Palaeomagnetic correlation of the Upper Triassic of Somerset, England, with continental Europe and eastern North America

Three Normal and three Reversed palaeomagnetic polarity zones were identifi ed in the exposed 67 In section of Mercia Mudstone at St Audrie's Bay, Some rset, which has been regarded as being of Norian age on limited biostratigr aphic evidence. The polarity sequence is correlated with magnetozones E15 t o E17 in the Newark Basin, New Jersey, further supporting the inferred Nori an age and tentatively placing it in the mid-Norian. Correlations with the northern North Sea and the Alps are also suggested. Results from Doniford B ay, where tectonic dips are steeper but which cannot be correlated precisel y with the St Audrie's section, are incorporated for the calculation of the mean direction of Characteristic Remanent Magnetization which has declinat ion 30.8 degrees and inclination +33.3 degrees (N=27 horizons, alpha(95)=5. 1 degrees). The corresponding palaeomagnetic pole is 49.6 degrees N. 128.4 degrees E (dp=3.3 degrees, dm=5.8 degrees), which also correlates with the Norian of the Newark Basin, while possibly indicating that small adjustment s should be made to the orientation of ail or part of Britain within the 19 65 Bullard et al. configuration as a representation of Late Triassic geogra phy.