Abstract

A palaeomagnetic pole is established at 25.1°N 273.9°E (dp = 10.6°, dm = 14.3°) from the norite-charnockite complex at Angmagssalik, emplaced at 1800 Ma. A somewhat older palaeomagnetic pole at 4.2°S 246.7°E (dp = 4.2°, dm = 8.3°) is obtained from Archaean gneisses close to the northern boundary of the Nagssugtoqidian mobile belt; reversals of magnetization are present here. Both magnetizations were imposed during slow cooling following the (late) Nagssugtoqidian metamorphism. In general the gneisses, dyke amphibolites and granite of the Nagssugtoqidian mobile belt are unstably magnetized; their magnetization is attributable to the Earth's present field, and is often extremely weak. A pseudotachylyte within the Archaean gneisses has had a long cooling history. A fragment of the remanence reflects the magnetization characteristic of the Archaean gneisses, whereas most of the magnetization corresponds to a palaeomagnetic pole near that of the Angmagssalik complex. The pseudotachylyte is much older than its magnetizations. An apparent polar wander path is presented for Greenland at ca. 1750 Ma based on the above results and data from west Greenland.

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