Whitlockite and apatite from lunar rock 14310 and fromÖdegården,Norway |
| |
Authors: | WL Griffin |
| |
Institution: | Institutt for Geologi, Oslo 3, Norway; Mineralogisk-Geologisk Museum, Oslo 5, Norway |
| |
Abstract: | Microprobe analyses show that whitlockite from lunar rocks is enriched in REE relative to the associated apatite, whereas a terrestrial whitlockite is severely depleted in REE relative to the associated apatite. After considering other possibilities, we suggest that the lunar whitlockite originally crystallized as the high-T polymorph, which is capable of taking up excess CaO (and REE?). Inversion to the low-T form has been inhibited by the non-stoichiometry, so that the present “whitlockite” phase is poorly crystalline. Similar relations may exist in terrestrial basalts of low water content, but would be easily overlooked in petrographic studies. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|