Paleomagnetism of the Precambrian Martin Formation, Saskatchewan

Abstract

Oriented samples of the Martin Formation were collected from 23 sites, both sediments and igneous rocks being represented. Detailed laboratory treatment yields an overall mean direction corresponding to a paleomagnetic pole at 9 °S, 72 °W (dp = 6.3°, dm = 11.5°). Strong evidence for the primary nature of the magnetization involved is provided by a positive fold test. The paleomagnetic pole obtained provides further evidence for a major eastward loop in the polar wandering path for North America during late Aphebian – early Helikian times. The exact age of Martin Formation deposition is the subject of debate, but extreme limits given by various authors are 1930 to 1490 m.y. However, the paleomagnetic results themselves somewhat restrict this range, and are of use in setting up a regional chronology, since they enable stratigraphic correlations between isolated sedimentary basins of the Canadian Shield to be made.