Clastic and carbonate metasediments, preserved in narrow synclines, have been correlated over an area of 2000 kmz. These strata, the Flinton Group, lie unconformably on metamorphosed volcanic, clastic, and carbonate rocks, and on large granitic intrusions. The group, which comprises six formations, has undergone at least two major folding episodes and one main regional metamorphism of varying grade. The only post-Flinton intrusions are pegmatites at high grade and one tectonically emplaced ultramafic slice.Depositional environment ranged from fluvial to moderate-depth marine. Rapid facies changes, coupled with persistence of some units along strike and close relationships between facies and underlying lithology, point to local sources and local tectonic control of deposition basins. At the onset of sedimentation, a deeply weathered source terrain yielded mature basal redbeds, which were succeeded by less mature clastics as block faulting caused increase of reliefbetween sources and basins. These facies passed offshore into finer, more reduced sediments. Deposition took place between 1050 and 1080 (+25) Ma ago, after arc volcanism, plutonism, uplift, and erosion, and before major regional metamorphism. All these events can be grouped within the Grenvillian orogenic cycle, spanning at least the interval 1300-1000 Ma and including, in eastern Ontario, the pre-Flinton Elzevirian Orogeny and post-Flinton Ottawan Orogeny.On a mis en correlation les metasediments clastiques et carbonates preserves dans des synclinaux etrois sur une region de 2000 kmz. Ces strates, le groupe de Flinton, reposent en discordance sur des roches volcaniques, clastiques et carbonatees metamorphisees et sur de vastes intrusions granitiques. Le groupe, qui comprend six formations, a subi au moins deux episodes importants de plissement et une phase principale de metamorphisme regional d'intensite variable. Les seules intrusions post-Flinton sont des pegmatites de haut niveau et une ecaille ultramafique mise en place tectoniquement.Le milieu de sedimentation variait de fluvial a marin de profondeur moyenne. Les changements rapides de facies, associes a la persistance de certaines unites selon la direction des strates et les relations etroites entre les facies et la lithologie sous-jacente, indiquent que la source des sediments etait locale et que le contr6le tectonique des bassins de sedimentation etait aussi local. Lorsque la sedimentation s'est amorcee, une region source profondement alteree a fourni les lits rouges matures a la base, immediatement suivis par des roches clastiques moins matures qui s'expliquent par une augmentation du relief entre les sources et les bassins comme resultat d'une tectonique cassante. Ces facies passaient au large en sediments plus fins, plus reduits. La sedimentation s'est produite entre 1050 et 1080 (f 25) Ma, apres les phases de volcanisme d'arc, de plutonisme, de soulevement et d'erosion et avant le metamorphisme regional de grande envergure. Tous ces evenements peuvent se regrouper dans le cycle orogenique de...
Detailed petrography across a metapelitic sequence in the eastern axial zone of the Montagne Noire, France, is the basis for a sequence of isograds marking the fist appearance of biotite-cordierite, staurolite, andalusite, and sillimanite. The juxtaposition of low-grade biotite-free rocks against medium-grade rocks at the gently dipping biotite-cordierite isograd is attributed to tectonic telescoping of the metamorphic sequence. Study of mineral assemblages with respect to an AFM reaction sequence indicates the staurolite isograd is related to changes in rock composition, and complex assemblages in the sillimanite zone may be the result of unstable persistence of minerals formed when metamorphic grade was lower. These assemblages are interpreted to contain a record of part of the P-T history during which pressure decreased as temperature increased. P-T profiles show that temperature gradients of 200-300"CIkm suggested by previous workers are not required to explain the isograd pattern; gradients of 3 7 " C h or less are sufficient.Une ktude p6trographique dktaillke au travers d'une sequence mktapklitique dans la zone axiale est de la Montagne Noire, en France, sert de base pour ktablir une skquence d'isogrades marquant la premiere apparition de biotite-cordikrite, staurotide, andalousite et sillimanite. La juxtaposition de roches faiblement mktamorphiques et sans biotite contre des roches de mCtamorphisme moyen le long de l'isograde biotite-cordikrite qui lui est lkgerement inclink est attribuke a un telescopage tectonique de la sCquence mktamorphique. L'examen des assemblages minkralogiques par rapport 5 une sequence de rkaction AFM indique que I'isograde a staurotide est lik aux changements de composition des roches, et que les assemblages complexes dans la zone a sillimanite peuvent rksulter de la persistence instable des minkraux formks lorsque I'intensitk du mktarnorphisme Ctait plus faible. Ces assemblages sont considkrks cornrne contenant les renseignements d'une partie de l'histoire P-T lorsque la pression diminuait et la temp6rature augmentait.-Les courbes P-T montrent que les gradients de temp6rature de 200-300"CIkm tels que proposks antCrieurement ne sont pas nkcessaires pour expliquer la distribution des isogrades; des gradients d'au plus 3 7 " C h sont suffisants.
The development and optimization of a scalable synthesis of sodium-dependent glucose cotransporter 2 inhibitor, ertugliflozin, for the treatment of type-2 diabetes is described. Highlights of the chemistry are a concise, four-step synthesis of a structurally complex API from known intermediate 4 via persilylation–selective monodesilylation, primary alcohol oxidation, aldol-crossed-Cannizzaro reaction, and solid-phase acid-catalyzed bicyclic ketal formation. The final API was isolated as the l-pyroglutamic acid cocrystal.
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