Newly analysed titanomagnetite–ilmenite (Tim–Ilm) intergrowths from Martian nakhlite meteorite Northwest Africa (NWA) 5790 yielded crystallisation temperature up to 1032 °C and oxygen fugacity (fO₂) up to ΔQFM + 1.6, notably higher than previous estimates for nakhlite magmas (temperature < 950 °C, fO₂ = ΔQFM − 0.5 to ΔQFM + 1). To interpret how the magma was reduced from ΔQFM − 0.5 to ΔQFM + 1.6, we used D-Compress to model the sulphur degassing process within a single thick lava pile. For fO₂ to significantly decrease in this extended range, a sulphur-rich (S content 4000–7000 ppm) Martian lava flow had to degas all the sulphur species at a certain final degassing pressure, which was 2–4 bar for NWA 988 and Lafayette and < 0.7 bar for Y-000593 and Nakhla. These final degassing pressure data are in good agreement with the Martian nakhlite burial depth estimated by other petrological and geochemical methods. These estimates are also comparable with the excavation depth of ~ 40 m based on the small (6.5 km in diameter) impact crater over the Elysium lava plain. The fO₂-controlled sulphur degassing pressure may constitute a method for estimating the burial depth of sulphur-rich lava flows on Mars.

新分析的来自火星 nakhlite 陨石西北非洲 (NWA) 5790 的钛磁铁矿-钛铁矿 (Tim-Ilm) 共生物产生高达 1032 °C 的结晶温度和高达 ΔQFM + 1.6 的氧逸度 ( f O ₂ )，明显高于之前对钠赫石的估计岩浆（温度 < 950 °C，f O ₂  = ΔQFM − 0.5 到 ΔQFM + 1）。为了解释岩浆如何从 ΔQFM - 0.5 减少到 ΔQFM + 1.6，我们使用 D-Compress 来模拟单个厚熔岩堆内的硫脱气过程。对于f O ₂为了在此扩展范围内显着降低，富含硫（S 含量为 4000-7000 ppm）的火星熔岩流必须在某个最终脱气压力下对所有硫物质进行脱气，NWA 988 和拉法叶为 2-4 bar，并且 < Y-000593 和 Nakhla 为 0.7 bar。这些最终的脱气压力数据与通过其他岩石学和地球化学方法估计的火星钠赫石埋藏深度非常吻合。根据 Elysium 熔岩平原上的小（直径 6.5 公里）撞击坑，这些估计值也与约 40 m 的挖掘深度相当。所述˚F Ô ₂ -controlled硫脱气压力可以构成一种用于估计富硫熔岩的埋藏深度上火星流动。