Geology of the Meta Incognita Peninsula, south Baffin Island, Northwest Territories: tectonostratigraphic units and regional correlations

Abstract

Tectonostratigraphic domains in southern Baffin Island contain units which can be correlated with those in northern Quebec (Cape Smith Belt þ Ungava Orogen) or central Baffin Island (Baffin Orogen). A grey tonalite gneiss is identified as possible Archean Superior Province basement. Siliciclastic-mafic-ultramafic rock sequences are correlated with the Povungnituk Group (Quebec). Carbonate and siliciclastic units of the Lake Harbour Group may be in part equivalent to the Sugluk Group (Quebec). Large felsic plutonic units comprise the southern extension of the Cumberland Batholith (central Baffin Island). Finally, panels of tonalite and monzogranite are correlated with the Narsajuaq arc (Quebec). Such correlations do not support suggestions that orthogneisses on southern Baffin Island constitute the southeastern arm of the Archean Rae craton. Correlations with the Povungnituk Group highlight the economic potential of the area.

Archean and Paleoproterozoic cratonic rocks of Baffin Island

“…Quartzite, marble, psammite and semipelite mapped on the eastern and western peninsulas of southern Baffin Island are lithologically similar to the metasedimentary strata of the contiguous Lake Harbour Group in its type locality of Kimmirut (Fig. 10;St-Onge et al, 1996Scott et al, 1997). Two lithologically and geographically distinct sequences can be recognized.…”

“…1) have documented that the composition, association, and context of metasedimentary rocks southwest of Cumberland Sound (Weller et al, 2015), on the adjacent Hall Peninsula (e.g. Rayner et al, 2012;Steenkamp et al, 2016), on eastern Meta Incognita Peninsula (St-Onge et al 2015c), on western Meta Incognita Peninsula (Scott et al, 2002a), and in the Markham Bay-Cape Dorset area (Scott et al, 2002a;Sanborn-Barrie et al, 2008) are similar and can be correlated with the type Lake Harbour Group assemblage in the Kimmirut area of western Meta Incognita Peninsula (St-Onge et al, 1996;Scott et al, 1997Scott et al, , 2002a.…”

“…• Level 1 -Archean tonalitic to granitic orthogneiss, interpreted as the northern continuation of the lower-plate Superior Craton crystalline basement, and associated middle Paleoproterozoic continental-margin supracrustal cover (Povungnituk Group;St-Onge et al, 1996).…”

Quantitative elemental mapping of granulite‐facies monazite: Textural insights and implications for petrochronology

“…Southern Baffin Island forms part of the northeastern segment of the Trans‐Hudson Orogen (THO), which is a Himalayan‐scale composite accretionary orogenic belt extending across North America that formed during gradual ocean basin closure between the lower Superior and upper Churchill plates from 1.92 to 1.80 Ga (Figure 1; Corrigan, Pehrsson, Wodicka, & de Kemp, 2009; Hoffman, 1988; St‐Onge, Van Gool, Garde, & Scott, 2009). In the southern Baffin Island region (Figure 2), three stacked tectonic levels have been identified (St‐Onge et al, 2020; Weller, Dyck, St‐Onge, Rayner, & Tschirhart, 2015): Archean tonalitic to granitic orthogneiss, interpreted as the northern continuation of the Superior craton crystalline basement (St‐Onge, Hanmer, & Scott, 1996). Middle Palaeoproterozoic dominantly monzogranitic and granodioritic orthogneiss, interpreted as a deformed magmatic arc terrane (Narsajuaq terrane; Scott, 1997; St‐Onge et al., 2009); and Archean to middle Palaeoproterozoic orthogneiss and middle Palaeoproterozoic supracrustal cover (Lake Harbour Group; Jackson & Taylor, 1972), collectively termed the Meta Incognita microcontinent by St‐Onge, Scott, and Lucas (2000), which either represents crust rifted from the Rae or Superior craton, or is exotic to both.…”

“…Meta Incognita Peninsula is underlain by quartzite, marble, psammite and semipelitic units that are lithologically similar to the metasedimentary strata of the contiguous Lake Harbour Group in its type locality of Kimmirut (Scott, St‐Onge, Wodicka, & Hanmer, 1997; St‐Onge et al., 1996; Figure 2). Two lithologically and geographically distinct sequences can be recognized across the length of the peninsula.…”