A revised Palaeozoic apparent polar wander path for Southern Britain (Eastern Avalonia)

Abstract

S U M M A R Y A revised apparent polar wander path (APWP) is presented for Palaeozoic Southern Britain. The new path, based on a structural reinterpretation of existing data combined with new data from Wales, differs significantly from previous estimates in the following ways:(1) the 1,ocus of the Ordovician path segment is extended by approximately 25 degrees of arc;(2) revised time-calibration of the APWP suggests more Ordovician APW than previously calculated; and(3) the new path implies Middle Ordovician separation across the British sector of Iapetus to be greater than previous palaeomagnetic estimates based on APWP analyses (c. 3300 km; Northern Britain c. 133, Southern Britain c. 45s).

Peri-Gondwanan terrane interactions recorded in the Cambrian–Ordovician detrital zircon geochronology of North Wales

“…Paleomagnetic studies from southern Britain have yielded declinations that support major Paleozoic rotations (e.g. Trench and Torsvik, 1991;Torsvik et al, 1993;Piper, 1997). Notably, declination data reported by Vizan et al (2003) suggest a 165°clockwise rotation of rocks in the Midland Platform between Late Ordovician and Carboniferous, entirely consistent with the geometry shown in Fig.…”

Paleogeography, accretionary history, and tectonic scenario: A working hypothesis for the Ordovician and Silurian evolution of the northern Appalachians

“…Paleomagnetic results from the Avalon terrane indicate intermediate to high paleolatitudes similar to those of northern Gondwana (Johnson and Van der Voo, 1986;Van der Voo, 1988;Torsvik and Trench, 1991;Trench and Torsvik, 1991), implying that this continental block was located along the southern margin of Iapetus. During Ordovician time, the Appalachian margin of Laurentia was oriented approximately east-west and located at low paleolatitudes of 10 to 20°S (Briden and others, 1988;Van der Voo, 1988).…”

Brigantian and Middle Triassic remagnetizations in Lower Carboniferous carbonates, Northern Ireland: Role of diagenesis and fluid flow

“…The B py -ChRM was isolated by best-fitting the vector directions from thermal demagnetization from 250°to 330°C without anchoring to the origin and the C mg -ChRM by best-fitting the remaining vector directions above 350°C from 30 to 90 mT with anchoring to the origin. After tilt (Trench and Torsvik, 1991) and for Laurentia rotated to European coordinates (Torsvik et al, 1996) and extended to 225 Ma for stable Europe (Torsvik et al, 2001). Also shown are the South Pole positions for: the remagnetized host rocks and primary lead-zinc ore (N) at Navan from , the remagnetized limestones with A hm -ChRM (sites 1-6), and, the remagnetized limestones with in situ B py -and C mg -ChRM (sites 7-18), respectively.…”

“…To estimate ages for the A, B, and C paleopoles, both the Eastern Avalonian apparent polar wander path (APWP) (data from Trench and Torsvik, 1991) and the Laurentian APWP rotated into European coordinates (data from Torsvik et al, 1996) were used for the 360 to 300 Ma period (Fig. 2B).…”