Renewal: Mineral Physics Studies under the Pressure-Temperature Conditions of Earth's Deep Lower Mantle

更新：地球下地幔深处压力-温度条件下的矿物物理研究

• 批准号: 1722515
• 负责人: Michael Walter
• 金额: $ 15万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-15 至 2021-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1722515&HistoricalAwards=false
• 关键词: Renewal; Mineral; Physics; Studies; under

The investigators believe they have discovered a giant oxygen reservoir at the extreme pressure-temperature conditions between the Earth's deep mantle and iron core. The reservoir consists of previously unknown iron superoxides which could suddenly release its excessive oxygen. In the present project, the team will further explore the different types of iron superoxides, the conditions for the explosive oxygen release, and the consequences of oxygen eruptions. The sporadic eruptions provide a new, unified mechanism for answering questions on a list of seemingly unrelated past events that occurred during Earth's 4.6 billion years history and shaped the present living planet. Where did the oxygen in the air come from? What caused the mass extinctions that killed the dinosaurs and ushered in the mammals? What was the driving force that pushed all continents to merge into a single supercontinent, and later pulled the supercontinent apart to form individual continents? From understanding the Earth's Past and Present, we may gain insights into the Earth's Future.The investigator's recent discovery of high P-T iron superoxides, FeO2 and FeO2Hx with the pyrite-type Pa3 structure has suggested potential paradigm changes in mineral physics and geodynamics of the deep lower mantle. The team proposes to further investigate the high P-T mineral physics properties of the superoxides, including the incorporation of other major components such as MgO2, AlO2 and SiO2 into the Pa3 iron superoxide, its interactions with silicate bridgmanite and post-perovskite, its electronic and magnetic spin states, and its valence states of iron and oxygen. The team will search for other stable structural types in addition to Pa3 for firon-based superoxides with the apparent Fe oxidation state 3+, and determine their elastic wave velocities for comparison for comparison with seismic observations in the deep Earth. The team's previous research suggested the existence of a massive amount of oxygen-rich patches at the core-mantle boundary. This research will investigate the metastability of such giant oxygen reservoirs, and the consequences when the stored oxygen is released, particularly the resulting geodynamics of the super plate tectonics that may explain the origin of merging and rifting of supercontinents.

研究人员相信，他们在地球深部地幔和铁核之间的极端压力-温度条件下发现了一个巨大的氧气库。 该储层由以前未知的铁超氧化物组成，它们可能会突然释放出过量的氧气。 在目前的项目中，团队将进一步探索不同类型的铁超氧化物、爆炸性氧气释放的条件以及氧气喷发的后果。 零星的喷发提供了一种新的、统一的机制，可以回答一系列看似无关的过去事件的问题，这些事件发生在地球 46 亿年的历史中，并塑造了现在的生命星球。 空气中的氧气是从哪里来的？ 是什么导致了灭绝恐龙并迎来哺乳动物的大规模灭绝？ 推动所有大陆合并成一个超级大陆，又将超级大陆分裂成各个大陆的驱动力是什么？ 通过了解地球的过去和现在，我们可以洞察地球的未来。研究人员最近发现了具有黄铁矿型 Pa3 结构的高 P-T 铁超氧化物 FeO2 和 FeO2Hx，这表明深部矿物物理和地球动力学的潜在范式变化下地幔。 该团队建议进一步研究超氧化物的高P-T矿物物理性质，包括将MgO2、AlO2和SiO2等其他主要成分掺入Pa3铁超氧化物中，其与硅酸盐桥锰矿和后钙钛矿的相互作用，其电子和磁性铁和氧的自旋态及其价态。该团队将寻找除 Pa3 之外的其他稳定结构类型，以寻找表观 Fe 氧化态为 3+ 的铁基超氧化物，并确定其弹性波速度，以便与地球深处的地震观测进行比较。 该团队之前的研究表明，核幔边界处存在大量富氧斑块。这项研究将研究这种巨大氧气库的亚稳定性，以及储存的氧气释放时的后果，特别是由此产生的超级板块构造的地球动力学，这可能解释超级大陆合并和裂谷的起源。

项目成果

Altered chemistry of oxygen and iron under deep Earth conditions

• DOI: 10.1038/s41467-018-08071-3
• 发表时间: 2019-01-11
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: Liu, Jin;Hu, Qingyang;Mao, Wendy L.
• 通讯作者: Mao, Wendy L.

Solids, liquids, and gases under high pressure

• DOI: 10.1103/revmodphys.90.015007
• 发表时间: 2018-03-20
• 期刊: REVIEWS OF MODERN PHYSICS
• 影响因子: 44.1
• 作者: Mao, Ho-Kwang;Chen, Xiao-Jia;Wang, Lin
• 通讯作者: Wang, Lin

Discovery of a hexagonal ultradense hydrous phase in (Fe,Al)OOH

• DOI: 10.1073/pnas.1720510115
• 发表时间: 2018-03
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Li Zhang;Hongsheng Yuan;Y. Meng;H. Mao

Diamond anvil cell behavior up to 4 Mbar

• DOI: 10.1073/pnas.1721425115
• 发表时间: 2018-02-20
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Li, Bing;Ji, Cheng;Mao, Ho-kwang
• 通讯作者: Mao, Ho-kwang

New high-pressure tetragonal polymorphs of SrTiO 3 —molecular orbital and Raman band change under pressure

新型高压四方多晶型SrTiO 3 – 分子轨道和拉曼带在压力下的变化

• DOI: 10.1088/1361-648x/aabef3
• 发表时间: 2018
• 期刊: Journal of Physics: Condensed Matter
• 作者: Yamanaka, Takamitsu;Ahart, Muhtar;Mao, Ho-kwang;Yan, Hao
• 通讯作者: Yan, Hao