg0.07)Σ1.99(Ti4+0.93Zr0.06Si0.01)Σ1.00O5 and the orthorhombic Cmcm pseudobrookite-type structure with the cell parameters: a = 3.80(1) Å, b = 9.85(1) Å, c = 9.99(1) Å, V = 374(1) Å3, Z = 4. Mizraite-(Ce) (Ce(Al11Mg)O19; IMA 2022-027) occurs as euhedral crystals, <1-14 µm in size, with Ce-silicate, Ti-sulfide, Ti,Al,Zr-oxide, ziroite, and thorianite in corundum Grain 198-8. Mizraite-(Ce) has an empirical formula (Ce0.76Ca0.10La0.07Nd0.01)Σ0.94(Al10.43Mg0.84Ti3+0.60Si0.09Zr0.04)Σ12.00O19 and the hexagonal P63/mmc magnetoplumbite-type structure with the cell parameters: a = 5.61(1) Å, c = 22.29(1) Å, V = 608(2) Å3, Z = 2. Yeite (TiSi; IMA 2022-079) occurs as irregular-subhedral crystals, 1.2-3.5 µm in size, along with wenjiite (Ti5Si3) and zhiqinite (TiSi2) in Ti-Si alloy inclusions in corundum Grain 198c. Yeite has an empirical formula (Ti0.995Mn0.003V0.001Cr0.001)(Si0.996P0.004) and the orthorhombic Pnma FeB-type structure with the cell parameters: a = 6.55(1) Å, b = 3.64(1) Å, c = 4.99(1) Å, V = 119.0(4) Å3, Z = 4. The five minerals are high-temperature oxide or alloy phases, formed in melt pockets in corundum xenocrysts derived from the upper mantle beneath Mt. Carmel.

Rift-induced disruption of cratonic keels drives kimberlite volcanism.

Kimberlites are volatile-rich, occasionally diamond-bearing magmas that have erupted explosively at Earth's surface in the geologic past1-3. These enigmatic magmas, originating from depths exceeding 150 km in Earth's mantle1, occur in stable cratons and in pulses broadly synchronous with supercontinent cyclicity4. Whether their mobilization is driven by mantle plumes5 or by mechanical weakening of cratonic lithosphere4,6 remains unclear. Here we show that most kimberlites spanning the past billion years erupted about 30 million years (Myr) after continental breakup, suggesting an association with rifting processes. Our dynamical and analytical models show that physically steep lithosphere-asthenosphere boundaries (LABs) formed during rifting generate convective instabilities in the asthenosphere that slowly migrate many hundreds to thousands of kilometres inboard of rift zones. These instabilities endure many tens of millions of years after continental breakup and destabilize the basal tens of kilometres of the cratonic lithosphere, or keel. Displaced keel is replaced by a hot, upwelling mixture of asthenosphere and recycled volatile-rich keel in the return flow, causing decompressional partial melting. Our calculations show that this process can generate small-volume, low-degree, volatile-rich melts, closely matching the characteristics expected of kimberlites1-3. Together, these results provide a quantitative and mechanistic link between kimberlite episodicity and supercontinent cycles through progressive disruption of cratonic keels.

Vertical depletion of ophiolitic mantle reflects melt focusing and interaction in sub-spreading-center asthenosphere.

Decompressional melting of asthenosphere under spreading centers has been accepted to produce oceanic lithospheric mantle with vertical compositional variations, but these gradients are much smaller than those observed from ophiolites, which clearly require additional causes. Here we conduct high-density sampling and whole-rock and mineral analyses of peridotites across a Tibetan ophiolitic mantle section (~2 km thick), which shows a primary upward depletion (~12% difference) and local more-depleted anomalies. Thermodynamic modeling demonstrates that these features cannot be produced by decompressional melting or proportional compression of residual mantle, but can be explained by melt-peridotite reaction with lateral melt/rock ratio variations in an upwelling asthenospheric column, producing stronger depletion in the melt-focusing center and local zones. This column splits symmetrically and flows to become the horizontal uppermost lithospheric mantle, characterized by upward depletion and local anomalies. This model provides insights into melt extraction and uppermost-mantle origin beneath spreading centers with high melt fluxes.

Perturbation of the deep-Earth carbon cycle in response to the Cambrian Explosion.

Earth's carbon cycle is strongly influenced by subduction of sedimentary material into the mantle. The composition of the sedimentary subduction flux has changed considerably over Earth's history, but the impact of these changes on the mantle carbon cycle is unclear. Here, we show that the carbon isotopes of kimberlite magmas record a fundamental change in their deep-mantle source compositions during the Phanerozoic Eon. The 13C/12C of kimberlites before ~250 Ma preserves typical mantle values, whereas younger kimberlites exhibit lower and more variable ratios-a switch coincident with a recognized surge in kimberlite magmatism. We attribute these changes to increased deep subduction of organic carbon with low 13C/12C following the Cambrian Explosion when organic carbon deposition in marine sediments increased significantly. These observations demonstrate that biogeochemical processes at Earth's surface have a profound influence on the deep mantle, revealing an integral link between the deep and shallow carbon cycles.

Poor Patient Follow-up After Metal-on-Metal Total Hip Arthroplasty.

Routine follow-up approximately every 2 to 5 years after total hip arthroplasty (THA) is a common practice. However, although patients are informed of the importance of follow-up, our mean follow-up rate for patients after standard non-metal-on-metal (MOM) THA is only 19%. The US Food and Drug Administration has released several statements on the importance of follow-up every 2 years after MOM THA. With the potential risks of MOM THA apparently widely known, we report on our ability to obtain timely follow-up at 2 separate centers. Two separate centers performed 570 MOM THA procedures between 2002 and 2010. An attempt was made to reach every patient by either telephone or letter to obtain ion levels, radiographs, and examinations. Repeat telephone calls and/or letters to those not reached were made annually. Patients were told of the unique importance of follow-up at each contact. Of the patients, 43% had not been seen within the past 5 years, and only 26% had been seen within the past 2 years. Only 61% had their first measurement of ion levels, and only 30% of patients had a second set of measurement of ion levels. A total of 48 revisions occurred in this group, and 36 patients died. Despite the apparent widespread dissemination of information regarding the potential risks of MOM THA and concerted efforts to contact patients for follow-up, we have been able to achieve a follow-up rate of only 26%. This rate is only marginally better than the mean follow-up for non-MOM THA in our practices. The implications of this poor follow-up are unknown. [Orthopedics. 2022;45(4):e196-e200.].

High-Dose Antibiotic Cement Spacers Independently Increase the Risk of Acute Kidney Injury in Revision for Periprosthetic Joint Infection: A Prospective Randomized Controlled Clinical Trial.

BACKGROUND: Standard treatment for periprosthetic joint infection (PJI) involves 2-stage exchange with placement of an antibiotic-impregnated cement spacer (ACS). Conflicting evidence exists on the role of ACS in development of acute kidney injury (AKI) after first-stage surgery. In this randomized clinical trial, we aimed to compare the incidence of AKI between the first-stage of a planned 2-stage exchange vs 1-stage exchange. This study design isolates the effect of the ACS in otherwise identical treatment groups. METHODS: The primary outcome variable was AKI, defined as a creatinine ≥1.5 times baseline or an increase of ≥0.3 mg/dL. Risk factors for AKI were evaluated using bivariate statistical tests and multivariable logistic regression. RESULTS: Patients who underwent the first stage of a planned 2-stage exchange were significantly more likely to develop AKI compared with the 1-stage exchange group (15 [22.7%] vs 4 [6.6%], P = .011). On multivariable regression analysis, ACS placement (odds ratio 7.48, 95% confidence limit 1.77-31.56) and chronic kidney disease (odds ratio 3.84, 95% confidence limit 1.22-12.08) were independent risk factors for AKI. CONCLUSION: Our study provides evidence that high-dose antibiotic cement spacers for treatment of PJI are an independent risk factor for AKI. Therefore, efforts to minimize nephrotoxicity should be employed in revision for PJI when possible.

Light oxygen isotopes in mantle-derived magmas reflect assimilation of sub-continental lithospheric mantle material.

Oxygen isotope ratios in mantle-derived magmas that differ from typical mantle values are generally attributed to crustal contamination, deeply subducted crustal material in the mantle source or primordial heterogeneities. Here we provide an alternative view for the origin of light oxygen-isotope signatures in mantle-derived magmas using kimberlites, carbonate-rich magmas that assimilate mantle debris during ascent. Olivine grains in kimberlites are commonly zoned between a mantle-derived core and a magmatic rim, thus constraining the compositions of both mantle wall-rocks and melt phase. Secondary ion mass spectrometry (SIMS) analyses of olivine in worldwide kimberlites show a remarkable correlation between mean oxygen-isotope compositions of cores and rims from mantle-like 18O/16O to lower 'crustal' values. This observation indicates that kimberlites entraining low-18O/16O olivine xenocrysts are modified by assimilation of low-18O/16O sub-continental lithospheric mantle material. Interaction with geochemically-enriched domains of the sub-continental lithospheric mantle can therefore be an important source of apparently 'crustal' signatures in mantle-derived magmas.

Ti3+ in corundum traces crystal growth in a highly reduced magma.

Aggregates of corundum crystals with skeletal to hopper morphology occur in pyroclastic rocks erupted from Cretaceous basaltic volcanoes on Mt Carmel, N. Israel. The rapid growth of the crystals trapped volumes of the parental Al2O3-supersaturated melt; phenocrysts of tistarite (Ti2O3) in the trapped melts indicate crystallization at oxygen fugacities 6-7 log units below the Iron-Wüstite buffer (fO2 = ΔIW - 6 to - 7), induced by fluxes of mantle-derived CH4-H2 fluids. Cathodoluminescence images reveal growth zoning within the individual crystals of the aggregates, related to the substitution of Ti3+ in the corundum structure. Ti contents are < 0.3 wt% initially, then increase first linearly, then exponentially, toward adjacent melt pockets to reach values > 2 wt%. Numerical modelling indicates that the first skeletal crystals grew in an open system, from a moving magma. The subsequent linear increase in Ti reflects growth in a partially closed system, with decreasing porosity; the exponential increase in Ti close to melt pockets reflects closed-system growth, leading to dramatic increases in incompatible-element concentrations in the residual melts. We suggest that the corundum aggregates grew in melt/fluid conduits; diffusion modelling implies timescales of days to years before crystallization was terminated by explosive eruption. These processes probably operate in explosive volcanic systems in several tectonic settings.

Kimberlite genesis from a common carbonate-rich primary melt modified by lithospheric mantle assimilation.

Quantifying the compositional evolution of mantle-derived melts from source to surface is fundamental for constraining the nature of primary melts and deep Earth composition. Despite abundant evidence for interaction between carbonate-rich melts, including diamondiferous kimberlites, and mantle wall rocks en route to surface, the effects of this interaction on melt compositions are poorly constrained. Here, we demonstrate a robust linear correlation between the Mg/Si ratios of kimberlites and their entrained mantle components and between Mg/Fe ratios of mantle-derived olivine cores and magmatic olivine rims in kimberlites worldwide. Combined with numerical modeling, these findings indicate that kimberlite melts with highly variable composition were broadly similar before lithosphere assimilation. This implies that kimberlites worldwide originated by partial melting of compositionally similar convective mantle sources under comparable physical conditions. We conclude that mantle assimilation markedly alters the major element composition of carbonate-rich melts and is a major process in the evolution of mantle-derived magmas.

Immiscible metallic melts in the deep Earth: clues from moissanite (SiC) in volcanic rocks.

The occurrence of moissanite (SiC), as xenocrysts in mantle-derived basaltic and kimberlitic rocks sheds light on the interplay between carbon, hydrogen and oxygen in the lithospheric and sublithospheric mantle. SiC is stable only at ƒO2 < ΔIW-6, while the lithospheric mantle and related melts commonly are considered to be much more oxidized. SiC grains from both basaltic volcanoclastic rocks and kimberlites contain metallic inclusions whose shapes suggest they were entrapped as melts. The inclusions consist of Si0 + Fe3Si7 ± FeSi2Ti ± CaSi2Al2 ± FeSi2Al3 ± CaSi2, and some of the phases show euhedral shapes toward Si0. Crystallographically-oriented cavities are common in SiC, suggesting the former presence of volatile phase(s), and the volatiles extracted from crushed SiC grains contain H2 + CH4 ± CO2 ± CO. Our observations suggest that SiC crystalized from metallic melts (Si-Fe-Ti-C ± Al ± Ca), with dissolved H2 + CH4 ± CO2 ± CO derived from the sublithospheric mantle and concentrated around interfaces such as the lithosphere-asthenosphere and crust-mantle boundaries. When mafic/ultramafic magmas are continuously fluxed with H2 + CH4 they can be progressively reduced, to a point where silicide melts become immiscible, and crystallize phases such as SiC. The occurrence of SiC in explosive volcanic rocks from different tectonic settings indicates that the delivery of H2 + CH4 from depth may commonly accompany explosive volcanism and modify the redox condition of some lithospheric mantle volumes. The heterogeneity of redox states further influences geochemical reactions such as melting and geophysical properties such as seismic velocity and the viscosity of mantle rocks.

Fate of Two-Stage Reimplantation After Failed Irrigation and Debridement for Periprosthetic Hip Infection.

BACKGROUND: Irrigation and debridement is an attractive treatment option for acute perioperative and acute hematogenous periprosthetic hip infections. We ask the following questions: (1) What are the results of a two-stage reimplantation if preceded by debridement, antibiotics, and implant retention (DAIR) compared with two-stage reimplantation without an antecedent DAIR? and (2) Do McPherson Musculoskeletal Infection Society (MSIS) host criteria influence results? METHODS: A total of 114 patients were treated with two-stage exchange for periprosthetic hip infection. Sixty-five patients were treated initially with a two-stage exchange, whereas 49 patients underwent an antecedent DAIR before a two-stage exchange. Patients were classified based on MSIS host criteria. Demographics demonstrated homogeneity between cohorts. Failure was defined as return to the operating room for infection, draining sinus, or systemic infection. RESULTS: Treatment failure occurred in 42.9% (21 of 49) of patients treated with an antecedent DAIR. In contrast, treatment failure occurred in only 12.3% (8 of 65) of two-stage only procedures (P < .001). Relative risk of return to the operating room after a two-stage reimplantation with an antecedent DAIR compared with initial resection was 4.52 (95% confidence interval: 1.71, 11.9). MSIS host grading was similar between groups and did not influence the rate of failure in a regression model. The DAIR cohort was also found to consume more resources in terms of hospitalization length and operative procedures (P < .001). CONCLUSIONS: Two-stage exchange procedures for prosthetic hip infections have a higher failure rate and consume more health-care resources when preceded by a failed DAIR. Surgeons and patients should be aware that a failed DAIR may compromise the results of future two-stage procedures.

Balanced, Stemmed, and Augmented Articulating Total Knee Spacer Technique.

Explantation and placement of an antibiotic spacer is a well-recognized treatment for periprosthetic infection after total knee replacement. Although static spacers may be occasionally indicated, many patients benefit from an articulating spacer that preserves the function and range of motion. However, many articulating spacer techniques provide an imbalanced cement-on-cement articulating knee that cannot tolerate full weight-bearing or provide adequate stability for daily function. A more durable articulating spacer may be ideal by permitting unrestricted weight-bearing, a functional range of motion, and potentially delayed reimplantation for medically complex patients. We present our evolved and reproducible technique for gap-balanced articulating spacers using cement augments and dowel stems. The result is a stable construct that permits full weight-bearing and a functional range of motion.

Initial metal ion levels predict risk of elevation in metal on metal total hip arthroplasty.

INTRODUCTION: Screening protocols for asymptomatic patients with metal on metal (MoM) total hip arthroplasty (THA) are evolving. Most surgeons began screening patients around 2010 by obtaining cobalt (Co) and chromium (Cr) metal ion levels. There is currently no data available to guide repeat screening in this familiar clinical scenario. Therefore, the following study evaluated how metal ion levels change after an initial metal ion level in patients with MoM THAs. MATERIALS AND METHODS: 171 consecutive patients (265 hips) underwent primary MoM THA. All patients had at least one Co and Cr ion level draw. 84 patients (136 hips) had 2 ion level draws. Ion levels were divided into elevated levels (⩾4.5 ppb) and normal levels (<4.5 ppb). The probability of an ion level returning elevated after an initial normal level was identified. Additionally, a threshold value was determined that reliably identified every patient that did not subsequently rise above 4.5 ppb. RESULTS: 12 metal ion levels were ⩾4.5 ppb on the first lab draw. On the second draw, all 12 remained ⩾4.5 ppb. Of the 121 hips with initial metal ion levels <4.5 ppb, 5 metal ion levels became ⩾4.5 ppb. Utilising an initial screening cutoff of 3.0 ppb, no patient was identified with a second lab value ⩾4.5 ppb. DISCUSSION: Initial metal ion levels reliably predicted those that would remain elevated or remain normal with a subsequent metal ion level. An initial metal ion level above 3.0 ppb may represent a cutoff at which further workup is necessary.

Kinematic Performance of Gradually Variable Radius Posterior-Stabilized Primary TKA During Various Activities: An In Vivo Study Using Fluoroscopy.

BACKGROUND: Posterior-stabilized total knee arthroplasty (TKA) with gradually variable radii (G-curve) femoral condylar geometry is now available. It is believed that a G-curve design would lead to more mid-flexion stability leading to reduced incidence of paradoxical anterior slide. The objective of this study was to assess the in vivo kinematics for subjects implanted with this type of TKA under various conditions of daily living. METHODS: Tibiofemoral kinematics of 35 patients having posterior-stabilized TKA with G-curve design were analyzed using fluoroscopy while performing three activities: weight-bearing deep knee bend, gait, and walking down a ramp. The subjects were assessed for range of motion, condylar translation, axial rotation, cam-spine engagement, and condylar lift-off. RESULTS: The average weight-bearing flexion during deep knee bend was 111.4°. On average, the subjects exhibited 5.4 mm of posterior rollback of the lateral condyle and 2.0 mm of the medial condyle from full extension to maximum knee flexion. The femur consistently rotated externally with flexion, and the average axial rotation was 5.2°. Overall movement of the condyles during gait and ramp-down activity was small. No incidence of condylar lift-off was observed. CONCLUSION: Subjects in this study experienced consistent magnitudes of posterior femoral rollback and external rotation of the femur with weight-bearing flexion. The variation is similar to that previously reported for normal knee where the lateral condyle moves consistently posterior compared to the medial condyle. Subjects experienced low overall mid-flexion paradoxical anterior sliding and no incidence of condylar lift-off leading to mid-flexion stability.

Inferomedial Hip Center Decreases Failure Rates in Cementless Total Hip Arthroplasty for Crowe II and III Hip Dysplasia.

BACKGROUND: We sought to evaluate the outcomes of cementless acetabular components used in patients with Crowe II and III dysplasia, and to compare outcomes between cups placed within vs outside of an "anatomic" zone. Our specific aims were to (1) plot hip centers in these patients at our institution to characterize "anatomic" vs "nonanatomic" positions, (2) evaluate the association between hip center and radiographic loosening, (3) determine whether hip center was associated with acetabular component revision, and (4) compare patient-reported outcome scores between groups. METHODS: We retrospectively reviewed 88 primary cementless total hip arthroplasties at a mean follow-up of 10 years (range 2-26 years). Patients were 85% female, with a mean age of 44 years (range 28-61 years) and a body mass index of 27 kg/m2 (range 19-42 kg/m2). Medical records and radiographs were reviewed, and a survey was conducted for all patients. Anatomic hip center was defined using the 4-zone system, wherein centers are "anatomic" if they are <1 cm superior and <1 cm lateral to the approximate femoral head center. Cox proportional analyses were used to compare outcomes between groups. RESULTS: Seventy hips (80%) had an anatomic hip center. Anatomic hips had a lower incidence of radiographic acetabular loosening (0% vs 17%, P = .007) and cup revision (0% vs 28%, P = .0002). There were no differences in Hip Disability and Osteoarthritis Outcome and Joint Replacement Scores (96.2 ± 5 vs 91.9 ± 12, P = .7). CONCLUSION: The incidence of aseptic loosening and cup revision were lower when hip center was <1 cm superior and 1 cm lateral to the approximate femoral head center.

Synthesis of inverse ringwoodite sheds light on the subduction history of Tibetan ophiolites.

Tibetan ophiolites are shallow mantle material and crustal slabs that were subducted as deep as the mantle transition zone, a conclusion supported by the discovery of high-pressure phases like inverse ringwoodite in these sequences. Ringwoodite, Mg2SiO4, exhibits the normal spinel structure, with Mg in the octahedral A site and Si in the tetrahedral B site. Through A and B site-disorder, the inverse spinel has four-coordinated A cations and the six-coordinated site hosts a mixture of A and B cations. This process affects the density and impedance contrasts across the boundaries in the transition zone and seismic-wave velocities in this portion of the Earth. We report the first synthesis at high pressure (20 GPa) and high temperature (1600 °C) of a Cr-bearing ringwoodite with a completely inverse-spinel structure. Chemical, structural, and computational analysis confirm the stability of inverse ringwoodite and add further constraints to the subduction history of the Luobusa peridotite of the Tibetan ophiolites.

GZ7 and GZ8 - Two Zircon Reference Materials for SIMS U-Pb Geochronology.

Here, we document a detailed characterisation of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.84 g) each; both came from placer deposits in the Ratnapura district, Sri Lanka. The U-Pb data are in both cases concordant within the uncertainties of decay constants and yield weighted mean 206Pb/238U ages (95% confidence uncertainty) of 530.26 Ma ± 0.05 Ma (GZ7) and 543.92 Ma ± 0.06 Ma (GZ8). Neither GZ7 nor GZ8 have been subjected to any gem enhancement by heating. Structure-related parameters correspond well with the calculated alpha doses of 1.48 × 1018 g-1 (GZ7) and 2.53 × 1018 g-1 (GZ8), respectively, and the (U-Th)/He ages of 438 Ma ± 3 Ma (2s) for GZ7 and 426 Ma ± 9 Ma (2s) for GZ8 are typical of unheated zircon from Sri Lanka. The mean U mass fractions are 680 µg g-1 (GZ7) and 1305 µg g-1 (GZ8). The two zircon samples are proposed as reference materials for SIMS (secondary ion mass spectrometry) U-Pb geochronology. In addition, GZ7 (Ti mass fractions 25.08 µg g-1 ± 0.18 µg g-1; 95% confidence uncertainty) may prove useful as reference material for Ti-in-zircon temperature estimates.

Plume-subduction interaction forms large auriferous provinces.

Gold enrichment at the crustal or mantle source has been proposed as a key ingredient in the production of giant gold deposits and districts. However, the lithospheric-scale processes controlling gold endowment in a given metallogenic province remain unclear. Here we provide the first direct evidence of native gold in the mantle beneath the Deseado Massif in Patagonia that links an enriched mantle source to the occurrence of a large auriferous province in the overlying crust. A precursor stage of mantle refertilisation by plume-derived melts generated a gold-rich mantle source during the Early Jurassic. The interplay of this enriched mantle domain and subduction-related fluids released during the Middle-Late Jurassic resulted in optimal conditions to produce the ore-forming magmas that generated the gold deposits. Our study highlights that refertilisation of the subcontinental lithospheric mantle is a key factor in forming large metallogenic provinces in the Earth's crust, thus providing an alternative view to current crust-related enrichment models.The lithospheric controls on giant gold deposits remain unclear. Here, the authors show evidence for native gold in the mantle from the Deseado Massif in Patagonia demonstrating that refertilisation of the lithospheric mantle is key in forming metallogenic provinces.