U-PB GEOCHRONOLOGY AND TECTONIC DEVELOPMENT OF THE SOUTHERN BANK OF THE KISSEYNEW DOMAIN, TRANS-HUDSON OROGEN, CANADA

The southern flank of the Kisseynew Domain, northern Manitoba, underwe nt polyphase deformation and metamorphism during the Palaeoproterozoic Trans-Hudson Orogen, and represents a lithological, metamorphic and s tructural transition from greenschist-grade volcano-plutonic rocks of the Flin Flon Domain to amphibolite-grade paragneisses of the central Kisseynew Domain, The timing of geological events has previously been constrained using widely dispersed sample sites, but this study has in tegrated U-Pb geochronology with detailed lithological and structural mapping in the Cleunion Lake area. Pink gneisses, interpreted as Missi supracrustal rocks, were deposited after 1855 Ma, but prior to simila r to 1835 Ma, and thus are similar in age to fluvial sedimentary rocks in the lower-grade Flin Pion Domain. All the zircons in the pink gnei sses appear to be inherited, or resorbed during later amphibolite-grad e metamorphism, and a late Archaean component is also indicated. Corun dum-bearing gneisses in the Missi Group and leucosomes in Burntwood Ri ver Group rocks are deformed by F-1 and are indicative of an early hig h-T, low-P metamorphic event (M(1)) that may have been synchronous wit h the intrusion of 1835 to 1827 Ma intrusions, and related to regional crustal extension. The above rocks are folded during a continuous com pressional deformation event (D-2) related to terminal collision betwe en the Palaeoproterozoic rocks of the Trans-Hudson Orogen and the Supe rior Province, Three main fold generations (F-1, F-2, F-3) have been i dentified, which occurred during D-2. A 1818 Ma granitic vein is appro ximately synchronous with F-2 and peak metamorphic (M(2)) conditions i n the Cleunion Lake area. Cooling, uplift, and intrusion of pegmatites during F-3 at similar to 1800 Ma provides a time limit on the waning stages of compressional deformation. The main phase of compressional d eformation (D-2) in the southern flank of the Kisseynew Domain thus la sted for about 30 million years.