The Abrat Suite was introduced in the Koroc River and Point Le Droit area (Mathieu et al., 2018). Most of the anatectic granites in the southeastern part of the Churchill Province (SECP) had been assigned to the Aveneau Suite by Simard et al. (2013), Lafrance et al. (2014, 2015, 2016) and Charette et al. (2016). Following the subdivision of the SECP into lithotectonic domains performed as part of a synthesis (Lafrance et al., 2018), the definition of the Aveneau Suite (pPavn) was revised to contain only anatectic granites located within the Baleine Lithotectonic Domain (Lafrance et al., 2020). In the Falcoz Lithotectonic Domain, anatectic granites have been assigned to either the Abrat Suite, when interpreted as being derived from partial melting of the Lake Harbour Suite paragneisses, or to the Fougeraye Complex, when interpreted instead as being derived from melting of the Kangiqsualujjuaq Complex orthogneisses (Mathieu et al., 2018). Lafrance and Vanier (2022) also reassigned anatectic intrusions previously attributed to the Sukaliuk Complex (ApPsuk5) by Lafrance et al. (2015, 2016) and Mathieu et al. (2018) to the Abrat Suite. The table below summarizes the correlations between the current and previous units.

Description

Abrat Suite 1 (pPaba1): Garnet-Bearing Anatectic Granite

Thickness and Distribution

The Abrat Suite forms a series of elongated intrusions less than 2 km wide by 1 to 18 km long. It covers an area of ~247 km² within the Falcoz Lithotectonic Domain. It is more prevalent in the Koroc River and Point Le Droit areas (Mathieu et al., 2018), where metasedimentary sequences of the Lake Harbour Suite are most important. 

Dating

A sample from outcrop 1998-PV-1011 was isotopically dated. Monazite crystallization at ~1830 Ma is interpreted as the age for the emplacement of the garnet-bearing granite in the Paleoproterozoic (David et al., 2009).

In the localized area east of the blmSZ, migmatization of the Lake Harbour Suite paragneiss is estimated to be between 1825 ±7 Ma (U-Pb age on monazites) and 1811 ±6 Ma (U-Pb age on zircons; Davis et al., 2018; Charette et al., 2021).

Stratigraphic Relationship(s)

The whitish intrusions of the Abrat Suite are considered to represent an anatectic granite derived from melting of paragneiss of the Lake Harbour Suite. They are similar to the leucosome observed in the paragneisses; they contain numerous paragneiss enclaves and layers, in which they are emplaced as decimetric to kilometric sills and intrusions.

Paleontology

Does not apply.

References

Publications available through SIGÉOM Examine

Other publications

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