We present the first isotopic (noble gases and CO₂) characterization of fluid inclusions coupled to Raman microspectroscopy analyses in mantle xenoliths from Central Mexico, a geodynamically complex area where the Basin and Range extension was superimposed on the Farallon subduction (terminated at 28 Ma). To characterize the isotopic signature of the Central Mexican lithospheric mantle, we focus on fluid inclusions entrapped in mantle xenoliths found in deposits of the Joya Honda maar (JH), a Quaternary monogenetic volcano belonging to the Ventura Espiritu Santo Volcanic Field (VESVF) in the state of San Luis Potosí (central Mexico). Thirteen ultramafic plagioclase-free xenoliths were selected, all exhibiting a paragenesis Ol > Opx > Cpx > > Sp, and being classified as spinel-lherzolites and harzburgites. All xenoliths bring textural evidence of interstitial glass veins bearing dendritic trails of secondary melt and fluid inclusions (composed of silicate glass ± CO₂ ± Mg-Ca carbonates ± pyrite). These are related to pervasive mantle metasomatism driven by carbonate-rich silicate melt. The Ar and Ne systematics reflect mixing between MORB-like upper mantle and atmospheric fluids, the latter interpreted as reflecting a recycled air component possibly inherited from the Farallon plate subduction. The ³He/⁴He ratios vary between 7.13 and 7.68 Ra, within the MORB range (7–9 Ra), and the ⁴He/⁴⁰Ar* ratios (0.4–3.11) are similarly close to the expected range of the fertile mantle (1–5). Taken together, these pieces of evidence suggest that (i) either the mantle He budget was scarcely modified by the Farallon plate subduction, and/or (ii) that any (large) crustal contribution was masked by a later metasomatism/refertilization episode, possibly during the subsequent Basin and Range extension. A silicate melt-driven metasomatism/refertilization (revealed by the association between glass veins and fluid inclusions) is consistent with calculated helium residence time for the Mexican lithospheric mantle (20 to 60 Ma) that overlaps the timing of the above geodynamic events. We propose that, after the refertilization event (e.g., over the last ~20 Ma), the lithospheric mantle has evolved in a steady-state, becoming slightly more radiogenic. We also estimated ³He fluxes (0.027–0.080 mol/g), ⁴He production rates (340–1000 mol/yr), and mantle CO₂ fluxes (3.93 × 10⁷ mol/yr to 1.18 × 10⁸ mol/yr) using the helium isotopic values measured in JH mantle xenoliths. Finally, the JH xenoliths exhibit CO₂/³He ratios comparable to those of the upper mantle (from 3.38 × 10⁸ to 3.82 × 10⁹) but more positive δ¹³C values (between −1.0 and − 2.7‰), supporting the involvement of a crustal carbonate component. We propose that the metasomatic silicate melts recycled a crustal carbonate component, inherited by the Farallon plate subduction.

我们介绍了第一个同位素（稀有气体和CO ₂）流体包裹体的表征，结合拉曼显微技术对墨西哥中部地幔异种岩进行分析，该地幔是地球动力学复杂的区域，盆地和范围扩展叠加在Farallon俯冲上（终止于28 Ma）。为了表征中部墨西哥岩石圈地幔的同位素特征，我们集中于在乔亚本田玛尔（JH）矿床中发现的地幔异岩中包裹的流体包裹体，乔亚本田玛尔（JH）是第四纪单系火山，属于圣文图拉埃斯皮里图桑托火山场（VESVF）圣路易斯波托西州（墨西哥中部）。选择了十三种不含超镁铁质斜长石的异岩，它们均表现出共生作用，即Ol> Opx> Cpx>> Sp，并被归类为尖晶石-水辉石和harzburgite。₂  ±Mg-Ca碳酸盐±黄铁矿）。这些与富含碳酸盐的硅酸盐熔体驱动的普遍的地幔交代作用有关。Ar和Ne系统反映了类似MORB的上地幔与大气流体之间的混合，后者被解释为反映了可能来自Farallon板块俯冲作用的再循环空气成分。的³他/ ⁴的7.13和7.68之间镭He比值变化时，MORB范围（7-9 Ra）为内，和⁴赫/ ⁴⁰Ar *比率（0.4–3.11）类似地接近肥沃地幔的预期范围（1-5）。综上所述，这些证据表明，（i）法拉隆板块俯冲几乎没有改变He地幔的预算，和/或（ii）后来的交代/转导作用掩盖了任何（大）地壳的贡献在随后的盆地和范围扩展中。硅酸盐熔体驱使的交代作用（通过玻璃脉和流体包裹体之间的联系揭示）与墨西哥岩石圈地幔的氦停留时间（20至60 Ma）一致，与上述地球动力学事件的发生时间重叠。我们建议，在岩石化作用事件之后（例如，在最后一个〜20 Ma内），岩石圈地幔已经处于稳定状态，变得略有放射成因。³ He流量（0.027–0.080 mol / g），⁴ He生产率（340–1000 mol / yr）和地幔CO ₂流量（3.93×10 ⁷  mol / yr至1.18×10 ⁸ mol / yr） JH地幔异岩中测得的同位素值。最后，将包体JH显示出CO ₂ / ³ He比值媲美上地幔（从3.38×10 ⁸ 3.82×10 ⁹），但更积极的δ ¹³ C值（-1.0之间，并且- 2.7‰），支撑所述地壳碳酸盐组分的参与。我们提出，交代硅酸盐熔体回收了法拉第板块俯冲作用继承的地壳碳酸盐组分。