English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The results of geological and 40 Ar/ 39 Ar geochronological investigations of several gold districts hosted by the Meguma Group are presented. Observations at both the macro- (deposit to ore zone) and micro- (hand sample to thin section) scale indicate that quartz vein formation followed major Acadian folding and metamorphism (ca. 400 ±10 Ma) and was broadly coincident with mafic-felsic magmatism at ca. 370 Ma. 40 Ar/ 39 Ar analyses of vein-fill mica and amphibole from the Beaver Dam, Moose River, Fifteen Mile Stream, Upper Seal Harbour and Caribou deposits indicate ages of ca. 380 Ma to ca. 362 Ma. The age data are interpreted to reflect discrete hydrothermal events with rapid cooling following crystallization of vein constituents. The age data do not reflect either variable amounts of resetting by later granitic intrusions or diachronous cooling. Genetic models that interpret the generation of the auriferous quartz veins as either before or during major Acadian folding are considered to be inconsistent with the present results. Instead, a model is favored that interprets quartz vein formation in the context of continued transpression of the Meguma Terrane following regional folding and metamorphism.   RESUME  On presente les resultats d'etudes geologiques et geochronologiques [ 40 Ar/ 39 Ar] effectuees dans plusieurs districts auriferes au sein du Groupe de Meguma. Des observations tant macroscopiques (du gite a la zone de mineral) que microscopiques (de l'echantillon a la lame mince) indiquent que la formation des veines de quartz suivit un metamorphisme et un plissement majeurs acadiens (env. 400 ± 10 Ma) et coiincida d'une facon generale avec unmagmatisme mafique a felsique vers 370 Ma. Des analyses 40 Ar/ 39 Ar effectuees sur des micas et des amphiboles de remplissages de veine provenant des gites de Beaver Dam, Moose River, Fifteen Mile Stream, Upper Seal Harbour et Caribou revelent des âges aux environs de 380 a 362 Ma. On interprete ces donnees d 'âge comme le reflet d'episodes hydrothermaux distincts avec un refroidissement rapide suite a la cristallisation des constituants filoniens. Ces donnees ne refletent ni un degre variable de remise a ziro par des intrusions granitiques ulterieures, ni un refroidissement diachrone. On considere que les modeles genetiques interpretant la formation des veines de quartz auriferes comme precedent ou ayant eu lieu pendant le plissement majeur acadien, sont en contradiction avec les resultats actuels. En leur lieu, on favorise un modele qui interprete la formation des veines de quartz dans le contexte d'une transpression continue de la Laniere de Meguma a la suite d'un plissement et d'un metamorphisme regionaux.  [Traduit par le journal]

Geological and 40Ar/39Ar geochronological constraints on the timing of quartz vein formation in Meguma Group lode-gold deposits, Nova Scotia