Paleomagnetic constraints on the duration of the Australia-Laurentia connection in the core of the Nuna supercontinent

Abstract

The Australia-Laurentia connection in the Paleoproterozoic to Mesoproterozoic supercontinent Nuna is thought to have initiated by ca. 1.6 Ga when both continents were locked in a proto-SWEAT (southwestern U.S.–East Antarctic) configuration. However, the longevity of that configuration is poorly constrained. Here, we present a new high-quality paleomagnetic pole from the ca. 1.3 Ga Derim Derim sills of northern Australia that suggests Australia and Laurentia were in the same configuration at that time. This new paleopole also supports a connection between Australia and North China and, in conjunction with previously reported data from all continents, indicates that the breakup of Nuna largely occurred between ca. 1.3 and 1.2 Ga.

The role of megacontinents in the supercontinent cycle

“…The existence of a Paleoproterozoic-Mesoproterozoic supercontinent Columbia (a.k.a. Nuna) has been proposed (Zhao et al, 2002;Kirscher et al, 2020). There is debate over its name, and legitimate cases for precedence can be made for either option (Meert, 2012;Evans, 2013).…”

“…Peripheral constituents of supercontinent Columbia such as Australia were sutured by ca. 1.6 Ga, heralding final supercontinent amalgamation (Kirscher et al, 2020). The internal orogens of Laurentia indicate the assembly of the Nuna megacontinent by ca.…”

Structural Evolution of a 1.6 Ga Orogeny Related to the Final Assembly of the Supercontinent Nuna: Coupling of Episodic and Progressive Deformation

“…The final assembly of the supercontinent Nuna (Figure 1a) is suggested to have occurred after the collision between Australia and Laurentia (North America) at circa 1600 Ma (Betts et al, 2016; Kirscher et al, 2020, 2019; Pehrsson et al, 2016; Pisarevsky et al, 2014). This orogenic event (i.e., Isan Orogeny) was widely recorded in Proterozoic inliers (Figure 1b) across NE Australia (Betts et al, 2016; Kirscher et al, 2019; Nordsvan et al, 2018; Pehrsson et al, 2016; Pisarevsky et al, 2014; Pourteau et al, 2018).…”

“…We present a new 1600-1500 Ma 3-D structural model for the orogenic event recorded in the GTI marking the final assembly of the supercontinent Nuna (Nordsvan et al, 2018;Pourteau et al, 2018). Kirscher et al, 2020). North Australian Craton is marked in darker blue and the red star represents the location of the study area.…”

Heterogeneous Exhumation of the Mount Isa Orogen in NE Australia After 1.6 Ga Nuna Assembly: New High‐Precision40Ar/39Ar Thermochronological Constraints

“…Despite the period of global orogenesis between circa 2.10 and 1.80 Ga, the supercontinent Nuna (also known as Columbia; Evans & Mitchell, 2011; Evans et al, 2016; Rogers & Santosh, 2002; Zhang et al, 2012; Zhao et al, 2002) was not completely assembled until the juxtaposition between Australia with Laurentia (North America) at circa 1.60 Ga (Figure 1a) (Betts et al, 2016; Kirscher et al, 2019, 2020; Nordsvan, Collins, Li, Spencer, et al, 2018; Pehrsson et al, 2016; Pisarevsky et al, 2014). In western Laurentia, this final Nuna amalgamation event was recorded by the Racklan and Forward orogenies (Furlanetto et al, 2013; Thorkelson et al, 2005), whereas in northeast Australia coeval orogenesis was recorded by the Isan and Jana orogenies of the Mount Isa and Georgetown inliers (Figure 1b), respectively (Betts et al, 2008; Pourteau et al, 2018; Volante, Collins, et al, 2020; Volante, Pourteau, et al, 2020; Withnall & Hutton, 2013).…”