Structural, petrological and U–Pb SHRIMP geochronological study of the western Beaverlodge domain: Implications for crustal architecture, multi-stage orogenesis and the extent of the Taltson orogen in the SW Rae craton, Canadian Shield

Bethune, Kathryn M.; Berman, R G; Rayner, N M; Ashton, K

doi:10.1016/j.precamres.2013.01.001

Cited by 35 publications

(50 citation statements)

References 53 publications

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“…1.94–1.90 Ga west‐vergent Taltson arc–continent collision (Fig. ; Dumond et al ., , ; Bethune et al ., ; Regan et al ., ).…”

Section: Discussionmentioning

confidence: 99%

“…These earliest structures are interpreted to have resulted from granulite facies lower crustal flow at 2.60–2.55 Ga in the Rae cratonic province (Dumond et al ., ; Regan et al ., ). Younger generation structures (D 2 –D 5 ) include SW‐dipping gneissic foliations that are overprinted by upright, open to tight folds with localized axial planar and shear foliations, and transposition of folds and gneissic fabrics into sub‐vertical to steeply dipping NE‐striking mylonitic shear zones (Mahan et al ., , ; Dumond et al ., , , ; Martel et al ., ; Bethune et al ., ; Regan et al ., ). All D 2 –D 5 structures are attributed to sub‐horizontal shortening related to the Taltson and Wopmay orogenies (to the west) and the Trans‐Hudson orogeny (to the east) during the interval of 1.94–1.80 Ga (Dumond et al ., , ; Bethune et al ., ; Regan et al ., ).…”

Section: Geological Backgroundmentioning

confidence: 99%

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Monazite as a monitor of melting, garnet growth and feldspar recrystallization in continental lower crust

Dumond

Gonçalves

Williams

et al. 2015

Journal Metamorphic Geology

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Monazite is a common accessory phase in felsic granulite ribbon mylonites exposed in the Upper Deck domain of the Athabasca granulite terrane, western Canadian Shield. Field relationships, bulk rock geochemistry and phase equilibria modelling in the Na 2 O-CaO-K 2 O-FeO-MgO-Al 2 O 3 -SiO 2 -H 2 O-TiO 2 -Fe 2 O 3 system are consistent with the garnet-rich rocks representing the residual products of ultrahigh temperature melting of biotite-bearing paragneisses driven by intraplating of mafic magma in continental lower crust. The c. 2.64-2.61 Ga Y-rich resorbed monazite cores included in garnet are interpreted as relicts of detrital grains deposited on the Earth's surface after c. 2.61 Ga. Yttrium-poor monazite domains in garnet are depleted in Sm and Gd and linked to fluid-absent melting of biotite + plagioclase + quartz AE sillimanite during a prograde loading path from ≤0.8 to ≥1.4 GPa. The c. 2.61-2.55 Ga Y-depleted, Th-rich monazite domains crystallized in the presence of garnet + ternary feldspar AE orthopyroxene + peraluminous melt. The c. 2.58-2.52 Ga monazite rims depleted in Th + Ca and enriched in Eu are linked to localized melt extraction synchronous with growth of high-pressure (HP) grossular-rich garnet at the expense of plagioclase during crustal thickening, culminating at >950°C. Re-heating and dextral transpressive lower crustal reactivation at c. 1.9 Ga resulted in syn-kinematic growth of (La + Ce)-enriched monazite and a second generation of garnet, concurrent with recrystallization of feldspar and orthopyroxene at 1.0-1.2 GPa and 600-700°C. Monazite grains in this study are marked by positive Eu-anomalies relative to chondrite. A direct link is implied between Y, Sm, Eu and Gd in monazite and two major phases in continental lower crust: garnet and plagioclase. Positive Eu-anomalies in lower crustal monazite associated with modally abundant garnet appear to be directly related to Eu-enrichment and depletions of Y, Sm and Gd that are consequences of garnet growth and plagioclase breakdown during HP melting of peraluminous bulk compositions.

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“…1.94–1.90 Ga west‐vergent Taltson arc–continent collision (Fig. ; Dumond et al ., , ; Bethune et al ., ; Regan et al ., ).…”

Section: Discussionmentioning

confidence: 99%

Section: Geological Backgroundmentioning

confidence: 99%

Monazite as a monitor of melting, garnet growth and feldspar recrystallization in continental lower crust

Dumond

Gonçalves

Williams

et al. 2015

Journal Metamorphic Geology

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“…Initially, the collision of the Slave craton with the Rae Province caused E-W shortening during the ca. 1980-1910 Ma Taltson-Thelon orogen (Hoffman 1988;Hildebrand et al 2010;Bethune et al 2013), and subsequent indentation of the Slave into the Rae Province (Hanmer et al 1992). Following this phase of E-W shortening, convergence along the western margin ended, while the Lynn Lake and La Ronge arcs were accreted along the southern periphery of the Hearne domain during the Reindeer Orogeny (Corrigan et al 2009).…”

Section: Kinematic Evolution Of the Athabasca Granulite Terranementioning

confidence: 99%

“…Ma, exemplified by the 1930ca. -1910 Ma Great Slave Lake shear zone, that accommodated major indentation of the Slave craton into the Churchill Province (Hanmer et al 1992;Hildebrand et al 2010;Bethune et al 2013; and references therein). The southern margin of the Churchill Province is defined by the Reindeer Zone (Chiarenzelli et al 1998;Corrigan et al 2005;Corrigan et al 2009), which represents the orogenic internides of the Trans Hudson orogen between Churchill, Sask, and Superior cratons.…”

Section: Kinematic Evolution Of the Athabasca Granulite Terranementioning

confidence: 99%

The Cora Lake shear zone, Athabasca granulite terrane, an intraplate response to far-field orogenic processes during the amalgamation of Laurentia

et al. 2014

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The Cora Lake shear zone (CLsz) is a 4-6 km wide localized high-strain zone that bisects the polydeformed Athabasca granulite terrane, northern Saskatchewan. It also coincides with the geophysical trace of the Snowbird tectonic zone. The CLsz represents a major lithotectonic and thermobarometric discontinuity within the exposure of >20 000 km 2 of high-pressure granulites. Most rocks have a strong mineral lineation plunging moderately to the southwest. The Northwestern subdomain (hangingwall) is characterized by ca. 2.6 Ga plutonic rocks that contain an early, subhorizontal gneissic layering (ca. 2.57 Ga) that was overprinted by large amplitude folds and a partitioned, but pervasive, axial planar, dextral, shear fabric at ca. 1.9 Ga. Thermobarometry suggests metamorphic conditions of ϳ0.9 GPa and ϳ750°C during both of the phases of tectonism. The footwall is predominantly underlain by the ca. 3.3-3.0 Ga Chipman tonalite, layers of intercalated mafic and felsic granulite, and the widespread 1.9 Ga Chipman mafic dyke swarm. Early subhorizontal layering in the footwall was also folded at ca. 1.9 Ga and transposed into a steeply dipping, northeast-striking axial planar shear fabric that corresponds with the metamorphic peak (1.1-1.2 GPa and 800-900°C). These distinct domains were juxtaposed across the CLsz, which contains a gneissic foliation striking 231°and dipping moderately to steeply to the northwest. Abundant sinistral-normal kinematic indicators are consistent with the distinctly lower pressures to the northwest. The shear zone is characterized by very fine grain sizes, despite its hightemperature assemblages including clinopyroxene and garnet. Thermobarometry from the CLsz displays progressive decompression of reworked footwall rocks with increasing mylonitization. In situ monazite geochronology indicates shearing at 1.89-1.87 Ga shortly after the granulite facies metamorphic peak. The anomalous sinistral kinematics of the CLsz, bracketed in time between periods of dextral shearing, can be explained by changing regional stresses during alternating convergent tectonics to the west and to the southeast of the Athabasca granulite terrane.Résumé : La zone de cisaillement de Cora Lake (CLsz) est une zone localisée de fortes déformations; elle a une largeur de 4 à 6 km et elle divise en deux parties le terrane de granulite polydéformé d'Athabasca, dans le nord de la Saskatchewan. Cette zone coïncide aussi avec la trace géophysique de la zone tectonique Snowbird. La CLsz représente une importante discontinuité lithotectonique et thermobarométrique dans l'affleurement de plus de 20 000 km 2 de granulites de haute pression. La plupart des roches ont une forte linéation minérale plongeant modérément vers le SO. Le sous-domaine nord-ouest (l'éponte supérieure) est caractérisé par des roches plutoniques d'environ 2,6 Ga qui contiennent un rubanement gneissique précoce subhorizontal (ϳ2,57 Ga) lequel a été surimprimé par des plis à grande amplitude et une texture de cisaillement envahissante, partitionnée, à axe planaire ...

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“…Recent detrital zircon U-Pb geochronological data sets from Paleoproterozoic sedimentary successions on the Rae and Hearne cratons have highlighted important similarities and differences in their provenance. Approaches combining geochronology with other available tools, such as radiogenic and tracer isotopic analysis, geochemical data, and stratigraphy, have been effectively applied in determining sedimentary provenance, correlating sedimentary basins, and inferring tectonic setting (e.g., Tran et al, 2008;Rainbird et al, 2010;Bethune et al, 2010Bethune et al, , 2013Ashton et al, 2013;Partin et al, 2014;Wodicka et al, 2014). In particular, Rainbird et al (2010) present a compilation of stratigraphy and detrital zircon U-Pb geochronology, comparing Paleoproterozoic sedimentary successions on the Rae craton with the broadly coeval Hurwitz Group on the Hearne craton.…”

Section: Introductionmentioning

confidence: 99%

Provenance approaches in polydeformed metasedimentary successions: Determining nearest neighboring cratons during the deposition of the Paleoproterozoic Murmac Bay Group

2016

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The proximity and positions of cratons constituting the western Canadian Shield prior to and during the Rhyacian Period (2.30-2.05 Ga) are poorly known. In the absence of paleomagnetic data, stratigraphic correlation and detrital zircon isotopic data from sedimentary successions can be used to constrain relative craton positions during their time of deposition. The Murmac Bay Group, a multiply deformed meta sedimentary succession located on the Rae craton margin in Canada, provides an opportunity to test hypotheses regarding its nearest cratonic neighbors during deposition. The polydeformed nature of the Murmac Bay Group, however, presents challenges in determining detailed stratigraphic relationships in the upper succession, which lacks distinct marker beds. Provenance analysis from detrital zircon geochronology provides one strategy for overcoming these challenges. Previous U-Pb geochronology indicates the lower succession was deposited <2.32 Ga, and the upper succession was deposited between <2.17 Ga and >1.94 Ga. We provide new U-Pb detrital zircon ages for the upper succession, including a new maximum depositional age at <2.00 Ga. We integrate our new data with published detrital zircon ages and compare them with published and public-domain igneous crystallization ages stored within a large geochronological database to identify potential provenance locations. While there is no known local source for the ca. 2.17 Ga age population, potential 2.17 Ga sources are found on the neighboring Slave craton and Buffalo Head-Chinchaga domain. Geographically, sources for the remaining dominant age populations (e.g., 2.33 Ga) exist either locally, or between the potential sources for ca. 2.17 Ga zircon grains and our study area. Our results support the interpretation that the Rae and Slave cratons were already amalgamated during upper Murmac Bay Group deposition (<2.00 to >1.94 Ga). This provides an important constraint on the timing of Rae-Slave amalgamation.

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Structural, petrological and U–Pb SHRIMP geochronological study of the western Beaverlodge domain: Implications for crustal architecture, multi-stage orogenesis and the extent of the Taltson orogen in the SW Rae craton, Canadian Shield

Cited by 35 publications

References 53 publications

Monazite as a monitor of melting, garnet growth and feldspar recrystallization in continental lower crust

Monazite as a monitor of melting, garnet growth and feldspar recrystallization in continental lower crust

The Cora Lake shear zone, Athabasca granulite terrane, an intraplate response to far-field orogenic processes during the amalgamation of Laurentia

Provenance approaches in polydeformed metasedimentary successions: Determining nearest neighboring cratons during the deposition of the Paleoproterozoic Murmac Bay Group

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