Early terrestrial and lunar anorthosites:Comparative geochemistry and evolutionary processes  

作　　者：Paul Sotiriou Ali Polat Tim Kusky Brian F.Windley 

机构地区：[1]School of the Environment,University of Windsor,Windsor,ON N9B 3P4,Canada [2]GeoZentrum Nordbayern,Friedrich-Alexander-Universität,Erlangen 91054,Bayern,Germany [3]Center for Global Tectonics,State Key Laboratory for Geological Processes and Mineral Resources,China University of Geosciences,Wuhan,Hubei Province,PR China [4]School of Geography,Geology and the Environment,University of Leicester,Leicester LE17RH,UK

出　　处：《Geoscience Frontiers》2024年第6期348-366,共19页地学前缘（英文版）

摘　　要：In a paper in 1970,Brian Windley first recognised that early terrestrial and lunar anorthosites both have calcic plagioclase,and low TiO_(2)and high CaO and Al_(2)O_(3)contents.Despite these similarities,the geochemistry of early terrestrial and lunar anorthosites has not been rigorously compared and contrasted.To this end,we compiled 425 analyses from 212 early terrestrial anorthosite occurrences and 306 analyses from 16 lunar anorthosite occurrences.This was supplemented by a compilation of plagioclase anorthite(An)contents and pyroxene Mg#from early terrestrial and lunar anorthosites.Early terrestrial anorthosites have lower whole-rock An contents but similar Mg#to lunar anorthosites.The CaO contents of lunar anorthosites are higher than those of early terrestrial anorthosites for a given MgO and Al_(2)O_(3)content,early terrestrial anorthosites have higher SiO_(2)contents than lunar anorthosites at a given MgO content,and lunar anorthosites have higher Eu/Eu*anomaly ratios yet broadly similar La/Yb and Nd/Sm ratios than early terrestrial anorthosites.Some early terrestrial anorthosites have less fractionated chondrite-normalised rare earth element(REE)patterns and less prominent positive Eu anomalies than lunar anorthosites.Lunar anorthosites have higher plagioclase An contents,yet a similar range of pyroxene Mg#compared to their early terrestrial counterparts.Some early terrestrial anorthosites are more fractionated than some lunar anorthosites.Our interpretations imply that most early terrestrial anorthosites crystallised from basaltic parental magmas that were generated by high-degree partial melting of sub-arc asthenosphere mantle wedge sources that were hydrated by slab-derived fluids,with the remainder being associated with mid-ocean ridge and mantle plume settings.Some of the arc-related early terrestrial anorthosites were influenced by crustal contamination.In addition,early terrestrial anorthosites originated from partial melting of the mantle at various depths with variable garnet residua,whereas lu

关 键 词：Early terrestrial anorthosites Lunar anorthosites GEOCHEMISTRY Mineral chemistry 

分 类 号：P512.2[天文地球—地质学] P59