PALEOMAGNETISM OF THE CLAM BANK FORMATION AND PALEOLATITUDE ESTIMATESFOR WESTERN NEWFOUNDLAND

The Pridolian Clam Bank Formation around Lourdes Cove on the Port au P ort Peninsula, western Newfoundland, underwent deformation during the Acadian orogeny. As a result, some of the beds were overturned, but th e stratification planes can be accurately determined everywhere. Paleo magnetic studies of the Clam Bank Formation have yielded three well-de fined components of magnetization, all acquired subsequent to the defo rmation event: component A with D = 337.3-degrees. 1 = - 28.3-degrees. (N = 16 sites, k = 25.3, alpha95 = 7.5-degrees), with a corresponding paleopole at 23.2-degrees-N, 145.0-degrees-E (dp, dm = 4.5-degrees, 8 .2-degrees); component B with D = 172.9-degrees, 1 = 5.7-degrees (N = 35 specimens, k = 10.2, alpha95 = 6.4-degrees), with a corresponding p alepole at 38.2-degrees-N, 130.1-degrees-E (dp, dm = 3.2-degrees, 6.4- degrees); component C with D = 350.4-degrees, I = 69.8-degrees (N = 33 specimens, k = 8.9, alpha95 = 8.9-degrees). A pre-Mesozoic origin of the A and B components is indicated by the presence of normal and reve rsed components in specific sites; by the lack of correspondence betwe en the A and B paleopoles and the Mesozoic and later pole positions fr om the Appalachians and the North American craton; and by agreement wi th Paleozoic poles from the region. The A component was probably acqui red immediately after deformation during the Acadian orogeny. The B co mponent is probably a chemical remanence that was acquired during Perm o-Carboniferous (Kiaman) time. The C component is of recent origin, pr obably acquired in the present Earth's field, Paleomagnetic data from western Newfoundland are used in a localized setting to construct a pa leopole sequence and to estimate paleolatitudes for western Newfoundla nd during the Paleozoic. Keeping in mind the paucity of data for Silur o-Devonian age from this region, western Newfoundland seems to have be en at its southern-most position at die end of the Ordovician and to h ave occupied equatorial latitudes during the Permo-Carboniferous. The paleolatitude trend suggests that this block, which is part of the Nor th American craton, moved in a southerly direction during the early Pa leozoic and in a northerly direction during the middle and late Paleoz oic.