Oldhamite:a new link in upper mantle for C-O-S-Ca cycles and an indicator for planetary habitability  

作　　者：Yuegao Liu I-Ming Chou Jiangzhi Chen Nanping Wu Wenyuan Li Leon Bagas Minghua Ren Zairong Liu Shenghua Mei Liping Wang 

机构地区：[1]CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions,Institute of Deep-sea Science and Engineering,Chinese Academy of Sciences,Sanya 572000,China [2]Hainan Deep-Sea Technology Innovation Center [3]Xi'an Center of Geological Survey,China Geological Survey,Xi'an710054,China [4]Department of Geoscience,University of Nevada,LasVegas,Las Vegas,NV89154,USA [5]Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen518055,China

出　　处：《National Science Review》2023年第10期36-45,共10页国家科学评论（英文版）

基　　金：supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021CXLH0027 to Y.G.L.);the Central Guidance on Local Science and Technology Development Fund(ZY2021HN15to S.H.M.);the Chinese Academy of Sciences(QYZDY-SSWDQC029 and XDA22040501 to S.H.M.);the National Natural Science Foundation of China(41973055 and 42130109 to I.M.C);the Major Science and Technology Infrastructure Project of Material Genome Big-Science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhen(L.P.W.)。

摘　　要：In the solar system,oldhamite(CaS)is generally considered to be formed by the condensation of solar nebula gas.Enstatite chondrites,one of the most important repositories of oldhamite,are believed to be representative of the material that formed Earth.Thus,the formation mechanism and the evolution process of oldhamite are of great significance to the deep understanding of the solar nebula,meteorites,the origin of Earth,and the C-O-S-Ca cycles of Earth.Until now,oldhamite has not been reported to occur in mantle rock.However,here we show the formation of oldhamite through the reaction between sulfide-bearing orthopyroxenite and molten CaCO3 at 1.5 GPa/1510 K,0.5 GPa/1320 K,and 0.3 GPa/1273 K.Importantly,this reaction occurs at oxygen fugacities within the range of upper-mantle conditions,six orders of magnitude higher than that of the solar nebula mechanism.Oldhamite is easily oxidized to CaSO4 or hydrolysed to produce calcium hydroxide.Low oxygen fugacity of magma,extremely low oxygen content of the atmosphere,and the lack of a large amount of liquid water on the celestial body’s surface are necessary for the widespread existence of oldhamite on the surface of a celestial body otherwise,anhydrite or gypsum will exist in large quantities.Oldhamites may exist in the upper mantle beneath mid-ocean ridges.Additionally,oldhamites may have been a contributing factor to the early Earth’s atmospheric hypoxia environment,and the transient existence of oldhamites during the interaction between reducing sulfur-bearing magma and carbonate could have had an impact on the changes in atmospheric composition during the Permian-Triassic Boundary.

关 键 词：oldhamite middle-ocean ridge large igneous province Great Oxidation Event oxygen fugacity 

分 类 号：P185[天文地球—天文学]