A NEW DEVONIAN PALEOMAGNETIC POLE FOR THE RUSSIAN PLATFORM AND BALTICA, AND RELATED APPARENT POLAR WANDER

Comparison of published palaeomagnetic data from the Russian platform and Britain for Mid-Palaeozoic times places an ocean between the two of the order of 2000 km latitudinal width. This contradicts geological evidence, which favours contiguity between the two continental units by Devonian times. We propose that this discrepancy can be attributed to the incorrect dating of palaeomagnetic remanence. We strove to remedy this situation by conducting a new palaeomagnetic investigation of Silurian and Devonian sediments in west Ukraine, USSR (latitude 48.7-degrees-N, longitude 26-degrees-E). That investigation uncovered a pervasive Upper Palaeozoic remagnetization corresponding to a palaeomagnetic pole at lat. 45.8-degrees-S, long. 348.2-degrees-E, dp/dm 1.6-degrees/3.1-degrees, N = 25 sites (reversed polarity). A second primary or near-primary Devonian remanence was identified with pole at lat. 3.7-degrees-N, long. 325.5-degrees-E, dp/dm 5.2-degrees/8.7-degrees, N = 25 samples (mixed polarity). The age determination for this Devonian result is based on its dual polarity, evidence for a detrital remanent mode, and early host mineral phase (haematite). The new Devonian result for the Russian platform is conformable with the Devonian parts of the British apparent polar wander paths and therefore eliminates the aforementioned discrepancy between palaeomagnetic and geological evidence for the timing of assembly of the 'Old Red Continent'.