MAGNETIC INVESTIGATIONS OF A RING DIKE, BUELL PARK, ARIZONA

Abstract

Remanent, induced, and total‐magnetic properties are measured for a suite of specimens from a north‐trending ring dike, Buell Park, Arizona. The direction of remanent magnetism is essentially across the dike in an easterly or westerly direction and has low‐angle positive or negative inclinations. The remanent magnetism has an average value of [Formula: see text]. The total magnetism is controlled in part by the remanent magnetism. A ground magnetometer survey, with anomalies exceeding 10,000 gammas, was made for the area and profiles are presented. The results of these measurements, which suggest a shallow magnetization, are correlated with rock‐magnetic measurements with good agreement. The importance of remanent and induced magnetism in the understanding of anomalies is emphasized. Variability of the remanent magnetism is related to a magnetism acquired after the thermal‐remanent magnetism of the rocks and most likely is related to a secondary magnetization caused by lightning.