... subcontinental lithosphere. The lamprophyres are only slightly younger than ∼1010 Ma Labrieville massif, which is also alkalic and enriched in Sr and Ba relative to most other anorthosites. The lamprophyres provide unequivocal evidence for a Sr- and Ba-rich component in the lithospheric mantle that may have...

...Brent E. Owens; Robert F. Dymek Abstract Newly discovered orthopyroxene and clinopyroxene megacrysts (OPMs and CPMs) in the Labrieville massif provide additional constraints on megacryst origins and their significance in massif anorthosite petrogenesis. Pyroxene megacrysts (~ 1–15 cm across) occur...

...Alfred T. Anderson, Jr. Abstract The Labrieville anorthosite massif is an example of crystallization differentiation in a plutonic environment. As in other St. Urbain-type anorthosites (characterized in particular by andesine anti-perthite and hemo-ilmenite), the lithologic sequence is: anorthosite...

...- to post-tectonic ∼1060–1010 Ma andesine anorthosite belt that includes the Château-Richer, St. Urbain, and Labrieville massifs. The dominant rock type at MAT is foliated andesine anorthosite or leuconorite, and orientations of foliations indicate that the pluton has the shape of a dome. MAT contains...

... the Château-Richer, Labrieville, and St. Urbain massifs in Quebec; from the Roseland massif in Virginia; and from the Carthage massif in New York. Our data set includes X-ray fluorescence (XRF) and instrumental neutron activation (INA) analyses of whole-rock samples, as well as electron-microprobe (EMP...

... plot for Montpelier and Roseland samples. Data for Roseland from Owens & Dymek (1999) . Also shown for comparison is a field for anorthosites from the Labrieville, Québec massif ( Owens & Dymek 2001 ). Normalizing values from Boynton (1984) . The REE patterns for all samples...

... massive hemo-ilmenite deposits ( Dymek and Owens 2001 ) Valin Anorthositic Suite, 1020–1008 Ma Labrieville Alkalic Anorthositic Massif, 1010–1008 Ma (U–Pb, z; Owens et al. 1994 ) Andesine Apatite Hemo-ilmenite and magnetite OAGN, nelsonite, and massive hemo-ilmenite OAGN as sill-like layers...

... composition into andesine and labradorite anorthosites ( Anderson & Morin 1969 ). Massif anorthosites also differ in their silica activity and oxygen fugacity ( Hébert et al. 2005 , Morse 2006 ). Andesine anorthosites, such as Labrieville ( Owens & Dymek 2001 ), are commonly quartz-saturated...

... of the shoshonite rock association . Lithos 13 , 97 – 108 . Owens , B.E. & Tomascak , P.B. ( 2002 ): Mesoproterozoic lamprophyres in the Labrieville Massif, Québec: clues to the origin of alkalic anorthosites? Can. J. Earth Sci . 39 , 983 – 997 . Peccerillo , A. ( 2001...

... to 1125 Ma ( Table 1 ). Similar efforts by Emslie & Hunt (1990) in the central Grenville Province yielded five multigrain TIMS ages (1160–1123 Ma) for massif MCG suites, [excluding the Labrieville (1018 Ma), Rivière-Pentecôte (1365–1350 Ma), and Mealy Mountains (1646–1635 Ma), all of which...

...F ig . 1. Massif anorthosites in the Grenville and adjacent Provinces, after Davidson (2008) . Dark grey is the parautochthon, bounded to the NW by the Grenville Front, white is the Allochthonous Polycyclic Belt (APB), and light grey is the Allochthonous Monocyclic Belt (AMB). Anorthosite...