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TitleNew U-Pb zircon ages of plutonic rocks from the Jeannin Lake area, Quebec: an evaluation of the Kuujjuaq Domain and Rachel-Laporte Zone
AuthorRayner, N M; Lafrance, I; Corrigan, D; Charette, B
SourceGeological Survey of Canada, Current Research (Online) 2017-4, 2017, 14 pages,
PublisherNatural Resources Canada
Mediaon-line; digital
File formatreadme
File formatpdf (Adobe® Reader®); rtf; csv; xlsx (Microsoft® Excel®)
NTS23O/14; 23O/15; 23O/16; 23P/13; 24A/04; 24B; 24C/09; 24C/16
AreaJeannin Lake; Wheeler River; Lhande Lake; Champdoré Lake
Lat/Long WENS -68.5000 -65.5000 57.0000 55.7500
Subjectsgeochronology; stratigraphy; tectonics; structural geology; Archean; bedrock geology; lithology; igneous rocks; intrusive rocks; monzonites; granites; tonalites; pegmatites; diorites; structural features; faults; shear zones; tectonic history; tectonic interpretations; rifting; crystallization; deformation; metamorphism; foliation; recrystallization; radiometric dates; uranium lead dating; zircon; correlations; New Quebec Orogen; Rachel-Laporte Zone; Boullé Complex; Wheeler Complex; Kuujjuaq Domain; Lhande Plutonic Suite; Champdoré Plutonic Suite; Saffray Suite; Dancelou Suite; Turcotte Lake Fault; Superior Craton; Core Zone; Trans-Hudson Orogeny; Sensitive High Resolution Ion Microprobe (SHRIMP) analysis; Precambrian; Proterozoic
Illustrationsgeoscientific sketch maps; tables; photographs; photomicrographs; Concordia diagrams
ProgramHudson/Ungava Core Zone, GEM2: Geo-mapping for Energy and Minerals
Released2017 12 12
AbstractThree strongly foliated or recrystallized samples were identified in the field as potential Archean basement and were collected for geochronology in order to compare their crystallization ages with the ages of known basement in the Superior Craton and Core Zone. A porphyritic monzonite from the thrust-bound Boullé Complex within the Rachel-Laporte Zone yields a crystallization age of 2690 ± 4 Ma. A 2696 ± 4 Ma magnetite granite of the Saffray Suite is similar in age and composition to large potassic suites of the Superior Craton. These ages stand in contrast to a younger 2668 ± 5 Ma crystallization age for a tonalite of the Wheeler Complex from a separate structural dome within the Rachel-Laporte Zone.
The ages of the Champdoré and Lhande plutonic suites are 1839 ± 6 Ma and 1835 ± 4 Ma, respectively. As these units are metamorphosed and strongly foliated, they also provide a maximum age constraint on peak Paleoproterozoic tectonothermal overprint. The post-tectonic pegmatite of the Dancelou Suite provides a 1793 ± 4 Ma constraint on the cessation of deformation in that area.
Summary(Plain Language Summary, not published)
Knowledge of the age of rocks (geochronology) is critical in the making of a geologic map as it allows scientists to add the measurement of time to their field observations and permits comparisons with rocks elsewhere of similar age and appearance. This report presents ages from 6 samples in the lac Jeannin area of Quebec, approximately halfway between Schefferville and Kuujjuaq. The results presented in this report help test conflicting correlations and refine tectonic models. New data will provide a more robust tectonostratigraphic and magmatic context in which to undertake mineral exploration.