Evidence for diagenetic remanent magnetization in the Maringouin Formation
Samples were obtained at 13 sites in the Maringouin Formation (late Mississippian red sediments) in New Brunswick and subjected to routine thermal demagnetization. After thermal cleaning at 550 °C, the results fall into two groups of comparable stability, but with different mean directions, direction dispersions, and intensities. Group I directions have a small dispersion (mean 179°, + 21°; k = 46; pole 117° E 34° N) after correction for folding. The folding was early Pennsylvanian so that the magnetization was acquired before that time. Comparison with results from somewhat younger formations indicates that there was an apparent polar shift of about 14° between late Mississippian-early Pennsylvanian time and late Pennsylvanian-early Permian time. Group II directions, although thermally stable, have a large dispersion (mean k = 4) and the intensities are generally lower than those of Group I. The Group II results may be explained by supposing that the magnetization was acquired not at a single point in ti...