U-Pb ages of plutonism, sedimentation, and metamorphism of the Paleoprotemzoic Kisseynew metasedimentary belt, Trans-Hudson Orogen (Manitoba, Canada)

摘要

The Kisseynew Domain is a metasedimentary beltin the central Reindeer Zone of the Trans-Hudson Orogen. It isbounded by 1.92-1.86 Ga volcanic-plutonic belts to the northand south, by an Archean terrane to the east (Superior Province),and by a volcanic-plutonic terrane underlain by an Archeanterrane to the southwest (Glennie Domain). The KisseynewDomain developed in an arc-related setting in the final stages ofplate convergence involving the northward migration of arc-ocean floor complexes toward the Archean Hearne Craton.Terminal collision, involving also the Superior Craton,originated multiple fold-thrust systems and high-grademetamorphism. U-Pb ages of 1874-1860 Ma for pretectonicplutonic units in southern Kisseynew Domain are identical toages of plutonism intruding the arc-ocean floor accretionarycomplex in the Flin Flon domain (Amisk collage) and indicateits northern extension. Deposition of the Burntwood Groupturbidites started at ca. 1860 Ma, indicating uplift and erosion ofthe volcanic complexes and was coeval with arc magmatism thatsucceeded the Amisk collage. From 1848 Ma, Burntwoodsedimentation was coeval with deposition of Missi Groupcontinental sediments, with continental arc magmatism andearly deformation. New and published ages for detrital zirconindicate that sediments were derived both from local 1.89-1.84Ga units and also from 2.55-2.36 Ga sources. The latter suggestthat a Neoarchean-Paleoproterozoic cratonic block wasundergoing erosion, remnants of which occur in the Flin FlonBelt. Basin closure started after 1823 Ma and is marked byregional high-grade metamorphism lasting for ca. 30 millionyears from 1818 Ma to 1785 Ma; late- to posttectonicmetamorphic activity lasted until ca. 1775 Ma.