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Preliminary paleomagnetic results from 64 oriented hand samples belonging to 20 unmetamorphosed dikes from west of Belo Horizonte, Minas Gerais (Fig. 1) are presented. The paleomagnetic analysis showed a complex magnetic behavior after AF (alternating field) and thermal treatments, when staole but incoherent directions were disclosed by samples of many dikes. For example, Figure 2displays results obtained for three specimens from different samples of the same dike. In spite of this, however, two characteristic magnetization directions could be isolated for some of the dikes. Three dikes presented an eastern direction with high negative inclination (Fig. 3) similar to that found for Middle Proterozoic (WAr/39Ar radiometric ages batween 1.00 and 1.08 Ga) dikes from the IIhéus-Olivença and Salvador regions (O'AGRELLA-FILHO et ai., 1989, 1990), suggesting that this magmatic intrusive event may have aftected severa! areas of the São Francisco Craton. 40 Ar ;39 Ar datings of the Pará de Minas dikes are in progress and if their ages prove similar to those of the IIhéusOlivença and Salvador areas, this would imply that these portions of the craton did not undergo great relative movements following dike formation, unless their poIes of rotation remained very near to the geographic pole. The other characteristic magnetization, presented by 7 dikes, is less consistent and corresponds to a southwestern direction with low inclinations similar to that found for some granulitic rocks of the Jequié Complex in northern São Francisco Craton (Figures 4 and 5) . 4OAr/39Ar age deterrnlnations on these granulites are in progress in order to constrain the age of this component of magnet1zation.

Paleomagnetism of the Para de Minas Mafic dike swarm, west of Belo Horizonte, MG, Brazil