Paper No. 3
Presentation Time: 8:30 AM
PALEOMAGNETIC RESULTS OF MOROCCAN ~280 MA EXTRUSIVES: TESTING THEIR AGREEMENT WITH THE PANGEA-A RECONSTRUCTION
The pre-Triassic configuration of Pangea has been debated ever since paleomagnetists postulated an overlap of the continents when trying to fit together the APWP’s of Gondwana and Laurussia. Late Permian rocks have been examined to better develop the position of Pangea during this pre-Triassic time; however, analysis for the earlier Permian remains incomplete. The results of this study agree with previously published directions and add more precise age determinations (average U/Pb 284.7±6 Ma). This age puts the rocks in the late Early Permian (at the base of the Artinskian Stage). Half of the samples display hematite as the remanence carrier and half reveal magnetite. All samples have SE declinations and near-zero inclinations. From this study, two conclusions can be drawn, involving the age and the inclination. Firstly, some previous analyses of Early Permian paleopoles have compared results from Baltica, the southern Alps in Italy, and Morocco. The Italian and Moroccan rocks have ages about 270-280 Ma, whereas the Early Permian rocks from Baltica are mostly confined to the 290-300 Ma interval. Comparing the ~295 Ma results from Baltica and the ~275 Ma results from Italy and Morocco, causes a 20 m.yr. mismatch. This may result in an error of up to 8 degrees, because of Pangea’s drift of 0.4 degrees per m.yr. during the Early Permian. Lastly, the near-zero inclinations (as well as the average declination of about 135 degrees from Morocco) are what is to be expected of a conventional Pangea-A fit.