The Sabaloka ring complex revisited: palaeomagnetism and rockmagnetism

Abstract

The isotopically dated Lower to Middle Devonian Sabaloka complex (16.3"N, 32.6"E) in Northern Sudan, for which a palaeomagnetic pole position close to the present geomagnetic pole had been derived in a previous investigation, has been revisited. The formerly determined direction of remanence is shown to be of secondary origin (possibly due to recent or Pleistocene weathering, as shown by ore microscopy and a negative conglomerate test) and a further component of magnetization is detected at several sites. Rockmagnetic studies give strong arguments in favour of a primary origin of the newly found remanence direction. In this paper the palaeomagnetic results (site means) of the two laboratories (Munich and Leeds) for the Sabaloka complex have been combined yielding D = 340.1", I = -43.9", N = 15, k = 20.6, ag5 = 8.0". This gives a palaeomagnetic South Pole position (site mean) at 42.0"s and 55.7"E which is discussed in the context of other Palaeozoic pole positions of Gondwana.

Palaeomagnetism of Devonian ring complexes from the Bayuda Desert, Sudan-new constraints on the apparent polar wander path for Gondwanaland

“…In this paper we report the results of a palaeomagnetic study on mid to late-Devonian volcanic rocks from the Bayuda Desert in Sudan, which address the first of these issues. (Salmon et al 1988;Aifa, Feinberg & Pozzi 1990), flat lying Palaeozoic clastic sediments from Mauritania (Kent, Dia & Sougy 1984) and volcanic rocks from the Sabaloka ring complex, Sudan (Soffel et al 1990) yield a fairly tight cluster of palaeomagnetic south poles, conspicuously close to the location of the Permo/Carboniferous palaeo-south pole, located to the southeast of Southern Africa. The directions reported in the Moroccan and Algerian studies either fail fold tests (Salmon et al 1988) or point towards a synfolding age of remagnetization (e.g.…”