Matching mid-to-latest Carboniferous pole path segments for eastern Australia and northern Armorica indicate a late Carboniferous Pangea-B configuration and a mid Carboniferous inertial interchange true polar wander event

A long and detailed pole path has been defined from ignimbritic successions across the Tamworth Belt forearc basin of a Carboniferous continental arc in the southern New England Orogen (SNEO) of eastern Australia. Stratigraphic successions spanning about 50 myr have been studied paleomagnetically in 400 sites covering 4500 samples. The Carboniferous SNEO path is thought representative for Australia and Gondwana. Its prominent from-south-over-east-to-north loop with a mid Carboniferous apex differs fundamentally from conventional Australian and Gondwanan Carboniferous pole paths featuring from-south-over-west-to-north loops. The eastern loop of the SNEO path is supported by poles from other workers on the Tamworth Belt. The western loop of conventional paths may reflect unrecognised overprinting and alternative polarity interpretation. Mid-to-latest Carboniferous segments of the SNEO path and of a Carboniferous-to-Permian pole path for the northern Variscan massifs of Armorica (AR) are comparable in shape and length, each spanning more than a hundred degrees of arc. Visual matching of the two pole path segments by rotation around an Euler pole, with the SNEO segment taken as representative for Gondwana and representation of the AR segment tentatively extended to Laurussia, locates Armorica off northwestern Gondwana, and with it Laurussia, in a mid-to-latest Carboniferous Pangea-B configuration. The two mid-to-latest-Carboniferous pole path segments are each bounded by prominent mid Carboniferous and latest Carboniferous-to-earliest/early Permian loops, likely reflecting global tectonic events, dating the Pangea-B configuration as extending from the Sudetic phase to the Asturian phase of the Variscan Orogeny, with transformation to Pangea-A starting likely therefrom. Such a Pangean evolution offers new insights in location of a northern Gondwanan Armorican Spur, causes of the late Carboniferous Hercynian Unconformity and early Permian Pangea-wide extension, and drivers for contemporaneous oroclinal deformation of the Ibero-Armorican Arc and the SNEO. Global movements described by the SNEO and AR pole paths suggest causality between a Visean northern excursion of Gondwana that likely disturbed the earth's moment-of-inertia, a latest Visean-to-Serpukhovian inertial interchange true polar wander (IITPW) event that led to the Serpukhovian biodiversity crisis and latest Visean-Serpukhovian onset of continental glaciation consolidating the Late Paleozoic Ice Age (LPIA), and the Bashkirian start of the Permo-Carboniferous Reverse Superchron (PCRS).