Contributions to Mineralogy and Petrology最新文献

{"title":"Effects of post-cumulus processes on chromite compositions in layered intrusion cumulates and implications for the origins of chromitite layers","authors":"Stephen J. Barnes,&nbsp;M. Michael Langa,&nbsp;William E. Smith","doi":"10.1007/s00410-026-02306-z","DOIUrl":"10.1007/s00410-026-02306-z","url":null,"abstract":"<div>\u0000 \u0000 <p>In several studies of chromite-rich cumulates in layered intrusions, the Cr/Al ratio of chromite varies significantly within centimetre-to-decimetre scale layering. In the G-H chromitite section of the Stillwater Complex (United States), Cr/Al ratios are consistently higher, by up to relative 20%, in the most chromite-rich rocks compared with immediately adjacent layers. Systematic relationships between Cr/Al ratios and chromite modes are also observed in cumulate rocks of the Bushveld Complex (South Africa). This is a critical observation for models of chromitite genesis involving mechanical sorting of chromite from silicate minerals in gravity flows; there is no plausible mechanism for sorting small chromite crystals on the basis of subtle variations in composition. A possible explanation could be in the combined effects of subsolidus re-equilibration and trapped liquid reaction. To test this possibility, a series of model calculations was carried out, solving for conservation of mass, relationships between distribution coefficients, composition and temperature, and stoichiometry. Although Mg/Fe ratios are indeed predicted to be highly mode-dependent, Cr# values (atomic Cr/[Cr + Al]) are insensitive to post-cumulus effects where chromite proportions are greater than 20 wt%. Variation comparable to natural data is only possible for chromite modes less than about 10 wt%. The difference in Cr# between rocks with 20–80 wt% and &gt; 80 wt% chromite, and the short-range cyclicity of Cr# within individual massive chromitite layers, cannot be explained by post-cumulus processes. This variation, therefore, must reflect primary liquidus compositions. This argues in favour of in-situ boundary layer crystallisation models over ones invoking mechanical deposition and hence supports models of in-situ growth of chromitites from large convecting magma bodies.</p>\u0000 </div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00410-026-02306-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disequilibrium enhanced equilibration: dynamics and textural evolution of cumulate interface","authors":"Dominika Linzerová,&nbsp;Václav Špillar,&nbsp;Martin Racek","doi":"10.1007/s00410-026-02303-2","DOIUrl":"10.1007/s00410-026-02303-2","url":null,"abstract":"<div><p>Understanding the textural cues hidden within cumulate rocks is a crucial component to decoding their formational processes and development throughout the active lifetime of their parental intrusions. However, given the complicated nature of field observations, often resulting in contrasting interpretations, the studies of cumulates benefit from an effective use of textural analysis utilizing parameters unaffected by alterations and equilibration. This study aims to contribute to the present knowledge of cumulate textural evolution and present its exploration through a set of textural parameters. With the main objective being to observe and analyze the textural development of an olivine cumulate, a special focus is paid to the behaviour of cumulate interface. The environment was simulated in high-temperature experimental conditions using a mixture of haplobasaltic glass with crushed forsterite crystals, forming a loose suspension capable of mechanical settling. The resulting cumulate layer was then subjected to <i>T</i>=-40 °C of undercooling to induce overgrowth and porosity reduction, for a duration between 2 and 48 h. Surprisingly, the cumulates experienced only a short period of kinetic growth, followed by gradual equilibration. For both of these processes, the system showed a contrasting behaviour of the interface and the deeper mush, observing prominent textural changes solely in the shallower layers. The results of textural analysis imply a strong effect of initial crystallinity on textural development, explore the evolution of skeletal morphologies, and point out the role of system’s heterogeneity on the process of equilibration.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00410-026-02303-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melt-mediated coupled dissolution-precipitation of zircon in metagranite, Bohemian Massif","authors":"Pavla Štípská,&nbsp;Stephen Collett,&nbsp;Andrew R. C. Kylander-Clark,&nbsp;Martin Racek,&nbsp;Prokop Závada,&nbsp;Pavlína Hasalová","doi":"10.1007/s00410-026-02296-y","DOIUrl":"10.1007/s00410-026-02296-y","url":null,"abstract":"<div><p>In zircon, transgressive textures cutting oscillatory zoning and associated chemical modifications are usually attributed to fluid-mediated coupled dissolution-precipitation (CDP). Here, we show an example of melt-mediated CDP in zircon from metagranite, with consequences on calculated ages and chemical composition. Zircon oscillatory zoning is commonly blurred and truncated by embayments and channels of replaced zircon with irregular and sharp boundaries. These are interpreted as replacement fronts and may be spatially associated with micro-porosity. Some superimposed replacement fronts indicate repeated CDP and porosity healing. Micro-porosity and inclusions are associated with replaced domains and thus are epigenetic. We highlight the necessity of combined high-resolution back-scattered electron imaging, otherwise the CDP textures may be overlooked in cathodoluminescence images. Inclusions of Ph–Grt–Ttn–Ap–Qz–Bt are compatible with the matrix assemblage Grt−Ph−Bt−Ttn−Kfs−Pl−Qz ± Rt ± Ilm, which equilibrated at c. 15−17 kbar, 690–740 °C with partial re-equilibration to c. 12 kbar, 680 °C. Since the conditions were above the wet solidus, the zircon changes happened through melt-mediated CDP. The replaced domains show an overall decrease of REE, Y, Th and Th/U, P, a large variation in Yb/Gd, shallower Eu anomaly, and increased U, and Hf. The chemical changes indicate a tendency of zircon purging trace elements during reequilibration with migrating melt. Spots with high LREE are probably due to the effect of micro-inclusions. Based on textures, inherited zircons are c. 540–600 Ma, protolith granite is c. 507–496 Ma, and CDP replacement occurred down to c. 335 Ma. But, the melt-mediated CDP resulted in a smear of mostly concordant, but spurious spot dates between inherited, protolith and modified domains, spanning &gt; 200 Myr.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00410-026-02296-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apatite saturation revisited: new model formulations and applications to igneous rocks","authors":"Benjamin Z. Klein,&nbsp;Othmar Müntener,&nbsp;Jack Gillespie,&nbsp;Felix Marxer","doi":"10.1007/s00410-026-02300-5","DOIUrl":"10.1007/s00410-026-02300-5","url":null,"abstract":"<div><p>Apatite is the primary phosphate mineral in the Earth’s crust and is present in a range of intrusive and extrusive igneous rocks, typically at minor to trace quantities. Similarly, apatite is a stable phase in many equilibrium crystallization experiments conducted with phosphorus-bearing starting compositions. We leverage this experimental stability to produce a large compilation of apatite-saturated liquid compositions, supplemented by additional apatite trace element and volatile partitioning and explicit apatite solubility experiments, as well as analyses of natural rhyolitic glasses. Using this compilation, we calibrate two new, independent models: for apatite saturation temperature as a function of melt P₂O₅ and SiO₂ contents and aluminum saturation index (ASI; molar Al/(2Ca + Na + K)); and for melt P₂O₅ contents at apatite saturation as a function of temperature, melt SiO₂ contents and ASI. The first model reproduces apatite saturation temperatures with an accuracy of ~ 32 °C, significantly outperforming existing apatite saturation models as well as recent zircon saturation thermometers. The second model reproduces melt P₂O₅ contents at apatite saturation by better than a factor of two across four orders of magnitude. Our new calibrations show that, within uncertainty, apatite stability does not differ regardless of the specific volatile species present (H₂O, F or Cl) or on the quantity of H₂O dissolved in the melt. Further, we find that apatite stability is not sensitive to pressures at least in the range of 1 atm to 2 GPa. This model accurately describes the saturation of apatite in a wide range of liquids, including metaluminous liquids, moderately alkaline liquids, and most peraluminous liquids. Experimental and natural peraluminous liquids with unusually high P₂O₅ contents that are not well described by our model contain CaO:P₂O₅ ratios below apatite stoichiometry (‘perphosphorous melts’), indicating that apatite saturation in these liquids is at minimum jointly controlled by CaO and P₂O₅ contents.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12920737/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147269423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase equilibria modelling of trace element evolution in arc magmas: implications for petrogenesis and copper porphyry indicators","authors":"Caroline R. Soderman,&nbsp;Owen M. Weller","doi":"10.1007/s00410-026-02297-x","DOIUrl":"10.1007/s00410-026-02297-x","url":null,"abstract":"<div><p>Trace element ratios in arc magmas are widely used to infer petrogenetic conditions, particularly those associated with porphyry-forming versus barren systems. However, quantitatively linking whole-rock signatures to pressure, water content, or redox conditions remains challenging, as trace elements are sensitive to mineral assemblage and compositions, which both evolve during fractional crystallisation. Here, we integrate a recently updated thermodynamic model suite appropriate for arc systems with dynamic (composition-, temperature-dependent) mineral-melt partitioning to track trace element evolution. Benchmarking the model against published experiments, including apatite saturation, shows that the methodology successfully reproduces phase assemblages and compositions. We simulate fractional crystallisation of an average primitive arc magma across mid- to lower-crustal pressures (4–10 kbar), 2–4 wt% initial H<span>(_2)</span>O, and a range of redox conditions (<span>(sim )</span>2 log units <span>(Delta )</span>FMQ). We demonstrate how mineral-specific vectors evolve in trace element ratio (e.g. Sr/Y, Dy/Dy*) and rare-earth element shape coefficient (<span>(lambda )</span>) space. Results highlight that amphibole and garnet may produce overlapping <span>(lambda )</span>-space vectors under deep, hydrous conditions—contrary to orthogonal vectors inferred using static (composition-, temperature-independent) partitioning. Multiple petrogenetic paths can yield similar whole-rock trace element outcomes, particularly with poorly constrained primitive melt compositions. High Sr/Y, for example, commonly associated with porphyry systems, can form without particularly deep, hydrous, or oxidised conditions, when dynamic partitioning behaviour is considered. Overall, our modelling framework enables evaluation of arc magma petrogenesis and trace element evolution, with implications for porphyry indicators.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12909399/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146218140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subduction-accretion of sub-ridge mantle in the south Tibetan mélange zone","authors":"Zhen Zhang,&nbsp;Tong Liu,&nbsp;Chuan-Zhou Liu,&nbsp;Chang Zhang,&nbsp;Riccardo Tribuzio,&nbsp;Dong-Fang Song,&nbsp;Fu-Yuan Wu","doi":"10.1007/s00410-026-02298-w","DOIUrl":"10.1007/s00410-026-02298-w","url":null,"abstract":"<div><p>Sub-ridge mantle is widely exposed on the seafloor at slow- and ultraslow-spreading ridges, where it forms magma-poor, mantle-dominated oceanic core complexes (OCCs). Although mantle denudation processes at such ridges have been extensively documented, the emplacement mechanism of sub-ridge mantle in orogenic belts and the recognition of such magma-poor OCCs remain challenging. In this study, we present integrated field, petrological, and geochemical investigations of mantle peridotites from the Zhongba ophiolite, together with basaltic blocks from the surrounding mélange in the Yarlung–Tsangpo suture zone. The Zhongba peridotites are relatively refractory, recording &lt; 15% anhydrous partial melting, followed by limited refertilization by discrete, weakly aggregated melts, consistent with a low and episodic magma supply. Both geological architectures and geochemical characteristics suggest a mid-ocean-ridge rather than arc-related origin for the Zhongba ophiolite, which is further supported by the sub-solidus cooling history of the mantle section. In combination with the ocean-island-basalt (OIB)-affinity of basaltic blocks within the mélange, we propose a subduction-accretion model for the emplacement of such sub-ridge OCC, due to its high topography and the “lubricant effect” of mélange. Our study underscores the recognition of fossil mantle-dominated OCCs within global OIB-hosting accretionary orogens and provides far-reaching insights into the reconstruction of the architecture and evolution of those paleo-oceans.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147339483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of plagioclase textural evolution and the impact of thermal history on nucleation","authors":"Melvyn Billon,&nbsp;Jacqueline Vander Auwera,&nbsp;Olivier Namur,&nbsp;Marian B. Holness,&nbsp;Bernard Charlier","doi":"10.1007/s00410-026-02301-4","DOIUrl":"10.1007/s00410-026-02301-4","url":null,"abstract":"<div><p>The solidification history of silicate melts strongly controls melt composition and the textures and compositions of crystalline phases. In particular, increasing supersaturation markedly affects crystal nucleation and growth dynamics. Here, we investigate how different crystallization paths influence plagioclase nucleation and crystal habit. Three sets of solidification experiments were performed at atmospheric pressure using a crystal-poor anhydrous andesitic starting material containing plagioclase fragments: (1) isothermal experiments across super- and sub-liquidus conditions, (2) continuous cooling from super-liquidus conditions, and (3) cooling runs held at final temperature. To evaluate the effect of initial superheating, we repeated the isothermal and continuous cooling experiments with a crystal-free melt pre-heated to 1450 °C from a higher initial temperature. Isothermal runs produced numerous small, homogeneous crystals, reflecting spontaneous nucleation. Continuous cooling promoted both growth and nucleation, yielding euhedral to dendritic plagioclase habits with increasing cooling rate. Greater initial superheating or nucleation suppression led to fewer but larger dendritic crystals, similar to those in the fastest cooled seeded runs. These results demonstrate the strong control of thermal pre-treatment on crystal habit and clarify the relative roles of homogeneous and heterogeneous nucleation. Superheating suppresses nucleation by reducing sites for heterogeneous crystallization, favoring growth-dominated textures with limited morphological variability. Although sample edges and Pt wire promote early crystallization, most nucleation occurs on heterogeneities such as gas bubbles, seeds, or impurities, suggesting that homogeneous nucleation may be indistinguishable from heterogeneous nucleation on nano- to micrometric heterogeneities.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147339482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age and geochemistry of carbonatites and associated silicate rocks in Sarnu-Dandali alkaline complex, Deccan Large Igneous Province: Evidence for melt immiscibility and plume-lithosphere interaction","authors":"Milan K. Mahala,&nbsp;Jyotiranjan S. Ray,&nbsp;Kanchan Pande","doi":"10.1007/s00410-025-02285-7","DOIUrl":"10.1007/s00410-025-02285-7","url":null,"abstract":"<div><p>Carbonate–silicate liquid immiscibility is the most widely accepted petrogenetic model for explaining the origin of carbonatites, accounting for approximately three-quarters of global carbonatite occurrences. Many, however, attribute the coexistence of carbonatites and alkaline silicate rocks to the coincidental emplacement of two independent parental magmas through a single crustal conduit. Thus, the exact cause of the carbonatite-alkaline silicate rock association remains equivocal. Here, we present the results of ⁴⁰Ar/³⁹Ar dating, geochemical, and C-O-Sr–Nd-Pb isotopic investigations of the Sarnu-Dandali carbonatite-alkaline complex, part of the Deccan Large Igneous Province (LIP), to shed light on this coexistence. Additionally, we explore the roles of the Deccan-Reunion mantle plume and the Indian continental lithosphere in generating the carbonatites of the complex. ⁴⁰Ar/³⁹Ar age data reveal that, although the complex underwent multiple cycles of alkaline magmatism, the activity at ~ 68.8 Ma was synchronous with the carbonatite intrusion. Interlaced spatial association of carbonatites and alkaline silicate rocks, including melt inclusions of the former in the latter, their complementary trace element patterns (and δ¹³C and δ¹⁸O), and overlapping initial Sr–Nd-Pb isotopic ratios indicate their co-genesis through carbonate–silicate liquid immiscibility. Trace element and isotopic ratio modeling suggests that the parental melanephelinitic magma for the complex evolved through concurrent crustal assimilation (up to 6%), fractional crystallization of silicates, and immiscible separation of carbonate melt, with the latter occurring before phonolite crystallization. The least contaminated isotopic ratios suggest that the parental carbonated-silicate magma derived from a mantle source with a mixed signature of the Reunion plume and metasomatized continental lithosphere.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147337125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: The solubility of N2 in silicate melts and nitrogen partitioning between upper mantle minerals and basalt","authors":"Hans Keppler,&nbsp;Laura Cialdella,&nbsp;Frédéric Couffignal,&nbsp;Michael Wiedenbeck","doi":"10.1007/s00410-025-02289-3","DOIUrl":"10.1007/s00410-025-02289-3","url":null,"abstract":"","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00410-025-02289-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147337116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revised PVT equations of state for almandine and spessartine garnets: implications for piezobarometry","authors":"Ross J. Angel,&nbsp;Marta Morana,&nbsp;Sergio Speziale,&nbsp;Nicola P. M. Casati,&nbsp;Alan B. Woodland,&nbsp;Matteo Alvaro,&nbsp;Guy L. Hovis,&nbsp;Mario Tribaudino","doi":"10.1007/s00410-025-02294-6","DOIUrl":"10.1007/s00410-025-02294-6","url":null,"abstract":"<div>\u0000 \u0000 <p>Previously published thermal expansion data for almandine and spessartine garnets are sparse and inconsistent. We have therefore measured the thermal expansion of two garnets of compositions Alm90 Grs2.7 Py2.3 Ski4.5 (sample Alm90) and Sps81 Alm15 Grs3 And1 (sample Sps81) from ca. 90 K to ca. 780 K by synchrotron X-ray powder diffraction using quartz as an internal calibrant for temperature. The adiabatic elastic tensors of these two samples have been determined by single-crystal Brillouin scattering at room conditions; for the Alm90 sample c₁₁ = 302.0(5), c₁₂ = 111.3(4), c₄₄ = 93.3(1), giving K_S = 174.9(4) GPa, and for the Sps81 sample c₁₁ = 303.1(4), c₁₂ = 109.5(4), c₄₄ = 93.6(2), giving K_S = 174.0(4) GPa. These new data have been used in combination with P-V, P-T-V and P-T-Ks data from the literature to determine the equations of state (EoS) of end-member almandine and spessartine. The parameters of <i>q</i>-compromise Mie-Grüneisen-Debye thermal pressure EoS with a third-order Birch-Murnaghan EoS to describe the compressional properties at room temperature are:</p>\u0000 <div><div><div><table><thead><tr><th> </th><th><p>Almandine</p></th><th><p>Spessartine</p></th></tr></thead><tbody><tr><td><p>V₀: cm³/mol</p></td><td><p>115.25</p></td><td><p>117.92</p></td></tr><tr><td><p>K_0T: GPa</p></td><td><p>174.1(4)</p></td><td><p>172.2(7)</p></td></tr><tr><td><p><span>(:{K}_{0}^{{prime:}})</span>  </p></td><td><p>5.56(14)</p></td><td><p>5.6(3)</p></td></tr><tr><td><p>θ_D: K</p></td><td><p>549(4)</p></td><td><p>569(5)</p></td></tr><tr><td><p>γ₀</p></td><td><p>1.186(4)</p></td><td><p>1.135(6)</p></td></tr><tr><td><p>K_0S: GPa</p></td><td><p>175.6(4)</p></td><td><p>173.5(7)</p></td></tr></tbody></table></div></div></div>\u0000 <p>The parameters are available in .eos files for the EosFit suite of programs in the supplementary data, and from www.rossangel.com and www.mineralogylab.com. The most significant changes from the previous EoS are the lower Debye temperatures because our data show higher thermal expansion above room temperature. The biggest consequence for host-inclusion piezobarometry is that these new EoS lead to lower entrapment temperatures for zircon inclusions in garnet. We also show that there is no significant difference in the P-V/V₀ behaviour of almandine and spessartine and that the available experimental data for intermediate compositions does not indicate any significant non-ideality in the compressional or thermal expansion behaviour of almandine-spessartine garnets.</p>\u0000 </div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"181 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}