Paleomagnetic directions in Late Precambrian glaciomarine sediments of the Mirbat Sandstone Formation, Oman

A paleomagnetic study has been carried out in the Late Precambrian glaciomarine Mirbat Sandstone Formation in the Sultanate of Oman. Limited availability and geographical distribution of outcrops restricted the sampling to six sites. Of these, three were in laminated, fine-grained clay- to siltstones and three in laminated carbonates. One of these sites was rejected. The remaining five sites, represented by a total of 21 samples, displayed a similar magnetic component during progressive thermal demagnetization between 0 and 500°C. The site mean pole calculated from this component is at 86.5°N 328.1°E (δ p=11.2°, δ m=19.7°). This low-temperature component is interpreted as the direction of the average recent geomagnetic field in Oman. Two sites (10 samples) revealed a consistent magnetic component above 500°C. The sample mean declination of 68.4° and inclination of 18.4° ( k=46.4, α ₉₅=7.2°) are interpreted as the characteristic remanent magnetization. The Late Precambrian Arabian pole position computed from the samples at these two sites lies at 23.3°N 141.8°E (δ p=3.9°, δ m=7.5°). Rotated into West African coordinates, the resulting pole position is at 31.6°N 153.2°E, in good agreement with published poles from Gondwana of Late Precambrian age (∼550 Ma). The resulting paleolatitude is about 9.4° indicating a low-latitude of deposition for the glaciomarine deposits of the Mirbat Sandstone Formation.