Paleomagnetic results from the upper Keweenawan Chequamegon Sandstone: implications for red bed diagenesis and Late Precambrian apparent polar wander of North America

Abstract

Two components of magnetization have been isolated from Chequamegon Sandstone samples using chemical demagnetization. A characteristic magnetization resides in magnetite of detrital origin. The pole calculated from this magnetization is 12.3°S, 177.7°E (K = 111.5, A₉₅ = 4.6°). This pole lies with other poles of late Keweenawan age and is very close to the Jacobsville Sandstone poles. A secondary magnetization resides in authigenic hematite and yields a pole close to the present north pole. This high-latitude pole is known from an earlier study of the Chequamegon and has been used as evidence for the Hadrynian APW track. However, most if not all of the high-latitude poles that define the Hadrynian track are secondary and undated. Our preferred alternative to the Hadrynian track is that the high-latitude poles are recent remagnetizations and that the antipodal equatorial poles that mark its end points represent field reversals.