Paleomagnetic data from the Coso Range, California and current status of the Cobb Mountain normal geomagnetic polarity event

Two basalt flows which erupted about 1.08 m.y. ago in the Coso Range, California, have normal magnetic polarity and thus provide additional evidence for the Cobb Mountain normal polarity event. A review of available data confirms that this event was of geomagnetic origin. A mean age of 1.10 ± 0.02 m.y. B.P. for the Cobb Mountain normal polarity event was found to best fit all available radiometric and geologic data.