Re-evaluating monazite as a record of metamorphic reactions

作     者：Kyle P.Larson Sudip Shrestha John M.Cottle Carl Guilmette T.Alex Johnson H.Daniel Gibson Félix Gervais Kyle P.Larson;Sudip Shrestha;John M.Cottle;Carl Guilmette;T.Alex Johnson;H.Daniel Gibson;Félix Gervais

作者机构：Department of EarthEnvironmental and Geographic SciencesUniversity of British Columbia Okanagan3247 University WayKelownaBC V1V 1V7Canada Fipke Laboratory for Trace Element ResearchUniversity of British Columbia Okanagan3247 University WayKelownaBC V1V 1V7Canada Department of Earth ScienceUniversity of CaliforniaSanta BarbaraSanta BarbaraCA 93106-9630USA Géologie et Génie GéologiqueUniversitéLavalQuébec CityQuebecCanada Department of Earth SciencesSimon Fraser University8888 University DriveBurnabyBC V5A 1S6Canada Départment des Génies CivilGéologique et des MinesPolytechnique MontréalMontréalQC H3T 1J4Canada 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2022年第13卷第2期

页      面：237-254页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：Canada Foundation for Innovation  CFI 

主　　题：Monazite petrochronology Phase equilibria modelling Geochronology P-T-t paths 

摘      要：This study presents a re-examination of historical specimens(DG136 and DG167)from the Monashee complex in the southeastern Canadian Cordillera that are critical to the current understanding of rare earth element(REE)distribution between garnet and monazite(and other accessory minerals)during ***-hundred and fifty-one new monazite petrochronology spot analyses on 29 different grains across two specimens outline detailed(re)crystallization *** element data collected from the same ablated volume,interpreted in the context of new phase equilibria modelling that includes monazite,xenotime and apatite,link ages to specific portions of the pressure-temperature(P-T)paths followed by the *** linkages are further informed by garnet Lu-Hf geochronology and xenotime *** clockwise P-T paths indicate prograde metamorphism was ongoing by ca.80 Ma in both *** structurally deeper specimen,DG136,records peak P-T conditions of~755-770℃and 8.8-10.4 kbar,interpreted to coincide with(re-)crystallization of low Y monazite at~75-70 ***-rim garnet isopleths from DG167 cross in the observed peak assemblage field at~680℃ and 9.3 *** conditions are interpreted to correspond with low Y monazite(re-)crystallisation at~65 *** specimens record decompression along their retrograde path coincident with high Y 70-55 Ma and 65-55 Ma monazite populations in DG136 and DG167,*** findings broadly agree with those initially reported~20 years ago and confirm early interpretations using trace elements in monazite as generally reliable markers of metamorphic *** phase equilibria modelling and in situ petrochronological analysis,however,provide additional insight into monazite behaviour during anatexis and the effects of potential trace element buffering by REE-bearing phases such as apatite.