2025-04-25 テキサスA&M大学
＜関連情報＞
- https://stories.tamu.edu/stories/new-study-unveils-volcanic-history-and-clues-to-ancient-life-on-mars/
- https://www.science.org/doi/10.1126/sciadv.adr2613
火星ジェゼロクレーターの多様で高度に分化した溶岩群： 火星2020 PIXLが明らかにする地殻内マグマティズムの制約条件 Diverse and highly differentiated lava suite in Jezero crater, Mars: Constraints on intracrustal magmatism revealed by Mars 2020 PIXL
Mariek E. Schmidt, Tanya V. Kizovski, Yang Liu, Juan D. Hernandez-Montenegro, […], and Meenakshi Wadhwa
Science Advances Published:24 Jan 2025
DOI:https://doi.org/10.1126/sciadv.adr2613
Abstract
The Jezero crater floor features a suite of related, iron-rich lavas that were examined and sampled by the Mars 2020 rover Perseverance, and whose textures, minerals, and compositions were characterized by the Planetary Instrument for X-ray Lithochemistry (PIXL). This suite, known as the Máaz formation (fm), includes dark-toned basaltic/trachy-basaltic rocks with intergrown pyroxene, plagioclase feldspar, and altered olivine and overlying trachy-andesitic lava with reversely zoned plagioclase phenocrysts in a K-rich groundmass. Feldspar thermal disequilibrium textures indicate that they were carried from their crustal staging area. Bulk and mafic minerals have very high FeO and low MgO to FeOtotal ratios, which are partially reproduced by thermodynamic models involving high-degree fractional crystallization of a gabbroic assemblage and possibly also assimilation of iron-rich basement. Together, these in situ constraints on petrogenesis provide a uniquely detailed record of intracrustal processes beneath Jezero crater during a time period not represented by Mars samples to date.
