地学前缘 ›› 2020, Vol. 27 ›› Issue (4): 340-354.DOI: 10.13745/j.esf.sf.2019.8.21

• 非主题来稿选登 • 上一篇    

火星陨石和火星表面泥岩中蚀变过程对比研究

付晓辉1,2(), 凌宗成1, 周琴2, Bradley L.JOLLIFF3, 尹庆柱4, 王阿莲3, 李勃1, 武中臣1, 张江1   

  1. 1.山东大学山东省光学天文与日地空间环境重点实验室, 空间科学与物理学院, 空间科学研究院, 山东 威海 264209
    2.中国科学院国家天文台月球与深空探测实验室, 北京 100012
    3.Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA
    4.Department of Earth and Planetary Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
  • 收稿日期:2018-07-20 修回日期:2019-03-20 出版日期:2020-07-25 发布日期:2020-07-25
  • 作者简介:付晓辉(1985—),男,副研究员,主要从事月球与行星表面地质作用研究。E-mail: fuxh@sdu.edu.cn
  • 基金资助:
    国家自然科学基金项目(4159085);国家自然科学基金项目(41490633);国家自然科学基金项目(41473065);国家自然科学基金项目(41573056);山东省自然科学基金项目(JQ201511);山东省自然科学基金项目(ZR2015DM001);中国科学院月球与深空探测重点实验室开放基金项目

Alteration minerals in Martian surface rocks: a comparative study of Martian meteorites and in-situ exploration in the Gale crater

FU Xiaohui1,2(), LING Zongcheng1, ZHOU Qin2, Bradley L.JOLLIFF3, YIN Qingzhu4, WANG Alian3, LI Bo1, WU Zhongchen1, ZHANG Jiang1   

  1. 1. Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Institute of Space Sciences, Shandong University, Weihai 264209, China
    2. Key Laboratory of Moon and Deep Space Exploration, National Astronomy Observatories, Chinese Academy of Sciences, Beijing 100012, China
    3. Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA
    4. Department of Earth and Planetary Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
  • Received:2018-07-20 Revised:2019-03-20 Online:2020-07-25 Published:2020-07-25

摘要:

火星次生含水蚀变矿物是火星地质历史时期水环境和气候演变历史的真实记录,一直以来都是火星探测、火星陨石研究的重点,是认识火星环境特征和气候演化的重要研究对象。文中对比研究了表土角砾岩NWA7034、火成堆晶岩MIL03346等两块最富蚀变矿物火星陨石,以及Gale撞击坑出露的Sheepbed泥岩3种岩石类型的蚀变程度及其蚀变矿物类型和组合,分析了层状硅酸盐、铁氧化物/氢氧化物、钙硫酸盐等蚀变矿物的成因及环境指示意义。发现这3类岩石的蚀变作用各不相同。火星陨石NWA7034的蚀变作用以氧化和加热作用为主,无蒸发盐类矿物。火星陨石MIL03346的蚀变程度最低,为后期水溶液进入缝隙而引发的,蚀变作用以橄榄石的伊利石化、裂隙和缝隙中填充次生矿物细脉为主。而火星Sheepbed泥岩经历了后期的等化学风化过程(isochemical weathering),次生过程包括成岩蚀变和成岩后蚀变两个阶段。其中,成岩过程中的蚀变以橄榄石蚀变为铁氧化物和蒙皂石矿物为主,成岩后以形成蒸发盐类矿物硫酸钙为主。以上3种岩石蚀变矿物组成差异反映了火星上不同地质背景中、不同气候条件下蚀变过程的复杂性。文中对火星含水矿物及部分典型矿物的形成条件和过程进行系统总结,这对于理解未来火星探测任务、识别含水矿物的形成、揭示火星水环境和地质历史具有重要指导意义。

关键词: 次生矿物, 蚀变过程, 火星陨石, “好奇”号

Abstract:

Alteration minerals record the aqueous conditions and climate changes in Mars geological history. They are key to revealing the habitable environments on Mars, as well as the most signification objects of Mars exploration mission and Martian meteorite investigations. We present here detailed studies of alteration minerals in a Martian regolith breccia NWA7034, a Nakhlite meteorite MIL03346, and Sheepbed mudstone detected by Mars Curiosity rover. We compared the inventory of hydrous minerals in these rocks, and determined the formation mechanisms and conditions of smectite, Fe-oxides/hydroxides, and CaSO4 found in these rocks. We concluded that NWA7034, MIL03346, and Sheepbed mudstone were all altered during diagenesis or after lithification. However, the secondary alteration processes they experienced are distinct with each other. NWA7034 were mostly altered by oxidization and heating. For the meteorite MIL03346, secondary minerals are mostly present in veining within brittle fractures in the mafic minerals and mesostasis. This indicates the vein-filling alteration products result from hydrothermal fluid introduced by an impact event. Compared with two Martian meteorites, the Sheepbed mudstone in Gale crater is more altered with Chemical Index of Alteration (CIA) of 47 and 50. The original debris with basaltic mineral composition experienced at least two stages of secondary alterations: olivine altered to smectite and magnetite during diagenetic processes, and CaSO4 veins formation after lithification. This result suggests aqueous conditions in various geological setting are different, and chemical weathering under different climate conditions could produce diverse alteration mineral assemblages. This study summarized the secondary mineral found by Mars missions and in Martian meteorites and their possible origins. It could help understand the formation of secondary minerals and future data interpretation in the China Tianwen-1 Mars mission.

Key words: secondary minerals, alteration process, Martian meteorite, Mars Curiosity rover

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