Geomagnetic polarity event recorded at 1.1 m.y. B.P. on Cobb Mountain, Clear Lake volcanic field, California
January 1, 1978
Paleomagnetic studies show that a normal polarity event within the Matuyama reversed polarity epoch is recorded by one of the volcanic units on Cobb Mountain in northern California. K-Ar age determinations show that this event has an age of 1.12 ± 0.02 m.y. and clearly preceded the Jaramillo normal polarity event. These data provide the first confirmation from a subaerial volcano that a brief polarity event occurred at this time, as suggested by published studies of some marine sedimentary cores and magnetic anomalies. This new event is herein named the “Cobb Mountain normal polarity event.”
Citation Information
Publication Year | 1978 |
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Title | Geomagnetic polarity event recorded at 1.1 m.y. B.P. on Cobb Mountain, Clear Lake volcanic field, California |
DOI | 10.1130/0091-7613(1978)6<653:GPERAM>2.0.CO;2 |
Authors | Edward A. Mankinen, J.M. Donnelly, C. S. Grommé |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Geology |
Index ID | 70197174 |
Record Source | USGS Publications Warehouse |
USGS Organization | Geology, Minerals, Energy, and Geophysics Science Center |